Steering systems, steering and speed coordination systems, and associated vehicles.

(54) Title: STEERING SYSTEMS, STEERING AND SPEED COORDINATION SYSTEMS, AND ASSOCIATED VEHICLES.

(54) Title: STEERING SYSTEMS, STEERING AND SPEED COORDINATION SYSTEMS, AND ASSOCIATED VEHICLES.

(57) Summary

The present invention relates to a steering system, which comprises: a first pair of gears that controls the rotation of a non-driving wheel, wherein the first pair of gears includes a non-circular driving gear that mates with a driven gear not circulate; wherein the non-circular drive gear has a pitch line and a pivot axis, wherein the pivot axis is at a greater distance from the pitch line at two locations on the pitch line than at one location on the pitch line. pitch positioned between the two places; and a second pair of gears that controls the rotation of another non-driving wheel, wherein the second pair of gears includes a second non-circular driving gear that mates with a second non-circular driven gear; wherein the steering system is in a vehicle that has a pair of driving wheels driven by a transmission system capable of driving the driving wheels at different speeds and in different directions, wherein the transmission system is capable of making the wheels drives produce a first turning radius of the vehicle, and the first and second pairs of gears are configured to cause the non-drive wheels to produce a second turning radius of the vehicle equal to the first turning radius of the vehicle for a given steering input.

(57) Abstract

In a broad respect, vehicles that are capable of making a low- to zero-radius turn using the independent rotation of drive wheels and by turning the non-driving steerable structure or structures (such as wheels) with a steering input device (in some embodiments, the driving wheels also may be capable of being turned). This may be accomplished using a steering system, a speed control system and an integration device (together, a control system) that are configured to work together to provide correct steering in forward and reverse, and, in some embodiments, to reduce the speed of the outboard drive wheel of the vehicle when it enters an extreme turn under constant speed input. Different systems configured for use in such vehicles are included.

<img file="MX348252B_D0001.tif" />

PATENT TITLE No. 348252

<td>Headlines):</td><td>MTD PRODUCTS INC</td>

<td>Home:</td><td>5965 Grafton Rd., Valle City, Ohio, 44280, USA</td>

<td>Denomination;</td><td>STEERING SYSTEMS, STEERING AND SPEED COORDINATION SYSTEMS, AND ASSOCIATED VEHICLES</td>

<td>Classification:</td><td>CIP: B62D11 / 24; B62D3 / 02; B62D7 / 08; B62D9 / 00; B62D11 / 00 CPC: B62D11 / 24 ; B62D3 / 02; B62D7 / 08; B62D9 / 00; B62D11 / 006</td>

<td>Inventor (s):</td><td>AXEL SCHAEDLER; HANS HAUSER; RICK RUEBUSCH; IAN DAVID CORNWELL; CHRIS GREENWOOD ',, REQUEST</td>

Number; * *,. I dated PKMseiwti ^ lán International:

MX / a / 2012/005451. '¹ July 21, 2006

<td></td><td>Divisional Patent Number: 299049 ^ζ ' PRIORITY* ·' '</td>

<td>Country: US</td><td>, Date: Number: Jul 22, 2005 60 / 701,716</td>

<td>US Validity: Twenty &lt;Expiration Date Issue Date</td><td>August 22nd, 2005 60 / 710,231 years '&gt;,' &lt;- p. nent: July 21, 2026 ' Ition: June 1,^:2017 .</td>

<td>The reference patent is</td><td>It is granted based on Articles 1 · 2 ° fácc «fel V, 6 ° fraction II! ,, and 69 of the Industrial Property Law.</td>

In accordance with article 23 of the Law of the RAiefjilf'tadustflal, the present patent has a non-extendable term of twenty-one years from the date of presentation of the application and will be subject to the payment of the fee to keep the rights in force. *

Whoever signs this title has done so »based on the provisions of articles 6^or sections III and 7 bis 2 of the Industrial Property Law (Official Gazette of the Federation (D.OF.) 27W1991, amended, on 08/02/1994, 25/10/1998, 12/26/1997, 17 / 06/1999, 26/01/2004, 16/06/2005, 25/01/2006, 06/05 / 2009,06 / 01/2010, 18/06 ^ 010, £ 8/06 / 20ÍQ 27/0172012 items 1^or 3^or fraction V part a), 4^or and 12th fractions I and III of the

Regulation of the Mexican Institute of Property lrtCfUsttiai (OOP, 12/14/1999, amended, on 07/01/2002 07/15/2004, 07/28/2004 and 09/07/2007); items 1^or, 3^or, 4^or, 5^or fraction V subsection a), 16 J y ΙΠ y ®'dpl EstatdW-Qrgániee * ápj Mexican Institute of Industrial Property (DOF

12/27/1999, amended 10/10/2002, 07/29/2004, 04ÍW7W4 and -Ο / ρβ ^ άρ?); one·,¹»And £ #» «# '»&gt; 4 · »Agreement that delegates powers to the Deputy General Directors, Coordinator, Division Directors, Titula) ^ jir IMi ^ Office ^ ÍRégionales, Divisional Deputy Directors, Departmental Coordinators and other subordinates of the Mexican Institute of the PropfedatWndtístrial. (DOF 12/15/1999, amended on 02/04/2000, 07/29/2004, 08/04/2004 and 09/13/2007),

This document is signed with an advanced electronic signature (FIEL), based on articles 7 BIS 2 of the Industrial Property Law; 3 of its Regulations, and 1 section III, 2 section V, 26 BIS and 26 TER of the Agreement establishing the guidelines for the use of the Payment and Electronic Services Portal (PASE) of the Mexican Institute of Industrial Property, in the procedures indicated.

THE DIVISIONAL DIRECTOR OF PATENTS

<img file="MX348252B_D0002.tif" />

NAHANNY CANAL REYES

Original string:

NAHANNY MARISOL CANAL REYES | 00001000000403252793 | Administration Service

Tax | 1695 || MX / 2017/43593 | MX / a / 2012/005451 | Normal patent title with divisional PCT | 1027 | RGZ | Page (s) 2 | ANLfsaW2f5ZdLLI6pxrZ5yaz8ug =

Digital stamp:

VfsXb2GdG6UQRgg1qakZ2c9vvhhAPi5zANsBcLCPcCZUPZZzhZSezmNWtHGNmm \ / J77dboE + 67pwsXswNUZNHbrgjDj 8mRsod7zCJEydMCZy3zRoliZve9imFMQoG8DVA1GWg4RRQsAyHI9odihkizR4J3mLIVbWdx / HUKATKF88h2MSvYPP7 fDn5xuEQhkOwTE7pqyhsFV + Y9DEKRg3CFT6nC + 7CE / S9GNzyoNcetlmzzZOgC + hyBjz5kxGnoyOBijaU / NBHwrndQC KjugpUHkyhmSYjwjnO27DjxOnWxpZpGS03LXmBGkrYvSrXB / SDHVxBEIVw6l2N5hAyXHps9g == • Additional information on the back

Arcual No. 550 Floor 1, Pueblo Santa María Tepepan. Xochimilco, 16020.

Mexico City . (55) 53340700 www.gob.mx/irnpi

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STEERING SYSTEMS, DEBIRECTION SYSTEMS AND

SPEED COORDINATION, AND ASSOCIATED VEHICLES

This application claims priority over U.S. Provisional Patent Application Serial Number 60 / 701,716, filed July 22, 2005, U.S. Provisional Patent Application Serial Number 60 / 710,231, filed August 22, 2005, and US Provisional Patent Application Serial Number 60 / 731,593, filed October 26, 2005 on behalf of Axel Schaedler, Hans Hauser, Rick Ruebusch, Ian David Cornwell and Chris Greenwood, and entitled Steering Systems, Speed ​​Steering and Coordination Systems, and Associated Vehicles. The content of the three provisional applications is incorporated herein by reference. Background of the Invention 1. Field of the Invention

The invention generally relates to vehicles that have a turning capability with a radius of at least zero. Zero radius turn vehicles are often described as ZTR vehicles. However, this name has also been used to describe vehicles capable of turning in a radius other than zero. More specifically, the invention relates to steering systems, steering and speed coordination systems, and vehicles that include one or both types of * 2 'systems.

2. Description of Related Art

ZTR vehicles are generally driven by rear drive wheels, which can be driven at different speeds to achieve drive. The speed and direction of rotation of the drive wheels on some ZTR vehicles are controlled by separate manual levers. Some users find these levers confusing because they control both the speed and direction of the vehicle.

Some ZTR vehicles use a steering wheel instead of separate joysticks. However, some of these vehicles do not provide correct steering when the vehicle is in reverse. For example, when backing up and turning the steering wheel to make a left-hand turn, some of these vehicles produce a right-hand turn where the front of the vehicle, rather than the rear, moves to the left. . See US Patent No. RE 34,057 as an example of this type of ZTR vehicle.

John Deere introduced a series of tractors with Spin-Steer Technology ™ (SST). SST tractors have a rear wheel drive differential steering system controlled by a steering wheel, and a vacuum actuated reverse logic system that provides conventional steering in reverse. The front wheels are steerable wheels that are not steerable. See U.S. Patent No. 6,256,357 for a

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US Patent No. 6.60P, G € - »Clg5er¡t7c — crrr ZTR vehicle that uses a steering wheel to control steering, and a single variable displacement hydraulic pump and dual variable displacement hydraulic motors, each of which It is attached to a wheel that attaches to the ground, which is used to steer and steer the vehicle. This ZTR vehicle provides proper forward and reverse steering.

US Patent Application Publication No. 2003/0102171 also discloses a ZTR vehicle capable of proper forward and reverse wheel steering. Independently activated rear wheels steer the vehicle. They also steer the vehicle by turning in different speeds and / or directions. A problem with using caster wheels as non-steerable front wheels on ZTR vehicles is noticeable when driving on the side of a hill. Gravity will tend to pull the vehicle down the hill. This can cause the part of the vehicle supported by the caster wheels to roll downhill against the operator's wishes. Additionally, when attempting to turn the ZTR vehicle uphill, the drive wheels may lose traction as the operator tries to produce the torque required to point the caster wheels uphill.

Steerable front wheels have been used in

-mü ZTR vehicles. See the⁴_fc 'IM Pl

LAPEUlIfuAO US Patents

3,362,493 (Davis, et al.) And 5,042,238 and the p 11 hl iⁿ US Patent No. 2003/0019682 JülicttOV R ¡ó n. However, each of them has drawbacks. For example, the device of the Davis patent is not equipped with a system that can reduce the speed of the outer driving wheel of a vehicle entering an extreme turn at a constant speed input.

US Patent Nos. 6,196,342 and 6,129,164 describe reverse steering logic mechanisms that are coupled to and interact with a type of dual differential transmission and steering transmission to cause the transmission to turn the vehicle in the direction the steering wheel is turned. when operating in forward or reverse. These patents describe the use of caster wheels, and do not describe the use of steerable front wheels.

US Patent No. 6,921,109 describes a reverse steering logic mechanism and a mechanism for providing variable steering responsiveness. It describes the use of these mechanisms with differential type dual transmission in US Patent No. 6,196,342.

US Patent No. 6,905,985 discloses a complicated articulated linkage system that purportedly provides steering control of the steerable front wheels and steering effected by transmission that rotates the rear wheels so that the vehicle turns in the direction

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DlLAMOTiriAD INOUSTRIAl is operated forward or use of this system in which the steering wheel is turned when in reverse. This patent describes the combination with a differential type dual transmission.

US Patent No. 6,152,248 describes the use of a pair of non-circular gears in the steering mechanism of a vehicle, but that pair of gears does not control the rotation of a non-driving wheel.

Brief description of the invention

In a broad aspect, the invention relates to vehicles that are capable of making a minimum to zero radius turn (for example, a small radius turn) using independent drive wheel rotation and turning the non-steerable wheel or wheels. with a steering input device (in some modes the drive wheels may also be able to turn). This can be accomplished using a steering system, a speed control system, and an integration device (together, a control system) that are configured to work together to provide correct forward and reverse steering, and, in some modes, to slow the vehicle (specifically the outer drive wheel) when the vehicle enters a sufficiently extreme turn (for example, one in which the wheel that engages the ground can no longer be rotated under constant speed input.

In some embodiments, these vehicles include a frame; a steerable structure (such as a wheel that attaches to the

<img file="MX348252B_D0005.tif" />

floor, which can also be characterized as a non-driving wheel) coupled to the frame; two drive wheels attached to the frame; a transmission system capable of driving the two driving wheels at different speeds and in different directions; a steering assembly configured to control the steerable structure; a speed control assembly coupled to the transmission system; and an integration device that integrates a steering input with a speed input to steer and propel the vehicle. The steering assembly, speed control assembly, and integration device are configured to work together to reduce the speed of the outer drive wheel during extreme turn while the speed input received by the speed control assembly is constant.

