Lift truck with optical load sensing structure

Patent metadata

Field	Value
Publication number	US-9932213-B2
Application number	US-201514847087-A
Country	US
Kind code	B2
Filing date	Sep 8, 2015
Priority date	Sep 15, 2014
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

A lift truck includes a frame, a pair of laterally spaced apart outriggers extending from the frame, and a load handling assembly secured to the frame adjacent to the outriggers. The load handling assembly includes a mast assembly positioned between the outriggers and a carriage assembly including fork structure for supporting a load on the load handling assembly. The carriage assembly is movable vertically along the mast assembly and laterally with respect to the mast assembly. Optical sensor structure of the truck monitors for conditions wherein movement of the carriage assembly would result in contact between the load and the outrigger(s). A vehicle controller receives a signal from the optical sensor structure and prevents movement of the carriage assembly toward the outrigger(s) if the signal from the optical sensor structure indicates that such movement would result in contact between the load and the outrigger(s).

First claim

What is claimed is:

1. A lift truck comprising:
a frame defining a main structural component of the lift truck;
a pair of laterally spaced apart outriggers extending from the frame, each outrigger including at least one wheel;
a vehicle controller for controlling at least one function of the lift truck;
a load handling assembly secured to the frame adjacent to the outriggers, the load handling assembly comprising:
a mast assembly positioned between the outriggers; and
a carriage assembly including fork structure for supporting a load on the load handling assembly, the carriage assembly being movable vertically along the mast assembly and the fork structure also being moveable laterally with respect to the mast assembly via a sideshift assembly; and

optical sensor structure that monitors for conditions wherein movement of the carriage assembly would result in contact between the load and at least one of the outriggers;
wherein the vehicle controller receives a signal from the optical sensor structure and prevents movement of the carriage assembly in a direction toward the at least one of the outriggers if the signal from the optical sensor structure indicates that such movement would result in contact between the load and the at least one of the outriggers.

2. The lift truck of claim 1 , wherein the fork structure comprises a pair of laterally spaced apart forks extending longitudinally away from the frame.

3. The lift truck of claim 1 , wherein the optical sensor structure comprises a pair of laterally spaced apart contactless optical sensors, each contactless optical sensor being located adjacent to a corresponding outrigger.

4. The lift truck of claim 3 , wherein each contactless optical sensor monitors a respective area around the corresponding outrigger for a portion of the load to enter the respective area, wherein a portion of the load entering the respective area causes the vehicle controller to prevent movement of the carriage assembly toward the at least one of the outriggers.

5. The lift truck of claim 4 , wherein the area monitored by each contactless optical sensor extends longitudinally forward from and vertically downward from the respective contactless optical sensor.

6. The lift truck of claim 4 , wherein the contactless optical sensors are located laterally inwardly of the corresponding outriggers.

7. The lift truck of claim 4 , wherein the contactless optical sensors are affixed to the mast assembly.

8. The lift truck of claim 4 , wherein the contactless optical sensors are laser sensors.

9. The lift truck of claim 1 , wherein the vehicle controller is capable of operating the sideshift assembly to cause the fork structure to move to a position such that the load is centered with respect to the outriggers if the signal from the optical sensor structure indicates that movement of the fork structure toward at least one of the outriggers would result in contact between the load and the at least one of the outriggers.

10. The lift truck of claim 9 , wherein the vehicle controller operates the sideshift assembly to cause the fork structure to move only upon authorization to do so by an operator.

11. The lift truck of claim 9 , wherein the controller discontinues attempting to center the load with respect to the outriggers after the expiration of a predetermined time period.

12. The lift truck of claim 1 , wherein the load handling assembly is movable to a home position only if the signal from the optical sensor structure does not indicate that such movement would result in contact between the load and the outriggers.

13. The lift truck of claim 1 , wherein:
the mast assembly is movable in a longitudinal direction relative to the frame;
the optical sensor structure also monitors for conditions wherein movement of the mast assembly would result in contact between the load and at least one of the outriggers; and
the vehicle controller also prevents movement of the mast assembly in a direction toward at least one of the outriggers if the signal from the optical sensor structure indicates that such movement would result in contact between the load and the at least one of the outriggers.

14. The lift truck of claim 13 , wherein the optical sensor structure comprises a pair of laterally spaced apart contactless optical sensors, each contactless optical sensor being located adjacent to a corresponding outrigger.

15. The lift truck of claim 14 , wherein each contactless optical sensor monitors a respective area around the corresponding outrigger for a portion of the load to enter the respective area, wherein a portion of the load entering the respective area causes the vehicle controller to prevent movement of at least one of the mast assembly and the carriage assembly toward the at least one of the outriggers.

16. The lift truck of claim 14 , wherein the area monitored by each contactless optical sensor extends longitudinally forward from and vertically downward from the respective contactless optical sensor.

17. The lift truck of claim 14 , wherein the contactless optical sensors are located laterally inwardly of the corresponding outriggers.

18. The lift truck of claim 14 , wherein the contactless optical sensors are located vertically above the carriage assembly when the load handling assembly is positioned in a home position.

19. The lift truck of claim 14 , wherein the contactless optical sensors are affixed to the mast assembly.

20. The lift truck of claim 13 , wherein the vehicle controller is capable of operating the sideshift assembly to cause the fork structure to move to a position such that the load is centered with respect to the outriggers if the signal from the optical sensor structure indicates that movement of the fork structure toward at least one of the outriggers would result in contact between the load and the at least one of the outriggers.

21. The lift truck of claim 20 , wherein the controller discontinues attempting to center the load with respect to the outriggers after the expiration of a predetermined time period.

22. The lift truck of claim 1 , wherein the carriage assembly is movable in a longitudinal direction relative to the mast assembly.

23. The lift truck of claim 1 , further comprising a control element that is adapted to be implemented by an operator to override the prevention of movement of the carriage assembly in the direction toward the at least one of the outriggers even if the signal from the optical sensor structure indicates that such movement would result in contact between the load and the at least one of the outriggers.

24. The lift truck of claim 23 , wherein the operator is able to override the prevention of movement of the carriage assembly in the direction toward the at least one of the outriggers for as long as the operator implements the control element.

25. A lift truck comprising:
a frame defining a main structural component of the lift truck;
a pair of laterally spaced apart outriggers extending from the frame, each outrigger including at least one wheel;
a vehicle controller for controlling at least one function of the lift truck;
a load handling assembly secured to the frame adjacent to the outriggers, the load handling assembly comprising:
a mast assembly positioned between the outriggers; and
a carriage assembly including fork structure for supporting a load on the load handling assembly, the carriage assembly being movable vertically along t

Assignees

• Crown Equip Corp

Inventors

• Buchmann Jürgen
• Gumpp Thomas
• Simon Andreas

Classifications

• B66F9/147

  Whole unit including fork support moves relative to mast · CPC title

• B66F9/146

  Side shift, i.e. both forks move together sideways relative to fork support · CPC title

• B66F17/003

  for fork-lift trucks · CPC title

• B66F9/07

  Floor-to-roof stacking devices, e.g. "stacker cranes", "retrievers" · CPC title

• B66F9/122

  longitudinally movable · CPC title