US2777592A

US2777592A - Load engaging attachment for industrial trucks

Info

Publication number: US2777592A
Application number: US417399A
Authority: US
Inventors: Edward P Repke
Original assignee: Clark Equipment Co
Current assignee: Doosan Bobcat North America Inc
Priority date: 1954-03-19
Filing date: 1954-03-19
Publication date: 1957-01-15
Anticipated expiration: 1974-01-15

Description

E. P. REPKE 2,7

LOAD ENGAGING ATTACHMENT FOR INDUSTRIAL TRUCKS Jan. 15, 1957 3 Sheets-Sheet 1 Filed March 19, 1954 INVENTOR.

EDWARD P. REPKE ATTY.

United States Patent LOAD ENGAGING ATTACHNIENT FOR INDUSTRIAL TRUCKS Edward P. Repke, Coloma, Mich, assignor to Clark Equipment Company, a corporation of Michigan Application March 19, 1954, Serial No. 417,399

6 Claims. (Cl. 214-513) My present invention relates generally to a load engaging attachment for an industrial truck, and, more specifically, to an attachment for engaging lumber, logs, and similar goods.

For some time, industrial trucks have been used to load logs and lumber on railroad cars of the type having a fiat V bottom. As will be understood by those in the field, portions of each side of the car must be loaded alternately in order to prevent the railroad car from overturning. This alternative loading procedure, as carried out with pesently known truck attachments, requires the industrial truck to be driven back and forth from one side of the car to the other. Obviously, considerable time is wasted in such maneuvering of the truck; moreover in many instances, the car is so situated (e. g., because of adjacent interfering railroad tracks) that the truck can be driven only along one side of the car and thus proper loading of the latter is prevented. Consequently, present methods of loading logs on railroad cars are unsatisfactory.

It is an object of my present invention to provide an attachment for an industrial truck which will make possible the loading of both sides of a railroad fiat car from one side thereof.

The attachment of my present invention comprises frame means which is adapted to be pivotally mounted at its lower end to the upwardly and downwardly movable load supporting carriage of an industrial truck. Suitable power operated means is adapted to be carried by the load supporting carriage for pivoting the frame means forwardly and rearwarlly. In addition, cable means for defining a load supporting sling is suspended from the upper end of the frame means.

With the truck adjacent to and facing the side of a railroad flat car, and with the frame means upright, the cable means is in position for loading the near side of the car.

By actuating the power operated means so as to effect forward tilting of the frame means relative to the load supporting carriage, the cable means may be swung to a forward position for loading the far side of the car. My present attachment is thus suitable for loading both sides of a railroad car from the same side thereof and eliminates the necessity of the truck having to be driven back and forth from one side of the car to the other during a loading operation.

A specific form of load supporting cable means embodied in my present invention comprises a plurality of cables suspended at their upper ends from the frame means and hook means for securing the lower ends of the cables together.

It is a feature of my present invention that power operated means is employed for releasing the hook means whereby the lower ends of the cables may be disconnected so as to permit the cables to be withdrawn from the load. Moreover the power means may be arranged so that it is possible to release the hook means only when the load is resting on a support, thus preventing the accidental dropping of a load. I

A further feature of my present invention resides in the ruggedness of the construction and the simplicity of the design.

Now, in order to acquaint those skilled in the art with the manner of constructing and using load engaging attachments in accordance with the principles of my present invention, I shall describe in connection with the accompanying drawings a preferred embodiment of my invention.

In the drawings:

Figure 1 is a side elevational view of an industrial truck and the load engaging attachment of my present invention;

Figure 2 is an enlarged side elevational view of the load engaging attachment of Figure l; V

Figure 3 is an enlarged front elevational view of the load engaging attachment of Figure 1;

Figure 4 is an enlarged side elevational view of the hook means used to secure together the lower ends of the load engaging cables shown in Figure 1; and

Figure 5 is a side elevational view of the hook means and cables shown in Figure 4, but wherein the hook means is tripped to disengage the load engaging cables.

Referring now to the drawings, there is indicated generally by the reference numeral 10 an industrial truck having a main frame 12 supported at its forward end on spaced wheels 14 and at its rear end on a central pair of wheels 16. The truck 10 is further provided with prime mover means 18, an operators seat 20, and a steering column 22.