In some embodiments, these vehicles include a frame; a steerable structure (such as a wheel that engages the ground) attached to the frame; two drive wheels attached to the frame; a transmission system capable of driving the two driving wheels at different speeds and in different directions; a steering assembly configured to control the steerable structure; a speed control assembly coupled to the transmission system, the speed control assembly includes a speed input device configured to be manipulated by an operator; and an integration device that integrates a direction input with a speed input

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INSTITUTO MEXICANO · ζ Qb l&gt; FXOPIEDAD 'to produce a combined vehicle steering output ^ 7 ^ 3001 ^ 11--031 that is transmitted to the do-tronom¡sió'n ~ TTmTü— result of manipulation by the operator speed input device. The steering assembly, speed control assembly, and integration device are configured to work together to properly steer the vehicle both forward and in reverse during a turn. In other words, the steering assembly, the speed control assembly, and the integration device are configured to work together such that when the vehicle is turned, the direction of the turn is the same for a given steering input. whether the vehicle is moving forward or in reverse. As a result, the direction of the turn does not change when going from forward to reverse.

In some aspects, any of the vehicles identified in the preceding two paragraphs may also include another steerable structure coupled to the frame, and the steering assembly is configured to control each steerable structure. Each steerable structure can include a wheel that engages the ground. The address set may include an address input device configured to receive an address input. The steering input device can be a steering wheel. The steering assembly may include two sets of wheels, one coupled to each wheel that sits on the floor. One of the wheel sets may include a drive gear and

IMPIOS Mexican Institute / A • t LA fiwif; ad ς ·· »2 ^ βί jA / 'NPUSTRlAL a driven gear. The driving gear may be coupled to the driven gear with a chain. The drive gear may be coupled to the driven gear with a belt. One or more teeth of the drive gear may be engaged with one or more teeth of the driven gear. The driving and driven gears can both be circular. The driving and driven gears can both be non-circular. One of the wheel sets may include a planetary gear. Each set of wheels may include a gear pair that includes a drive gear and a driven gear. The drive gear and the driven gear of each gear pair may be coupled with a chain. The drive gear and the driven gear of each gear pair may be coupled with a belt. In that arrangement, one or more teeth of the drive gear of a pair of gears may be engaged with one or more teeth of the driven gear of that pair of gears; the driving and driven gears of each pair of gears can both be circular; the driving and driven gears of each gear pair can both be non-circular. Each set of wheels can include a planetary gear.

The steering assembly of either vehicle may include a steering cam coupled with the steering input device and movable in response to the steering input. The address set may include

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INSTITUTO MEXICANO ue lanenEDA., WOIISTMIAI steering rod that couples the steering cam to one of the wheels that are attached to the ground. The steering assembly may include a wheel assembly that couples the steering rod to the wheel that sits on the floor. The steering assembly may include two steering cams coupled to the steering input device, each steering cam being movable in response to the steering input. The steering cams can be moved in different directions in response to steering input. The steering assembly may include two steering rods, one engaging each steering cam to one of the wheels that engage the ground. The steering assembly may include two sets of wheels, one couples each steering link to one of the wheels that engage the ground. One of the wheel sets may include a drive gear and a driven gear, and the drive gear may be coupled to the driven gear with a chain or belt. One or more teeth of the drive gear may be engaged with one or more teeth of the driven gear. The driving and driven gears can be both circular or non-circular. One of the wheel sets comprises a planetary gear.

Each set of wheels on any vehicle can include a gear pair that includes a drive gear and a driven gear. The driving gear and the driven gear of each pair of gears are coupled with a chain or belt. One or more teeth of the drive gear

INSTITU Γ&gt; MEXICANO 1 'a pair of gears may be mated with one or more teeth of the driven gear of that pair of gears.' 'The drive and driven gears of each pair of gears may be both circular or non-circular. Each set of wheels can include a planetary gear.

The transmission system of any vehicle can include two hydrostatic transmissions, one coupled to each drive wheel. Alternatively, it may include two continuously variable ratio toroidal drives, one coupled to each drive wheel. The speed control assembly may include a speed cam that can be moved in response to a speed input. The speed control assembly can include two speed cams, each can be moved in response to a speed input. The speed control assembly may include a regulating bar that couples the speed cam to the transmission system. The speed control assembly may include two regulating bars, each one couples one of the speed cams to the transmission system. The steering assembly can include a steering cam that can be moved in response to the steering input, and the integration device can include an assembly that couples the speed cam to the steering cam. The speed cam may include a speed cam slot, the steering cam includes a steering cam slot, and the assembly may include a steering cam extender that mounts to

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the steering cam slot and a speed cam extender that mounts in the speed cam slot. '-

The transmission system of any vehicle can include a drive unit to which the speed cam is coupled, the drive unit can be actuated at a drive location, the speed cam can include a speed cam slot and a axis of rotation separated from the drive location by a drive distance, and the speed cam slot may include an arc having a radius that is equal to the actuation distance. The speed cam extender may be able to move in response to the steering cam, and the position of the speed cam extender in the speed cam slot can control the steering. The drive system will turn one of the drive wheels in response to the speed input. The position of the speed cam extender in the speed cam slot can also control the amount by which the drive system will rotate one of the drive wheels in response to speed input.

The steering assembly of any vehicle can include two steering cams, each can be moved in response to steering input, and the integration device can include two assemblies, each coupling one of the speed cams to one of the steering cams. Each speed cam can

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IN «nWTOM? XICANQ .- .. 1 include a speed cam slot, each cam. ^ G ^ ire ^^ ru? May include a steering cam slot, and each set may include a steering cam extender that mounts in one of the steering cam slots and a speed cam extender that mounts in one of the speed cam slots. Each speed cam extender may be capable of moving in response to its associated steering cam, and the position of the speed cam extender in the slot for the associated steering cam may control steering. The drive system will turn one of the drive wheels in response to the speed input. The position of the speed cam extender in the slot for the associated steering cam can also control the amount by which the transmission system will rotate one of the drive wheels in response to speed input.

In another aspect, the invention relates to a propulsion and steering system comprising two steering cams that move in opposite directions in response to a steering input; a speed cam coupled to each steering cam and movable in response to a speed input; and an assembly that couples each steering cam to one of the speed cams.

With this arrangement, the two steer cams and the speed cams can be oriented vertically with respect to a driving surface when attached to a vehicle and se r— · ίί »··: JA

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INRUSTRIAL ** »use. Each speed cam can include a speed cam slot, and each assembly can include an extension that mounts in one of the speed cam slots. Each extender can be coupled to a vehicle's drive system via a regulator bar so that the position of an extender in its associated speed cam slot can control the direction in which the drive system turns the vehicle's drive wheel. . The position of an extender in its associated speed cam slot can also control the magnitude of the speed at which the transmission system rotates the drive wheel of the vehicle.

In another aspect, the invention relates to a propulsion and steering system comprising at least one steering cam configured to receive a steering input and to be coupled to and articulating a non-drive wheel; a speed cam coupled to the steering cam and movable in response to speed input; and an assembly that couples the steering cam to the speed cam. The system can include two steering cams positioned on opposite sides of a steering input device (such as a steering wheel), and a speed cam can be coupled to each of the speed cams to form two pairs of steering cams. and speed. The steering cams can be configured to have the same shape, and the speed cams can be configured to have the same shape. The set can be configured to

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INSTITUTO MfXiCANO oe IA FR E'tFiMD move steering cams in opposite directions ^ 'éW'fesp'ue'Sta to a given address input and for ΐ! Ϊ́υνΰ7' ··· Τ3Ή Feva * 5 CTS “speed at the same direction in response to a given speed input.

With this arrangement, the steering cam and the speed cam can be oriented vertically with respect to a driving surface when attached to a vehicle and in use. The speed cam may include a speed cam slot, and the assembly may include an extension that mounts in the speed cam slot. The extender can be coupled to a vehicle drive system via a regulator bar so that the position of the extender in the speed cam slot can control the direction in which the drive system rotates the drive wheel. vehicle. The position of the extender in the speed cam slot can also control the amount of speed at which the drive system rotates the drive wheel of the vehicle.

In another aspect, the invention refers to a steering system comprising a first pair of gears that control the rotation of a non-driving wheel (which means that the transmission system is not involved with this control), the first pair of gears. gears includes non-circular drive gears that engage a non-circular drive gear. Each pair of gears in the system can be designed to make the

<img file="MX348252B_D0006.tif" />

Non-driving wheels follow the turning radius of a vehicle that matches (or at least substantially matches) the turning radius of the vehicle produced by the driving wheels (under the control of the transmission system).

With this arrangement, the non-circular drive gears can include two splined portions. One ridged part may include more teeth than the other ridged part. The non-circular drive gear may include a substantially parabolic shaped portion. The steering system may also include a second pair of gears that control the rotation of another steerable structure, the second pair of gears includes a non-circular drive gear that engages a non-circular driven gear; the first and second gear pairs can work in tandem to produce a substantially aligned Ackermann steering of a vehicle. Each non-circular drive gear can include two splined parts, and a splined part of each non-circular drive gear can include more teeth than the other splined part of that non-circular drive gear. Each non-circular driven gear may include a substantially parabolic shaped portion.

In another aspect, the invention relates to a steering system comprising a pair of gears having a non-uniform gear ratio, the gear pair is configured to control the rotation of a non-driving wheel (meaning that the system transmission is not involved with

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INSTITUTO MEXICANO &amp; this control). The pair of gears can include ^ '^ M &amp; eabé ^^^ configured as described above.

In another aspect, the invention relates to a vehicle comprising a frame; at least two drive wheels not coupled to the frame; at least two drive wheels coupled to the frame; a transmission system capable of (a) propelling the two driving wheels at different speeds and in different directions and (b) causing the driving wheels to produce a first turning radius of the vehicle; and a steering assembly configured to cause the non-drive wheels to produce a second turning radius of the vehicle, the steering assembly includes two pairs of non-circular gears configured so that the second turning radius of the vehicle can be equal to the first radius rotation of the vehicle during vehicle operation. The gears can be configured as described above.

In another aspect, the invention relates to a steering system in a vehicle having at least two non-driving wheels, at least two driving wheels, and a transmission system capable of (a) propelling the driving wheels at different speeds and at different speeds. different directions and (b) cause the drive wheels to produce a first turning radius of the vehicle, the steering system comprising first and second pairs of non-circular gears configured to work together in order to cause the non-drive wheels to produce a second turning radius of the vehicle that is equal to

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PE LA .'Κ'ΙΠΕΓΆ! - '2 first turning radius of the vehicle for an input of''di? Fftci &amp; T &lt;^?'' given. The gears can be set c'amtr ^ endesrTrbe --------— in the above.

In another aspect, the invention relates to a steering system in a vehicle having at least two non-driving wheels, at least two driving wheels, and a transmission system capable of (a) propelling the driving wheels at different speeds and at different speeds. different directions and (b) cause the drive wheels to produce a first turning radius of the vehicle, the steering system comprising first and second pairs of gears each having a non-uniform gear ratio and which are configured to work together in order to cause the non-drive wheels to produce a second turning radius of the vehicle that equals the first turning radius of the vehicle for a given steering input. The gears can be configured as described above.

In another aspect, the invention relates to a steering system comprising a first pair of gears including a first driving gear coupled to a first driven gear that is coupled to a kingpin, The first pair of gears is configured to rotate the kingpin through a greater angle in response to an inward rotation produced by a first steering input than in response to an outward rotation produced by a ¹⁸ IMPI ^

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D * Ι.Λ PROPERTY IΝ ΓΧ) s Τ RIA t second address entry that is of equal magnitude but in the opposite direction to the first address entry.

With this arrangement, the first drive gear can include two gear lines, one of which has more teeth than the other gear line. The first driven gear may include a substantially parabolic shaped portion. The steering system may also include a second gear pair that includes a second drive gear coupled to a second driven gear that is coupled to a second kingpin, the second gear pair is configured to rotate the second kingpin through a greater angle in response to an inward turn produced by the first steering input, that in response to an outward turning produced by the second steering input; the first and second pair of gears can work in tandem to produce a substantially aligned Ackermann steering of a vehicle. Each of the first and second drive gears may include two gear lines. One gear line of each drive gear may include more teeth than the other gear line of that drive gear. Each of the first and second driven gears may include a substantially parabolic shaped portion.

Different aspects of these devices (eg, vehicles) and systems are described below, as well as other devices and systems.

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Brief description of the drawings

The following drawings illustrate by way of example and not limitation. Identical reference numerals do not necessarily indicate an identical structure. Instead, the same reference number can be used to indicate a similar feature or a feature with similar functionality. Each feature of each mode is not always marked on each figure in which that mode appears, in order to maintain clarity in the figures. At least Figures 5 through 13 are drawn to scale, which means that the sizes of the illustrated elements are accurate relative to each other for at least one set of embodiments of the present devices and systems.

