US2390268A - Truck elevator - Google Patents

Description

vR. A. PENNEY TRUCK ELEVATOR Filed June 2, 1944 3 Sheets-Sheet l RAYMONDA. Pemmev @5% QM/Q/HM/ A922 A Dw 4,11945. R. AfPENNEY 2,390,268

TRUCK ELEVATOR Filed June 2, 1944 3 Sheets-Sheet 2 RAYHoquo A. Penn" @541 CML-bf'r R. A. PENNEY TRUCK ELEVATOR Dec. 4,

Filed June 2, 1944 3 Sheets-Sheet 3 Syvum/viuz `vated position.

UN l TEDI STATS\rP'TjII` `4 'FFF v 2,390,258 A TRUCK ELEVATOB f Raymnd A. Penney, Minneapolis, Minn., assigner to St. Paul Hydraulic Hoist lCompanLMinneapols, Minn., a corporation of Michigan l Application Juno a, i944, serial No. 5323.495

`9 Claims.

This invention relates to improvements in loading and unloading elevators for trucks.

The invention further relates to,l and has as load is rolled or slid onto the truck floor, 'and relieving the lifting-.hoist ofthe load. Still another object is to provide an improved construction of the main lifting roll yas used in such devices making it adjustable to"fit trucks of various types.

These and other objects of the invention win be made apparent in the course of the following its primary object, the improvement of that type i detailed specification forming a part hereof, and 1 in which reference is made to the accompanying drawings wherein- Fig. 1 is a side elevation of the rear portion of a truck equipped with the load elevator of my invention and showing Fig. 2 is an enlarged fragmentary plan view of the forward portion of the hoist and associated parts, taken substantially along the line 2--2 in Fig. 1.

Fig. 3 is a rear end view of the truck as shown inFig. 1.

Fig. '4 is an enlarged fragmentary detailed view of the forward end of the hoist and 'showing the latch mechanism. i

Fig. 5 is an enlarged longitudinal and vertical section along theline 5--5 in Fig. 3, showing the elevator in its lowered position.

Referring Vnow more particularly andby reference characters to the drawings, A designates "generally a truck having the usual chassis B over which is mounted a truck body C open at its rear end D and adapted to be closed thereat by a tail gate E. Said tail` gate E also constitutes 'the load carrier or platform by which the truck is loaded and unloaded, and for this purpose the tail gate may be swung downwardly to the horizontal position shown and there supported by chains F connected between rear corners of the gate and upper ends of side members G. The truck chassis B .is conventional in form and includes the usual longitudinal beams 6 and 'I above the same in its elet which the bed 8 of the truck body C is supported in any conventional manner.

Each side member G is pivotally connected at 9 and I0 to therear swinging ends of upper and lower arms I I and I2. The forward end of the arm` I2 is secured rigidly to the ends of a transversely extending roll or rock shaft I3 which is supported below the truck body C near the rear end thereoin brackets I4. The brackets I4 are four in number as here shown, and are secured at upper ends to the bed 8 while at lower ends they have bearings `I5 in which the roll I3 is- I directly above. the roll I3 at about the same sp acing as that existing between the pivots 9 and I0. and that the arms .II and I2 will therefore have a parallel link motion such that the tail gate E may be raised and lowered by oscillating the roll I`3 while maintaining the. tail gate substantially horizontal at all elevations.

For oscillating the roll I3 I provide a conventional hydraulic hoist unit, designated generally at I8, which comprises ,a cylinder I9 supported rigidly on Vthe chassis B by means Yof brackets 20 and an angle 2|. inder I9.is a plunger 22 and the cylinder is arranged 4lengthwise on the chassis B with this plunger, directed rearwardly toward and at an elevation above the roll I3. Fluid under pressure is provided for actuating the plunger 22 by a conventional pump4 23. operated from th'e truck engine, and the fluid is admitted to either end of the cylinder in `a conventional fashion u nder i control of avalve 2,4. The valve 24 ispositioned` by meansof an arm 25 `to which is connected one end of an operating rodl 26, as shown at 21. The operating rod 26 extends rearwardly beneath the truck body C and is pivotally connected-at Vits rear end 28 to a lever arm 29 which is secured to the vinner end of a transversely extending shaft 30 journaled inthe bed 8. The outer end of the shaft 30 is equipped with a hand lever 3| disposed alongside thebody-C. and it will be evident that 'by swinging the hand lever forwardly and rearwardly the operating rod 26 may be reciprocated to swing the arm 25 and actuate valve 24. As here shown, movement of the hand lever toward the forward end of the truck actuates the valve -24 to admit fluid-tn .the rear end of the hoist cylinder I9 and draw the plunger 22 inwardly or in a forward direction. Movement Slidably mounted in the cyl.`

operation, causing the plunger 22 to be projected in a rearward direction from the cylinder;` while positioning the lever 3l in a central/or holding position will cause the hoist to hold the plunger 22 in any position during its forward and rearward movement.