A generally vertically extending mast or upright 24 is pivotally mounted at its lower end to the forward end of the truck frame 12, and power shiftable frame means 26 is provided for effecting limited tilting of the mast 24 forwardly and rearwardly from the position shown in Figure 1. A conventional load supporting carriage 28 is mounted for upward and downward movement within the mast 24, and the carriage 28 carries the load handling attachment of my present invention which is indicated generally by the reference numeral 30. The details of construction of the load handling attachment 30 are best shown in Figures 2 and 3.

The load handling attachment 30 comprises a generally rectangular transversely extending vertical frame or boom member 32, which is secured to the load supporting carriage 28 for upward and downward movement therewith. Pivotally mounted about a transverse axis on pin members 33 carried at the lower end of the frame 32 is a tiltable frame 34 which comprises vertical side legs 36 interconnected by a latticed grid 35. The upper ends of the side legs 36, as viewed in Figure 3, are bent inwardly toward each other and are connected to the rear ends of parallel arm members 38 which are interconnected by forward and rearward transverse braces 40.

Limited forward and rearward tilting of the frame 34 is effected by a pair of hydraulic piston andcylinder assemblies 44 which are arranged at the sides of the mast 24. The hydraulic assemblies 44 comprise cylinders 46, Which are pivotally secured to the vertical sides of the rectangular frame 32, and piston rods 48, which are pivotally secured to the vertical side legs 36 of the tiltable frame 34. The hydraulic assemblies 44 are actuated for distending and retracting the piston rods 48 and tilting the frame 34 by selectively admitting fluid under pressure t-o-the appropriate ends of the cylinders 46. Fluid under pressure is developed by the prime mover means 18 of the truck and is adapted to be carried to the cylinders 46 by suitable hose lines (not shown). The flow of fluid is controlled through valve means conveniently locatednear, and actuatable by, the operator of the truck.

If desired, means such as a pair of pins 49, one adja-,

cent each side of the truck, may be provided ,to .lock together the tiltable and non-tiltable components of the anchored at 66 to the adjacent arm member 3.8.

attachment. When these pinsare. in place the hydraulic assemblies 44 are relieved of the necessity of. supporting the tiltable frame 34 in a vertical position. Thus if the frame 34 :is =to-remain :in ,a vertical :position for a prolonged period the use of pins 49 prevents the possibility of'leakagedn the assemblies 44 allowingthe frame 34 to tilt when suchtilt is not: desired.

The load engagingmeans which is suspended from .the tiltable frame 34 includes four cables 50 that areaflixed at their upper ends to floatingxbell cranks 52 supported by bolts 54 at the forward ends of the arm members 38. The lower ends of the cables 50 at oneside of-the .attachment are each tied, as shown in Figure 4, to one of a pair of hook-members 56,;While the lower ends of the. cables 50 at the other side of the attachment are each looped so as to bereceivable bythe hook members 56. With the hook member-sfifi-engaged, the cables serve to provide a sling for supporting a load such as the legs 58 shown in Figure l. 1

I also provide power operated means for effecting .release of the hook members 56 so that the cables SO-may be withdrawn from theloadSS. The power operated release means includes a cable 60 which has a bifurcated portion at its lower end. The twoparts of the bifurcated portion are tied respectively to the hook members 56. As shown. in Figure 2, the. upper end of the release cable 60 is trained over a pair of

pulleys

62 and 64, and is The pulley 62 rotates about .a pin member secured in the adjacent arm member 33, while the pulley 64 rotates about a pin member secured to the end of the piston rod 68 of a hydraulic piston and cylinder assembly 70. The hydraulic assembly 70 includes a cylinder 72 that is anchored to the arm member 38 and is connected to the fluid pressure developing means ofthe truck through

hose lines

73 and 75. The necessary control valve (not shown) is conveniently disposed adjacent the operators seat 20.

