Energy Storage on an Elevated Platform and Transfer Method

• US 20110209949A1
• Filed: 03/01/2010
• Published: 09/01/2011
• Est. Priority Date: 03/01/2010
• Status: Active Grant

• Current Assignee: The Raymond Corporation (Toyota Motor Corporation)
• Original Assignee: The Raymond Corporation (Toyota Motor Corporation)
• Inventors: McCabe, Paul P.
• Granted Patent: US 8,689,943 B2
• Time in Patent Office: Days
• US Class Current: 187/222
• CPC Class Codes: B66F 9/24 Electrical devices or systems
• CPC Class Codes: H02J 7/007184 in response to battery voltage gradient
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A lift truck includes a secondary rechargeable energy storage device on a vertically movable platform that is separate from a primary rechargeable energy storage device on the lift truck'"'"'s main tractor unit without the use of wires or hoses for transfer of power or controls between the main tractor unit and the platform. The quantity of energy stored in the secondary rechargeable energy storage device is sufficient to power platform electrical loads for a predetermined amount of time until the platform is lowered. When the platform is lowered, the secondary rechargeable energy storage device is recharged by the primary energy storage device.

Claims

1. A lift truck comprising:

a tractor unit;

a primary energy storage device disposed on the tractor unit, the primary energy storage device adapted to provide operating power to the tractor unit;

a vertically movable platform mounted relative to the tractor unit, the platform being vertically movable between an upper position and a lower position; and

a rechargeable secondary energy storage device disposed on the platform, the rechargeable secondary energy storage device being rechargeable upon moving the platform toward the lower position; and

the rechargeable secondary energy storage device including at least one capacitor, the at least one capacitor adapted to accept an energy transfer from the primary energy storage device and temporarily store the energy transfer, the rechargeable secondary energy storage device further including a DC-to-DC voltage converter, the voltage converter adapted to convert a voltage from the at least one capacitor to a recharge voltage to recharge the rechargeable secondary energy storage device.

2. The lift truck according to claim 1:

further including an energy transfer coupling, the energy transfer coupling adapted to transfer energy from the primary energy storage device to the rechargeable secondary energy storage device to recharge the rechargeable secondary energy storage device.

3. The lift truck according to claim 2:

wherein the primary energy storage device comprises a rechargeable device.

4. The lift truck according to claim 3:

wherein the energy transfer coupling is adapted to transfer energy from the secondary energy storage device to the primary energy storage device.

5. The lift truck according to claim 2:

wherein the energy transfer coupling comprises at least one of a physical coupling and an inductive coupling.

6. The lift truck according to claim 1:

further including a operator station, the operator station including controls adapted for use by the operator to control the tractor unit and the platform.

7. The lift truck according to claim 1:

wherein the tractor unit includes a first wireless communication unit and the platform includes a second wireless communication unit, the first and second wireless communication units adapted to provide a wireless communication link between the tractor unit and the platform.

8. The lift truck according to claim 7:

further including an operator station, the operator station including controls adapted for use by the operator to control the tractor unit and the platform via the first and second wireless communications units.

11. The lift truck according to claim 1:

further including a vertically extendable mast mounted relative to the tractor unit, the mast including a fixed base and an extendable mast section; and

the platform attached to the extendable mast section, the platform being vertically movable with the extendable mast section between the upper position and the lower position.

24. The lift truck according to claim 1:

wherein the voltage converter stops charging the rechargeable secondary energy storage device when the voltage from the at least one capacitor reaches a predetermined level.

25. The lift truck according to claim 1:

wherein the rechargeable secondary energy storage device includes at least one capacitor and at least one battery, the at least one capacitor adapted to accept an energy transfer from the primary energy storage device and temporarily store the energy transfer, the rechargeable secondary energy storage device further including a DC-to-DC voltage converter, the voltage converter adapted to convert a voltage from the at least one capacitor to a recharge voltage to recharge the at least one battery.

26. The lift truck according to claim 3:

wherein the energy transfer coupling is adapted to transfer energy from the secondary energy storage device to the primary energy storage device so as to recharge the primary storage device.

9. (canceled)

10. (canceled)

12. A lift truck comprising:

a tractor unit;

a rechargeable primary energy storage device disposed on the tractor unit,

a vertically movable platform mounted relative to the tractor unit, the platform being vertically movable between an upper position and a lower position;

a rechargeable secondary energy storage device disposed on the platform; and

an energy transfer control circuit adapted to sense a voltage potential difference between the primary energy storage device and the rechargeable secondary energy storage device; and

an energy transfer coupling, the energy transfer coupling adapted to transfer energy from the rechargeable primary energy storage device on the tractor unit to the rechargeable secondary energy storage device on the platform to recharge the rechargeable secondary energy storage device.

13. The lift truck according to claim 12:

wherein the energy transfer coupling further includes at least one capacitor, the at least one capacitor adapted to accept an energy transfer from the rechargeable primary energy storage device; and

a voltage converter, the voltage converter adapted to convert a voltage from the at least one capacitor to a recharge voltage to recharge the rechargeable secondary energy storage device.

15. The lift truck according to claim 12:

further including a vertically extendable mast mounted relative to the tractor unit, the mast including a fixed base and an extendable mast section; and

the platform attached to the extendable mast section, the platform being vertically movable with the extendable mast section between the upper position and the lower position.

27. The lift truck according to claim 12:

further including a primary side sensor and a secondary side target, such that when the sensor and target are aligned, a transfer coupling sense circuit indicates an aligned condition to the energy transfer control circuit.

28. The lift truck according to claim 12:

wherein the energy transfer coupling is adapted to transfer energy from the rechargeable primary energy storage device on the tractor unit to the rechargeable secondary energy storage device on the platform to recharge the rechargeable secondary energy storage device when the voltage potential is sensed.

14. (canceled)

16. A method comprising:

providing a lift truck, the lift truck comprising

a tractor unit;

a primary energy storage device disposed on the tractor unit;

a vertically movable platform mounted relative to the tractor unit; and

a rechargeable secondary energy storage device disposed on the platform;

lowering the platform from an upper position to a lower recharge position; and

sensing for a voltage potential difference between the primary energy storage device and the rechargeable secondary energy storage device; and

recharging the rechargeable secondary energy storage device by transferring energy from the primary energy storage device to the rechargeable secondary energy storage device when the platform is in the lower recharge position.

17. The method according to claim 16:

further including recharging only when the voltage potential difference is sensed.

18. The method according to claim 16:

wherein transferring energy from the primary energy storage device to the rechargeable secondary energy storage device occurs automatically when the platform in the lower recharge position.

19. The method according to claim 16:

further including using the potential energy generated from lowering the platform for recharging the rechargeable secondary energy storage device.

20. The method according to claim 16:

further including using wireless communications to operate the lift truck.

21. The method according to claim 16:

further including operating the tractor unit and the platform using energy supplied by the rechargeable secondary energy storage device when the primary energy storage device is non-operational.

22. The method according to claim 16:

wherein the rechargeable secondary energy storage device comprises at least one capacitor, a DC-to-DC voltage converter, and at least one battery.

23. The method according to claim 16:

wherein the tractor unit further includes a vertically extendable mast mounted relative to the tractor unit, the mast including a fixed base and an extendable mast section; and

lowering comprises lowering the platform with the extendable mast section from the upper position to the lower recharge position.

29. The method according to claim 16:

further including operating the tractor unit and the platform using energy supplied by the rechargeable secondary energy storage device when the primary energy storage device is non-operational.

30. The method according to claim 16:

further including reversing the flow of energy so the rechargeable secondary energy storage device recharges the primary energy storage device.