Lift truck having hydraulically separate main frame and power unit assembly

• US 7,610,977 B2
• Filed: 09/23/2004
• Issued: 11/03/2009
• Est. Priority Date: 09/23/2004
• Status: Active Grant

• Current Assignee: Crown Equipment Corporation
• Original Assignee: Crown Equipment Corporation
• Inventors: Kuck, Jay L., Kluver, Leroy M.
• Primary Examiner(s): Ellis; Christopher P
• Assistant Examiner(s): COOLMAN, VAUGHN
• Application Number:
  US10/947,908
• Publication Number:
  US 20060151249A1
• Time in Patent Office: 1,867 Days
• Field of Search: 180/65.2, 180/305, 180/306, 180/307, 180/308, 187/222, 187/226, 187/231, 187/234, 187/237, 414/663, 414/664, 414/668, 414/349
• US Class Current: 180/65.51
• CPC Class Codes: B66F 9/07545 Overhead guards
• CPC Class Codes: B66F 9/07568 Steering arrangements
• CPC Class Codes: B66F 9/07572 Propulsion arrangements

Abstract

A lift truck is provided comprising: a power unit assembly comprising a power unit base, a wheel coupled to the base, and a system for driving the wheel; and a main frame assembly detachably connected to the power unit assembly. The main frame assembly comprises a main frame base, a mast assembly coupled to the main frame base, a carriage assembly coupled to the mast assembly, and hydraulic drive apparatus coupled to the mast assembly. Preferably, substantially the entirety of the hydraulic drive apparatus is provided on the main frame assembly such that the main frame assembly is detachable from the power unit assembly without requiring disconnecting hydraulic connections to the power unit assembly.

Claims

1. A lift truck comprising:

a power unit assembly comprising a power unit base, at least one wheel coupled to said base, and a system for driving said at least one wheel;

a main frame assembly detachably connected to said power unit assembly, said main frame assembly comprising a main frame base, a mast assembly coupled to said main frame base, a carriage assembly coupled to said mast assembly, and a hydraulic drive apparatus comprising a hydraulic motor/pump assembly receiving power from a battery of said power unit assembly, wherein substantially the entirety of said hydraulic drive apparatus including said hydraulic motor/pump assembly is provided on said main frame assembly such that said main frame assembly is detachable from said power unit assembly without requiring disconnecting hydraulic connections to said power unit assembly; and

a control module controlling the operation of said hydraulic motor/pump assembly of said hydraulic drive apparatus, wherein said control module is mounted on said power unit base.

2. A lift truck as set forth in claim 1, wherein said hydraulic drive apparatus further comprises a hydraulic fluid reservoir, and a manifold system.

3. A lift truck as set forth in claim 2, wherein said main frame base comprises front and rear portions, said mast assembly, said hydraulic fluid reservoir and said hydraulic motor/pump assembly being located at said rear portion of said main frame base, and said reservoir being positioned on a first side of said mast assembly and said motor/pump assembly being positioned on a second side of said mast assembly.

4. A lift truck as set forth in claim 1, wherein said system for driving said at least one wheel comprises at least one traction motor, said battery providing power to said at least one traction motor, and a traction motor control module for controlling the operation of said at least one traction motor.

5. A lift truck as set forth in claim 4, wherein said main frame base comprises front and rear portions and said power unit base comprises front and rear portions, said rear portion of said main frame base being positioned adjacent to said front portion of said power unit base, and said at least one traction motor and said traction motor control module being located in said rear portion of said power unit base.

6. A lift truck as set forth in claim 5, wherein said power unit assembly further comprises a steer motor for effecting steering movement of said wheel and a steer motor control module for controlling the operation of said steer motor, said steer motor and said steer motor control module being located in said rear portion of said power unit base.

7. A lift truck as set forth in claim 1, wherein said mast assembly comprises a fixed first mast, a second mast movable relative to said first mast and a mast piston/cylinder unit for effecting movement of said second mast relative to said first mast.

8. A lift truck as set forth in claim 7, wherein said carriage assembly comprises a platform assembly coupled to said second mast so as to move with said second mast.

9. A lift truck as set forth in claim 8, wherein said platform assembly is capable of moving relative to said second mast.

