US3034831A - Tilting control for dump truck bodies - Google Patents

Description

May 15, 1962 F. BlszAN-rz ET AL TILTING CONTROL FOR DUMP TRUCK BODIES Filed Oct. iO, 19"? 2 Sheets-Sheet 1 @MR QM A 7 Tof? NEYS May 15, 1952 F. BlszANTz ET AL 3,034,831

TILTING CONTROL FOR DUMP TRUCK BODIES Filed Oct. lo, 195

ATTORNEYS Unite States Pater@ 3,034,831 TILIING CNTROL FOR DUMP TRUCK BODES Fred Bszantz and Arthur H. Ruth, Galion, hio, assignors to Hercules Galion Products, Inc., Galion, Ohio, a corporation of Delaware Filed Oct. 10, 1957, Ser. No. 639,328 Claims. (Cl. 298-21) This invention relates to a control for dump truck bodies and is particularly directed to a control for such bodies in which the tilting movement is derived from the operation of a hydraulic hoisting mechanism.

It is conventional practice to provide a dump truck body with a hydraulic hoist which will raise the forward end of the body to give a dumping angle of about 50 if the load is to be discharged all at one time. Such a body is used only part of the time for dumping its contents into a storage pile and is frequently used to spread material over .a wide area by running the truck with the body partially tilted. Gravel, stone chips, cinders and salt are frequently discharged in this manner. Under these circumstances it is not desirable that the body be raised to its full dumping angle, initially because the load will spill over the top of the end gate and the center of gravity will have moved so far to the rear as to make driving dangerous with the greatly reduced weight on the front wheels.

It is thus common practice for drivers to use the conventional body controls to raise the body part way for an initial spreading operation and to make periodic increases in the dumping angle as the vehicle moves forward until nally the established ultimate angle is attained. Such practice not only requires a high degree of skill on the part of the driver but requires that he divert his attention from the road during the time that the body angle is being changed. Because the operation must be done frequently under adverse Weather conditions and at night and because the driver cannot always properly correlate the movement of the body without stopping, getting out of the cab, and making a Visual check of the angle to which the body is tilted, present controlsJ for hydraulically operated vehicle dump bodies are inadequate. n The present invention overcomes all of the disadvantages that are present in the conventional dumping control devices and has for its primary object to provide a control within easy reach of the driver by which he can pre-select the dumping angle of a tilting body, and can increase the dumping angle in predetermined steps without stopping the vehicle or without diverting his attention from its safe operation.

Another object of the invention is to provide a simple and efficient adjustable link between a movable portion of a hydraulically lifted vehicle body and a control valve therefor by which the operator can preselect the angle of lift of the vehicle body and can increase the angle of lift in predetermined steps from locked horizontal position to the lhighest angle for which the hoist is capable.

Other objects and advantages of the invention willbecome apparent from the following detailed description of a preferred form, reference being had to the accompanying drawings, in which- Y FIG. 1 is a fragmentary side elevational View of a truck equipped with a body control constructed in accordance with the present invention;

FIG. 2 is a View taken'along the line 2 2 of FIG. l of the body lifting mechanism with the body bed removed;

FIG. 3 is a fragmentary section taken on line 3-3 of FIG. 2, with a suitable control valve being shown diagrammatically in central vertical section;

3,034,831 Patented May `15", 1962 FIG. 4 is a fragmentary section taken Ion line 4-4 of FIG. 2;

FlG. 5 is a section taken on line 5-5 of FIG. 3;

FIG. 6 is a top elevational view of a cab control device used with the present invention; and

FIG. 7 is a fragmentary section on line 7-7 of FIG. 6.

Referring to the drawings, and particularly to FIG. l, the present invention comprises a control for the dump body of a truck designated 10 in the drawings. Briefly stated, the invention represents an improvement used in combination with such a body having hydraulic means to raise and lower the same, and a control device for said hydraulic means including a control valve to initiate and cut oif the flow of operating duid to the hydraulic lifting means. The improvement comprises means operable by the body during a lifting movement, and adjustable means operable from the cab of the truck to select the point during the operation when said last named means becomes effective to operate the control valve and thus stop the lifting movement. In the preferred form of the invention said adjustable means comprises an adjustable link, the length of which can be made longer or shorter from the cab of the truck. One end of the link is connected to the tilting body and the opposite end thereof is connected to the control valve for the hydraulic lifting system.