When fluid under pressure is admitted to the rear end of the cylinder 72 of the hydraulic assembly 7% through hose line 73 for distending the piston rod 68, the release cable 60 is lowered and the hook members 56 are then free to be used to hook or connect the lower ends of the load supporting cables together to define a load supporting sling. On the other hand, when fluid under pressure is admitted to the forward end of the cylinder 72 through hose line 75, and fluid is bled from the rear end, the piston rod 68 is retracted and the cable is pulled upwardlyfor swinging the hook members 56 to a released position disconnecting the cables 50 and permittingthe latter to be withdrawn from the load.

The load handling attachment of my present invention is particularly adapted for transferring small, short logs (such as pulpwood) from a commercial truck to a railroad flat car. 'In operation, the industrial truck is driven to a position adjacent to the commercial truck and the cables 50 are manually arranged about the logs to be picked up while the hook members 56 are piaced within the loops of the cables 50. Then the load supporting carriage 28 is elevated within the mast 24, in a manner which is well known in the art, until the load 58 is freed from the commercial truck. At this point, the industrial truck may be backed away and driven to a position at one side of a railroad car 78 having a flat V bottom.

'With the load handling attachment 30 in an upright position, as shown in solid lines in Figure l, the load of logs 58 may be deposited on the near side of the car 78 by lowering the load supporting carriage 28, until the load contacts the floor of the car 78, and releasing the cables 50.

Now if the attachment 30 is supporting a load and it is desired to deposit the load on thefar side of the railroad car 78, the frame 34 need only be-tilted from the solid line position, shown in Figure l,"to the dashed line position. Then, the load supporting carriage need only be lowered, until the load contacts the floor of the car 4 7.8,.and .the cable .60 released. After the load has been deposited at either side of. the car, the industrial truck may be used to repeat the described load transporting steps. It is to be understood that the frame 34 may be tilted forwardly for engaging a load as well as depositing a load.

After the railroad car 78 has been fully loaded with logs my attachment may be used for hunting ,up the logs. In the so-called bunting .up operation the lift truck is used to push inwardly any legs which project from the side of the railroad car beyond the width limits specified by the railroad. In this operation the latticed grid 35 which forms a portion of the. attachment is located so that it engages the ends of any projecting logs. Then the truck is driven forward to push such logs inwardly.

An added feature which may be provided in my attachment if desired is means for preventing an operator from inadvertently releasing a load while it is suspended in the air. The result of such inadvertent operation could seriously endanger workmen and equipment. By providing a hydraulic pressure limiting valve 77 in hose line 75, as shown schematically in Fig. 2, it is possible to prevent such an inadvertent operation. The valve 77 may be a commercially available valve which is adjustable to limit the pressure which may be applied to the forward end of cylinder 72.

By adusting the valve 77 to a sulficiently low value, the tripping force provided by the cylinder 72 may be adjusted so that cylinder 72 will be effective to disengage the .hooks only after the load on the slings has been placed on the car and cannot disengage the hooks while the load is suspended. It will be understood that a considerably greater force is required to disengage the hooks while the load is suspended than after it has been dcposited on the car. The valve 77 is adjusted so that it provides a force which is greater than the latter but smaller than the former.

'From the foregoing description it will be readily apparent that the attachment of my present invention=facilitates the loading of both sides of a railroad car from one side thereof. Thus the industrial truck'does not have to be driven from one side of a railroad car to the other side as portions of each side .of the car are being alternately loaded. Furthermore, it is to be noted that the tilting mechanism, and release mechanism, are both power operated.

Now while .I have shown and described what I believe to be a preferred embodiment of my present invention, it will be understood by those skilled in the art that various modifications and rearrangementsmay be made therein without departing from the spirit and scope of my invention.

I claim:

1. For use with an industrial truck having an upwardly and downwardly movable load supporting carriage, the combination of frame means pivotally mounted at its lower end to the load supporting carriage and having a forwardly extending portion, a plurality of cables suspended at their upper ends from the forwardly extending portion of said frame means, hook means for securing the lower ends of said cables together whereby a load supporting sling is defined, power operated means carried by the load supporting carriage for pivoting said frame means forwardly and rearwardly relative to the load supporting carriage whereby the distance between said cable means and the load supporting carriage may be selectively varied so that a load may be engaged and deposited by said cable means at varying distances from the load supporting carriage, second power operated means carried by said frame means for releasing said hook means whereby the lower ends of said cables may be disconnected so as to permit the cables to be withdrawn "from the load, and means connected in operative relation with the said second power operated means whereby the said hook means may be released only when the load is-restingon a support.

