A suspension system for a vehicle.

© Patent holder (s):

Delft University of Technology in Delft.

© Patent granted:

24.11.2014 © Patent issued:

03.12.2014 * 72) Inventor (s):

Bram van der Grinten in Delft.

Jeroen Canton in Delft.

Sebastiaan Frederik Johan Flipsen in Delft. Gideon de Mooij in Delft.

© Authorized representative:

ir. J. van Breda et al. in Amsterdam .

© A suspension system for a vehicle.

© A suspension system for a vehicle comprising front suspension linkage means which operatively connect to one or more front wheels, and rear suspension linkage means which operatively connect to one or more back wheels, wherein the front suspension linkage means and rear suspension linkage means are connected with each other through an intermediate frame, wherein the frame comprises horizontal links on a first level and on a second level, wherein the first level is above the second level and the link or links on the first level are connected with the link or links on the second level with arms that connect with the said links on the first level and on the second level with hinges, and that for any arm that connects to a link on the first level and with a link on the second level, the hinge connecting said arm to the link on the first level is at a greater distance from its neighboring hinges in the first level than the distance between the hinge connecting the same arm to the link on the second level and the neighboring hinges in the second level of said hinge at the second level.

LC 2010824

This patent has been granted regardless of the attached result of the prior art research and written opinion. The patent corresponds to the documents originally filed.

A suspension system for a vehicle

The invention relates to a suspension system for a vehicle comprising front suspension linkage means which operatively connect to one or more front wheels, and rear suspension linkage means which operatively connect to one or more back wheels, wherein the front suspension linkage means and rear suspension linkage means are connected with each other through an intermediate frame.

Such a suspension system is for instance known from US2010 / 0171282. According to this known prior art which relates basically to a motorcycle, the construction tends to tilt forwardly during acceleration and tilt rearwardly during hard deceleration, thereby retaining a significant load on the front wheel during acceleration and a significant load on the rear wheel during braking. This is opposite to the typical situation. A disadvantage is however that the construction is quite complicated and does not easily translate to applications in other motorized vehicles such as automobiles.

It is an objective of the invention to provide a suspension system in which the combination of driver (including possible other loads) and vehicle (exlusive its suspension and wheels) tilts forward when the vehicle accelerates, and tilts backwards when the vehicle decelerates, for instance during braking. It is an object of the invention to provide such means that can be applied in all types of vehicles and which can be easily tuned to the extent that this behavior is desired.

It is a further objective of the invention to make it possible that an automobile turning a corner will exhibit the behavior to tilt sideways to the center of rotation pertaining to such corner.

It is still a further objective of the invention to make riding a vehicle more comfortable in the sense that the rider of the vehicle is less exposed to inertia forces, such as sliding off the seat by an effective use of the sought for tilt of the suspension system.

Still another objective is that when the suspension system is applied to a vehicle that moves at constant speed, yet traverses an inclining or a declining surface, the inclination / declination of the surface is compensated at least in part by the tilting of the suspension system so as to contribute to the level of comfort experienced by the rider of the vehicle.

These and other objectives of the invention are provided by application of a suspension system in accordance with one or more of the appended claims.

To realize the benefits of the invention first and foremost the frame of the suspension system comprises horizontal links on a first level and on a second level, wherein the first level is above the second level and the link or links on the first level are connected with the link or links on the second level with arms that connect with the said links on the first level and on the second level with hinges, and that for any arm that connects to a link on the first level and with a link on the second level, the hinge connecting said arm to the link on the first level is at a greater distance from its neighboring hinges in the first level than the distance between the hinge connecting the same arm to the link on the second level and the neighboring hinges in the second level of said hinge at the second level. This construction of the suspension system according to the invention basically corresponds with an upside down trapezium, meaning that the basis of the trapezium is of shorter length than the roof of the trapezium. It is essential that the virtual or true trapezium has interconnected bars or links that connect to each other with hinges. The hinges provide flexibility to the frame of the suspension system and enables the frame to transfer any variation in the position of the front suspension linkage means with reference to the part of the frame to which it is connected to a corresponding variation in the position of the rear suspension linkage means with reference to the frame, and vice versa. In this manner the suspension system tends to maintain the frame as much as possible in a horizontal position, which improves the comfort of the driver and accords with the desired behavior during acceleration and deceleration. Likewise this behavior can be implemented in a four-wheel vehicle when turning corners; the front suspension linkage means and the rear suspension linkage means most than be understood as the left wheel suspension linkage means and the right wheel suspension linkage means.

It is possible that the horizontal links on the first level of the suspension system, that is the top level, are embodied as the frame supporting the driver. A simple and straightforward construction is however that the horizontal links on the first level and on the second level are bars.

