US2750060A

US2750060A - Sling attachment for industrial lift trucks

Info

Publication number: US2750060A
Application number: US473807A
Authority: US
Inventors: Sherriff Fred
Original assignee: Clark Equipment Co
Current assignee: Doosan Bobcat North America Inc
Priority date: 1954-12-08
Filing date: 1954-12-08
Publication date: 1956-06-12
Anticipated expiration: 1973-06-12

Description

F. SHERRIFF June 12, 195 6 SLING ATTACHMENT FOR INDUSTRIAL LIFT TRUCKS 3 Sheets-Sheet Filed Dec. 8, 1954 ATTY.

June 12, 1956 F. SHERRIFF SLING ATTACHMENT FOR INDUSTRIAL. LIFT TRUCKS 3 Sheets-Sheet Filed Dec. 8, 1954 ATTY United States Patent SLING ATTACHMENT FOR INDUSTRIAL LIFT TRUCKS Fred Sherriif, Battle Creek, Mich., assignor to Clark Equipment Company, a corporation of Michigan Application December 8, 1954, Serial No. 473,807

1 Claim. (Cl. 214-620) My present invention relates generally to load handling attachments for industrial lift trucks and, more specifically, to sling attachments for handling lumber, logs and other similar material.

Industrial lift trucks have been used heretofore to load logs, lumber and similar material on railroad cars having a fiat V type bottom. Usually portions of each side of these cars mu st be loaded alternately to prevent them from overturning. This alternative loading procedure as accomplished with presently known truck attachments requires the truck to be driven from one side of the car to the other. This method is obviously time consuming and sometimes impossible because, in many instances, the car is so situated, that is, because of adjacent interfering railroad tracks or buildings, that it is possible to drive the industrial lift truck only along one side of the car, preventing the proper loading of the latter. Consequently present industrial truck attachments for loading logs or similar material on railroad cars are unsatisfactory.

A further problem in the loading of V type flat bottom railroad cars results from the fact that many such cars are constructed with a gusset or brace centrally located at each end of the car. This vertical brace protrudes partially into the bed of the car, preventing the logs or other similar material from being placed on the car perpendicularly to the longitudinal axis of the car at the ends in the same manner as is employed in loading the re mainder of the car. Therefore for complete loading of the railroad car the logs near the ends must be turned parallel to the longitudinal axis of the car.

It is an object of my present invention to provide an attachment for an industrial truck which makes possible the loading of both sides of a railroad car, either parallel or perpendicularly to the longitudinal axis of the car, from one side thereof.

The attachment of my present invention comprises a main frame which is adapted to be mounted on the upwardly and downwardly movable load supporting carriage of an industrial lift truck. This main frame is positioned at an angle, so that it extends forwardly of a vertical plane when the mast of the lift truck is in a vertical position. This arrangement facilitates the loading of both sides of the railroad car without the necessity of driving the industrial truck from one side to the other of the railroad car.

My attachment includes also a boom member projecting outwardly from the top of the main frame, a rotatable hook assembly mounted on the outer extremity of the boom, and a rectangular sling support member suspended by suitable means from said rotatable hook assembly. Suspended from the rectangular sling support member are four cables and power operated sling release means. The latter means are employed for releasing hook means at the ends of cables whereby the lower ends of the cables may be disconnected to permit the withdrawal of the cables from under a load.

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

In the drawings:

Figure l 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 Fig. 1, and

Figure 3 is an enlarged front elevational view of the load engaging attachment of Fig. 1, showing the slings in a partially released position.

Referring now to the drawings, in Fig. 1 there is indicated generally by the reference numeral 10 a conventional industrial lift truck having a main frame 12 supported at its forward end on spaced drive wheels 14 and at its rear end on a pair of dirigible wheels 16. This truck 10 is further provided with prime mover means indicated generally at 18, for propelling the vehicle and providing power for operating devices and attachments thereon, an operators seat 20 and an operators steering wheel 22.

