Pallet clamping device

• US 20070014654A1
• Filed: 07/12/2006
• Published: 01/18/2007
• Est. Priority Date: 07/13/2005
• Status: Active Grant

• Current Assignee: Crown Equipment Corporation
• Original Assignee: Crown Equipment Corporation
• Inventors: Haverfield, Forrest, Meyers, Douglas, Heitkamp, Michael, Soder, Patrick
• Granted Patent: US 7,544,037 B2
• Time in Patent Office: Days
• US Class Current: 414/621
• CPC Class Codes: B62B 2203/29 Stops on the tines to arrest the pallets or other objects
• CPC Class Codes: B62B 3/06 for simply clearing the load from the ground masted lift trucks B66F
• CPC Class Codes: B66F 9/18 Load gripping or retaining means
• CPC Class Codes: B66F 9/183 Coplanar side clamps
• CPC Class Codes: B66F 9/19 Additional means for facilitating unloading

Abstract

A pallet clamping device is mounted between forks of a material handling vehicle. The device clamps to a stringer of a pallet using a pair of horizontally moveable jaws. The jaws are resiliently forced toward one another for clamping a stringer so that a clamped pallet will not move off the forks. The jaws are mounted for pivoting and sliding motion relative to mounting pins which, together with links coupling the jaws to a base of the device, tighten jaw closure if a pallet moves away from the forks. The pivoting and sliding motion of the jaws helps align the jaws with pallets not perfectly aligned with the vehicle. Depression of a foot pedal moves the jaws from a closed position to a latched open position for receiving a pallet stringer. The jaws can also be moved to an unlatched open position for receiving a greater width center stringer. Upon release of the operating device from the unlatched open position, the jaws move toward their closed position.

Claims

1. A material handling vehicle comprising:

a pair of forks to be inserted into a pallet having a center stringer;

a hoisting device for raising said forks;

a pallet clamp device mounted between said forks, said pallet clamp device including a pair of jaws having a closed position wherein said jaws are resiliently forced toward one another for engagement with the center stringer; and

an operating device for moving said jaws from their closed position to a latched open position wherein said jaws are separated by a first distance and to an unlatched open position wherein said jaws are separated by a second distance greater than said first distance.

2. The material handling vehicle of claim 1, wherein attempted movement of a pallet off said forks causes said jaws to increase the gripping force on the stringer.

3. The material handling vehicle of claim 2, including pivot pins mounting said jaws to a support frame for pivoting movement about said pivot pins as said jaws move between said closed and open positions.

4. The material handling vehicle of claim 3, wherein each jaw includes a gripping surface for engaging the stringer, said gripping surface for each jaw being located on a side of the stringer opposite from a respective pivot pin.

5. The material handling vehicle of claim 4, including a pivot link extending between each of said jaws and said support frame.

6. The material handling vehicle of claim 1, including a pivot link extending between each of said jaws and a support frame.

7. The material handling vehicle of claim 6, including pivot pins mounting said jaws to said support frame for pivoting movement about said pivot pins as said jaws move between said closed and open positions.

8. The material handling vehicle of claim 7, wherein said jaws are further mounted for sliding movement about said pivot pins.

9. The material handling vehicle of claim 6, wherein each pivot link is connected to a respective jaw by a coupling, and said operating device includes a linkage connected to said jaws at said coupling.

10. The material handling vehicle of claim 9, wherein said couplings connect said jaws to said linkage of said operating device for pivoting and sliding movement about said couplings.

11. The material handling vehicle of claim 1, wherein said jaws are mounted to a support frame and said support frame is pivotally mounted to a clamp support by a connector, said support frame being pivotally movable about said connector to enable said jaws to align with the stringer.

12. The material handling vehicle of claim 1, wherein said operating device includes a foot pedal movable between a fully depressed position, corresponding to said unlatched open position of said jaws, and a fully up position, corresponding to said closed position of said jaws, and including a predetermined partially depressed position, corresponding to said latched open position.

13. A material handling vehicle comprising:

a pair of forks to be inserted into a pallet having a center stringer;

a hoisting device for raising said forks;

a pallet clamp device mounted between said forks, said pallet clamp device including a pair of jaws having a closed position wherein said jaws are resiliently forced toward one another for engagement with the center stringer; and

pivot pins mounting said jaws for pivoting and sliding movement about said pins as said jaws move between said closed and open positions for receiving the center stringer.

14. The material handling vehicle according to claim 13, wherein said jaws each include a gripping end and an opposite spring receiving end, each of said pivot pins being engaged with a laterally extending jaw portion located intermediate said gripping and spring receiving ends.

15. The material handling vehicle according to claim 14, including an operating device for moving said jaws between said closed and open positions and attached to said jaws at couplings spaced from respective pivot pins.

16. The material handling vehicle according to claim 15, wherein said couplings are located intermediate said gripping and spring receiving ends, each said coupling being connected to a pivot link extending between each jaw and a support frame.

17. The material handling vehicle according to claim 16, wherein said pivot links are pivotally movable with pivoting movement of said jaws about said pivot pins.

18. The material handling vehicle of claim 16, wherein said support frame is pivotally supported to a clamp support by a connector, said support frame being pivotally movable about said connector to enable said jaws to align with the stringer.

19. The material handling vehicle according to claim 15, wherein the distance between said couplings and respective pivot pins of each jaw changes during pivoting movement of said jaws.

20. The material handling vehicle according to claim 15, wherein said couplings connect said jaws to a linkage of said operating device for pivoting and sliding movement about said couplings.

21. The material handling vehicle according to claim 13, including an operating device for moving said jaws between said closed and open positions wherein said operating device includes a latch for holding said jaws in a latched open position wherein said jaws are separated by a first distance.

22. The material handling vehicle according to claim 21, wherein said operating device is operable to move said jaws to an unlatched open position wherein said jaws are separated by a second distance greater than said first distance.

23. The material handling vehicle according to claim 22, wherein said operating device comprises a foot pedal, and said latch defines a predetermined partially depressed position for said foot pedal between a fully depressed position and a fully up position.

24. The material handling vehicle according to claim 23, wherein said foot pedal is releasable from said partially depressed position to said fully up position to move said jaws to said closed position engaged with the stringer.