10. A lift truck as set forth in claim 8, wherein said carriage assembly further comprises a load handler assembly movably coupled to said platform assembly and a fork carriage assembly movably coupled to said load handler assembly.

11. A lift truck comprising:

a power unit assembly comprising a power unit base having front and rear portions, at least one wheel, at least one traction motor for driving said at least one wheel, a battery for providing power to said at least one traction motor, and at least one traction motor control module for controlling the operation of said at least one traction motor, said at least one wheel, at least one traction motor and at least one traction motor control module being mounted in said rear portion of said power unit base;

a main frame assembly comprising a main frame base having front and rear portions, a mast assembly, a carriage assembly coupled to said mast assembly, and hydraulic drive apparatus coupled to said mast assembly, said front portion of said power unit base being coupled to said rear portion of said main frame base such that said main frame assembly is detachable from said power unit assembly without requiring disconnecting hydraulic connections to said power unit assembly, and said hydraulic drive apparatus comprising a hydraulic motor/pump assembly receiving power from said battery of said power unit assembly; and

wherein said power unit assembly further comprises a hydraulic drive apparatus control module mounted in said rear portion of said power unit base for controlling the operation of said hydraulic drive apparatus.

12. A lift truck as set forth in claim 11, wherein said hydraulic drive apparatus further comprises a hydraulic fluid reservoir, and a manifold system.

13. A lift truck as set forth in claim 12, wherein said mast assembly, said hydraulic fluid reservoir and said hydraulic motor/pump assembly are located at said rear portion of said main frame base, said reservoir being positioned on a first side of said mast assembly and said motor/pump assembly being positioned on a second side of said mast assembly.

14. A lift truck as set forth in claim 11, wherein said power unit assembly further comprises a steer motor for effecting steering movement of said at least one wheel and a steer motor control module for controlling the operation of said steer motor, said steer motor and said steer motor control module being located in said rear of said power unit base.

15. A lift truck as set forth in claim 11, wherein said carriage assembly comprises a platform assembly which moves along said mast assembly.

16. A lift truck as set forth in claim 15, wherein said carriage assembly further comprises a load handler assembly movably coupled to said platform assembly and a fork carriage assembly movably coupled to said load handler assembly.

17. A lift truck comprising:

a power unit assembly comprising a power unit base, at least one wheel coupled to said base, and a system for driving said at least one wheel;

a main frame assembly detachably connected to said power unit assembly, said main frame assembly comprising a main frame base, a mast assembly coupled to said main frame base, a carriage assembly coupled to said mast assembly, and a hydraulic drive apparatus, wherein substantially the entirety of said hydraulic drive apparatus is provided on said main frame assembly such that said main frame assembly is detachable from said power unit assembly without requiring disconnecting hydraulic connections to said power unit assembly, said hydraulic drive apparatus comprising a hydraulic motor/pump assembly receiving power from a battery of said power unit assembly; and

a control module controlling the operation of said hydraulic motor/pump assembly of said hydraulic drive apparatus, wherein said control module is mounted on said power unit base.

18. A lift truck as set forth in claim 17, wherein said hydraulic drive apparatus further comprises a hydraulic fluid reservoir, and a manifold system.

19. A lift truck as set forth in claim 18, wherein main frame base comprises front and rear portions, said mast assembly, said hydraulic fluid reservoir and said hydraulic motor/pump assembly being located at said rear portion of said main frame base, and said reservoir being positioned on a first side of said mast assembly and said motor/pump assembly being positioned on a second side of said mast assembly.

20. A lift truck as set forth in claim 17, wherein said system for driving said at least one wheel comprises at least one traction motor, said battery providing power to said at least one traction motor, and at least one control module for controlling the operation of said at least one traction motor.

21. A fork lift truck comprising a power unit assembly detachably connected to a main frame assembly, wherein substantially all truck hydraulic components including a hydraulic motor/pump assembly are mounted on the main frame assembly while all truck electronic control modules including a module for controlling said hydraulic motor/pump assembly are mounted on the power unit assembly, and wherein said hydraulic motor/pump assembly receives power from a battery of said power unit assembly, and said main frame assembly is detachable from said power unit assembly without requiring disconnecting hydraulic connections to said power unit assembly.