Figure 1 is a perspective view of a vehicle of the type used for lawn and garden;

Figure 2A is a top view of the steering and front axle assembly of the vehicle of Figure 1;

Figure 2B is a top view of the speed control assembly and transmission system of the vehicle of Figure 1;

Figures 3A and 3B schematically illustrate the positions of the steerable front wheels that sit on the floor of one embodiment of the present vehicles;

Figure 4 is a partial perspective view of the vehicle speed and direction control assemblies of Figure 1 coupled together with an integration device;

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Figure 5 illustrates a perspective view of the front axle of the vehicle of Figure 1; "----- Figure 6A is an enlarged partial perspective view of one of the vehicle front wheel assemblies of Figure 1;

Figures 6B-6E are enlarged partial perspective views of different embodiments of front wheel assemblies that may be used with the vehicle of Figure 1;

Figure 7 illustrates a perspective view of another embodiment of the front axle of the vehicle of Figure 1;

Figures 8A-8C illustrate views of a pair of gears used with the front wheel assembly of Figure 6;

Figure 9A-9C illustrate views of an alternate embodiment of a pair of gears used with the front wheel assembly of Figure 7;

Figure 10 is a perspective view showing aspects of the speed control assembly of Figure 2B;

Figure 11 is a perspective view showing the interaction between the steering assembly and the speed control assembly of the vehicle of Figure 1;

Figure 12 is a close-up view of one of the steering control members hereof in the form of a steering cam;

Figure 13 is a close-up view of one of the speed control members hereof in the form of

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Mu » ¹ • Nn&gt; l $ T&gt; i |_AI a speed cam; Figures 14A-14C show the position of the speed control member of Figure 13 in neutral, forward and reverse, where the vehicle is steered in a straight forward direction;

Figures 15A-15C show the position of the speed control member of Figure 13 in neutral, forward and reverse, where the vehicle is at maximum turn and the illustrated speed control member is on the inside of the vehicle. turn;

Figure 16 is a graph of wheel speed for one embodiment of the present vehicle versus applied steering for constant speed input;

Figure 17 is a top view of an alternate embodiment of a steering assembly, a speed control assembly, and an integration device that can be used with the vehicle of Figure 1;

Figures 18 and 19 are different perspective views of a variable pitch worm of the steering assembly of Figure 17;

Figure 20 is a side view of a part of the arrangement shown in Figure 17;

Figure 21 is an exploded view of another embodiment of a steering assembly, a speed control assembly, and an integration device that can be used with the vehicle of Figure 1;

Figure 22 is a bottom perspective view of the. . . . .. _. INSTITUTO MEXICANO system of figure 21; οεια ^ ο ^ μγ »

Figure 23 is a top perspective view of the system of Figure 21;

Figures 24 and 25A-25D represent, in schematic form, various configurations of the system of Figure 21;

Figure 26 is a cross-sectional illustration of one embodiment of a speed and direction control assembly;

Figure 27 is a plan view of a further embodiment of parts of the system of Figure 21;

Figure 28 is a side view of the embodiment of Figure 27;

Figure 29 is a section in a longitudinal plane through a transmission suitable for use as one of the power units herein;

Figure 30 is a schematic representation of the transmission of Figure 29; Y

Figure 31 is a cross-sectional view (without cross hatching) of the transmission of Figure 29 looking in the direction of arrows III-III.

Detailed description of the illustrative modalities

The terms comprise (and any form of comprises, such as comprising and comprising), has (and any form of having, as it has and having), contains (and any form of contains, such as containing and containing), and includes (and any forms of includes, such as includes and including) are open-ended linking verbs. Thus, a vehicle comprising a frame; a steerable structure attached to the frame; two drive wheels attached to the frame; a transmission system capable of steering the two driving wheels at different speeds and in different directions; a steering assembly configured for the steerable structure; a speed control assembly coupled to the transmission system; and an integration device that integrates a steering input received by the steering assembly with a speed input received by the speed control assembly to steer and propel the vehicle; wherein the steering assembly, the speed control assembly, and the integrating device are configured to work together to reduce the speed of the outer drive wheel during extreme turn while the speed input received by the speed control assembly is constant, is a vehicle that possesses the listed items, but is not prohibited from having non-listed items (such as an additional airship structure).

Similarly, an item of apparatus that comprises, has, contains, or includes one or more features, possesses those one or more features, but is not limited to possessing only those features. Additionally, a structure that is configured in a certain way can also be configured in at least that way,

IMPI INSTITUTO MÍ.MCAN, but it can also be configured in a formTá ^ iSKX ^ are not specified. -_________

The terms a, "an" and an "are defined as one or more than one, unless this description explicitly requires otherwise. The terms substantially and about are defined as at least close to (and include) a given value or state (preferably within 10% of, more preferably within 1% of, and most preferably within 0.1% of). General configuration

Referring now to the figures, Figure 1 illustrates a vehicle (10), such as a lawn and garden tractor. The vehicle (10) includes a prime mover (12), such as an engine, that is mounted on a structural frame or chassis (14). The vehicle (10) includes drive wheels (16), such as left and right rear drive wheels that are coupled to the frame (14). The drive wheels (16) are operatively coupled to the engine (12) through a transmission system to provide locomotion to the vehicle (10). The vehicle (10) also has a steerable structure (18), such as the left and right front wheels that sit on the ground, which can be non-drive wheels. Other forms of vehicles have only a steerable structure (for example, all-terrain vehicles with three wheels). Additionally, in some embodiments, steerable structures such as skis can be used instead of wheels.

The chassis (14) supports an operator station comprising a seat (22). Vehicle (10) also includes a mower deck (26) mounted on the vehicle (10) chosen in some way with sound engineering criteria. The invention is applicable to other types of vehicles, including but not limited to utility vehicles, ATVs, tractors, golf carts, and even automobiles.

As shown in Figures 2A and 2B, the front wheels (18) are coupled to the vehicle frame through a pivotable connection with respect to a front axle (19) mounted on the chassis (14). The front wheels (18) are also coupled to a steering assembly (20), which is configured to control the direction in which they turn as described in greater detail below. In the embodiment of the present vehicles shown in the figures, the front wheels are the steer wheels (18) and the rear wheels are the drive wheels (16). However, a person skilled in the art will understand that the rear wheels can be the steer wheels and the front wheels can be the drive wheels without departing from the scope of the invention. Similarly, the front wheels can be both the steer wheels and the drive wheels.

A steering input device (24) (which is part of the embodiment of the steering assembly (20) shown in the figures) and a speed input device (28) (which is

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INSTITUTE MtXlCAN An operator can apply a steering input to the steering input device (24), which transfers the steering input to the steering assembly (20). The steering input device (24) can take the form of a conventional steering wheel. However, the steering input device 24 may be another suitable steering device, including, but not limited to, a steering rod or joystick (not shown).

The speed input device (28) provides a speed input for balancing the speed control assembly (21), and (at least in part) regulates the forward and reverse speed of the vehicle (10). The speed input device 28 may take the form of a single pedal, such as a pedal arrangement mounted on a single axle. In this mode, the speed input device (28) is balanced forward to select the forward direction, or balanced backward to select the reverse direction. The speed input device (28) can be biased towards a central position corresponding to a neutral or stationary condition.

The vehicle (10) also includes an integration device (27) that is configured to integrate a steering input received by the steering assembly (20) via the steering input device (24) with a speed input. a¡7Véc¡b¡ (Jsr ~ by the speed control assembly (described later) by means of the speed input device (28) to drive and steer the vehicle (10). The configurations of the steering assemblies, speed control assemblies, and integration devices herein allow the vehicle to make minimum to zero radius turns.

The left and right drive wheels (16) are driven through a transmission system which, in the illustrated embodiment, comprises left and right drive units (29). The vehicle (10) includes a speed control assembly (21) that controls the direction and magnitude of the rotation of the rear drive wheels (16). The propulsion units 29 may be transmissions of the continuously variable type, capable of providing a continuous range of ratios from forward to reverse direction. Examples of a suitable transmission using a ratio variation device, or variator, in conjunction with an epicyclic shunt gear to provide a meshed neutral installation is described in international application PCT / GB03 / 00332, published under WO 03/064892, and in International Application PCT / GB03 / 02332, published under WO 03/100295, both incorporated by reference for these disclosures. Alternatively, the propulsion units (29) can be hydrostatic transmissions (HST) or electric motors, both well known in

MPI '&gt; MEXICAN' ONtDAI •! | 1 »! AI __— the technique. The drive units (29) can be used to independently drive the drive wheels (16).

The driver dictates the speed and direction of the vehicle (10) by manipulating the steering input device (24) and the speed input device (28), which transmits the direction and speed inputs received from the driver for the balance of the steering and speed control assemblies that are linked by the integration device (27). The manner in which the speed and steering control assemblies work together through the integration device to drive and steer the vehicle is described in greater detail below. In the vehicle mode (10) shown in the figures, the amount of torque that the rear drive wheels have to produce to turn the vehicle (10) is reduced because the front wheels (18) are maneuverable. In contrast, the drive wheels 16 of some conventional ZTR vehicles with non-steerable caster wheels have to produce significant torque to cause the caster wheels to react and point in the desired direction. Additionally, grabbing requires a certain amount of familiarity and dexterity to avoid skidding the drive wheel indoors and loosening the grass under the wheel.

In the vehicle mode (10) shown in the figures, the left and right driving wheels (16) are coupled to the chassis (14) so ​​that their direction is fixed and their ^τ Μ ΡI

-UOMÍXiCAN,) hW-SSSjW) »; -» Ο? Ι € Πα: · »L · **** ^ '- ** · ^ ni j íT λ iat rotational axes are in constant alignment. In contrast, the steerable front wheels (18) are coupled to the chassis (14) in a way that provides them with the ability to change direction. Figures 3A and 3B are schematic top views of the vehicle 10 illustrating that the vehicle has the ability to achieve substantially aligned Ackermann steering. Figure 3A shows a turn with a non-zero radius, and Figure 3B shows a turn with a zero radius. When the front wheels (18) make the turn illustrated in figure 3A, they take two routes with different arcs P, and Po, which ideally will have a common center point C located along the axis that extends through the center. of both driving wheels (16). The lines L¡ and L_or extend from the central point C and intersect the routes Pi and P_or, respectively, of the two wheels at the rotational centers of the wheels. The use of substantially aligned Ackermann geometry (which can be achieved using some of the modalities described below) can help avoid scraping the tire tread rubber on the outer wheel or damage to vegetation under the front wheels.

Steering Assembly (20)

Some aspects of the steering assembly (20) are illustrated for example in Figures 2A-12. One function of the steering assembly (20) is to couple the steering input device (24) to the steerable front wheels (18) to help guide

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I ν '. Ιν '. 'H the vehicle (10). Another function of the steering assembly (20) is to provide a steering input to the integration device (27), which can coordinate that steering input with a speed input received through the speed input device (28). Another function of the steering assembly (20) is its ability to turn the vehicle (10), even in a zero turn radius mode (or a minimum turn radius mode), while receiving input from an input device. steering such as a steering wheel.

In one embodiment, the steering assembly (20) includes a steering shaft (30) that extends downwardly from the steering input device (24) and terminates in a toothed steering pinion (32). The steering shaft (30) is coupled so that it can rotate the chassis (14) with a bushing (34) or any other appropriate means using sound engineering criteria. The steering axle (30) and pinion (32) takes the steering input received through the steering input device (24) and takes part in its transmission to the front wheel assemblies (50), which then convert the steering input at the desired steering angles of the front wheels (18), as explained below. In one embodiment, the coupling between the steering axle (30) and the front wheel assemblies is accomplished using, in part, left and right bevel gears (36). The pinion (32) is positioned between and the left and right bevel gears (36) and simultaneously

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coupled to them so that the rotation of the pro pinion Jlrck 'simultaneous rotation of the left bevel gears and Oéreóhff' --- (36). The steering input device (24) and the steering pinion (32) can be rotated through approximately 120 degrees of movement. For example, the steering input device 24 can be selectively rotated 60 degrees in a first direction relative to a neutral steering position and 60 degrees in a second direction. However, the steering input device (24) and the steering pinion (32) can be configured to rotate through any range of appropriate angles for a given application.

Rotating the steering input device (24) and pinion (32) in a first direction causes one of the bevel gears (36) to rotate forward or to the front of the vehicle (10) and the bevel gear (36 ) turn back or to the rear of the vehicle (10). The left and right bevel gears (36) are coupled to the left and right drive shafts (38), respectively. Preferably, the left and right sides of the steering assembly (20) are substantially identical but are mirror images of each other. Accordingly, only the right side of the steering assembly (20) will be described below.

As shown in Figure 4, the drive shaft (38) is positioned generally orthogonal to the steering shaft (30) and is coupled to a steering gear (40)

<img file="MX348252B_D0008.tif" />

at its outer end. In one embodiment, the steering mechanism is a steering cam (40). The steering cam (40) is coupled to the transmission shaft (38) in such a way that it can be rotated by movement of the transmission shaft (38) in the first and second directions on the pivot (41), through which the shaft of the driveshaft (38) is extended. An outer portion of the steering cam (40) is coupled to a steering rod (42). In the embodiment of Figure 4, when the steering cam (40) is rotated clockwise (which could occur during an outward turn for the illustrated steering cam), the steering rod (42 ) moves in the forward direction or towards the front of the vehicle (10), and when the steering cam (40) is rotated counterclockwise (which could occur during an inward turn), the steering rod (42) moves towards the rear of the vehicle (10). (The direction in which the tie rod (42) moves depends on the position of the tie rod (42) relative to the pivot (41)). Thus, the rotation of the steering input device (24) is transmitted in forward or backward motion of the steering rod (42). Preferably, the steering link (42) is coupled to the steering cam (40) with an appropriate linkage (44), such as a ball linkage. The steering rod (42) is also coupled to a set of front wheels (50), which converts the steering input received by the

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WximiAL steering input device (24) at a steering angle of the front wheel (18). More specifically, the front wheel assembly (50) translates the position of the support structure on which the front wheel (18) rotates in response to the steering input received through the steering rod (42) from the device. address input (24).

