US2722327A - Clamp for industrial truck - Google Patents

Description

Nov. 1, 1955 D. w. GAULT CLAMP FOR INDUSTRIAL TRUCK 5 Sheets-Sheet 1 Filed Sept. 8, 1950 FIG. I

INVENTOR. DONALD W. GAULT ATTYS.

Nov. 1, 1955 D. w. GAULT 2,722,327

CLAMP FOR INDUSTRIAL TRUCK Filed Sept. 8, 1950 5 Sheets-Sheet 3 INVENTOR.

DONALD w. GAULT W I W ATTYS.

Nov. 1, 1955 D. w. GAULT 2,722,327

CLAMP FOR INDUSTRIAL TRUCK Filed Sept. 8, 1950 5 Sheets-Sheet 4 INVENTOR. DONALD W. GAULT ATTYS.

Nov. 1, 1955 D. w. GAULT CLAMP FOR INDUSTRIAL TRUCK 5 Sheets-Sheet 5 Filed Sept. 8. 1950 R u m u a m A w W G M u I W "H" 1/ W "I l" h D I hm n N- mm I N mm M w w B6 v Z hlc ms. uNl mm 1 Q \JH l\ P m \T& u E

United States Patent Ofiice 2,722,327 Patented Nov. 1, 1955 CLAMP FOR INDUSTRIAL TRUCK Donald W. Gault, Battle Creek, Mich., assignor to Clark Equipment Company, Buchanan, Mich., a corporation of Michigan Application September 8, 1950, Serial No. 183,730

8 Claims. 01. 214-653) My invention relates generally to load engaging means for industrial trucks, and, more specifically, is directed to clamp means adapted to engage the upper horizontal edge, rim, bead, or chime of a crate or like container.

It is an object of my present invention to provide clamp means which is adapted to be mounted to the load supporting carriage of an industrial truck for engaging the upper horizontal rim of a container, whereby the latter may be transported, stacked, and deposited by the industrial truck. It is another object of my present invention to provide a clamp construction comprising vertically extending frame means, which defines fixed clamp means, and substantially horizontally movable clamp means adapted to cooperate with the fixed clamp means for gripping the rim of a container.

In one form of my present invention, I contemplate the provision of vertically extending frame means adapted to be secured to the load supporting carriage of an industrial truck. A fixed clamp element is secured along the forward surface of the frame means, adjacent the upper end thereof. Disposed adjacent the ends of the frame means are substantially horizontally movable clamp elements which are adapted to be moved toward and away from the fixed clamp element by means of horizontal hydraulic piston and cylinder assemblies. pivotally mounted to the frame means. Preferably, substantially vertically downwardly depending cam members are secured to the movable clamp elements and are adapted to engage ramp members carried by the frame means, which engagement causes the cam members and movable clamp elements to move upwardly when the piston rods of the hydraulic piston and cylinder assemblies are extended. Thus, when it is desired to release a crate gripped by'the clamp elements, the hydraulic piston and cylinder assemblies are actuated causing the piston rods to be extended which, as described above, effects upward movement of the movable clamp elements, permitting the latter to clear the rim of the crate when the industrial truck is backed away. When a container or crate is gripped by the clamp elements, a portion of the downward force exerted by the weight of a load within the crate or container is taken by the frame means, against which the lower portion of the crate or the container is adapted to bear.

In another and preferredform of my present invention, I contemplate the provision of a pair of clamp assemblies which are adapted to be secured to the load supporting carriage of an industrial truck, one adjacent each side thereof. Each clamp assemblycomprises a vertically extending box-like frame member, the forward surface of which defines a fixed clamp element. Disposed adjacent the upper end of each of the frame members is a substantially horizontally movable clamp element which is moved towardand away from the fixed clamp element by means of a hydraulic pistonand cylinder assembly, operatively connected thereto'by force transmittingmeans. Both the hydraulic piston and cylinder assembly and the force transmitting means are disposed within the confines of the frame member. The upper horizontal rim, edge, head, or chime of a crate or like container is adapted to be gripped between the fixed and movable jaw elements. Preferably, an additional auxiliary frame memher is mounted to the load supporting carriage below each of the clamp assemblies. When a container is gripped by the clamp elements, a portion of the downward force exerted by the weight of a load within the crate or container is taken by the auxiliary frame members, against which the lower portion of the container is adapted to bear.

