Flexible potentiometer

• US 5,157,372 A
• Filed: 07/13/1990
• Issued: 10/20/1992
• Est. Priority Date: 07/13/1990
• Status: Expired due to Term

• Current Assignee: Sensitron
• Original Assignee: Gordon B. Langford
• Inventors: Langford, Gordon B.
• Primary Examiner(s): Lateef, Marvin M.
• Application Number:
  US07/552,575
• Time in Patent Office: 830 Days
• Field of Search: 338/211, 338/212, 338/210, 338/154, 338/114, 73/781, 73/849, 73/862.32, 73/862.45, 73/862.47, 73/517 AV, 73/655, 73/767, 73/781, 73/862.04, 73/865.8, 73/862.46, 73/862.48
• US Class Current: 338/211
• CPC Class Codes: G01B 7/18 using change in resistance
• CPC Class Codes: G01D 5/165 by relative movement of a point of contact or actuation and a resistive track
• CPC Class Codes: G01L 1/20 by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids of piezo-resistive materials G01L1/18; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
• CPC Class Codes: H01C 10/00 Adjustable resistors
• CPC Class Codes: H01C 10/106 on resistive material dispersed in an elastic material H01C10/103 and H01C10/12 take precedence; for electric switches H01H1/029
• CPC Class Codes: H01C 3/06 Flexible or folding resistors, whereby such a resistor can be looped or collapsed upon itself

Abstract

A deflectable substrate such as a phenolic resin has a conductive ink deposited thereon in a pattern preferably with a segmented conductor position on top to form a flexible potentiometer in which the resistance consistently and predictably changes upon deflection or the bending of the substrate.

Claims

1. A flexible potentiometer comprising:

a substrate formed of a deflectable electrical insulating material, said substrate having a length, an upper surface and a lower surface which is spaced from and in general alignment with said upper surface;

conductor means to conduct electricity as part of an electrical circuit and adhered to one of said upper surface and said lower surface of said substrate in a preselected pattern extending along the said length of said substrate, said conductor means being formed of an electrically conductive ink which changes electrical resistance upon movement of said conductor means and said upper surface and said lower surface all together generally transversely to the length of said substrate between a first configuration and a second configuration; and

connector means associated with said conductor means for interconnection to external electrical components.

3. The flexible potentiometer of claim 1 wherein the substrate is elastically deflectable.

4. The flexible potentiometer of claim 1 wherein said electrically conductive ink is of the type which is applied to said substrate in liquid form.

2. A flexible potentiometer comprising:

a substrate formed of a deflectable electrical insulating material having an upper surface and a lower surface spaced from and in general alignment with said upper surface;

conductor means adhered to one of said upper surface and said lower surface of said substrate in a preselected pattern, said conductor means being formed of an electrically conductive ink which changes electrical resistance upon deflection of said conductor means and said upper surface and said lower surface all together between a first configuration and a second configuration;

connector means associated with said conductor means for interconnection to external electrical components; and

segmented conductor adhered to said conductor means, said segmented conductor being formed of an electrically conductive material in segments each spaced from the other.

6. The flexible potentiometer of claim 2 wherein said segmented conductor is a solid material to be pressed onto said conductor means.

7. The flexible potentiometer of claim 2 wherein said substrate has a length with a longitudinal axis and is deflectable between said first configuration and said second configuration along said longitudinal axis.

8. The flexible potentiometer of claim 7 wherein said preselected pattern of said conductor means is a circuit having a first leg extending along said length, a second leg extending along said length and a third leg interconnecting said first leg with said second leg.

9. The flexible potentiometer of claim 8 wherein said first leg and said second leg are substantially parallel to said longitudinal axis.

10. The flexible potentiometer of claim 8 wherein said conductor means has a width, wherein said segmented conductor has a plurality of segments each having a width substantially the width of said conductor means and a length selected to regulate the electrical resistance of said conductor means.

11. The flexible potentiometer of claim 10 wherein said segmented conductor is made of a soft conductive metal.

12. The flexible potentiometer of claim 11 wherein the segmented conductor is made of silver or a silver alloy.

13. The flexible potentiometer of claim 10 wherein the segmented conductor is made of carbon or a carbon compound.

5. A flexible potentiometer comprising:

a substrate formed of a deflectable electrical insulating material having an upper surface and a lower surface spaced from and in general alignment with said upper surface;

conductor means adhered to one of said upper surface and said lower surface of said substrate in a preselected pattern, said conductor means being formed of an electrically conductive ink which changes electrical resistance upon deflection of said conductor means and said upper surface and said lower surface between a first configuration and a second configuration;

a segmented conductor adhered to said conductor means, said segmented conductor being formed of an electrically conductive material in segments each spaced from the other, said segmented conductor being of the type that is applied to said conductor means in liquid form and dries to a solid form.

14. The flexible potentiometer of claim -0 wherein each segment is from about two millimeters to about ten millimeters in length.

15. For measuring or detecting deflection, a flexible potentiometer comprising:

a substrate having a length and a width, said substrate being formed of an elastically deflectable and electrically insulating material;

an electrically conductive ink adhered to said substrate in a pattern having a first leg and a second leg each extending lengthwise of said substrate and elastically deformable to predictably change electrical resistance upon deflection of said substrate from a first configuration to a second configuration;

a segmented conductor adhered to said electrically conductive ink, said segmented conductor being formed of an electrically conductive material deposited on said electrically conductive ink in spaced apart segments; and

connector means associated with said electrically conductive ink for interconnection to external electrical components.

16. A flexible potentiometer comprising:

a substrate formed of an electrical insulating material, said substrate having an upper surface and a lower surface, spaced from and in general alignment with said upper surface, said substrate having a longitudinal axis and said substrate being bendable generally transversely to said longitudinal axis between a first configuration and a second configuration in which said upper surface and said lower surface are together bent transverse to said longitudinal axis;

conductor means adhered to one of said upper surface and said lower surface of said substrate in a preselected pattern to be bendable upon bending of said substrate, said conductor means being formed of an electrically conductive ink which changes electrical resistance upon said bending of said conductor means and said substrate between said first configuration and said second configuration; and

connector means associated with said conductor means for interconnection to external electrical components.

17. A method for varying the resistance in an

electrical circuit comprising:

providing a substrate formed of a deflectable electrical insulating material, said substrate having a length, an upper surface and a lower surface which is spaced from and in general alignment with said upper surface;

providing conductor means for conducting electricity as part of an electrical circuit and adhering said conductor means to one of said upper surface and said lower surface of said substrate in a preselected pattern extending along the said length of said substrate, said conductor means being formed of an electrically conductive ink which changes electrical resistance upon movement of said conductor means and said upper surface and said lower surface all together generally transversely to said length between a first configuration and a second configuration;

providing connector means for connection to external electrical components;

connecting said connector means to said conductor means and to external electrical components in said electrical circuit; and

bending said substrate and said conductor means between a first position and a second position.