A wire cable 32 is secured at its forward end by a conventional coupling 33 to the rear `encl of the hoist plunger 22, and extendsrearward therefrom over an operating member or sector 34. The sector 34 is secured rigidly to the center of the roll I3 and has a curved track 35 located between side anges 36, which track is concentric with the axis of the roll I3. The cable 32 is secured as indicated at 32e' to arear corner portion of the sector 34, and it will be obvious that with the cable 32 of proper length the forward or inward movement of the hoist plunger 22 will pull on said cable to oscillate the sector 34 and roll I3 in a clockwise direction as viewed in Fig. 1. 'I'he arms II and I2 will thus be swung upwardly and the tail gate E raised to the level of the bed 8 of truck body C, and in this position the plunger 22 is drawn inwardly into the hoist cylinder nearly to the limit of such movement. On the other hand, the rearward or outward movement of the hoist plunger 22 will pay out the cable 32 enabling the sector 34 and roll I3 to oscillate in a counterclockwise direction to lower the arms II and I2 and tail gate E, and in this operation the cable will come to rest about the curved track 35 as seen in Fig. 5.

In the operation of the structure as thus far described, it will be evident that the manipula-` tion of the control lever 3I will permit the tail gate E'to be raised or lowered as required. Thus in loadingthe truck the tail gate E may be lowered to ground level and heavy boxes, crates or the like may be pushed thereon without lifting. Then by raising the tail gate E it will act as a load carrier, lifting the articles up to the level of the bed 8 of the truck body, and they may then be rolled or 'slid into the body without great effort. .Obviously the truck may be unloaded with equal ease. When not in use as a load carrier or platform the tail gate E may be readily folded upwardly and forwardly to close the rear end D of the truck body in the usual manner.

It is desirable that with the load in its maximum elevated position as seen in Fig. 1v some means be provided to lock the lift mechanism and relieve the hoist I8 of the strain of holding the load in this position. This is particularly true where, as is frequently the case, the truck is driven from place to place with a part of the load proz jecting over and supported on the tail gate. For this purpose I provide a latch mechanism, designated generally at 31, and comprisinga latch member 38 and a stop member 39. As best shown in Fig. 4, the stop member 39 is threaded on the cable coupling 33which is in turn threaded into a tapped lbore 40 formed in the rear end of the plunger 22. The stopmember 39 is circular and has a rear face 4I which is hollowed out and angles forwardly toward the center on all sides. The latch member 38 is pivotally mounted by a pin 42 on an ear 43 formed on the rear end of the cylinder I9, and from this point the latch member extends in a rearward direction substantially parallel with thepath, of plunger 22 and has a hook 44 turned inwardly to engage the face 4I of stop member 39. The latch member has an arm 45 extending outwardfrom its pivoted end, and braced between this arm 45 and a lug46 on the hoist cylinder I9 is an expansion CFI coil spring 41 which biases the latch member in a direction such as to swing its rear end toward 'the plunger 22, this movement being limited by y viouslyy be locked against Vrearward movement,

holding the tail gate E ush with the bed 8 of t the truck body, and relieving the uhoist I 8 o f the load.

To swing the latch member 38 clear of stop member 39 I provide a link 5I which is pivotally connected at a forward end 52 to the valve operating arm 25 and which, at its rear end, is slidably mounted through an opening 53 formed in the' arm 45. Rearwardly of the opening 53l the link 5I is provided with lock nuts 54 which act as an adjustable stop. Assuming now that the valve operating arm 25 is. moved forwardly in order to pay out the cable 32, as indicated in Fig.

' 2, it will be obvious that this movement wilLexert a pull upon the link'5l. With the lock nuts 54 properly adjusted the pull on the link 5I will oscillate the latch member 38 in such direction as to swing the hook 44 clear of stop member 39. Thus it will be evident that the normal movement of the hand lever 3|l in a direction forlowering the load will automatically disengage the latch, and it will be understood,` of course, that the latch is actually disengaged by the initial part ofthe -movement of the hand lever 3| and prior to the opening of the valve 24 to project the plunger 22 in a rear direction.. It may here be noted, however, that' the angularly. engaging faces of' the latch hook 44 and stop 39, while providing a positive latching effect at that point, have a tendency to seize under a load, making it difficult to free the hook from the stop member. I find, however, that this tight frictional engagement may be broken, so that the latch member may swing freely away from the stop member 39, by simply moving the hand lever 3l first in a direction to raise the load before it is swung in the opposite direction to lower the same. This action has the effect of admittingfluid to the rear end I of the cylinder I9, causing the plunger 22 to move forwardly a slight amountto free the hook from the face 4I of the stop member, as indicated in Fig. 4. Then as the lever is swung in the opposite direction, the latch 38 will be swung clear before the stop member comes into tight engagement with the hook 44 again. Only a very slight forward movement of the plunger 22 is required,

of course, and the wire cable 32 willvbe found seen in Fig. 3.- and complete "with separate end sections 56 and 51 which telescope into the ends of center section 55 as clearly indicated in the drawings. In the installation of the roll, the end sections 56 and 51 may be moved inwardly or outwardly to form a roll of an over-all length suitable to any particular truck and the parts may then be anchored solidly together by any suitable means such as the welds indicated at 58, causing the vario- us roll sections 55,56 and 51 to operate as a unit.