Now, in order to acquaint those skilled in the art with the manner of constructing and using the devices of my present invention, I shall describe, in connection with the accompanying drawings, certain preferred forms of my invention.

In the drawings:

Figure 1 is a perspective view of an industrial truck to which, at the forward end thereof, is secured one form of clamp construction of my present invention;

Figure 2 is a front elevational view of the clamp construction of Figure 1;

Figure 3 is a side elevational view of the clamp construction of Figure 1;

Figure 4 is a partial plan view of the clamp construction of Figure 1;

Figure 5 is a front elevational view of another and preferred form of clamp construction of my present invention;

Figure 6 is a side elevational view of the clamp construction of Figure 5;

Figure 7 is a partial plan view of the clamp construc tion of Figure 5; and

Figure 8 is a plan view of a bearing frame member which is adapted for use with the clamp construction of Figure 5.

Referring now to Figure 1, there is shown an industrial truck, indicated generally by the reference numeral 10, which has a pair of driving wheels 11 disposed adjacent the forward end thereof and a pair of steeringwheels 12 disposed adjacent the rear end thereof. Mounted on the industrial truck 10 is a drivers seat 13 and disposed at one side thereof are a plurality of control levers, indicated generally by the reference numeral 14, which are provided for controlling the various devices of the industrial truck 10. Disposed adjacent the seat 13 is a hand steering wheel 15 which is mounted at the upper end of a steering column 16, operatively connected at its lower end to the rear steering wheels 12.

Secured to the main frame of the industrial truck 10, adjacent the forward end thereof, is a substantially vertically extending mast construction, indicated generally by the reference numeral 17, which is of conventional construction and comprises a pair of outer fixed channel members 18, in which are slidably mounted a pair of inner channel members 19. The inner channel members 19 are interconnected, at their upper ends, by a -The loadsupporting carriage of the industrial truck. 10 provides a support for one form of clamp mechanism, of my present invention, indicated generally by refer-. ence numeral '25. Referring now to Figures 2} 3," a'nd"4,"

Ishall describe in detail the construction of the clamp mechanism 25. A pairof vertically spaced transversely extending frame members 26 and 27 are adapted to be secured to the load supporting carriage of the industrial truck 10. A pair of vertically extending horizontally spaced frame members 28 have secured to their rear surfaces, adjacent the upper ends thereof, hook-shaped brackets 29 which are disposed-over the upper edge of the upper transverse frame member 26. Also mounted, by bolts 30, to the vertical frame members 25, inter mediate of the ends thereof, are hook-shaped members 31 which are adapted to engage the lower surface of the upper transverse frame member 26. The hook-shaped members 29 and 31 are thus adapted to securely mount the vertical frame members 28 to transverse frame member 26, while the lower portions of the vertical frame members 28 are adapted to bear against the lower transverse frame member 27. Suitablysecured to the forward surfaces of the vertical frame members 28 is a plate member 32 which is provided with openings 33 for receiving the heads of the aforementioned bolts 39. The ends of the transversely extending frame members 26 and 27 are interconnected by vertical brace members 34.

Formed along the upper'edge of the plate member 32 is a forwardly projecting fixed clamp element 36. Also secured, as by welding, to the upper edge of the vertical transverse plate member 32, adjacent each side thereof, are horizontal rearwardly extending L-shaped support members 40. The support members 40 are reinforced by triangular braces 41 which are suitably secured to the bottom surfaces of the support members 40 and the rear surface of the vertical transverse plate member 32. A rearwardly extending vertical guide plate member 42 is secured to the upper surface of each of the support members 46, Mounted along the upper leading edge of the support members 40 are aligned triangular ramps 44which, at their one ends, are secured to the vertical guide plate members 42. Mounted to the triangular ramps 44, along the angular faces thereof, horizontally spaced fromthe guide plate members l2, are guide plate members 45.