The steering input device (24) may be coupled to a set of front wheels (50) in other ways in other embodiments using sound engineering criteria.

Returning to Figure 5, the front wheel assembly (50) includes a transmission or steering mechanism (52) pivotally mounted on a column (54) received on the front axle (19). The steering gear (52) has an articulated connecting portion (56) to which the steering rod (42) can be coupled with an appropriate connector, such as a ball connector (58). As can best be seen in the enlarged view of Figure 6A, the steering gear (52) has teeth (60), one or more of which meshes with one or more of the teeth (62) of the driven wheel or gear. (70). The drive gear (70) is coupled to the front wheel (18) in order to steer the front wheel to the left or to the right. In one embodiment, the drive gear (70) is mounted on a kingpin (74) such that rotation of the drive gear (70) causes rotation of the kingpin (74). In the illustrated embodiment, the kingpin

- «tXICAN ·· '(74) has a square head on which the transmission gear (70) rotates. The kingpin (74) is pivotally coupled to the chassis (14) of the vehicle (10) by virtue of being rotatably mounted, to the front axle (19) using a bearing, bushing or the like (79 ) suitable. A pivot shaft (76) extends generally orthogonal to the kingpin (74), and the front wheel (18) is rotatably mounted on the pivot shaft (76).

As shown in Figure 6A, the steering mechanism (52) can pivot on the column (54) due to the force transmitted through the steering rod (42) as a result of the steering input received through the device. address input (24). The rotation of the steering mechanism (52) is transmitted to the transmission gear (70) to change the direction of the front wheel (18). The front wheel sets (50) allow the two front wheels (18) to be steered in substantially aligned Ackermann steering geometry.

In one embodiment, the articulated connecting part (56) to which the steering rod (42) is coupled, is positioned inward of the column (54) over which the steering mechanism (52) pivots and towards the part behind a line L connecting the two columns (54), as can best be seen in Figure 2A. Line L is generally parallel to the transverse axis of the vehicle (10) and perpendicular to the longitudinal axis or

INSTITUTO MF.XlCAN * OF IA FMWOAP ΙΝΠΙΙΓΠΙΙΑΙ - principal of the vehicle (10). During a turn, the tie rod (42) on the inward side moves in a first direction (for example, towards the rear) while the tie rod (42) on the outward side of the turn moves in a second direction (eg forward). Movement of the steering rod (42) inward causes the articulated connecting portion (56) to move further rearward relative to the column (42) and away from the L-line as the steering mechanism (52 ) pivots around column (54). On the outward side, the outboard tie rod (42) causes the articulated connecting portion (56) to move further towards the front of the vehicle as the steering mechanism (52) pivots.

At first, the outwardly hinged connecting part (56) moves closer to the line L. Continuous rotation of the steering input device (24) can cause the hinged connecting part (56) to pass through the line L and then move away from, and forward of, line L. The steering assembly (20), and more specifically each assembly of wheels (50), is configured such that the magnitude of the component of movement of the steering rod (42) that causes the rotation of the steering mechanism (52) increases. As the articulated connecting part (56) moves away from the line L. Thus, the movement of the steering rod (42) on the inward side in the rearward direction produces a movement

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Jl lOWaOO crank of the wheel more for larger rotational of the steering mechanism (5 ^ j inward than the forward movement of the steering (42) on the outward side. Therefore, front (18) which is inward turns faster and contribute to the geometry of a substantially aligned Ackermann headset.

As shown in Figures 5 and 6A, the front axle (19) is preferably not straight. Instead, it has non-linear portions (90) near either end that has a forward sloping portion (91) attached to a rearward sloping portion (92). Each rearward sloping portion (92) leads to an outer portion (93) of the axle (19) located near where the front wheel (18) is mounted. Each non-linear part (90) of the front axle (19) forms a cavity (94) for the rear of the front axle (19) which receives the front steerable wheel (18) on the inward side during extreme turn. The cavity (94) allows the front steerable wheel (18) to be rotated inward by more than 90 degrees, and preferably between 100 and 120 degrees as illustrated in Figure 3B, without having the rear of the front wheel (18 ) inside the turn in contact with the front axle (19).

Other gear arrangements can be used alongside those shown in Figures 5 and 6A for the front wheel assemblies (50). For example, Figures 7 and 9A-9C, described below, show other non-circular gears that can be

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IN Γ&gt; υ&gt; Τ 11A L use for front wheel sets (50). Some other alternatives are those shown in Figures 6B-6E. These figures illustrate an enlarged partial view of the set of right front wheels (50). In contrast to Figure 6A, the front axle socket (19) in each of Figures 6B-6E faces the viewer of the figure, and the steering rod (42) and ball connector (58 ) are rotated away from the observer (as would be used on a steering pinion facing in front of the front axle (19)), although if used with the version of the steering assembly (20) shown in figure 2A it would point again in the direction of the observer. Figure 6B shows an example of a front wheel assembly (50) comprising a steering gear (52) and a transmission gear (70) that are both circular and engaged with a chain (59). The column (54) on which the steering gear (52) is mounted extends upward through the lever (51). The lever (51) may be coupled to the steering gear (52) using any suitable means, so that rotation of the lever (51) about the axis of the column (54) also causes a rotation of the steering gear (52 ). The angle of the lever (51) with respect to the straight forward position of the steering gear (52) can be set (taking into account other relevant factors, such as the engagement between the driving and driven gears, and the manner in which the which sets of

<img file="MX348252B_D0012.tif" />

front steering are coupled to each other) to provide a substantially aligned Ackermann steering (as can be seen in the embodiments shown in Figures 6C and 6D). Figure 6C shows an example of a front wheel assembly (50) comprising a steering gear (52) and a transmission gear (70) which are both circular and engaged with a belt 59A.

Figure 6D shows an example of a front wheel assembly (50) comprising a steering gear (52) and a transmission gear (70) which are both circular. The two gears are engaged by virtue of one or more of the drive gear teeth (60) meshed with one or more of the driven gear teeth (62).

Figure 6E shows another embodiment of the front wheel assembly (50). The lever (51) is coupled to the planet support (53) of the planet gear (57). The planet carrier (53) is coupled to the kingpin, which controls the articulation of the pivot shaft (76). The ring (71) of the planetary gear (57) is coupled through an arm to the column (54), which is shorter in this embodiment and does not extend through the bottom of the front axle (19). The angle of the lever (51) with respect to the "straight forward" position of the planet carrier (53) can be set (taking into account other relevant factors, such as the orientation of the planet carrier relative to the kingpin, and the way in which the front steering assemblies

IMPIOS are coupled to each other) to provide a substantially aligned Ackermann.

Figure 7 illustrates another embodiment of the set of wheels (50). In this embodiment, the articulated connection part (56) is still with the column (54) on which the steering mechanism (52) pivots when it is in the neutral position, such that the articulated connection part (56) and The column (54) are aligned parallel to the transverse axis of the vehicle (10). In this embodiment, the steering rods (42) on either side of the vehicle move in opposite directions but produce the same amount of rotation of the two steering mechanisms (52). In this mode, the shape of the gears (52) and (70) makes the front wheel (18) on the inside side turn faster and also provides the desired Ackermann steering geometry because they are configured as shown in the figures 9A-9C and as described below. Preferably, a front link bar (78) couples the two wheel assemblies (50) together to provide structural support. This type of connecting rod can be used to couple the two sets of wheels shown in the embodiments of Figures 5 and 6A-6E.

One purpose of the front tie rod is to help distribute loads, such as when one of the front wheels (18) hits a curb or other object. The force of striking the object can be distributed across both sets of

<img file="MX348252B_D0013.tif" />

wheels (50) through the front link bar and then to the chassis (14). This reduces the shock that is transmitted back through the steering system to the steering input device (24) and is felt by the operator.

Non-circular gears

Returning now to Figures 8A-8C, in one embodiment, the steering gear (52) and the transmission gear (70) combine to form a pair of non-circular gears (81). In a preferred embodiment, the steering gear (52) has a shape comprising two fluted portions (82), (84) connected by a valley-shaped portion (86). As can be seen in Figure 8A, the distance from the pivot axis A_s steering gear (52) to gear line P_s of the steering gear (52) in the splined portions (82), (84) is greater than the distance from the pivot axis A_s steering gear (52) to gear line P_s of the steering gear (52) in the valley-shaped part (86). The rear portion (85) of the steering mechanism (52) may have any shape selected to achieve the desired steering, such as the shape illustrated in Figure 6A. The transmission gear (70) has a substantially parabolic shaped portion 87 having an apex (88). The rear portion (89) of the transmission gear (70) may have any shape selected to achieve the desired direction, such as the shape illustrated in Figures 8A8C.

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In the neutral or forward position,^{1N [}ar'menas - one or more of the teeth (62) near the vertex - (88) of the-yarte ----— parabolic (87) of the transmission gear (70) engage at least one or more of the teeth ( 60) in the valley-shaped portion (86) of the steering gear (52) as illustrated in Figure 8A. As the steering gear (52) rotates about its axis A_s, one of the splined portions (82), (84) engages the side of the parabolic portion (87) as the driven transmission gear (70) rotates about its axis A_w, as illustrated in Figures 8B and 8C.

In one embodiment, the knurled portions 82, 84 of the steering gear have a different number of teeth. In the illustrated embodiment, the ridged portion (82) has five teeth (60) and the ridged portion (84) has seven teeth (60). The spline portion (84) has additional teeth (60) that further extend the steering mechanism (52) on the side that engages the drive gear (70) during an inward direction rotation. The inward facing front wheel (18) has to rotate through a greater angle than the outward facing front wheel (18) to comply with Ackermann geometry. Accordingly, the splined part (82) that engages the transmission gear (70) when turning on the outward side does not need as many teeth (60) because the front wheel (18) that remains outward does not turn as much .

The non-circular shapes of the steering gear (52) and _,

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OF LA MrWfnAb &lt;% inousth'ai. ^kof the transmission gear 70 (and, more specifically, the non-circular shapes of the toothed portions of the steering and transmission gears) allow the gear combination to have a non-uniform gear ratio. In the neutral position, the ratio of the distance between the axis of the pivot A_s of the steering gear (52) with respect to the gear line P_s of the steering gear (52) with respect to the distance between the axis of the pivot A_w of the transmission gear (70) and to the gear line P_w of the wheel curve is preferably between about 1.0: 1.0 and 2.0: 1.0, and more preferably about 1.5: 1.0. In the extreme pivot position illustrated in Figure 8C, the relationship of the distance between the axis of the pivot A5 of the steering gear (52) with respect to the gear line P_s of the steering gear (52) with respect to the distance between the axis of the pivot A_wof the transmission gear (70) and the gear line P_w of the wheel curve is preferably between about 2.0: 1.0 and 4.0: 1.0, and more preferably about 3.0: 1.0. However, any appropriate gear ratio can be chosen for the application. Thus, in a preferred embodiment, the gear ratio result can range from 1.0: 1.0 to 4.0: 1.0, and more preferably from 1.5: 1.0 to 3.0: 1.0 as the gears rotate as shown in the figures.

8A, 8B and 8C.

The position of the articulation part (56) in the gear

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ΙΝ^ΠΙ iSt WIA The drive (52) and the non-uniform gear ratio of the gear pair allows the steering angle of the front wheels (18) to respond to the desired amount of turn as determined by input to the steering input device ( 24). When the vehicle (10) is traveling straight ahead or in a slight turn and the steering input device (24) is close to the neutral position, it is preferable that the movement of the steering input device (24) produces only relatively small changes in the angle of the front wheels (18). This allows the operator to travel in straight lines and precisely control the vehicle. On the other hand, when the operator wishes to make an extreme turn, it is useful that the movement of the steering input device (24) produces a corresponding relatively larger change in the steering angle of the front wheels (18). Accordingly, in some embodiments, the steering system (20) is configured such that movement of the steering input device (24) in the range of plus or minus twenty degrees from the neutral position produces a relatively small change. in the steering angle of the vehicle. However, when the steering input device (24) is rotated to perform an extreme turn, such as a zero radius turn, the steering assembly (20) increases the change in steering angle such that the front wheels (18) quickly reach the largest steering angle.

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For example, some modes of the set of 'Jlre'cciSul' (20) can be configured so that the movement of the steering input device (24) to a position between approximately 10 degrees and approximately 20 degrees from the neutral position produces a corresponding change in vehicle steering angle of between about 5 and about 20 degrees. In these embodiments, movement of the steering wheel to a position of between about 20 degrees and about 40 degrees from neutral produces a corresponding change in vehicle steering angle of between about 20 and about 60 degrees. In these embodiments, movement of the steering wheel to a position between about 40 degrees and about 60 degrees from neutral produces a corresponding change in steering angle of between about 60 and about 120 degrees. The dimensions of the steering and transmission gears of a given pair of gears, such as the gear line, can be set in such a way that the rotational axes of both driveable front wheels (18) always intersect the single point C at the rotational axis of the drive wheels (16) to provide substantially aligned Ackermann steering.

