Truck with hydraulic spreader apparatus

Dec. 10, 1963

TRUCK

Filed Oct. 23, 1961

E. W. SWENSON ETAL 3,113,784

WITH HYDRAULIC SPREADER APPARATUS 2 Sheets-Sheet 1

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Dec. 10, 1963 e. w. swenson etal 3,113,784

TRUCK WITH HYDRAULIC SPREADER APPARATUS

Filed Oct. 23, 1961 2 Sheets-Sheet 2

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United States Patent Office

3,113,784

Patented Dec. 10, 1S63

3,113,734

TRUCK WITH HYDRAULIC SPREADER APPARATUS

Esksl W. Swenson, Cherry Valley, and Burl A. Wilder, Lindenwood, Ill., assignors to Swenson Spreader &amp; Mfg. Co., Lindenwood, Π!., a corporation of Illinois

Hied Oct. 23, 1951, Ser. No. 14'6,921

Ciaims. (Cl. 275—8)

This invention relates to improvements in trucks having apparatus for spreading chemicals, grit and the like, and particularly to an improved spreader apparatus and drive therefor.

In the spreading of chemicals and grit such as sand, cinders, salt and the like over roads, it is frequently desirable to vary the width of the spread area as well as the amount of the material applied to the selected area to accommodate different materials being spread and the different road conditions. Thus, the width of the desired spread area will vary with different roads, and, moreover, it is frequently advisable to momentarily increase the spread area in certain road sections such as when the truck passes an intersection. Broadcast type spreaders will spread over an area that varies with the speed at which the broadcast spreader is driven, and, in order to prevent changes in the width of the spread area with changes in truck speed, it has heretofore been the practice to use a separate drive, such as an auxiliary gasoline motor to operate the broadcast spreader. The auxiliary motor is mounted on the truck and connected to the broadcast spreader either mechanically or by an hydraulic circuit including a pump driven by the auxiliary motor and an hydraulic motor connected to the spreader. While the speed of the auxiliary gasoline motor can be changed to vary the speed of the pump and hence the speed of the spreader, this arrangement is not entirely satisfactory for accurate control over the spreader speed since it is difficult to maintain the speed of the auxiliary motor constant with varying loads on the spreader and, additionally, the speed of the auxiliary gasoline motor cannot be varied sufficient to give from zero to full soeed control over the spreader. Moreover, this arrangement requires an expensive auxiliary motor. It has also been poposed to control the width of the spread area by the use of an adjustable deflector plate which controls the spread pattern of the broadcast spreader. While the adjustable deflector plates do afford a measure of control over the width of the spread pattern, they are not entirely satisfactory since they frequently produce a non-uniform coverage of the area resulting in relatively heavier concentrations of material in one portion of the spread area than in the other. Moreover, since the spreaders are generally located remote from the cab, it is difficult to accurately adjust the position of the deflector plates from the cab and while the truck is in motion.

Difficulties have also been encountered in accurately controlling the amount of material spread by the spreader. The material being spread is frequently fed by gravity from the truck box under the spreader and an adjustable gate is provided for regulating the rate of flow. The rate °ffl°^w °’ ^mat®rial through the gate opening varies with different materials, particularly when there are lumps in the material being spread which tend to bridge the opening.. . Further, it is difficult to accurately control the gate position from the cab to enable changing of the amount of material being spread when the truck is in motion. In some applications, a conveyer has been used for conveying material irom the truck dump box to a remote spreader. However, the conveyer should be driven at a speed, that can be set independently of the truck speed and, in most installations, the conveyer is driven from a pump operated by the same auxiliary gasoline engine that 5 is used to drive the spreader. As a result, the conveyer and spreader are operated at speeds determined by the speed of the. gasoline engine with no provision for selectively adjusting the conveyer and spreader speeds independently of each other while the vehicle is in motion.

An important object of this invention is to provide a truck having a chemical and grit spreading apparatus and which enables selective control of the amount of material spread and the width of the spread area independent of the vehicles speed and independent of each other.

Another object of this invention is to provide a chemical and grit spreading apparatus in accordance with the foregoing object and which avoids the necessity of providing any separate auxiliary engine for driving the spreader apparatus at a selectively adjustable speed independent 20 of the truck speed.

Yet another object in this invention is to provide a truck having material spreading apparatus in accordance with the foregoing objects, in which the controls for the spreading apparatus can be located for easy operation 25 from the vehicle cab to enable adjustment of the spreader apparatus while the vehicle is in motion.