The body itself is designated 12 in the drawings and is pivoted to the truck chassis at 14. A hydraulic cylinder 16 is provided which is mounted on chassis members 17 by a trunnionrlS at one end and the conventional piston that is disposed within the cylinder is connected by a piston rod 20 to a pivot rod 21 Aand a pivoted bell crank Z2 and by an arm 24 to the body 12. Any conven tional lifting means may, of course, be used in place of the specic mechanism described.

The hydraulic lifting cylinder 16 is supplied with oper;- ating or power lluid from a pump 25 supported by a bracket 27 mounted on the chassis and which is conventionally driven from a power take off 25a from the truck engine. As best shown in FIG. 3 the usual intake 29 of the pump is connected to an oil storage vessel (not shown). and the pump discharge is taken to a `control valve 26. The valve 26 is shown only diagrammatically in FIG. 3, but usually comprises a valve body in which suitable passages are formed to cooperate with a spooltype valve to give three operative positions designated raise, hold and lowerf f In the diagrammatic form the spool is shown at 28 and comprises a cylindrical member having three spaced circumferential grooves or passages 30, 31 .and 32 formed therein corresponding to recesses 30a, 31a and 32a in the valve body. The valve body itself is supplied With a pressure passage 33 connected to the pump discharge and a relief passage 34 connected to the storage tank. In the raise position of the valve spool 28, the circumferential groove 31 is aligned with pressure passage 33 and oil under pressure is thus passed to a conduit 36 leading to the front or lower end of the lifting cylinder 16. At the same posi-tion of the valve spool the circumferential groove 30 is aligned with the'relief passage 34 and with a conduit 38 leading from the valve body to the opposite or body end (upper end) of the lifting cylinder 16 so that oil can llow from this end of the cyl'- inder back to the storage tank as power oil enters the cylinder to raise the body.

ln the form shown in the drawings the lifting cylinder 16 is double-acting, that is the motion of the body in both its raising and lowering movements is caused by positive pressure of oil from the pump. In many instances the balance of the body is such that lowering thereof can readily be done by gravity alone. Thus the showing of a Vsuitable valve and pressure connections for a doubleacting lifting cylinder is purely illustrative and is made only for the sake of enabling those skilled in the art to understand the invention.

If the valve spool 28 is moved from the previously described raise position rearwardly or to the right in FIG. 3 to the extent that its circumferential grooves 30 and 31 are not aligned with either the pressure passage 33 or relief passage 34 the valve is in the hold position and the truck body will remain stationary by virtue of the oil trapped in the lifting cylinder 16. Of course, the pump continues to run and circulate oil which oil flow must not be blocked. The third circumferential groove 32 in valve spool 28 makes connection between conduits 33 and a supplementary relief passage 34 leaving an open circuit for the oil while the valve is in the hold position.

A further movement of the valve spool 28 to the right in FIG. 3 brings the circumferential grooves 30 and 31 into alignment with valve body passages so arranged that the truck body is caused to lower. Thus, conduit 38 leading to the rear or body end of the lifting cylinder is connected to pressure conduit 33 while conduit 36 leading to the opposite end of the cylinder is connected to the vsupplementary relief conduit 34. In this position of the valve spool power oil is supplied to the rear or body 'end of the lifting cylinder 16 and the body is thus positively returned to its lowered position. The hold passages previously opened by groove 32 are now blocked by the land between grooves 31 and 32 so that the previously described short circuit for oil owing from the pump does not exist. In this position of the valve spool power oil is supplied to the rear or body end of the lifting cylinder 16 and the body is thus positively returned to its lowered position.

The structure so far described is usually operated by a 'simple lever connection in the truck cab. This conventional lever 'is not shown but its operating link is indicated diagrammatically in FIGURE 2. The conventional mechanism has no connection whatever between the valve spool and the body of the truck.