Figures 9A-9C illustrate another embodiment of a pair of non-circular gears (81A). This pair of gears (81A) has non-uniform mesh lines so that the shapes of the

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Steering gear (52A) and drive gear (70A) produce Ackermann Sustanci mind aligned steering geometry. This pair of gears (81A) can be used with the mode of the set of wheels (50) shown in the figure

The steering gear 52A is shaped to include two knurled portions 82A, 84A connected at a junction 86A. The splined portion (82 A) is engaged when the front wheel (18) to which the pair of gears (81A) is attached is on the outward side of the turn and the splined portion (84A) engages when the front wheel (18) is on the inside of the turn. In the embodiment of Figure 9A, the distance from the axis of the pivot A_sof the steering gear (52A) with respect to the gear line P_s of the steering gear 52A in the knurled portion 82A is substantially constant across the knurled portion 82A, so that this portion of the steering gear 52A resembles a sector of a circle. However, the distance from the pivot axis A_s of the steering gear (52A) with respect to the gear line P_s it is non-uniform in the fluted portion (84A). Accordingly, the steering gear embodiment 52A can be characterized as a non-circular gear, or as having a non-circular toothed portion.

Preferably, the distance from the pivot axis A_s up to gear line P_s progressively increases to between approximately 110% and approximately 150% of the distance

1Μ PI with respect to the gear line at the joint (86'A '^ É mode illustrated, the distance from the axis 4e4-p + vo-te-Aj-ooñ - with respect to the gear line P_s near the teeth that engage the drive gear (72A) during extreme inward rotation is about 123% of the gear line in the neutral position. The rear portion 85A of the steering gear 52A can be of any suitable shape, such as the shape shown in Figure 7.

The transmission gear (70A) also has a non-uniform mesh line configured to coincide with the gear line of the steering gear (52) A. In the illustrated embodiment, the transmission gear (72A) has a first part ( 83A) in which the distance from the axis of the pivot A_w of transmission gear (70A) with respect to gear line P_w The transmission gear 70A is substantially constant across the part 83A, so that this part of the transmission gear 70A resembles a sector of a circle. The transmission gear (70A) has a non-uniform part (87A) in which the distance from the axis of the pivot A_wof transmission gear (70A) with respect to gear line P_w of the transmission gear (70A) in the part (87A) is uneven. The uniform and non-uniform parts meet at a joint (88A).

In the neutral or forward position, one or more of the teeth (62A) near the joint (88A) of the drive gear

7 ϊ τα and 2i JLVf ;. A £ tb. · ^ '' - * i \ transmission (70A) couple one or more of the teethg ^ Jj ^: Nr&gt; isTkiAi.^:(~ - ·· 'of the joint 86A of the steering gear 52A as shown in Figure 9A. When turning in the inward direction as shown in Figures 9B and 9C, the steering gear direction (52A) rotates around axis A_s so that the splined portion (84A) engages the non-uniform side (87A) of the drive gear (70A) as the drive gear (70A) rotates around axis A_w.

Preferably, the distance from the pivot axis A_w with respect to gear line P_w progressively decreases to between about 50% and about 75% of the distance at the junction (88). In the illustrated embodiment, the distance from the pivot axis A_s with respect to gear line P₃near the teeth that engage the drive gear (72A) during an extreme inward turn as shown in FIG. 9C, it is about 65% from the gear line to the neutral position. The rear portion (89A) of the transmission gear (70A) may be of any shape selected using sound engineering criteria, such as the shape shown in Figure 7.

In one embodiment, the position of the teeth 60A, 62A and the gear lines P_s And p_w For the steering gear (52A) and the transmission gear (70A) they are chosen such that a substantially aligned Ackermann steering is provided by the gear pair (81A). A method to select

<img file="MX348252B_D0015.tif" />

..... ¹ ~ *** 4 * 'ί ri the gear lines P_s And p_w Starts with desired steering determiWiCT # ^ for the inner and outer dpiantprag (is) wheels. Referring again to Figure 3A, the inner wheel steering angle a and the outer wheel steering angle ω can be determined using the following formula:

Tan (90 ° - ω) = [tan (90 ° - a) - L + W] / L [Equation 1]

Using the desired steering angles, the gear lines P_s And p_w They can be set in such a way that the rotational axes of both maneuverable front wheels (18) are always made to intersect with a single point C located on the rotational axis of the driving wheels (16), as can be seen in Figures 3A and 3B.

In the illustrated embodiment, the parts of the steering gear (52A) and the transmission gear (70A) that engage each other when the gears are in the outward one-turn position (splined part (82A) and part 83A) have uniform mesh lines, while the parts of the gears that engage each other when the gears are in the inward position of a turn (splined part (84A) and part 87A) have non-uniform mesh lines . However, all parts of the gears can be non-uniform, as long as the gear lines P_s And p_w are selected to produce a substantially aligned Ackermann steering geometry for turning the front wheels (18).

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<img file="MX348252B_D0016.tif" />

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The front wheel (18) on the inboard side maneuvers through a greater angle than the front wheel (18) on the inward side, in order to achieve the Ackermann geometry. However, in the gear pair mode shown in Figures 9A-9C, the steering gear 52A on the in and out sides of the vehicle (10) will be rotated by the steering system substantially the same. speed and substantially the same magnitude. Preferably, the steering mechanism (52A) is configured to rotate approximately 90 degrees, with approximately 45 degrees in the knurled portion (82A) and approximately 45 degrees in the knurled portion (84A). The splined part (84A) has a longer gear line than the splined part (82A), and therefore more teeth. In the illustrated embodiment, the ridged portion (82A) has six teeth (60A) and the ridged portion (84A) has seven teeth (60A). Similarly, the part 87A of the transmission gear 70A has to match its splined part 84A on the steering gear 52A, such that it also has a large number of teeth 62A. As the gear line P_w is closer to axis A_w In portion 87A, teeth 62A extend a greater distance around the circumference of drive gear 70A. As a result, the gear teeth 62A in part 83A take a sector between about 70 and 89 degrees and the gear teeth 62A in part 87A take a sector between

.... ....,. ..CLEAN about 91 and 120 degrees. The variation ^^ J) ^^^ * DI LA PRÍ'PIÍJ'AÍ INDUSTRIAL - 'meshing between the inward side in the turn (84A, 87A) and the outward side in the turn (82A, 83A) makes the inward side front wheel (18) to achieve a greater steering angle than that of the outward side front wheel (18) according to Ackermann steering geometry. The non-circular shapes of the steering mechanism (52) A and the transmission gear (70A) allow the combination of gears to have a non-uniform gear ratio. In the neutral position, the ratio of the distance between the axis of the pivot As and the gear line Ps of the steering gear (52A) with respect to the distance between the axis of the pivot A_w and gear line P_w The transmission gear ratio 70A is preferably between about 1.0: 1.0 and 2.0: 1.0, and more preferably about 1.5: 1.0. The splined portion 82A of the steering gear 52A and the portion 83A of the transmission gear 70A have uniform mesh lines; therefore this relationship remains substantially constant for the front wheel (18) on the outside of the turn. However, in the extreme pivot position illustrated in Figure 9C, the relationship of the distance between the axis of the pivot A_s and gear line P_s of the steering gear (52A) with respect to the distance between the axis of the pivot A_w and gear line P_w The drive gear (70A) for the front wheel on the inner side is preferably between about 2.0: 1.0 and 4.0: 1.0, and more preferably '7 Τ · / Γ ΊΓί "_

.... Í&gt; 5 ϊνγγι / κγο μγ, χιο ^ π&gt; ϋ ηε ι λ? R &lt;v · κρa ¡* 1 '· ^ approximately 3.0: 1.0. However, you can '^NEITHER'éWog' ^ r ~ any appropriate relationship for a dacTa application ~ ~ ---—

Steering and speed control assemblies with integration device

Referring again to Figures 2B and 4, the speed control assembly is shown generally at (21) and its interaction with the steering assembly (20) by means of the integration device (27) to control the propulsion units. Transmission (29) will now be described. In a preferred embodiment, the integration device (27) includes components that mechanically integrate a steering input from the steering assembly (20) corresponding to the position of the steering input device (24) with a speed input corresponding to the position of the speed input device (28) to drive and steer the vehicle (10). The integration device (27) shown in the figures is configured to establish the direction of rotation of each drive wheel (16) and the relative rotational speed of each drive wheel (16) in response to the steering input that the integration device receives from steering assembly (20). The integration device, steering assembly, and speed control assembly illustrated, for example, in Figures 1-16 are configured to work together to reduce the speed (for example by decelerating) of the vehicle's outer drive wheel in a turn. extreme enough, even when the velocity input is constant (see «la ^ w

In some other embodiments, the speed and steering control assemblies and the integration device are not configured that way.

The integration device (27) includes an assembly (101), such as a connection assembly, that couples the speed control assembly (21) and the steering assembly (20) to the transmission drive units (29 ) so that the direction and speed inputs can be coordinated to control the magnitude and direction of rotation of the drive units of the transmission (29).

In one embodiment, the assembly (101) includes pivot connections (102) pivotally coupled to the drive units of the transmission (29). When the pivoted connections (102) are pivoted in a first and second direction, they provide an input to the transmission drive units (29) to control the direction and magnitude of rotational output from the drive units of the transmission. transmission, and thus the direction and magnitude of rotation of the corresponding driving wheels (16). The more the pivot connections (102) pivot, the greater the amount of speed at which the drive units (29) are propelled in each respective direction. The assembly (101) may also include regulation bars (104), which can be pivotally coupled to the pivot connections (102) on the

IMPIOS ^ F&gt; .A ΡΠρΡ'ΚΓ, Αΐ '\ ¿distal ends (105) of the regulation rods. aTMS-í- 'of regulation (104) can be moved towards ade-tefi + eyk &amp; G + a-at-r-á * - in such a way as to pivot the pivot connections (102) in the first and second directions. The regulation bars (104) can be changed independently of one another. Shifted independently means that the regulator bars (104) can be moved separately, such as in the longitudinal direction of the vehicle. As a result, the pivot connections (102) are independently pivoted so that the transmission drive units (29) can propel their associated drive wheels at different speeds and in different directions, although they can propel them at the same speed and in different directions. the same direction. The regulation rods (104) can be configured in any possible way that accommodates the orientation of the transmission system (and, more specifically, the drive units of the transmission). For example, two sections of a control bar (or two control bars) can be coupled together longitudinally using complementary rocker arms (see figure 21 for an example of a rocker arm) or a connecting plate (see figures 10 and 11 ). Alternatively, a change in the height of the tie rod can be made by bending it (see Figure 4).

The speed control assembly (21) of the vehicle (10) includes a speed input shaft (110) that is coupled to the chassis (14) in a way that allows it to

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UF IA PROPERTY (turn in res ^ Wést movement of the speed input device (28 -) - eri-which · · '---- is engaged (for example, through a fixed accessory). The input device The speed input shaft (28) is coupled to a speed input shaft (110) so that the speed input shaft (110) will rotate in the same direction that the speed input device (28) is depressed. When the steering input device (24) is in the neutral position (not facing left or right), rotating the shaft (110) in either direction will cause the left and right drive units (29) to be steered. in substantially the same magnitude and in the same direction, propelling the vehicle (10) forward or backward. The speed input device (28) can be biased by a spring or other mechanism into a neutral or undirected position.

As shown in Figure 10, the speed input shaft (110) is coupled to a speed mechanism (112). The speed mechanism comprises two speed cams (112), one that controls the left drive unit (29) and the other controls the right drive unit (29). The speed input shaft (110) is coupled to an arm (113) with a clamp (114). Arm (113) is coupled to a second speed shaft (115) by clamp (116). Thus, the speed input shaft (110) is coupled to the second speed shaft (115) by the arm (113), so that the rotation

<img file="MX348252B_D0017.tif" />

The speed input shaft (110) is transmitted in rotation (in the same direction) of the second speed shaft (115).

Each speed cam (112) is coupled to the second speed shaft (115) preferably with a clamp (117) at point (125). Each speed cam (112) has a speed slot (119). The integration device (17), and more specifically the articulated connection assembly (101), includes an extension (120) that is coupled to the end of the steering rod (104) and is mounted in the speed slot (119) . In the illustrated embodiment, for example, the extender (120) includes a clevis (121) having a pin (122) configured to mount in the speed slot (119). The extender (120) may include wheels, bearings, or other components to allow the extender (120) to slide in the speed slot (119).

As shown in Figure 10, activation of the speed input device (28) applies rotational force equally to both speed cams (112). The speed cams (112) rotate approximately at a pivot point (118) located on a line that extends along the axis of the second speed axis (115) and is located within the speed slot (119) (see Figure 13) as a result of the configuration of clamps 117, which act as bridges. The speed slot (119) is preferably curved, such that the extender (120) can slide freely from one end j! V? J industrial X ^ WT ^ CjÍ * from the speed slot (119) to the other as the steering rod (104) is pivoted approximately on a central axis * “positioned near the pivot connection (102). Additionally, the speed slot (119) can be formed as an arc having a radius that is equal to the distance from the pivot point (118) to the actuation location, which is the location where the pivot connection controls the activation of drive units. As a result, a speed input that causes the extender (120) to move in the speed slot will not activate either drive because the distance between the pivot connection and a line defining the arc of the speed slot (which runs through pivot point (118)) is constant throughout the entire slot.