These, together with various ancillary objects and advantages of this invention will be more readily appreciated as the same is better understood by reference to the 30 following detailed description when taken in connection wiffi the accompanying drawings wherein:

FIGURE 1 is a side elevational view of the truck having the spreader apparatus of the present invention mounted thereon;

FIGURE 2 is a rear elevational view of the truck; and FIGURE 3 is a diagrammatic view illustrating the hydraulic control circuit for the spreader apparatus.

The truck designated generally by the numeral 10 is of conventional construction and includes a main frame 40 11 having front steering wheels 12 and rear drive wheels 13. A truck motor 14 is connected through the transmission 15, drive shaft 16 and differential 17 to the rear wheels to propel the vehicle. A cab 18 is provided on the frame adjacent the forward end of the truck and a 45 material receiving box or hopper 19 is mounted at the rear end of the truck. The box or hopper 19 may be of any suitable type and, as illustrated herein, is of the type described in the copending application of E. K. Swenson et ah, Serial^ No. 707,978, filed January 9, 1958, and 50 assigned to tne assignee of the present invention, now Patent No. 3,010,727. In general, the box 19 illustrated has a first section 20 extending longitudinally of the truck and. a second section 21 hingedly connected to the first section for tilting movement about an axis 22 extending 55 longitudinally of the truck to transfer material laterally of the box toward the first section. A feed conveyer 41 is. mounted on the first section to convey material longitudinally of the truck to a discharge opening 43 adjacent one end of the truck box. While the conveyer is herein 60 shown arranged longitudinally of the truck, it is contemplated that the present invention is also adapted for use with different dump box and feed conveyer arrangements, and that the feed conveyer may, for example, extend crosswise of the box instead of longitudinally of the 65 box.

The spreader apparatus of the present invention includes a broadcast type spreader designated generally by the numeral 25, which throws the material fed thereto

3,113,784 used to designate corresponding parts of the valves. More particularly, the valves 71 and 72 comprise bodies 78 each having an inlet passage 79, a controlled outlet passage 81 and a by-pass outlet 82. The inlet passage 79 5 communicates with a bore 83 in the valve body and the controlled outlet passage also communicates with that bore. The valve bore 83 defines a passageway that communicates the inlet passage with the respective controlled outlet passage and an adjustable orifice is provided in this 10 passageway to enable adjustment of the rate of flow from the inlet to the controlled outlet. In the form illustrated, the controlled outlet passage defines an orifice 84 at its intersection with the valve bore §3 and a valve element 85 is mounted for adjustment in the bore crosswise of 15 the orifice 84 to adjust the effective opening of the orifice.

The valve element is adjustable from externally of the valve by means of a knob 86 and, conveniently, the valves are located in the cab as shown in FIGURE 1 to enable adjustment of the speed of the respective spreader and 20 feed mechanism while the vehicle is in motion. Alternatively, the valves could be located externally of the cab and operated through linkages or the like. The bore 82 in the valve body is counter-bored at 87 and the by-pass outlet passage communicates with the counter-bore 25 through a valve port 88. A pressure-compensated valve member 89 is provided for controlling flow through the valve port and the valve member is yieldably urged to a position closing the respective port 88 by means of a spring 9©. The liquid flowing through the adjustable 30 orifice 84 produces a pressure drop thereacross correlative with the rate of flow through the orifice. As will be noted, one end of the valve member is directly exposed to the fluid pressure in the bore 83 at the inlet side of the orifice and the relatively lower pressure at the outlet side 35 of the orifice 84 is applied to the other end of the valve member 89 through a passage 91. Thus, the pressure drop across the adjustable orifice is applied to the valve member 89 and, when the pressure differential across the orifice reaches -a preselected value, it overcomes the ⁴⁰ compression of spring 90 and moves the valve member to a position opening the valve port 88 to by-pass the excess fluid. Since the valve member 89 is operated in response to the pressure differential across the orifice, and not in response to the total pressure in the lines, the 45 valves operate to maintain a preselected pressure differential across the orifice substantially independent of the pressure in the lines. Since the pressure drop through the orifice is proportional to the rate of flow therethrough, for any given orifice setting, the valves operate to main50 tain the preset rate of flow through the valve under widely variating conditions of pressure at the pump and at the respective hydraulic motors such as 31 and 47. Suitable relief valves such as indicated at 98 are preferably provided to prevent damage to the apparatus in the event of 55 excessive pump pressure or excessive loads on the hydraulic motors.

