CONTROL SYSTEM FOR A PALLET TRUCK

• US 20090076664A1
• Filed: 09/13/2007
• Published: 03/19/2009
• Est. Priority Date: 09/13/2007
• Status: Active Grant

• Current Assignee: The Raymond Corporation (Toyota Motor Corporation)
• Original Assignee: The Raymond Corporation (Toyota Motor Corporation)
• Inventors: Fett, Douglas D., McCabe, Paul P., Gregory, Bryce A.
• Granted Patent: US 8,195,366 B2
• Time in Patent Office: Days
• US Class Current: 701/2
• CPC Class Codes: B60L 3/02 Dead-man's devices
• CPC Class Codes: B62B 3/0612 power operated
• CPC Class Codes: B62B 5/0076 Remotely controlled
• CPC Class Codes: G05D 1/0033 by having the operator tracking the vehicle either by direct line of sight or via one or more cameras located remotely from the vehicle
• CPC Class Codes: G05D 2201/0216 Vehicle for transporting goods in a warehouse, factory or similar

Abstract

A control system for controlling motion of a pallet truck vehicle includes three modes of operation for controlling coasting of the vehicle. In a first, constant pressure mode, the vehicle coasts for as long as an activation button is depressed. In a second, time controlled mode, the vehicle coasts for a predetermined period of time. In the third, distance controlled mode, the vehicle coasts for a predetermined distance. Each of these functions can be activated from a remote location using a remote activation device.

Claims

1. An improved pallet truck of the type having a deadman brake that activates upon release of the operator controls, and a coast system for selectively overriding the deadman brake to allow the vehicle to coast, the improvement comprising a selector for selecting between a constant pressure-controlled coast function, a time controlled coast function, and a distance controlled coast function.

2. The pallet truck of claim 1, further comprising a remote control including at least one actuator for activating the selected coast function.

3. The pallet truck of claim 2, wherein the remote control comprises a wireless control system.

4. The pallet truck of claim 2, wherein the remote control comprises a voice activated system.

5. The pallet truck of claim 2, wherein the remote control device further comprises a wireless transceiver and at least one actuator for actuating the selected coast function.

6. A pallet truck comprising:

a steerable wheel;

a brake coupled to said wheel;

a steering arm coupled to said wheel for steering said wheel, the steering arm being movable through an arc including a driving arc interposed between a generally vertical braking position and a generally horizontal braking position;

a deadman mechanism coupled to said steering arm for moving said steering arm into at least one of said generally vertical braking position and said generally horizontal braking position to brake said truck when said handle is released;

a vehicle control system receiving control signals from said steering arm and providing control signals to said brake;

a coast device coupled to said steering arm for locking said steering arm within said driving arc, said coast device preventing movement of said steering arm from activating the deadman mechanism when the steering arm is released;

a selector for selecting between a time control coast function, a distance control coast function, and a constant pressure coast function; and

a remote control for activating said coast device, the remote control providing a coast signal to the vehicle control system to activate the selected one of the time control coast function, the distance control coast function and the constant pressure coast function.

7. The pallet truck as defined in claim 6, wherein the vehicle control system includes a transceiver for receiving the signal from the remote control device.

8. The pallet truck as defined in claim 6, wherein the remote control device includes a controller programmed to encrypt the signal, and the vehicle control system includes a controller programmed to decrypt the signal and to determine whether the signal is provided for a specific truck.

9. The pallet truck as defined in claim 6, wherein the remote control provides a coast signal for activating the coast device, a stop signal for activating the brake, and a jog signal for activating a traction motor and applying a motive force to the truck.

10. The pallet truck as defined in claim 6, wherein the vehicle control system is programmed to monitor the signal from the remote control device and when the constant pressure coast function is selected, to drive the pallet truck at a predetermined speed while the signal is received.

11. The pallet truck as defined in claim 6, wherein the vehicle control system is programmed to monitor the signal from the remote control device and when the time control coast function is selected, to accelerate the pallet truck at a predetermined acceleration rate for a selected acceleration time period, to drive the pallet truck at a predetermined speed for a selected drive time period, and to decelerate the pallet truck at a predetermined deceleration rate for a selected deceleration time period.

12. The pallet truck as defined in claim 11, wherein the vehicle control system is further programmed to monitor the coast signal from the remote control device and to increment the selected time period to drive the pallet truck as a function of a number of actuation requests received.

13. The pallet truck as defined in claim 6, wherein the vehicle control system is programmed to monitor the signal from the remote control device and when the distance control coast function is selected, to retrieve an acceleration and a deceleration distance from a memory storage, accelerate the pallet truck for the predetermined acceleration distance, calculate a distance at a constant speed of the vehicle, and to drive the pallet truck at a predetermined distance.

14. The pallet truck of claim 13, wherein the acceleration distance is determined based on a stopped vehicle, and the vehicle control system is further programmed to adjust the acceleration distance as a function of the speed of the vehicle when the signal is received.

15. The pallet truck of claim 6, wherein the remote control device includes a processor programmed to encrypt the signal for a specific pallet truck.

16. The pallet truck of claim 15, wherein the vehicle control system is programmed to decrypt the signal and to determine if the signal is intended for the pallet truck.

17. The pallet truck of claim 6, wherein the remote control device further includes a stop actuator and a jog actuator providing a stop signal and a jog signal, and wherein the vehicle control system is programmed to actuate the coast mechanism when the coast signal is received, drive the pallet truck as a function of the selected one of the time control coast, the distance control coast, or the constant-pressure coast when the jog signal is received, and stop the pallet truck when the stop signal is received.

18. A pallet truck comprising:

a steerable wheel;

a brake coupled to said steerable wheel;

a steering arm coupled to said wheel for steering said wheel, the steering arm being movable through an arc including a driving arc interposed between a generally vertical braking position and a generally horizontal braking position;

a deadman mechanism coupled to said steering arm for moving said steering arm into at least one of said generally vertical braking position to brake said truck when said handle is released;

a vehicle control system receiving control signals from said steering arm and providing control signals to said brake;

a coast device coupled to said steering arm for locking said steering arm within said driving arc, said coast device preventing movement of said steering arm from activating the deadman mechanism when the steering arm is released;

a selector for selecting between a time control coast function, a distance control coast function and a constant pressure coast function; and

at least one coast actuation control for activating the coast device and providing a signal to the vehicle control system to activate the selected one of the distance control coast function, the time control coast function, and the constant pressure coast function.

19. The pallet truck of claim 18, wherein the coast actuation control is provided on the vehicle.

20. The pallet truck of claim 18, wherein the coast actuation control is provided on a remote control device.

21. The pallet truck of claim 19, wherein the coast actuator comprises a coast switch and a jog switch.