The present invention comprises a supplementary means to operate the valve spool 28 and to correlate this motion with the motion of the truck body during its lifting movements. For this purpose the valve spool 28 is connected to the truck body by means including a telescopic or collapsing connection such that a lifting motion of the truck body will be transferred to the valve spool at a predetermined point in the lifting operation and will cause the valve spool to move from the raise position to the hold position. In this latter position, as previously explained, the power oil is trapped in the lifting cylinder and since no additional oil is supplied thereto or exhausted therefrom the truck body will remain stationary.

The conventional valve mechanism includes a snap action detent to assure that the spool 28 will move completely from one position to the next and not lodge between its operative positions. The detent includes a ball 40 urged by a spring 42 in a holder 44 into a plurality of properly spaced grooves 46 in an end extension of the valve spool. The space between the centers of the grooves is the same as the space between centers of the grooves or passages 30, 31 and 32 in the spool 28.

In the-form shown in the drawings the telescopic or collapsing connection between the body and the valve spool 28 comprises a iirst link 50 and an adjustable spring connection 52 between this link and the valve spool 28. The spring connection 52 is used to assure that the spool 23 will move quickly from one operative position to another and will not follow a continuous progressive movement of the body Thus the spring of the connection stores energy during body movement until the detent above described lreleases its ball 40 from the spool grooves 46 at which time the spool valve 28 snaps to a new operative position. The spring connection 52 also permits the manual movement of the valve spool more or less independently of the link 50. Since only tension forces are transmitted from the body to the link 50 the specific mechanism hereinafter described as a preferred embodiment of the invention can be replaced by a chain, wire or similar means.

The first link 50 is bifurcated over a large portion of its length as shown in FIG. 5 and the arms thereof, designated 53 and 54 are held in properly spaced relation by a series of spaced upper and lower crosspieces 56. A telescoping second link 58 is received between the bifurcated ends or arms of the first link 50' and is maintained in freely sliding relationship thereto by the crosspieces 56. The opposite end of the second link 58 is connected to the truck body by a lost motion or pin and slot connection 59-60 as shown in FIG. 4. The pin 59 of this connection is attached to a portion of the body lifting linkage such as the bell crank 22 and the slot is formed in an extension of the second link 58. The pin rides freely in the slot during normal lifting movements until such time as the lost motion is taken up so that continued lifting movement of the body is transmitted in the form of a longitudinal pulling movement of the link 58 and thus the first link 50, which movement is ultimately transmitted to the valve spool 28 through the adjustable spring connection S2. The valve spool is thus pulled from the raise to the hold position by continued lifting movement of the body.

The effective length of the operating element formed by the telescoping links 50 and 58 can be varied in any suitable manner. For example, a lever 62 pivoted on a pin 64 carried by ears 66 extending upwardly from the first link 50 may be connected to the second link 58 by an operating rod 68. Rod 68 is preferably connected to a linger 70 extending from the second link so that the angle of movement of the rod is maintained more or less in parallelism with the movement of the link itself. The lever 62 may be operated by a rod 74 extending to a point convenient to the driver where it is attached to a pivoted operating handle or lever 76. The operating lever 76 is associated with a segment 80 to which the handle or lever can be latched in certain predetermined positions. A spring 82 pressing a dog 84 downwardly against the segment forms a convenient and simple latch. The dog 84 is formed to enter appropriate holes or recesses in the segment 80 and is turned over at the top to underlie a projecting handle 86 so that it may be grasped with one hand by the operator when he wishes to move the operating lever 76 and thus change the position of the lever 62. Changing the position of lever 62, of course, changes the eifective length of the operating element formed by the telescoping links 50 and 58 by pulling the sections into greater telescoping relationship or extending them.

The segment 80 is preferably graduated or marked in increments representing the angle of tilt of the body. Thus the segments may be marked, and the latching holes for the dog 84 placed, at 0, 10, 20, and so on to 50 or to the fully tilted position of the body.