A generally vertically extending mast or upright structure 24 is pivotally mounted at its lower end to the forward end of the truck frame 12 and power shiftable frame means 26 are provided for tilting of the mast 24. The mast may be tilted, under the control of: the operator of the vehicle, to any desired position between a forward position which is illustrated by the solid lines in Fig. l and a rear position illustrated by the dot-dash lines in this figure. For the sake of clarity in the drawing, I have illustrated a rear position of the mast which is only slightly to the rear of vertical; however, it should be understood that the mast preferably should be capable of being tilted rearwardly beyond the vertical by an amount such that the frame portion 31 of the attachment described hereinafter can be moved to a vertical position. The purpose for this will appear hereinafter. A load supporting carriage 2.8 is mounted for upward and downward movement within the mast 24. Affixed to the supporting carriage in a known manner is the load handling attachment of my present invention which is indicated generally by the reference numeral 30. The details of construction of attachment 30 are best shown in Figs. 2 and 3.

The load handling attachment 30 includes a vertically disposed main frame portion 31 which is positioned at an angle forwardly of the mast 24 as illustrated. The frame portion 31 comprises vertical side leg members 32 interconnected by horizontal bars or channels 36 and vertical bars or channels 38. The main frame portion 31 is attached by means of brackets 34 to the carriage 28. The upper ends of side legs 32 (as may be seen in Fig. 3) are bent inwardly toward each other and one end of a boom 39 is joined to the upper extremities of leg members 32.. The boom 39 is made up of forwardly extending members 40 which in turn are interconnected by forward and rear transverse braces 41 and 410. Also affixed to boom members 40 and side legs 32 are gusset plates 42. 7

Near the outer extremity of forwardly projecting boom 39, a pin 44 supports a pivotable and rotatable hook mechanism generally indicated by the numeral 46. The pin 44 is disposed horizontally and transversely to the truck and allows the depending hook mechanism to pivot about it in a vertical longitudinal plane. The hook mechanism includes a mounting block 48 which is pivotally supported by pin 44. Connected to and supported by block 4% is a dependent hook member 50 which is rotatable with respect to mounting block 48 about a vertically disposed axis. Preferably mounting block 48 is provided with anti-friction bearing means to facilitate the operation of book 50. Secured on mounting block 48 are a pair of stop members 52 spaced approximately apart,

3 and on dependent hook member 50 is another stop member 54 which cooperates with stop members 52 to limit the rotation of hook S to approximately 90.

Carried by hook 50 are four chains or other flexible support means 56 which in turn are connected to a rectangular sling support member 58 adjacent the four corners thereof. Secured to and carried by member 58 is a centrally disposed cross member 60 which supports an hydraulic piston and cylinder assembly 62 by a link 64. The hydraulic assembly 62 consists of cylinder 66 and piston rod 68. Secured to the lower extremity of piston rod 68, by link member 70, are two chains 72; the lower ends of chains 72 are secured respectively to a pair of cable connecting and release hooks 74.

Also afiixed to rectangular sling supporting member 58 adjacent the four corners are two pairs of

flexible members

76, 78. The lower extremities of the two flexible members 76 are connected respectively to cable connecting and release hooks 74 in the manner shown in Fig. 3. The lower ends 80 of flexible members 78 are formed into loops to be received by hook members 74. With loops 80 engaged with the hooks 74 in the manner shown in Fig. 3, the flexible members '76 and 78 serve to provide a sling for supporting a load such as the logs 32.

The hydraulic assembly 62 provides a power actuated means for the releasing of hook members 74 from cable loops 30 so that

cables

76 and 78 can be withdrawn from under the load 82.

When a control valve (not shown), which preferably is conveniently located adjacent the operators seat 20, is actuated, fluid under pressure is admitted to the top end of cylinder 66 of hydraulic assembly 62 through suitable hose lines (not shown) for distending the piston rod 68 and thereby lowering the release chains 72. This allows the hook members 74 to be connected to the loops 80 at the lower ends of cables 7 8 together to define a load supporting sling for supporting logs or other material.