Figure 11 shows the extender (120) received in the speed slot (119) of the speed cam (112) in the lower position. This can be the default position or the offset position. However, the neutral position may be at the top of the speed slot (119) depending on the arrangement of the steering rod (104) and the pivot connection (102) and how the pivot connection (102) is configured. ) to control the drive units (29). The speed control assembly (21) receives the steering input from the steering assembly (20) via the two steering cams (40). Each steering cam (40) is coupled to the steering cam

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HF LA »Ψ« Tlb'iAD I NDl &lt;«T« · * ♦ ** speed (112) with a steering control arm (124). Steering control arm (124) has a generally V-shaped body and is coupled to chassis (14) at pivot (126). One end of the steering control arm (124) contains an extension connection (128) which can be movably coupled to the steering cam (40). Specifically, in this embodiment, the steering cam (40) has a steering slot (127) that receives the extension connection (128). The other end of the steering control arm (124) is coupled to the steering rod (104) with a slide (133). The slide (133) can be attached to the steering control arm (124) in any appropriate way (see Figure 4) so ​​that it can pivot approximately on its immobilized axis and translate along the length of a portion of the slide. steering rod (104) without interrupting the longitudinal position of the steering rod and activating one of the propulsion units (29). The steering control arm (124) can selectively move the extender (120) in and along the length of the speed slot (119). As a result, the position of the steering cam (40) can control the position in the speed slot (119) where the extender (120) engages the speed cam (112).

As shown in Figure 12, the steering slot (127) in the steering cam (40) has a rest portion (130) that has a first contour to control the position of the extender connection (128) when steering cam (40) ⁵⁸ IMPI INSTITUTO MÜXICANC ΓΗ LA PROPERTY INDUSTRIAL - is on the outside of the vehicle (10) during a turn. The _______ resting portion (130) may include an end section (130A) having a different contour than an inner section (130B) of the resting portion (130). The steering slot (127) also has a cam portion (131) having a second contour to control the position of the extender connection (127) when the steering cam (40) is on the inward side of the vehicle (10) during a turn. The first contour of the rest portion (130) is different from the second contour of the cam portion (131). The cam part (131) may have an end section (131A) and an inner section (131B). The end section (131A) may have a different contour than the inner section (131B). When the steering cam (40) is in its neutral position, the extension connection (128) is housed in a joint (132) located between the rest portion (130) and the cam portion (131).

The operation of the speed assembly (21) will now be described with respect to a steering cam (40) and a speed cam (112) located on the right side of the vehicle (10) (as shown, for example, in Figure 4), to illustrate how the address input from the address input device (24) and the speed input from the speed input device (28) can be integrated. Figures 14A-14C and 15A-15C schematically show various positions of the speed cam (112), the extender (120) controlled by the steering cam (40) (which has been removed for clarity), and

<img file="MX348252B_D0018.tif" />

ι · a ΙΛ λοχ -ί ΐ. I- .INDUSTRY! . 'The pivot connection (102) for different combinations of speeds and turns for the vehicle (10). ”'

Figures 14A-14C illustrate a "straight forward" mode of operation where there is no direction input to the direction input device (24). Figure 14A shows a neutral condition where there is no speed input, or the speed input device 28 (Figure 10) is in the neutral position N. When the driver depresses the speed input device (28) in the first or forward direction, the speed cam (112) is rotated via the speed input shaft (110) (Figure 10) on the pivot ( 118). One result of this rotation is illustrated in Figure 14B. This action causes the pivot connections (102) to shift from the neutral position N, which causes the vehicle (10) to steer in the forward direction. During this process, the steering cam (40) (Figure 11) remains in a constant default position, which causes the extensions (120) to remain at one end of the speed slot (119). In the illustrated embodiment, this is the lower end of the speed slot (119). As shown in Figure 14C, depressing the speed input device (28) in the second direction or in reverse rotates the speed cam (112) in the opposite direction on the pivot (118). Rotation of the speed cam (112) in this opposite direction pushes the extender (120) in the opposite direction. This places the pivot connection (102) on the side

<img file="MX348252B_D0019.tif" />

opposite to the neutral position N, causing the drive (29) to be driven in reverse. ____ ___

The operation of the vehicle (10) will now be explained when a turn is commanded by the steering input device (24). Returning to Figures 4 and 12, rotating the steering cam (40) in a first direction (for example, commanding a turn that places the inlet member (40) illustrated on the outward side in a turn, causes the extender connection (128) to move along the curvature of the inner section (130B) of the rest portion (130) of the address slot (127). The contour of the inner section (130B) is such that the extension connection (128) slides into the steering slot (127) so that the steering control arm (124) remains stationary and does not move over. the pivot (126). When stationary, the steering control arm (124) does not change the position of the extender (120) in the slot (119) of the speed cam (112). However, if an extreme turn is attempted, for example one that would turn the front wheels approximately 60 degrees or more, the steering cam (40) is rotated so that the extension connection (128) reaches the end section ( 130A). The end section (130A) is contoured such that it cam actuates the extender connection (128) and causes the steering control arm (124) to pivot, thus repositioning the extender (120) to slow the drive unit. transmission propulsion (29)

X IVA ii exterior for extreme twist, as described further '^ WlWit &amp;' ó / ΝΠ1Κ ~ Γ_Η|_ΑΙ

Alternatively, turning the steering cam (40) counterclockwise (for example, commanding a right turn that places the input member (40) on the side that is outward in the turn) causes The extender connection (128) moves along the curvature of the cam portion (131) of the steering slot (127). The contour of the inner section part (131B) is such that the steering cam (40) exerts a force on the extension connection (128) causing the steering control arm (124) to move on the pivot ( 126). As the steering control arm (124) pivots, it moves the extender (120) along the length of the speed slot (119) of the speed cam (112). This provides a steering input from the steering cam (40) to be integrated with the speed input. This integration produces a combined output that is transmitted through the steering rod (104) to the transmission system as a result of manipulation by the speed input device (28) operator. A combined output in this context is one that results from a combination of a speed input (eg, pressing a pedal) and a direction input (eg, turning a steering wheel). Neither the result of the thrust multiplier (116) traveling through the thrust connection (38) to drive the transmission (30) nor the result of the

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UH'hCTplAL address multiplier (112) that scrolls through the '**' * '* * “*' '' 'T»¹¹ · Πΐ »» ΙΜ4., 4 ^ -flgm. -.nl · ·, steering mechanism (48) for steering transmission (32) in US Patent No. 6,904,985 are a combined output.

Referring now to Figures 15A-15C, Figure 15A shows the positions of the speed cams (112), the extender (120) controlled by the steering cam (40), and the pivot connection (102) at the condition in which the steering input device (24) (figure 1) is rotated to command a maximum inboard rotation, so that the speed cam (112) illustrated controls the drive unit (29) on the side that is outward in the turn. During an inward rotation, the steering cam (40) causes the extender (120) to shift in the speed slot (119) toward the opposite end of the speed slot (119) shown in Figures 14A14C. . Accordingly, when the speed input device (28) is depressed in the first or second direction as illustrated in Figure 15B, the geometry of the speed cam (112) for the drive unit (29 ) remaining inward causes the pivot connection 102 to move in the reverse direction. Pressing the speed input device (28) to propel the vehicle forward, with the steering input device (24) rotated to produce an inward turn, causes the pivot connection (102) to actuate the drive wheel (16) on the inside of the reverse swing. The extension (120) on the speed cam (112) tNSTITVTt 'MkXICANi Pt Ι.Λ l'ROPID'AI¹Opposite (not shown) for the propulsion unit '^ VexterióT ^ does not move toward the upper end of the rSTnrrá' dé ~ VéTocTcTad (119). Therefore, the outer wheel is steered forward, resulting in a zero-minus radius turn.

When the speed input device (28) is pressed in the second direction or reverse, the speed cam (112) rotates in the second direction as illustrated in FIG. 15C. This causes the pivot connection (102) to command the drive unit (29) in the inward direction to drive the drive wheel (16) in an inward, forward direction. Thus, ZTR steering (or at least steering with small turn radius) forward and reverse is realized as a result of the drive units receiving two combined outputs. While the steerable front wheels (18) can turn in Ackermann geometry as indicated above, the steering system (20) can be configured to steer the front wheels (18) in any desired way using sound engineering criteria.

As shown in Figures 14A-14C and 15A-15C, the position of the extender (120) within the speed slot (119) can be adjusted by applying a force with the steering cam (40) (as can be seen in the figure 11). Preferably, a biasing force, which can be applied by a spring (not shown) coupled to the extender (120) in a way well known in the art, biases the extender (120)

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<img file="MX348252B_D0020.tif" />

toward the neutral position. As the steering input device (24) is rotated, the steering rod (104) selectively moves through the speed slot (119) to cross from a first steering position to a second steering position. . Preferably, the extender (120) slides in an analogous manner from the bottom to the top of the speed slot (119) depending on the amount of rotation directed by the steering input device (24), establishing a series or a plurality of trajectories through which the extender (120) is selectively maneuvered. Therefore, the extender (120) is selectively positioned at various points between the first and second maximum positions in the speed slot (119). In this way, and because the steering cams (40) are rotated independently or asynchronously, the pivot connections (102) can be independently controlled through the reception of independent combined outputs from the regulation bars ( 104) to steer and propel the vehicle (10) in a manner consistent with proper steering in the forward and reverse directions. Additionally, the steering cams (40) and speed cams (112) are preferably configured such that the maximum distance from the neutral position N that the pivot connection (102) can be changed by the extender (120) it is greater in the forward direction than in the reverse direction. As

--——

IMPI Ο / Β result, a propulsion unit (29) generally, the transmission system) produces a greater maximum magnitude -, ___ of speed in the forward direction than in the reverse direction. For example, in one mode, the vehicle has a maximum forward speed of approximately 6 mph and a maximum speed in reverse of approximately 4 mph.

Preferably, the steering characteristics of the drive wheels (16) and the front wheels (18) coincide such that the directions provided by the drive wheels (16) and the front wheels (18) cooperate to steer the vehicle (10). . Accordingly, the degree of rotation produced by the drive wheels (16) can be made to coincide with the steering angle of the front wheels (18) in such a way that the drive wheels (16) do not try to turn the vehicle in a tighter turn the front wheels (18), and vice versa. In the illustrated embodiment, this is done by selecting the curvature of the steering slot 127 of the steering cam 140 to match the steering angle of the front wheels. This can also reduce the amount of torque required from the drive wheels (16) to turn the vehicle compared to the amount of torque required to turn the front caster wheels of some conventional vehicles. With the steer wheels (18), the vehicle operator does not need the level of dexterity required to operate ZTR vehicles

IMPI Mexican institute (• F THE PROPERTY controlled by lever of the current technique, and the tendency to damage the driving surface, for example, tearing the grass or skidding the drive wheel that remains on the inside side during a turn is reduced, and possibly It is eliminated.

In operation, the steering assembly (20), by means of the steering cam (40) on the inward side of the desired turn, provides a steering input that changes the condition of the speed command towards the drive unit. propulsion (29) received from speed cam (112A) through assembly (101). The steering cam (40) on the side facing away from the desired turn does not change the condition of the speed command to the drive unit (29) for small turns. Velocity curves

For extreme turns, it is preferable that the drive unit (29) on the outward side slows down so that the front wheels do not make grooves. Figure 16 illustrates an example of the wheel speed for the drive wheels (16) produced by the two drive units of the transmission (29) as a function of steering input, assuming a constant steering input from the device. speed input (28) (constant pedal). The graph shows that the inner wheel slows down, and faster than the outer wheel, during a turn. The inner wheel has zero speed for a spin of approximately

<img file="MX348252B_D0021.tif" />

degrees and has maximum speed in reverse where the .ate *, vac

IMPIOS inner wheel is rotated approximately^{! N}TW ^ $$ b ^^. Ni f&gt; i ¡'TAI AL wheel from the outer side desirably holds or even increases_r. its speed slightly for turns up to approximately 60 degrees. The outer side wheel is gradually slowed for larger turns until it reaches a speed of equal magnitude, but in the forward direction, as that of the inner wheel at 108 degrees to produce a zero turning radius. Figure 16, a graph of wheel speed vs. Steering applied, is just one example of how the steering assembly (20), the speed control assembly (21) and the integration device (17) can work. They can be configured to produce other security profiles.

The steering assembly (20), the speed control assembly (21) and the integration device (17) work together to provide a reduced average speed as the vehicle (10) turns, as shown in the curves of speed of figure 16. The steering assembly (20), the speed control assembly (21) and the integration device (17) work together to balance the torque supplied by the drive wheels (16) and provide the vehicle (10) with modulation. of infinite and prolonged speed through the desired speed ranges of the two drive units of the transmission (29) from forward to reverse direction.