It has proven beneficial that the link or links at the first level and / or second level are adjustable in length for varying the distance between the hinges on opposite sides of said link or links. This makes it easy to adjust the behavior of the suspension system to the desired needs, and thus have the suspension system act more sensitive or less sensitive to the actual driving conditions. It also enables to adjust the system to the weight of the driver and other users including their baggage.

The suspension system of the invention is beneficially applied with the vehicle being a motorcycle or a bicycle optionally provided with a motor. However, it is also possible that the vehicle has three or four wheels, in the latter case two front wheels and two back wheels.

The invention will hereinafter be further elucidated with reference to a schematic drawing showing the principles of the invention.

In the drawing:

-figure 1 schematically shows a minimal first embodiment of the suspension system of the invention;

-figure 2 schematically shows a second embodiment of the suspension system of the invention;

-figure 3 schematically shows a third embodiment of the suspension system of the invention intended for sideways stabilization;

-figure 4 schematically shows a fourth embodiment of the suspension system of the invention with omnidirectional stabilization;

- figure 5 shows the embodiment of figure 1 during acceleration; and

-figure 6 shows a variation to the embodiment of figure 2 executed as a motrorcycle.

Whenever in the figures the same reference numerals are applied, these numerals refer to the same parts.

With reference first to figure 1 the basic principles of the invention are explained. In this figure 1 a suspension system for a vehicle 1 is shown comprising front suspension linkage means 2 which operatively connect to one or more front wheels 3, and rear suspension linkage means 4 which operatively connect to one or more back wheels 5. The front suspension linkage means 2 and rear suspension linkage means 4 are connected with each other through an intermediate frame 6.

The frame 6 comprises horizontal links on a first level 7 and on a second level 8, wherein the first level 7 is above the second level 8 and the link or links on the first level 7 are connected with the link or links on the second level 8 with arms 9, 10 that connect with the said links on the first level 7 and on the second level 8 with hinges 11, 12 and 13, 14.

For any arm 9 (10) that connects to a link on the first level 7 and with a link on the second level 8, the hinge 11 (13) connecting said arm 9 (10) to the link on the first level 7 is at a greater distance from its neighboring hinges 13 (11) in the first level 7 than the distance between the hinge 12 (14) connecting the same arm 9 (10) to the link on the second level 8 and the neighboring hinges 14 (12) in the second level 8 of said hinge 12 (14) at the second level 8.

Figure 5 shows the embodiment of figure 1 during accelaration in the direction of arrow a. It is shown that the vehicle 1 (exlusive its suspension and wheels 3, 4) tilts forward during acceleration as represented by the angle alpha. Likewise the vehicle 1 will tilt backwards when it decelerates, for instance during braking.

With reference to figure 4 the suspension system of the invention is shown when applied to a four-wheel vehicle. In this figure 4 front suspension linkage means 2 ', 2' 'operatively connect to two front wheels 3', 3 '', and rear suspension linkage means 4 ', 4' 'operatively connect to two back wheels 5', 5 '' . The front suspension linkage means 2 ', 2' 'and rear suspension linkage means 4', 4 '' are connected with each other through an intermediate frame 6.

The frame 6 shown in figure 4 comprises horizontal links on a first level 7 and on a second level 8, wherein the first level 7 is above the second level 8 and the links on the first level 7 are connected with the links on the second level 8 with arms 9 ',', 10 ', 10' 'that connect with the said links on the first level 7 and on the second level 8 with hinges 11', 12 '; 11 '', 12 ''; 13 ', 14' and 13 '', 14 ''.

For sake of clarity reference is now only made to arm 9 'to show that this arm 9' connects to a link on the first level 7 and with a link on the second level 8, and that the hinge 11 'connecting said arm 9' to the link on the first level 7 is at a greater distance from its neighboring hinges 11 '' and 13 'in the first level 7, than the distance between the hinge 12 'connecting the same arm 9' to the link on the second level 8 and the neighboring hinges 12 '' and 14 'in the second level 8 of said hinge 12'.

Figure 3 shows a frontal view of the suspension system applied to a four-wheel vehicle in which the horizontal links on the first level 7 and on the second level 8 as well as the arms 9 ', 10'; 9 '', 10 '' connecting the said links are bars.

With reference to figure 2 it is remarked that the link or links at the first level 7 and / or second level 8 are adjustable in length for varying the distance between the hinges 11, 13 on opposite sides of said link or links. This alters the wheelbase between the wheels 3, 5 and influences the behavior of the suspension system of the invention. Figure 5 shows an embodiment-variation which is based on the construction of figure 2, and wherein the linkage 7 is not visible, yet it is present due to its function being provided by the frame of the motorcycle depicted in figure 5.

It is expressly remarked that the invention can be implemented in many different ways without departing from the scope of the invention as reduced to wording in the appended 5 claims. Correspondingly the invention is explained with reference to some explanatory schematic drawings, and the skilled person will understand that many variations are feasible to these schematic drawings without departing from the appended claims.