At the 0 or fully lowered position, a safety latch or lock 90 shown in FIG. 7 may be provided. The lock may comprise a pin 92 urged through an appropriate hole 93 in the segment 80 into a registering hole in the operating lever 76. A handle 94 for the pin is brought up into an accessible position over the `segment so that the pin may be withdrawn by the driver. It will be seen that since the operating lever 76 is locked in the 0 position both by pin 92 and the latch dog 84, both hands of the driver are required to start a tilting movement of the body. Thus if a truck body is used for carrying men or any material which is not under any circumstances to be dumped the latch or lock 90 serves as 'an adequate safety device since the handle which would normally control tilting of the body cannot inadvertently be moved out of the position in which any lifting movement of the body will immediately move the valve 28 to the position in which flow of operating fluid to the lifting cylinder is cut off. In some states it is required that any hydraulically actuated dump body that is to be used to carry men be modified by disconnecting the drive shaft to the hydraulic pump as a safety measure. With the present invention this drastic modification need not be made since `the lever 76 can be locked in the position of zero lift. When the lever is so locked, any accidental movement of the conventional valve operating handle which would normally start the pump 24 and direct oil to the lifting cylinder, will instantly result in a movement of the valve spool to the cut-olf position. As above noted actuation of the lever 76 out of the zero position requires both hands of the operator and cannot be accidentally accomplished.

In operation, assuming that the truck body is filled with cinders, salt, or other material which it is desired to spread along a roadway, the operator will move the operating lever 76 to the first incremental position such as l0. By so doing the handle 76 moves the connecting rod 74 and the lever 62 to an adjusted position. Adjustment of the lever 62 determines the effective length of the operating element formed by the telescoping links 50 and 58. Thereafter, when the driver reaches the section of the road over which the material is to be spread he operates the hoist mechanism in the usual manner by the conventional lever supplied for this purpose. The spool valve 28 is thus moved by this mechanism to the raise position shown in FIG. 3 and oil flows from the pump 25 through passage 33, around the spool groove 31 and to a conduit 36 to the lifting cylinder 16. When the body has tilted to the proper adjusted position the space between pin and slot connection between the bell crank 22 and the second link 58 closes and the body thereafter exerts a pulling force on the links 50 and S8, and through the spring connection 52 to the spool valve 28. The valve spool is thus snapped `quickly to the hold position as the detent is overpowered whereby operating liluid is cut olf from conduit 36 and the operating cylinder 16. The body will remain in this position and the driver will continue to dump the load until as much of it has been discharged as will move out with only a dumping angle. The operator thereafter moves the lever 76 to the next stop on the segment 80 re-adjusting the effective length of the links 50 and 5S. By then operating the conventional operating lever again to move the spool valve to the raise position from the hold position in which it had been standing the body will move to the next dumping angle Where the bell crank and link mechanism will again pick up the spool valve 28 and move it back to the hold position. This process lis repeated until the full dumping angle has been attained. Thereafter, the spool valve 28 can be moved to the lower position and the now empty body brought back to its horizontal position. It is apparent, of course, that if the operator wishes to return the body to its horizontal position at any time even though the body has not been fully tilted, this can be done simply by moving the spool valve 28 to the lower position through the conventional lever.

While the invention has been shown and described in conjunction with a specific form and disposition of the parts, it should be expressly understood that numerous modifications and changes may be made therein without departing from the spirit and scope of the appended claims.

What we claim is:

l. In a control for a hydraulically lifted durnp truck having a frame with a body pivotally connected to an end thereof and a lifting cylinder spaced from the end of said frame and interposed between the body and frame for moving the body about its pivotal connection, a source of fluid power lcarried by said truck, means connecting said source of fluid power to said cylinder for conducting fluid from said source ofvpower to said cylinder, a control valve interposed between said cylinder and source of power, the improvement comprising a first link connected to said control valve, a second link adjustably connected to said first link and having a lost motion connection for attachment to said truck -whereby force is exerted on said first link when the lost motion connection is taken up, operating means for attachment to said truck and connected to said links for adjusting said links with respect to one another whereby said links are operable by said body to actuate said control valve when said body assumes a predetermined angle of lift.