Secured to the rearwardly extending legs of each of the L-shaped support members 40 are a pair of vertical substantially triangular-shaped bracket members 46. The outer bracket 46 of each pair is secured, as by a plurality of bolts 47, to the support members 40, while the inner bracket 46 of each pair is suitably secured, as by welding, to the support members 40.

The rear ends of forwardly projecting hydraulic p'iston and cylinder assemblies, indicated generally by the reference numeral 48, are disposed between each pair of brackets 46. Laterally extending pins 49 are suitably secured to the cylinders 50 of the hydraulic piston and cylinder assemblies 48. The pins 49 are journaled in the vertical bracket members 46, adjacent the upper ends thereof.

The piston rods 51 of the hydraulic piston and cylinder assemblies 48 have secured to their outer ends clamp members 52 which have downwardly projecting jaw elements 37. The leading edges of jaw elements 37 are formed with camming surfaces 38.

Each of the piston rods 51 of the hydraulic piston and cylinder assemblies 48 is provided with a vertically extending plate follower or cam member 53, which is mounted thereto, adjacent its upper end, by means of a pin member 54. The plate followers 53 are adapted to ride up the angular surface of the triangular ramps 44 when the piston rod 51 is extended.

I shall now describe the operation of the embodiment of the clamp construction of my present invention shown inFigures 1 through 4. In practice, when it is desired to transport a container, as, for example, a crate, having a suitable rim, bead, or chime 39, the industrial truck'10 is maneuvered into a position where the vertical transverse plate member'32'is disposed closely'adjacent the crate to lever'of theigroup-at '14, the load supporting carriage of the industrial truck 10 is shifted vertically until the movable clamp members 52 are disposed closely adjacent the upper edge of the crate to be picked up. Then another lever of the group at 14 is actuated so as to admit fluid under pressure to the closed end of the cylinders 50, thereby causing the piston rods 51 to be extended. Extension of the piston rods 51 causes the lower camming edges 33 of the movable clamp members 52 to engage with the leading edge of the bead 39 of the crate, thereby causing the jaw elements 37 to move upwardly until the lower edges of the latter clear the upper edge of the bead 39 of the crate and drop into place behind the rim or bead 39 thereof.

After the clamp members 52 have been disposed about the rim or bead 39 of the crate, fluid under pressure is admitted to the forward ends of the cylinders 50 while fluid is bled from the closed ends of the cylinders 50, thereby causing the piston rods '51 to be retracted towards the industrial truck 10. This causes the rim or bead 39 of the crate to be urged toward the truck 10 until the rim 39 is securely clamped between the jaw elements 37 of the movable clamp members 52 and the fixed clamp element 36,as shown in Figure 3. By actuating one of the suitable control levers at 14 the load supporting carriage maybe raised, which effects raising of the crate from the ground. The crate is then supported at its upper end by the jaw element 37 and clamp element 36, and at its lower end is adaptedto bear against the vertical transverse plate member 32. The truck 10 may then be driven to the location where-it is desired to deposit the crate. The reverse procedure is then followed. That is, the load supporting carriage is lowered in the mast until the crate engages the ground, whereupon fiuid under pressure is admitted to the closed ends of the cylinders 50 of the hydraulic piston and cylinder assemblies 48, thereby causing the piston rods 51 and the movable clamp members 52 to be thrust outwardly. During outward'movement of the piston rods 51, theguide plate membersi53 are adapted to ride upwardly on the incline surfaces of the triangular ramps 44 causing the hydraulicpiston and cylinder assemblies 48 and movable clamp members 52 to rotate clockwise about pin members 49, as viewed in Figure 3, which raises the jaw elements37 .of the movable clamp members 52 above the upperedge of the chime or rim 39 of the crate deposited. The truck 10 may then be backed away.