In the embodiment illustrated, a single pump 51 is advantageously used for driving both the spreader motor 31 and the feed motor 47 and, accordingly, a conduit 68 60 from the selector valve 58 is connected to the inlet passage 79 of one of the valves 71 and the by-pass outlet passage §2 of that valve is connected through a conduit 95 to the inlet passage 79 of the next valve 72. The bypass passage 82 of the valve 72 is connected through a 65 conduit 96 to the reservoir to return the excess liquid.

With this arrangement, the pump 51 is selected to have an output capacity greater than the combined load requirements of the hydraulic motors 31 and 47, even at the lowest truck speeds at which the spreader is operated, 70 and the fluid delivered by the common pump to the valve 71, which is in excess of the requirements of the motor 31 connected thereto, is delivered to the next valve 72 which supplies the motor 47. When using a single pump for driving both the spreader and the feed motor, it is 75 preferable to connect the valve 71 that controls the outwardly over an area correlative with the speed at which the broadcast spreader is driven. Such broadcast spreaders are well known and in general include a disk or plate 26 mounted for rotation about a generally upright axis and a plurality of vanes 28 on the disk for engaging and throwing the material outwardly as the disk is rotated. In the embodiment illustrated, the broadcast spreader is mounted adjacent the rear end of the vehicle and at the side thereof, it being understood that the broadcast spreader could be mounted at different locations on the vehicle, for example at either side of the vehicle; intermediate the ends of the vehicle or at the front of the vehicle as desired. The spreader is hydraulically driven by a positive displacement type hydraulic motor 31, for example of the gear, vane or gerotor type, and which motor is mounted by brackets 32 on the truck frame. A chute 33 is preferably provided for directing the material onto the broadcast spreader.

The material feed conveyer may be of any construction which will operate to feed material to the delivery opening 43 above the spreader 25 at a rate correlative with the speed at which the conveyer is driven. In the embodiment illustrated, the conveyer is of the belt type. It is contemplated that other types of conveyers could be used for feeding the material through the delivery outlet, such as screw type conveyers, etc., and that the conveyers could be arranged to extend crosswise of the box instead of longitudinally of the box as specifically shown herein. The conveyer 41 is also driven by a positive displacement type hydraulic motor 47 herein shown mounted at the rear end of the conveyer.

Reference is now made more specifically to the hydraulic control circuit illustrated in FIGURE 3 of the drawings for operating the hydraulic spreader drive motor 31 and feed drive motor 47. The hydraulic control circuit includes a pump mechanism 51 herein diagrammatically shown as the gear type, and having an inlet 52 connected to a reservoir 53 and outlet 54. In accordance with the present invention, the pump mechanism 51 is driven from the truck engine 14 at a speed that varies with the speed of the truck. As shown, the pump is conveniently connected to a power take-off shaft 56 of the truck engine, it being apparent that the pump could be otherwise drivingly connected to the truck engine as by belts or the like. The pump outlet 54 is connected through a conduit 57 to a selector valve 58. This valve as shown herein has an inlet 59 connected to the conduit 57; a return outlet 61 connected through a conduit 62 to the reservoir 53, and a controlled outlet 64. A valve member 65 is movable as by a handle 66 between a position by-passing the pump discharge back to the reservoir, and the position shown in FIGURE 3 communicating with the inlet 59 with the controlled outlet 64 and blocking the by-pass outlet 61 to direct the pump discharge to the conduit 68.

The rate of discharge and the pressure at the outlet of the pump 51 varies widely with the changes in truck speed and moreover, the pressure required to drive the feed motor 47 also fluctuates substantially under different conditions such as when the feed conveyer 44 strikes a lump or the like. Provision is made for adjustably regulating the rate of flow of fluid to the spreader motor 31 and to the feed motor 47 in such a manner as to maintain accurate control of the rate of flow to the respective hydraulic motors substantially independent of the pressure and volume of fluid discharged from the pump and also substantially independent of the load requirements on the respective hydraulic motors. The rate of flow of fluid to tlie respective hydraulic motors 31 and 47 is independently adjustable as by pressure-compensated flow regulating valves 71 and 72. The valves 71 and 72 are respectively connected through conduits 73 and 74 with the fluid motors 31 and 47, which motors are otherwise connected through a return conduit 75 to the reservoir 53. The pressure-compensated flow control valves 71 and 72 are similarly constructed and like numerals are

3,113,784

6' driving the spreader, a second fixed displacement hydraulic motor for driving the feed means, first and second conduit means respectively connected to the first and second hydraulic motors, a fixed displacement pump- means connected to said truck drive motor to be driven thereby at a speed that varies with the speed of the truck, means connecting said pump means to -said first and second conduit means to supply fluid under pressure thereto, first and second flow control valves in said first and second conduit means for adjustably regulating the rate of flow of fluid therethrough to enable independent adjustment of .the speed of the spreader and the speed of the feed means for control of the -area covered and the amount of material -spread on the selected area, said flow control valves each including a selectively adjustable orifice for regulating the flow from the pump means to the respectively hydraulic motor and pressure operated valve means responsive to the pressure differential produced across said orifice means for maintaining a substantially constant pressure drop across said orifice means to thereby maintain a preselected rate of flow through said orifice means determined by the adjustment thereof and substantially independent of the speed of the pump means or the load on the respective hydraulic motor.