One turn produces a steering input to the inward direction extender (120) which causes the • IMPI

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OF THE rKWAt 'extender (120) is placed in the veloWáT slot (11yp closer to the point (118) about which the cam of vv I υυ pivots. This causes the magnitude of the movement of the steering rod (104) Correspondingly, the lateral displacement of the pivot connection 102 on the inward side is reduced and the drive wheel 16 in the inward direction is driven more slowly. The difference in rotational speed between the drive wheels (16) causes the vehicle (10) to turn. This rotation is maintained regardless of the position of the speed cam (112) as long as the setting of the steering input device (24) is not changed. Even when the driver places the vehicle (10) in reverse by changing the input in the speed input device (28), the magnitude of speed at the wheel in the inward direction (16) remains less than that of the wheel remaining inward. out (16), in such a way that the vehicle continues the turn in the same direction. Thus, a consistent or proper direction is maintained when traveling in reverse. Additionally, the movement of the steering cams (40) does not reposition the speed cams (112); this only changes the position in which each extender (120) is positioned in the speed slot (119) of one of the speed cams (112). And because the speed slot can be configured as an arc having a radius as described above, the movement of the steering input device (24) (figure 1) does not produce any rotation of the drive wheels (16 ) or

INOCSTklAL MOVEMENT OF THE VEHICLE (10). This will be in accordance with the expectation of the vehicle operator (10), who may be used to controlling the movement and speed of the vehicle with one control (for example, the speed input device (28)) and the steering with another control ( for example, the address input device (24)).

Coil mode

Referring now to Figures 17-20, an alternate embodiment is illustrated for integrating the address input of the address input device (24) and the speed input of the speed input device (28). As in the previous embodiment, the drive units (not shown) are coupled to a connection assembly that includes a pair of regulating rods (104A) pivotally coupled to the pivot connection (not shown). This embodiment illustrates the steering rod (104A) with a rocker (149) positioned at one end (and which may be coupled to a rocker positioned on another steering rod (not shown)) to accommodate the orientation of the drive unit. transmission.

Figure 17 shows the speed input shaft (110) coupled to two speed cams (112A) via a second speed shaft (115A). The rotation of the speed input shaft (110) causes the rotation of the second speed shaft (115A), which in turn rotates the speed cams (112A). The speed cams (112A) have a shape

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ΙΝλΤ: '-ΤΑ Μί&gt;! Ζ_ΛΝΟ substantially similar and a velocFdlet ^ i; ^ slot substantially similar to that of the speed cams (112) described in the above mode. The extensions (120A) positioned at the end of the regulating bars (104A) are coupled to the speed cams (112A) with a yoke (121A) and a pin (122A) slidably received in the slot (119A). No further description of the speed cams 112A and extensions 120A is necessary because they are similar to the speed cams 112 and extensions 120 of the embodiment described above.

Two steering cams (40A) are coupled to chassis (14) so ​​that they rotate on pivot (41A) and are coupled to steering input device (24) (Figure 1) by means of a helical gear (150). The worm gear (150) is positioned at the end of the steering shaft (30) such that the worm gear (150) is rotated in the first and second directions as a result of the rotation of the steering input device. (24). The worm gear has first and second variable pitch grooves 152, 153 cut around its outer circumference. The left steering cam (40A) engages the worm gear (150) by means of a clamp pin (154), and the right direction cam (40A) engages the helical gear by means of the clamp pin (155). The retaining pin (154) is

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FAQ IA PRO! I H&gt; AI JND »i &lt;tr · al * V received in the first variable pitch slot (152). Similarly, the holding pin (155) is received "in a" second variable pitch slot (153). Variable pitch slots (152), (153) are configured to cause clamp pins (154), (155) to selectively pivot steering cams (40A) as coil (150) is rotated.

Figure 18 shows that the variable pitch groove (152) has a rest portion (152A) in which the variable pitch groove (152) has a first contour. The variable pitch slot (152) also has a cam portion (152B) in which the variable pitch slot (152) has a second contour. The first contour is different from the second contour: the cam portion (152B) has a generally spiral configuration, while the rest portion (152A) extends around the circumference of the coil (150) at a uniform height along coil body. In one embodiment, the rest portion (152A) and cam portion (152B) each cover approximately 240 degrees around the circumference of the coil. However, the length of the rest portion (152A) and cam portion (152B) can increase or decrease this depending on the desired application, and using sound engineering criteria. When the steering cam (40A) is in its neutral position, the clamping pin (154) is housed in a joint (156) between the rest point and the cam portions (152A), (152B) of the passage slot. variable (152). The second variable pitch groove 153 has a rest part (153A) and a cam part (153B) simitare which they meet in a joint (157). --—-------------------- Figure 18 illustrates a condition in which the clamping pins (154) and (155) are in neutral positions;

specifically, the pins are in the joints (156), (157) in their respective slots (152) and (153).

Figure 19 illustrates a second condition after which the helical gear (150) has been rotated by rotation of the steering input device (24) (Figure 1). In this second condition, the clamping pin (154) has moved through the rest portion (152A) of the slot (152) and the clamping pin (155) has been moved through the cam portion ( 153B) from slot (153).

As best seen in the enlarged view of FIG. 20, a steering control arm (124A) extends from the steering cam (40A). The steering control arm (124A) is coupled to the link assembly (101A) with the slide (133A) and controls the position of the extender (120A) to provide steering input to the speed cams (112A) in substantially the same way that the steering control arm (124) controls the position of the extender (120) in the embodiment described above.

In operation, the worm gear (150) rotates in response to a steering input on the steering input device (24) (FIG. 1). When the worm gear (150) is rotated counterclockwise (for example, when attempting a counterclockwise turn it could ο'όΙδοθΓΊΤ'Γβν'Γ ”~ input (40A) illustrated in Fig. 20 on the outside side of the turn), the clamping pin (155) moves along the curvature of the rest portion (153A) of the slot (153). The contour of the rest portion (153A) is configured such as the pin (155) moving along it, the coil (150) does not cause the steering cam (40A) to rotate on the pivot ( 41A); instead, the steering cam (40A) remains generally stationary. Thus, the steering control arm (124A) does not cause the extender (120A) to reposition in the slot (119A) of the speed cam (112A).

Alternatively, when the worm gear (150) is rotated clockwise (for example, when attempting a clockwise turn you could position the input cam (40A) on the side facing outward on the rotation), the clamping pin (155) moves in the cam portion (153B) of the slot (153). The contour of the cam portion (153B) is configured such that the helical gear (150) exerts a force on the clamping pin (155) that causes the steering cam (40A) to pivot on the pivot (41A). As the steering cam (40A) pivots, the steering control arm (124A) causes the extender (120A) to shift in the slot (119A) of the speed cam (112A). The steering cam (40A) on the opposite side responds similarly.

ϊ Μ Ρ ϊ

MEXICAN INSTITUTE

In this mode, the steering cam (40A) in ei ^ a ^ O '^ is out of the desired turn does not change + »po91 ^ 440-4 ^ 4 - ^ —-— extender (120A) with respect to the cam speed (112A). On the other hand, the steering cam (40A) on the inward side alters the position of the extender (120A). The worm gear (150) (and, more particularly, the shape of the variable pitch slots (152), 153) can be configured to make the transmission system generally (and the outer-side drive unit specifically) go more slow during extreme turn to help prevent the front wheels (18) from forming grooves. The rotation of the speed cam (112A) through the operation of the speed input device (28) and the operation of the pivot connection via the articulated connection are substantially the same as in the operation of those elements in the mode. described in the foregoing and illustrated in Figures 14A14C and 15A-15C, and therefore do not need to be repaired.

In the embodiments described above, the vehicle includes left and right steering paddles (40 and 40A), left and right speed paddles (112 and 112A), and left and right extensions (120 and (120A)). The extension on the right side of the vehicle is coupled to the right transmission drive unit (29) and is controlled by the right side steering gear and the right side speed cam. The left extension is attached to the drive unit

<img file="MX348252B_D0022.tif" />

left drive gear (29) and is controlled by the left side steering gear and left speed cam. Each steering cam influences the position of its corresponding extension relative to the corresponding speed cam.

Alternatively, the vehicle (10) may include a single steering mechanism that interacts with a single speed mechanism with a link assembly having a single extension with multiple legs that interact with the transmission system generally, and the powertrains of the transmission (29) more specifically. Additionally, the steering gear can change the position of the speed gear relative to the extender in other embodiments of devices and systems herein, which are described below.

Rack and pinion modes.

Figures 21-25D illustrate a speed control assembly (21B) and a portion of a steering assembly (20B). The steering assembly (20B) includes a steering mechanism in the form of a sprocket (200) that is externally toothed to engage a steering gear or chain (omitted from the drawings for simplicity) coupled to the steering input device. (for example, address entry 24, not shown). Movement of the steering input device by the driver thus turns the sprocket

ΙΜΡΙ «^, iffeTiTino mf.xicaw α&gt; 'E La PFOHF.r.Ai VCZSYES -JV (200). The speed control assembly (21B) irftTliy «speed mechanism comprising cremSII'tíltfs — den + a4a« —_ master and slave (202), (204) which are coupled to the sprocket (200) so that they rotate together with it, but that they are capable of moving longitudinally in relation to it. As shown in figure 22, this coupling is achieved by lugs (206), (208) that project from the sprocket (200) and are slidably received in longitudinal grooves (210), (212) of the racks. (202), (204) corresponding. Another means can be adopted to provide a directionally positive fix. For example, both racks can be slidably attached (eg using bushings) to a base plate (not shown). The base plate can be attached to the mounting plate 219 (described below) with side walls (not shown) to enclose and protect the zippers.

Speed ​​cam (21B) also comprises a speed control rack (214) that is coupled to, and movable along, its longitudinal direction, by a speed input device (for example, the speed input (28), not shown). The speed control rack (214) meshes with a speed control pinion (216). Both gear (200) and speed control pinion (216) are bearing mounted on a shaft (217) of a mounting pinion (218). The shaft (217) is mounted on bearings in a die plate (2Ϊ§)^: so that it can rotate, but the axis is fixed. Although not shown, the mounting plate (219) may be provided with a slot and the speed control rack (214) may be attached to the mounting plate (219) with a lug projecting from the speed control rack. speed (214) that mounts in the slot. The sprocket (200) has a concave inner region into which the speed control pinion (216) projects. The dome is removed to allow engagement of the speed control pinion (216) with the speed control rack (214). The mounting pinion (218) engages with the slave rack (204) but runs in a non-serrated longitudinal recess (220) in the master rack (202), such that the master rack (202) does not restrict the longitudinal movement of either rack - when slave rack (204) moves, mounting pinion (218) rolls freely. The speed control pinion (216) engages with the master rack (202) such that movement of the speed control rack (214) produces a corresponding movement of the master rack (202).

An integration device that includes an extension pinion (224) (one type of extension) engages the lower regions of both the master and slave racks (202), (204). The extension pinion (224) is mounted so that it can rotate on a central journal (225) carried by a lever in

INSTITUTO MEXICANO LA HOFIIDAD t I «w.» . I ./ .. INQUMIAL.

T-shape (130). The lever (260) is provided with a fulcrum in the form of a guide (158) that can be moved along a guide path formed as a slot (160) in the mounting plate (219), and its The left and right arms are coupled to the ratio of the control levers 144L, 144R (which are comparable based on the pivot connections 102 described above) of the transmission drive units. (122L), (122R) (which can be HST as described above, or any other suitable transmission system, such as two continuously variable ratio transmissions, as described below). Although the extension pinion (224) shown is coaxial with the mounting pinion (218) in some of the drawings, it is capable of moving away from its position in response to input from the speed input device (not it shows).

The racks (202), (204), (214) together form a guide path that can rotate about a fixed axis defined by the shaft (217) by means of the steering input device through the sprocket (200) . The radial position of the extension pinion (224) (the distance from its center from the fixed axis) does not change by the rotation of the guide path and only depends on the position of the speed control rack (214). Fig. 24 shows the configuration when the speed input device is at zero or a neutral position, and the steering input device is in a "straight ahead" position. The axis of

IMPIOS iNRimni · m exica n &lt;i

D LA PRDPIU'At, extension pinion (224) rests on fixed shaft '^ 2'1T}, and ---' correspondingly lever (130) (omitted d e- ia »f-tgtr rare - 2-4 ------ 25D for simplicity of representation) is located to place both transmission drive units 122L, 122R in neutral. Figure 25A shows the configuration where the direction input device remains at zero (the orientation of the master and slave racks (202), (204) is the same as in the previous drawing) but the speed input device has caused the speed control rack (214) (not shown in these drawings) to advance, and this movement has been transmitted through the speed control pinion (216) to the master rack (202).

Consequently, the extension pinion (224) has been moved forward from the fixed axis (217). As in previous embodiments, the effect of this forward movement is to fix the two propulsion units of the transmission 122L, 122R with identical forward relationships, which makes the vehicle 10 move in a straight line. If the set control speed of Figure 25A is maintained, but the driver moves the steering input device to require a right turn, the configuration of Figure 25B is achieved. The master and slave zippers (202), (204) have rotated through ninety degrees. In the process, both the master and slave racks (202), (204) have rotated around the speed control pinion (216), causing them to move equally and in

<img file="MX348252B_D0023.tif" />

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opposite directions. As a result, the shallow displacement of the extension pinion (224) of the extension shaft (224) is now fixed (217) unchanged. The p^- sideways to produce a right turn.