2. In a control for a Ahydraulically lifted dump truck having a frame with a body pivotally connected to an end thereof and a lifting cylinder spaced from the end of said frame and interposed between the body and frame for moving the body about its pivotal connection, a source of fluid power carried by said truck, means connecting said source of fluid power to said cylinder for conducting fluid Ifrom said source of power to said cylinder, a control valve interposed between said cylinder and source of power, the improvement comprising a first member connected to said control valve, a second member having one end slidably connected to said iirst member and the other end having a lost motion connection for attachment to said truck, said members being actuated by said body upon the pivotal movement of said body to operate said control valve when said body assumes a predetermined angle of lift and linkage means for attachment to said truck and connected to said members for slidably adjusting one of said members with respect to the other member to limit the pivotal movement of said body.

3. In a control for a hydraulically lifted dump truck having a frame with -a body pivotally connected to an end thereof and =a lifting cylinder spaced from the end of said frame and interposed between the body and frame for moving the body about its pivotal connection, a source of fluid power carried by said truck, means connecting said source of fluid power to said cylinder for conducting fluid from said source of power to said cylinder, a control valve interposed between said cylinder and source of power, the improvement comprising a first link connected to said control valve, a second link telescopically connected to said irst link, said second link being arranged for slidable connection to said body, means to adjust the telescopic connection between said links comprising a lever pivotally connected to said body, la segmental member associated with said lever, and means carried by said lever to engage said member at predetermined points to telescopically position said links with respect to one another.

4. In a control for a hydraulically lifted dump truck having a frame with a body pivotally connected to an end thereof and a lifting cylinder spaced `from the end of said frame and interposed between the body and frame for moving the body about its pivotal connection, a source of fluid power carried by said truck, means connecting said source of fluid power to said cylinder for conducting ufid from said source of power to said cylinder, a control valve interposed between said cylinder and source of power, the improvement comprising a first link connected to said control valve, a second link telescopieally connected to said first 1in-k, said second link being positioned for slidable connection to said body, said links being actuated by said body upon the pivotal movement of said body and operating said control valve when said body assumes a predetermined angle of lift, linkage means for connection to said truck and connected to said first link, a member interconnected between said linkage means Iand said second link and means for actuating said linkage means and member for slidably adjusting said links with respect to one another to limit the pivotal movement of said body.

H 5. In a control for ,a Vhydraulically lifted dump truck having a frame with a body pivotally connected to kan end thereof and a llifting cylinder spaced from the end of said frame and interposed between the body andrframe for moving the body about its pivotal connection, a source of iluid power carried by said truck, means yconnecting said source of uid power to said cylinder for conducting fluid from said source of power to said cylinder, a control valve interposed between said cylinder and source of powenthe improvement comprising a first link connected l0 to said control valve, a second link telescopically connected to said rst link, said second lin-k being positioned lfor slidable connection to said body, said links being actuated by said body upon the pivotal movement of said body and operating said control valve when said body assumes a predetermined angle of lift, linkage means for connection to said truck, an operating handle carried on said truck, a rod having an end secured to said operating handle, a lever connected to .said rod and said Atirst link, an operating rod connected `to said lever and said 8 second`1ink,said Voperating handle upon being actuated slidably adjustingthe'rst link 'wit-hrespect ltol/said second link through said rod lever and operating rod to limit the pivotal movement of said body.

References Cited in the le of this patent UNITED STATES PATENTS 513,447 Trapp Jan. 23, 1894 525,727 Trapp' Sept. 11, 1894 959,786 Neal Mar. 31, 1910 999,520 Phillips Aug. 1, 1911 1,413,309 Wooldridge Apr. 18, 1922 1,904,345 Anthony et al Apr. 18, 1933 2,220,815 Feilcke Nov. 5, 194() 2,359,961 Anthony Oct. 10, 1944 2,547,552 Anderson Apr. 3, 1951 2,566,779 Stutzke Sept. 4, 1951 2,690,712 Foote Oct. 5, 1954

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