--. In combination with a truck having a drive motor for propelling the truck, a hopper on the truck for material to be spread, a rotary broadcast type spreader for spreading material -across an area -correlative with the speed of rotation of the spreader, feed means for feeding material from the hopper to the spreader at a rate correlative with the speed of said feed means, a first fixed displacement hydraulic motor -for driving the spreader, a second fixed displacement hydraulic motor for driving the feed means, a fixed displacement pump connected to said truck drive motor to be driven thereby at a speed that varies with the truck speed, first and second flow control valves each having an inlet, a controlled outlet port and a by-pass port, said flow control valves each having an adjustable orifice means between said inlet and said controlled outlet for regulating flow from the inlet to the controlled outlet, a pressure responsive valve means in each flow control valve for regulating flow -from said inlet to said by-pass outlet and responsive to the pressure differential produced across the respective adjustable orifice -to by-pass fluid from the inlet to -the by-pass outlet when the pressure differential across the orifice means reaches a preselected value to thereby maintain a substantially constant rate of flow through the orifice means determined by the setting thereof and substantially independent of the pressure at said inlet or said controlled Odtiet, first and second conduit means respectively connecting the controlled outlet ports of said first and second valves to said first and second hydraulic motors for adjustably controlling the rate of flow thereto, means including a conduit for connecting the inlet of one of said control valves to said pump, and means connecting the by-pass outlet of said one of said control valves to the inlet of the other of said conrtol valves whereby a single pump is operative to supply fluid to both said first and θθ said second hydraulic motors.

4. In combination with a -truck having a drive motor for propelling the truck, -a hopper on the truck for material to be spread, a rotary -broadcast type spreader for spreading material across an area correlative with the _6g speed of rotation of the spreader, feed means for feeding material irom the hopper to the spreader at a rate correlative with the speed o-f said feed means, a first fixed displacement hydraulic motor for driving the spreader, a second nxed displacement hydraulic motor for driving the rotary broadcast type ₇₀ feed means, a fixed displacement pump connected to said _truck ,_{dri tQ dr}._{ven th£reby a}varies with the truck speed, first and second flow control valves each having an inlet, a controlled outlet port and a by-pass port, said flow control valves each having an adjustable orifice means between said inlet and said conb spreader motor ahead of the valve 72 that controls the feed motor, as shown in the drawings, to assure proper spreading of all material fed to the spreader. It is to be understood, however, that the valve 71 could be connected after the valve 72 without departing -from -the present invention.. Alternatively, it is apparent that two separate hydraulic pumps could be provided and each individually connected to a respective one of the valve members in wnich case the by-pass passages of the respective valve members would be returned individually to a reservoir.

From the foregoing, it is deemed apparent that the speed of the spreader 25 and the feed mechanism 41 can be selectively and individually varied by adjusting -the effective size of the adjustable -orifice 34 in the valves 71 and 72. The pressure-compensated flow regulating valves operate to maintain the preselected drop across the respective orifice, and thus accurately maintain a preselected rate of flow from the inlet to the respective controlled cutlet , passage determined by the opening of the adjustable orifice. Moreover, the valves will maintain this preselected rate of flow substantially independent of the speed at which the pump 51 is operated, -and hence independent of the speed at which the truck is driven. In addition, since the pressure-compensated valves are operated only by the pressure differential across the orifice, and not in response to the total pressure in the system, the valves will maintain the adjusted rate of flow notwithstanding variations in load on the respective hydraulic motors 31 and 47, such as occur when the material being spread contains lumps and the like. More- 30 over, the pressure-compensated valves effectively isolate the motor circuits to the motors 31 and 47 so that two circuits can be operated from a single pump while enabling independent control of the speed and pressure at which the respective motors operate. Thus, the speed of 35 operation of the spreader and the feed motor can be readily adjusted from the vehicle cab and while the vehicle is in motion to enable changes in the width of the spread area as well as changes in the amount o-f material being spread.