2. For use with an industrial truck having an upwardly and downwardly movable load supporting carriage, the combination of first vertical transversely extending frame means secured to the load supporting carriage, second frame means pivotally mounted at its lower end to said first frame means about a transverse axis and having an upper forwardly extending portion, a plurality of cables suspended at their upper ends from the forwardly extending portion of said second frame means, hook means for securing the lower ends of said cables together whereby a load supporting sling is defined, hydraulic piston and cylinder assembly means carried by said first frame means at the upper end thereof and having connection with said second frame means for pivoting the latter forwardly and rearwardly relative to said first frame means whereby the distance between said cable means and the load supporting carriage may be selectively varied so that a load may be engaged and deposited by said cable means at varying distances from the load supporting carriage, and hydraulic piston and cylinder assembly means carried by said second frame means for releasing said hook means whereby the lower ends of said cables may be disconnected so as to permit the cables to be withdrawn from the load.

3. For use with an industrial truck having an upwardly and downwardly movable load supporting carriage, the combination of first vertical transversely extending frame means secured to the load supporting carriage, second frame means pivotally mounted at its lower end to said first frame means about a transverse axis and having an upper forwardly extending portion, a plurality of cables suspended at their upper ends from the forwardly extending portion of said second frame means, hook means for securing the lower ends of said cables together whereby a load supporting sling is defined, hydraulic piston and cylinder assembly means carried by said first frame means at the upper end thereof and having connection with said second frame means for pivoting the latter forwardly and rearwardly relative to said first frame means whereby the distance between said cable means and the load supporting carriage may be selectively varied so that a load may be engaged and deposited by said cable means at varying distances from the load supporting carriage, hydraulic piston and cylinder assembly means carried by said second frame means for releasing said hook means whereby the lower ends of said cables may be disconnected so as to permit the cables to be withdrawn from the load, and pressure limiting valve means connected in operative relation with the last-named hydraulic piston and cylinder assembly means for limiting the pressure to the said last-named hydraulic piston and cylinder assembly means whereby the said hook means may be releasedonly when the load is resting on a support.

4. In a material handling vehicle, the combination of forwardly projecting boom means, a plurality of cables suspended at their upper ends from the said forwardly extending boom means, hook means for securing the lower ends of said cables together whereby a load supporting sling is defined, power operated means carried by said boom means for releasing said hook means whereby the lower ends of said cables may be disconnected so as to permit the cables to be withdrawn from the load, and means connected in operative relation with the said power operated means in such a manner that the said hook means may be released only when the load is resting on a support.

5. A combination as claimed in claim 4 wherein said power operated means comprises an hydraulic cylinder and piston assembly, and said last mentioned hook releasing means comprises valve means for limiting the hydraulic force which may be applied to the power operated means to a value which is less that that required to disengage the hook means when a load is suspended above a support by said load supporting sling but greater than that force which is required to disengage said hook means whenever the load is resting on a support.

6. An attachment for an industrial truck comprising, upwardly and forwardly projecting frame means arranged to be connected near its lower end to the industrial truck, a plurality of cables suspended at their upper ends from the upper portion of said frame means, hook means for securing the lower ends of said cables together whereby a load supporting sling is defined, power operated means carried by said frame means for releasing said hook means whereby the lower ends of said cables may be disconnected so as to permit the cables to be withdrawn from the load, and means connected in operative relation with the said power operated means in such a mannor that the said hook means may be released only when the load is resting on a support.

References Cited in the file of this patent UNITED STATES PATENTS 696,115 Stillman Mar. 25, 1902 948,577 Gregg Feb. 8, 1910 994,608 Sevin et al. June 6, 1911 1,757,150 Stoner May 6, 1930 2,375,104 Heitshu May 1, 1945 2,493,750 Bucksath Jan. 10, 1950 2,550,185 Busch Apr. 24, 1951 2,608,315 Turner Aug. 26, 1952 2,643,012 Whal June 23, 1953 2,645,360 Raymond July 14, 1953 2,696,317 Toffolon Dec. 7, 1954