Still maintaining the same set control speed, but moving the steering input device (24) to require a counterclockwise turn, the configuration of FIG. 25C is produced. Again, the radial displacement of the extension pinion (224) does not change.

Figure 25D shows the configuration when the steering input device is set to zero but the speed control rack is removed to move the extension pinion (224) in the rearward direction, locking both transmission drive units (122L). , (122R) in identical reverse ratios and causing the vehicle (10) to reverse in a straight line.

It will be apparent that in the master rack / slave rack mode described above, the speed input device determines the radial distance of the extender (s) from the axis about which the guide path rotates. The displacement of the extender produced by moving the steering input device is a function of this radial distance. Rotating the guide path causes the ratio of one drive unit relative to the other to change, while moving the extender along the guide path changes both ratios in the same direction.

IMPI

MEXICAN INSTITUTE

O'IA NWPIIOaO industrial

<img file="MX348252B_D0024.tif" />

Figure 26 illustrates an arrangement that is similar to that of Figures 21-25D but is believed to be more convenient to assemble. The arrangement includes a master rack (402) and a slave rack (404), but in this embodiment the frames are received and mounted in a two-part housing (450), (452). The housing and structures are capable of rotating around axis (454). The mounting pinion (418) is spatially fixed through an integral hub (456), which is grooved in the mounting plate (419). Part of the housing (450) has an integral collar (458) through which the housing is hub-rotatable (456) mounted. Running through an axial hole in the mounting pinion (418) is an integral shaft (460) of a speed control pinion (416), the shaft is splined in an upper gear (462) through which it exerts speed control. The top gear (462) is coupled to the speed input device through an arrangement (not shown) using either a chain or other toothed structure. The rotation of the housing 450, 452 and the structures it contains is controlled through a steering mechanism 464 carried in the housing and coupled to the steering input device through an array (not shown ) using either an additional gear, chain or other toothed structure. A center trunnion (425) mounted on a “T” shaped lever (430) (similar to

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ΙΝΊίΠ'Κ ΜΙΛΙΟΥ. t Cl. _____. ... ... * 'ΛSL' ^ or lever (130) described above) will be projected^T,at tTñ7? * _ r * ^ axial hole of the extension pinion (424). The pJTJiiij (430) is coupled to the transmission system, and more particularly to two propulsion units, in the manner previously described with respect to Figures 21-23. The extension pinion (424) engages with both the master and slave racks (402), (404). The speed control pinion (416) engages only the master rack (402), such that moving this pinion by means of the speed input device moves the extension pinion (424) radially. Fixed mount pinion (418) engages only slave rack (404) to ensure that when the housing rotates, the slave rack again tries to compensate for the advance of the master rack. As a result, the rotation of the housing does not itself change the radial position of the extension pinion (424).

The whole of this arrangement involves placing all relevant parts in part of the housing (450), then adding the part of the housing 452 to hold them in place. Although not apparent from the drawing, the housing 450, 452 forms an elongated housing that contains the full length of the zippers and allows them room to move longitudinally. Center trunnion (425) and a surrounding hub (464) project through an elongated slot in housing portion (452) to give them freedom to move longitudinally. Seals, including O-ring seals (466), (468), ϊ Μ ΡI «

Mexican INSTITUTE

OF ROTATION &lt;* - * keep the lubricant in the housing (450), (452) í^N4Vr &amp; fttar&gt; 5I joint housing on mounting plate (T19) is completed by inserting shaft (460) through its hole in mounting plate and securing top gear (462) in place on shaft (460) to resist its subsequent withdrawal.

Figures 27 and 28 show a version of a transmission arrangement designed to match the characteristics of a set of wheels (50) of the Ackermann type. The mechanism that can be seen at 500 is used to control the position of the T-shaped lever 502, which is equivalent to the T-shaped lever seen in Figures 21-23. In this embodiment, the outer ends of this lever engage with the ratio control levers of the variators (which are not shown in this drawing) through spherical heads (503) received in complementary formed slots (504), the which is a slight modification of the figures 21-23 modality. A more significant difference from the present arrangement relates to an arrangement of gears (506), (508), through which the mechanism (500) is coupled to the steering input device (not shown). The sprocket (506) serves the same purpose as the sprocket (200) seen in Figures 21-23: it serves to rotate the mechanism (500) by rotating the lever (502) to provide the steering effect. required. The driver is able to rotate the sprocket 506 via the steering input device (e.g.

IM PI ¿3 INSTn-UT. «MMICAN .., The address input device (24) of figure T)^M,'^ITEMbT ciTa + is coupled to the steering gear (508) cftfS is ffiupld Luir the sprocket (506). The sprocket (506) and the steering gear (508) are not circular, and their shapes are chosen to provide the required relationship between the position of the steering input device and the relationships provided by the two drive units of the vehicle. transmission (eg, powertrains 29 or 122L, 122R described above). Determining the shapes of the two gears (506), (508) is a direct numerical exercise based on the characteristic (position of the steering input device against turning radius of the vehicle) of the Ackermann steering device and the characteristic (position ratio control lever versus ratio) of the transmission drive units. In the present embodiment, this produces a shape for the sprocket 506 that has three curved sides, as can be seen. Gears 506, 508 are formed to remain engaged at all times, such that the shape of one determines the shape of the other.

Figures 29-31 illustrate the construction of a continuously variable ratio (CVT) transmission having an engaged neutral condition that is suitable for use as a drive unit of the transmission (29). The drive unit illustrated is a wheel drive type toroidal race, although other types of CVT may be used.

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For example, a belt and pulley type transmission qυβ ^ β'όϋrí&gt;

be used consistently with systems and vehicles?

present is described in U.S. Patent No. 5,766,105, which is incorporated by reference

The illustrated CVT comprises a V variator having a toroidally sunken input disk (310) and a toroidally sunken facing output disk (312). Two wheels (314), (316) are mounted in the toroidal cavity defined between the opposite toroidally sunken faces of the input and output discs (310), (312) to transmit the impulse from the input disc (310) to the output disk (312) with a ratio that can be varied by tilting the wheels (314), (316).

The input disk (310) is coupled to, and rotates with, a transmission input shaft (318) that is driven from the vehicle engine (eg, vehicle (10) engine (12)). The V variator provides an output via an output tubular shaft (320), which is coupled to the output disk (312) and is arranged coaxially with and around the input shaft (318). Input shaft (318) and output shaft variator (320) provide inputs to an E1 compound mixing epicyclic gear train. As shown schematically, the end of the output shaft variator (320) away from the output disk (312) carries a first planetary gear S1 of the mixing epicyclic gear train E1. The E1 gear train bracket C1 is coupled to and driven by the input shaft

INSTITUTE M2XICANO *

D t LA F ROFIE DA D (318). The support C1 carries four radially identical planetary gears, with equal spacing, identical radially outer planetary gears, with equal spacing P2 of the same size as the radially inner planetary gears P1. The radially inner planet gears P1 are engaged with the first planet gear S1 and with a corresponding one of the four radially outer planet gears P2. The radially outer planet gears P2 also engage with an internally toothed ring A1, which forms the result of the mixing epicyclic gear train E1. The output ring A1 is coupled via the coaxial tubular output shaft (322) to a single set of E2 epicyclic reduction gears. The epicyclic reduction gear set E2 comprises an input planetary gear S2 carried by the shaft 322, which is coupled with four planetary gears P3 angularly spaced by equal distances, carried by the support C2. Planetary gears P3 also mesh with a ring A2 attached to the transmission housing. The rotation of the support C2 forms the result of the set of epicyclic reduction gears E2 and is transmitted outwards by an output shaft (24) which is coupled to the support C2. Output shaft (324) is coaxial with input shaft (318), one end of which is received in a recess (326) at the innermost end of output shaft (324). The output shaft (324) is coupled to the corresponding steered wheel of the vehicle.

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<img file="MX348252B_D0025.tif" />

The transmission is housed in a generally tubular casing (330) that supports the input and output shafts (318), (320). The end of the housing (330) adjacent to the input shaft (318) is closed by means of an end plate (332). A conical Belleville lock washer (334) extends between the inner face of the end plate (332) and an annular seat plate (336), which is in rolling contact with a flat outer face of the variator input disk ( 310). The Belleville lock washer applies a force (an end load) to the input disc (310) and allows the torque to be transmitted to the input disc (310) by means of the wheels (314), (316) towards the output disk (312).

By varying the camber of the two wheels 314, 316 (as described below), the speed of the output disk 312 relative to the input disk 310 can be varied. By combining the rotations of the drive input and variator output in the mixing epicyclic gear train E1, the drive result can be varied. In the arrangement illustrated, the transmission can be varied from full reverse, through neutral gear, to full forward, as well as anywhere in between. However, the drive's operating range can be adjusted to the requirements through proper gear selection. For example, the inverter can be positioned to vary between

<img file="MX348252B_D0026.tif" />

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INsTITUT 'MLXJCANO DI. 1-A PROi'll-J Ai 'INDI • STRIAL reverse low through neutral gear to high in forward gear if a vehicle to which the transmission is attached operates normally in the forward direction and will only operate occasionally in reverse.

The mechanism for varying the inclination of the two wheels (314), (316) is shown in greater detail in figure 30. Each wheel (314), (316) is mounted so that it can rotate in a wheel holder (340) by means of a central trunnion (342) which is rotatably mounted on flat support plates (44), (46) opposite the wheel carrier. One end of each of the wheel holders (340) is coupled to one of the two corresponding ends of the crossbar (348) of a control lever (350) by means of a spherical bearing (352) (for example, bearing Rose manufactured by Rose Bearings Limited). The control lever (348) is provided with a pivot pin (354) located midway between the center points of the two spherical bearings (352). The pivot pin is received in a slot (356) of the same width as the diameter of the pivot pin but elongated in a radial direction with respect to the rotational axis of the variator. The slot (356) is provided in a mounting lug (358) that projects into the variator in the space between the input and output discs (310), (312). The lever (350) is provided with an activator arm (360) that projects out the variator housing in a direction perpendicular to the line joining the center points of the two bearings.

Saw

<img file="MX348252B_D0027.tif" />

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i. 1 vxstit spherical OI 352 (perpendicular to the axis of the cross bar (348) of ** - *** -&gt; «» »&gt; —---_r , _aj the lever). This arm 360 forms the lever through which the transmission ratio is controlled and corresponds to the ratio of the control levers 144L, 144R described in connection with Figures 22-25E. As lever 350 pivots, one of wheels 310, 312 is pushed and the other is pulled, both with equal torque. Mounting the pivot pin (354) within the slot (356) in the mounting lug (358) allows the pin (354) to move radially in and out, which ensures that horizontal forces coming from the wheels are even and cancel each other out. This can be valuable with low-cost assemblies, where component manufacturing is likely to be less precise. The radial movement of the lever pivot allows the lever to be moved to a position in which any imbalance between the two wheels that appears due to differences in manufacturing will be canceled.

It will be apparent that when the drive is transmitted, the wheels are subjected to a net torque which tends to drive them circumferentially on the variator shaft. This torque has to be reacted with respect to a fixed point for the wheels, so that they maintain stable positions. The necessary reaction torque is provided by the lever (360), such that the force on the lever is related to the torques at the input and output of the transmission.

Instituto msxican? r¿ *** g &amp; * Jl

GIVE FRONITY J ·

INDUSTRIAL

When, for example, a wheel tends to lag below vehicle speed, in a way that could cause it to slip, the effect is to change the force on the lever in such a way that the speed of the corresponding wheel tends to increase. By allowing this adjustment, wheel slip is reduced or eliminated in the illustrated arrangements.

Descriptions of well known manufacturing and assembly techniques, components and equipment have been omitted in such a way as not to unnecessarily complicate the systems and devices herein with unnecessary detail.

For example, the address set that receives an address input from the address input device may be configured differently from that shown in the figures. In alternative embodiments, the steering mechanism for a given vehicle may be a single steering cam with two steering slots, instead of two steering cams with one steering slot each, as shown for example in Figure 12. Additionally, this doubly slotted steering cam can be oriented horizontally (or generally perpendicular to the ground), instead of being oriented vertically like the steering cams shown in the figures. Furthermore, this steering cam (like any of the steering cams herein) can be tilted at any appropriate steering angle for a given application and chosen using sound engineering criteria.

<img file="MX348252B_D0028.tif" />

Another alternative includes moving the gear set that initially translates the rotation of a steering input device (such as a steering wheel) into motion that is transmitted to the wheel sets. For example, this type of gear could move forward and be positioned between two bars that otherwise act as tie bars that link the two sets of front wheel gears together.

As yet another example, the steering grooves which are shown in the figures positioned on the steering cams could be positioned on the gears that make up the gear sets for the steerable front wheels.

As yet another example, the vertically oriented speed cams could be made to mesh with each other to some degree and oriented horizontally.

The appended claims are not to be construed as including limitations of means plus function, unless a limitation is explicitly stated in a given claim, using the expression (s) means for and / or step for respectively.

<img file="MX348252B_D0029.tif" />