It is understood that suitable modifications may be made `in the structure as disclosed, provided vention, what I claim to be new and desire to protect by Letters Patent is: y

1. In a load raising and lowering mechanism for a truck. a. member movable in a lengthwise direction with respect to the truck and an actuating means for said member for moving the same vin either direction, a load handling device operatively connected to said member and adapted to be raised and lowered with respect to the truck in response to opposite movements of said member, and latch means releasabfy engageable with said movable member as it substantially completes its movement in one direction to raise the load, said latch means being operative when engaged to lock the movable member against movement in the opposite direction to thereby maintain the load in a raised'position whilerelieving said actuating means of strain.`

2. In a truck load raising and lowering mechanism of the character described, a load carrier, a cable connected t raise and lower said carrier, a hoist unit connected to one end of the cable for pulling the cable in one direction for raising the load and paving out the cable in an opposite direction to lower the londe stop member rigid Having now face oi' the stop member may be counteracted by actuating the plunger in an inward direction to slightly stretch the cable and pull the stop member clear of the hook preliminary to swinging the latch clear to lower the load.

5. In a truck loading mechanism, a hoist unit having a plunger, a cable connected to the-plungergaload carrier operated by the cable and adapted to be raised by a pull on the cable and lowered `by paying out the cable, a stop member on the cable having an angular face, a, swingable latch member having a hook adapted to engage over said anguar face of the stop member as the cable is pulled to raise the load, and controlmeans forthe hoist including a swngable arm and a-link connected between the arm and latch member to release the latter from the stop member as said arm is swung in one direction to pay out the cable.

6. In a truck loading mechanism, a hoist unit having a plunger. a cable connected to the plunger, a. load carrier operated by the cable and adapted to be raised by a pull onthe cable and a hook adapted to engage over said stop member- Y as the cable is pulled to raise the load, and control with respect to the cable. and a latch' member adapted to automaticallvensage said stop member as the load is raised and to hold the cable against paying out.

3. In a truck load raising'andlowering mechanism of the character desc'ibd. a load carrier,

y a. cable connected to raise and lower said carrier,

and a hoist unit connected to one end ofthe cable for pulling the cable in one direction for raising the load and paying out the cable in an opposite direction to lower the load. a stop member rigid with respect to the cable, a latch member adapted to automatically engage sairistop member as the load is raised and to hold the cable against paying out. a control lever for the hoist unit and movable to one position to cause the hoist to pay out the cable and to another position to cause the hoist unit to pull 0n said cable, and means operative by movement of said control lever toward a position for paying out the cable to disengage said latch member from said stop member.

4. `The combination with a truck loading mechanism o! the character 'described including a hoist unit having a plunger and a flexible cable connected at one end thereto and atits other end operatively'arranged to raise a load in response to a pull exerted by the inward movement of the plunger and to lower the load as the plunger` moves outward, of a latch mechanism comprising a stop member securedrigidly with respect to the cable and plunger and having a beveled tace. a pivotaliy supported latch having a hooked end ladapted to engage said beveled face of the stop member as the plunger is drawn inward and the load raised substantially to highest position and to lock the cable against paying out to lower the load, means for swinging said latch to release said stop member and permit the load to be lowered, and the arrangement being such that the tendency of the latch hook to seize on the beveled means for the hoist including a swingable arm and a link connected between the arm and latch member adapted to swingthe latch member in one direction to release the hook from said stop member as the arm is swung to a position for paying out the cable. said link being freely slidable with respect to the latch member as the arm is swung to an opposite position for pulling in the cable.

7. In a truck loading mechanism oi.' the character described, a transverse roll rotatably supported from the truck. a load carrier supported from the roll and adapted to be raised and lowered by oscillation of said roll, and said roll comprising a tubular center section and separate Aend sections adapted to be telescoped at inner ends into said center section to adjust the overall length of the rol laccording `to the width of the truck and when thus adjusted secured to said center section to turn as a unit therewith.

v 8. In a truck loading mechanism of the character described, a load carrier, a hoist unit having a cable connected to said carrier for raising and lowering the same in response to opposite movements of the cable, a control member movable in opposite directions for controlling said hoist unit. latch means operative to automatically lock the load carrier in a raised position as it reaches said latch means.

matically as the load carrier is raised to lock it e in a raised position, a control memberior the hoist unit movable in one direction to raise the load carrier and in an opposite direction to lower the same, and means operative by movement of the control member in the last mentioned direction for automatically disengaging said latch mechanism. i

, RAYMOND A. PENNEY.

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