I shallnow describe, in connection with Figures 5, 6, 7, and 8, an improved form and preferred embodiment of clamp construction of my present invention.

The preferred form of clamp mechanism of mypresent invention comprises one or more clamp constructions, each of which comprises a vertically extending supporting plate member 70 and a clamp assembly, indicated gencrally by the reference numeral 71. The supporting plate member 70 has secured to its rear surface a hook-shaped bracket 72 which is adapted to be disposed over the upper edge of a transversely extending frame member 73, adapted to be secured to the load supporting carriage of an industrial truck. The supportingplate member 70 also hassecured to its rear surface a hook-shaped member 74 which is adapted to engage the lower edge of the aforementioned frame member 73. A mounting bolt 76 is threaded through the hookshaped bracket 72 and is adapted to be placed in engagement with the upper surface of thef rame member 73 for rigidly mounting the plate member 70 to the latter. A transverse frame member 75 is also adapted to be secured tothe load supporting car riage of the industrial truck, against which .frame member 75 the lower portion of the supporting plate member 70 is adapted to bear. The frame members 73 and 75 'are similar in construction to the aforementioned frame members 26 and 27.

'Two'sets of 'vertically'spaced key hole'slots 77 and 78 are formed in the vertical supporting plate member 70, adjacent the upper and intermediate portions thereof.

Each of the clamp assemblies 71 comprises a vertically extending box-like frame structure comprising a rear plate member 79 and a pair of forwardly extending horizontally spaced side plate members 80 and 81. A pair of locating pins 82 are suitably secured in openings formed in the rear plate member 79 of the clamp assembly 71. The enlarged head portions of the locating pins 82 are adapted to be disposed through the enlarged portions of the key hole slots 77 and then urged downwardly for mounting the rear plate member 79 to the supporting plate member 70.

The rear plate member 79 is also secured to the supporting plate member 77 by means of a locking bolt 83 which has a threaded end adapted to be disposed through an opening formed in the rear plate member 79 and to be threaded into engagement with a threaded opening formed in the supporting plate member 70.

The forward edges of the side plate members 80 and 81 are interconnected adjacent their upper and lower ends. respectively, by vertically extending fixed clamp elements 84 and 85. Pivotally mounted intermediate the side plate members 80 and 81, about a pin member 86, is the cylinder 87 of a hydraulic piston and cylinder assembly, indicated generally by the reference numeral 88. The cylinder 87 is maintained in a central position by spacer members 68. The hydraulic piston and cylinder assembly 88 has a piston rod 89 which, at its upper end, is pivotally mounted about a pin member 90 fixed at its ends within the depending legs of a triangular bell crank 91. The bell crank 91 is pivotally mounted about a pin member 92 which is fixed at its ends in the side plate members 80 and 81 of the clamp assembly 71. The bell crank 91 is maintained in a central position by spacer members 67. Pivotally mounted to the upper end of the bell crank 91, about a pin member 93 which extends laterally outwardly of the sides of the bell crank 91, are the rear ends of the spaced legs of a movable clamp element having a down wardly projecting forward jaw portion 69. Side frame members 95 are disposed on each side of the movable clamp element 94 and are secured, respectively, to the side plate members 88 and 81 for guiding the movable clamp element 94 in substantially rectilinear movement.

When the clamp assembly 71 is secured in the position shown in Figure 6, an H-shaped bearing frame member 96 is adapted to be secured to the supporting plate member 70 by means of a pair of locating pins 97 adapted to be disposed in the key hole slots 78 formed in the intermediate portion of the vertically extending supporting plate member 70. The bearing plate member 96 is provided in order that the lower portion of a crate or container may bear against the latter When gripped between the clamp elements 94 and 84.