When the fluid under pressure is admitted to the lower end of cylinder 66 and fluid is bled from the top of cylinder 66, the piston rod 68 is retracted and the chain members 72 are pulled upwardly for swinging the hook members 74 to a released position, disconnecting the loops 80 from hooks 74 and thus permitting the load supporting slings 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 lift truck is driven to a position adjacent to the commercial truck and the pairs of

cables

76, 78 are manually arranged about the logs to be picked up and the hook members 74 are placed within the loops 80 of cables 78. The load supporting carriage 28 is then elevated within the mast 24, in a manner well known in the art, until the load is freed from the commercial truck. The industrial lift truck may then be driven away, with the load supported in the sling members to a position alongside of a railroad car. During this transporting operation the mast 24 is tilted to a rearward position, illustrated by the dot-dash lines in Fig. 1, which is preferably at least to the rear of vertical, to steady the load against the

lattice work

36, 38 and prevent the load from swinging.

If the load is to be deposited on the near side of the car the mast is positioned in or near a vertical position when the lift truck reaches the railroad car. The load is lowered to contact the floor of the ear, the hydraulic motor 62 actuated to release hooks 74 from loops 80 and the

cables

76 and 78 then free are withdrawn from under the load by raising the carriage 28.

Now if it is desired to deposit the load on the far side of the car, the mast 24 is tilted forwardly by the tilting means 26 to the postion shown by the solid lines in Fig. l. The load then is lowered to the floor of the car on the far side and released in the aforedescribed manner.

Some railroad flat cars are so constructed at each end as previously described as to make it impractical to place the logs perpendicular to the longitudinal axis of the car. Provisions have been made on the present attachment, by the use of rotatable book 50, to turn the logs manually through an angle of so as to allow them to be placed parallel with the longitudinal axis of the car, thus facilitating better and more complete loading of the car.

After the car is fully loaded the lattice work formed on the front of the attachment 30 by the horizontal cross members 36 and vertical members 38, may be used for bunting up the load by driving the truck forward against the load and forcing any outwardly projecting logs inwardly, thus evening up the load. During this operation the mast 24 is tilted to or near its extreme rearward position so that the

lattice

36, 38 is vertical.

From the foregoing description it will be readily understood that the attachment of my present invention facilitates the loading of both sides of a railroad car from the same side, and makes possible placing the logs either perpendicular or parallel to the longitudinal axis of the car. Thus the industrial truck does not have to be driven from one side of the car to the other to load both sides of the car. In addition, the same truck and attachment is used to load logs in either direction on the car.

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 rearrangements may be made therein without departing from the true spirit and scope of my invention.

I claim:

For use with an industrial lift truck having an upwardly and downwardly movable load supporting carriage operating on a mast structure which is tiltable forwardly and rearwardly, the combination of vertically disposed frame means connected near the lower extremity thereof to the load supporting carriage and arranged in forwardly diverging relation with the lift truck mast, a horizontally disposed forwardly projecting boom portion secured to an upper part of the said frame means, a hook mechanism depending from the said boom portion near the forward extremity thereof, the said hook mechanism being pivotable with respect to the said boom portion about a transverse horizontal axis, the said hook mechanism including a dependent hook which is rotatable with respect to the remainder of the hook mechanism about a vertically disposed axis, a pair of stops on the said hook mechanism for limiting the rotation of said hook to approximately 90, a horizontally disposed rectangular sling supporting member suspended from the said hook, four cables suspended at their upper ends from the said sling supporting member, a pair of hooks for securing the lower ends of two of the said cables respectively to the other two cables whereby load supporting sling means is defined, an hydraulic motor comprising a cylinder and piston suspended from the said sling supporting member, and an additional pair of cables connected from the said hydraulic motor respectively to the said pair of hooks for unhooking the said four cables so as to permit the said four cables to be withdrawn from under a load.

References Cited in the file of this patent UNITED STATES PATENTS 948,577 Gregg Feb. 8, 1910 1,221,504 Bouzo Apr. 3, 1917 2,375,747 Brown May 15, 1945 2,603,522 Stair July 15, 1952 2,622,540 Stewart et a1 Dec. 23, 1952 2,699,879 Bertram Jan. 18, 1955