Flexible heater for heating electrical components in operator control handle

• US 20040155021A1
• Filed: 02/06/2003
• Published: 08/12/2004
• Est. Priority Date: 02/06/2003
• Status: Active Grant

• Current Assignee: The Raymond Corporation (Toyota Motor Corporation)
• Original Assignee: The Raymond Corporation (Toyota Motor Corporation)
• Inventors: Norton, David G., Kuss, Jeffrey J.
• Granted Patent: US 6,900,411 B2
• Time in Patent Office: Days
• US Class Current: 219/209
• CPC Class Codes: H05B 3/34 flexible, e.g. heating nets or webs
• CPC Class Codes: H05K 1/0212 Printed circuits or mounted components having integral heating means
• CPC Class Codes: H05K 1/189 characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: H05K 2201/10053 Switch
• CPC Class Codes: H05K 2201/10189 Non-printed connector
• CPC Class Codes: H05K 2201/10196 Variable component, e.g. variable resistor
• CPC Class Codes: H05K 2203/165 Stabilizing, e.g. temperature stabilization
• CPC Class Codes: H05K 5/0212 Condensation eliminators
• CPC Class Codes: H05K 5/0213 Venting apertures; Constructional details thereof

Abstract

Disclosed is a flexible printed circuit board for use in a control handle. The circuit board includes resistive heating elements for heating electrical components in the circuit to limit the formation of frost and condensation on the components.

Claims

1. A circuit board for use in an environment in which varying temperatures cause condensation, the circuit board comprising:

a substrate material;

an electrical component;

a first conductive trace for transmitting control signals from the electrical component through the circuit board; and

a second conductive trace including a heating element portion wherein the conductive trace is sized and dimensioned to provide a resistive heater, the heating element portion being positioned to provide heat to the electrical component, wherein the heating element portion heats the component when an electrical voltage is applied across the second conductive trace.

2. The circuit board as defined in claim 1, wherein the substrate material is a flexible substrate material.

3. The circuit board as defined in claim 1, wherein the electrical component is an electrical connector.

4. The circuit board as defined in claim 1, wherein the electrical component is an electrical switch.

5. The circuit board of claim 1, wherein the electrical component is a potentiometer.

6. The circuit board as defined in claim 1, further comprising a plurality of electrical components and a corresponding plurality of heating element portions, at least one of the heating portions being positioned to heat a corresponding electrical component.

7. The circuit board of claim 5, wherein the heating element portions are sized to provide an appropriate amount of heat to each component.

8. The circuit board as defined in claim 1, wherein the circuit board is sized and dimensioned for use in a control handle of a lift truck.

9. A control handle for a lift truck, the control handle comprising:

a housing;

an electrical component activatable by an actuator to provide a control function for the lift truck;

a circuit board sized and dimensioned to be located in the housing, the circuit board including;

a flexible substrate;

a first conductor provided on the substrate for carrying electrical signals from the electrical component to the lift truck;

a second conductor comprising a resistive heating portion;

wherein the resistive heating portion is positioned in the housing in proximity to the electrical component to heat the electrical component.

10. The control handle as defined in claim 9, further comprising a second electrical component mounted on the flexible substrate, and wherein the second conductor comprises a resistive heating portion, the second resistive heating portion being positioned in the control handle to heat the second electrical component.

11. The control handle as defined in claim 10, wherein the second electrical component is mounted to a first side of the flexible substrate and the second resistive heating portion is provided on an opposing second side of the flexible substrate.

12. The control handle as defined in claim 9, wherein the electrical component is mounted to the flexible substrate.

13. The control handle as defined in claim 9, wherein the electrical component is mounted in the housing of the control handle and is electrically connected to the printed circuit board.

14. The control handle as defined in claim 9, further comprising an electrical connector mounted on the flexible substrate, the electrical component being electrically connected to the electrical connector.

15. The control handle as defined in claim 9, wherein the resistive heating portion comprises a conductor having a surface area that is sized and dimensioned to provide an increased resistance which produces heat.

16. A vehicle for use in varying temperature conditions, the vehicle comprising:

a vehicle control system;

a temperature sensor, the temperature sensor electrically coupled to the vehicle control system to provide a control signal indicative of a temperature of operation of the vehicle;

a control handle including;

an electrical component for providing a control signal to the vehicle control system; and

a flexible circuit board including;

a control signal conductor for conducting electrical signals between the vehicle control system and the electrical component; and

a heating conductor provided in the handle in proximity to the electrical component to heat the electrical component, the resistive heating conductor being electrically connected to the vehicle control system;

wherein, when the temperature of operation of the vehicle falls below a first predetermined temperature level, the vehicle control system activates the heating conductor to heat the electrical component, and when the temperature of operation rises above a second predetermined temperature level, the vehicle control system deactivates the heating conductor.

17. The vehicle as defined in claim 16 wherein the vehicle comprises a lift truck.

18. The vehicle as defined in claim 16 wherein the control handle comprises a plurality of electrical components and a corresponding plurality of heating elements provided in the heating conductor, and wherein each of the heating elements are positioned to heat a corresponding electrical component.

19. The vehicle as defined in claim 16 wherein the electrical components are mounted to the flexible printed circuit board.

20. The vehicle as defined in claim 16, wherein the first predetermined temperature level is less than the second predetermined temperature level.

21. The vehicle as defined in claim 16, wherein the first predetermined temperature level is equivalent top the second predetermined temperature level.

22. The vehicle as defined in claim 16, wherein the first predetermined temperature level is greater than the second predetermined temperature level.