If it is desired to utilize the clamp assembly 71 for gripping a carton or container of low height, the clamp assembly 71 may be removed from the upper portion of the supporting plate member 77 by unloosening the locking bolt 83 and removing the locating pins 82 from the key hole slots 77 and thence disposing the locating pins 82 within the intermediate key hole slots '78 and again locking the lock bolt 83. If the clamp assemblies 71 are to be used in this position, the bearing frame members 96 are removed.

I shall now describe, in connection with Figures 5, 6, 7, and 8, the operation of the preferred form of clamp mechanism of my present invention.

One or more supporting plates 70 and associated clamp assemblies 71 may be secured to the load supporting carriage of the industrial truck, the precise number depending on the load carrying capacity required. For example, as shown in Figure 5, a pair of clamp assemblies 71 may be secured to the load supporting carriage. In picking up or engaging a container, the truck is maneuvered so as to dispose the pair of clamp assemblies 71 closely adjacent the container. The truck is then driven forwardly until the jaw portions 69 of the movable clamp members or elements 94 engage the leading edge of the rim, bead or chime of the carton or container to be picked up. Further movement of the industrial truck towards the container to bepicked up causes the jaw portions 69 of the movable clamp elements 94 to ride over the upper edge of the rim portion of the container and down into engagement with the rear edge thereof.

Fluid under pressure is then selectively admitted to the closed ends of the hydraulic piston and cylinder assemblies 88 which causes the piston rods 89 to be extended. When the piston rods 89 are extended, the bell cranks 91 are caused to rotate counterclockwise about the mounting pin members 92 which causes the movable clamp elements 94 to be retracted toward the industrial truck, thereby clamping the bead or rim portion of the container between the jaw portions 69 of the movable clamp elements and the fixed clamp elements 84. After the container has been securelyv gripped, the load supporting carriage of the industrial truck may be raised and the container delivered to the desired location.

When the industrial truck has been aligned with the space in which the box is to be deposited, the load supporting carriage is lowered until the carton contacts the ground. Then hydraulic fluid under pressure is admitted to the upper ends of the cylinders 87 of the hydraulic piston and cylinder assemblies 88, causing the piston rods 89 to be retracted. When the piston rods 89 are retracted, the bell cranks 91 are caused to be rotated clockwise about the pin members 92, thereby urging the movable clamp elements 94 away from the industrial truck and releasing the rim or chime portion of the container. The load supporting carriage of the industrial truck is then raised until the downwardly projecting jaw portions 69 of the movable clamp elements 94 clear the upper edge of the rim portion of the container, after which the truck 10 may be backed away.

While I have shown and described what I believe to be certain preferred embodiments of my present invention, it will be understood that various modifications and rearragements may be made therein without departing from the spirit and scope of my present invention.

I claim 1. For use with an industrial truck having a mast and a load supporting carriage movable therealong, load engaging means comprising, frame means adapted to be mounted to the load supporting carriage, a fixed clamp element carried by said frame means, substantially horizontally movable clamp means carried by said frame means, hydraulic piston and cylinder assembly means having the lengthwise axis thereof disposed substantially vertically carried by said frame means, and motion transmitting means connecting said hydraulic piston and cylinder means and said movable clamp means.

2. For use with an industrial truck having a mast and a load supporting carriage movable therealong, load engaging means including at least one clamp assembly comprising, a substantially vertically extending box-like frame means adapted to be carried by the load supporting carriage, for rectilinear vertical movement and defining a fixed clamp element, a substantially horizontally movable clamp element disposed at the upper end of said frame means, actuator means disposed within the confines of said frame means, and motion transmitting means joining said actuator means with said movable clamp element for moving said movable clamp element rectilinearly toward and away from said fixed clamp element.

3. The combination of claim 2 wherein said actuator means comprises a hydraulic piston and cylinder assembly and said motion transmitting means comprises a bell crank means between said hydraulic piston and cylinder assembly and said movable clamp element.

4. For use with an industrial truck having a mast and a load supporting carriage movable therealong, load engaging means including at least one clamp assembly

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