Conductive pressure sensitive textile

• US 20030119391A1
• Filed: 10/02/2002
• Published: 06/26/2003
• Est. Priority Date: 04/03/2000
• Status: Active Grant

• Current Assignee: Acha Peta-Thomson, Staley Shigezo Swallow
• Original Assignee: Acha Peta-Thomson, Staley Shigezo Swallow
• Inventors: Peta-Thomson, Acha, Swallow, Staley Shigezo
• Granted Patent: US 7,365,031 B2
• Time in Patent Office: Days
• US Class Current: 442/6
• CPC Class Codes: D02G 3/38 Threads in which fibres, filaments, or yarns are wound with other yarns or filaments, e.g. wrap yarns, i.e. strands of filaments or staple fibres are wrapped by a helically wound binder yarn; D02G3/32 takes precedence; covering endless core threads with fibres by using open-end spinning techniques D01H4/00
• CPC Class Codes: D02G 3/441 Yarns or threads with antistatic, conductive or radiation-shielding properties electroconductive, anti-static or radiation-shielding filaments D01F1/09, D01F1/106; anti-static fabrics D03D15/533; conducting, insulating or anti-static layers for floor coverings D06N7/0042
• 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: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: H01H 2203/0085 Layered switches integrated into garment, clothes or textile
• CPC Class Codes: H01H 2203/01 Woven wire screen
• CPC Class Codes: Y10S 2/902 Antistatic
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber
• CPC Class Codes: Y10T 428/2915 including textile, cloth or fabric
• CPC Class Codes: Y10T 428/2936 Wound or wrapped core or coating [i.e., spiral or helical]
• CPC Class Codes: Y10T 442/109 Metal or metal-coated fiber-containing scrim
• CPC Class Codes: Y10T 442/162 Including a natural or synthetic rubber layer
• CPC Class Codes: Y10T 442/30 Woven fabric [i.e., woven strand or strip material]
• CPC Class Codes: Y10T 442/3089 Cross-sectional configuration of strand material is specified
• CPC Class Codes: Y10T 442/3098 Cross-sectional configuration varies longitudinaly along the strand
• CPC Class Codes: Y10T 442/3114 Cross-sectional configuration of the strand material is other than circular
• CPC Class Codes: Y10T 442/3122 Cross-sectional configuration is multi-lobal
• CPC Class Codes: Y10T 442/313 Strand material formed of individual filaments having different chemical compositions
• CPC Class Codes: Y10T 442/3179 Woven fabric is characterized by a particular or differential weave other than fabric in which the strand denier or warp/weft pick count is specified
• CPC Class Codes: Y10T 442/3293 Warp and weft are identical and contain at least two chemically different strand materials
• CPC Class Codes: Y10T 442/3382 : Including a free metal or alloy constituent
• CPC Class Codes: Y10T 442/339 : Metal or metal-coated strand
• CPC Class Codes: Y10T 442/3976 : Including strand which is stated to have specific attributes [e.g., heat or fire resistance, chemical or solvent resistance, high absorption for aqueous composition, water solubility, heat shrinkability, etc.]
• CPC Class Codes: Y10T 442/641 : Sheath-core multicomponent strand or fiber material
• CPC Class Codes: Y10T 442/642 : Strand or fiber material is a blend of polymeric material and a filler material
• CPC Class Codes: Y10T 442/649 : Plural foamed layers
• CPC Class Codes: Y10T 442/654 : Including a free metal or alloy constituent
• CPC Class Codes: Y10T 442/68 : Melt-blown nonwoven fabric
• CPC Class Codes: Y10T 442/682 : Needled nonwoven fabric

Abstract

A fabric including within its construction a first elongated electrical conductor crossed by a second elongated electrical conductor, the conductors being normally biased apart at a crossover point of said fibres with an air gap between them, whereby application of pressure in a direction substantially normal to a plane of the fabric causes the conductors to make contact. The fabric may be woven, knitted, non-woven or plaited. The fabric can be used as a pressure sensor, switch or other sensor.

Claims

1. A fabric provided with a single layer including warp and weft filaments within said single layer, wherein the warp filaments include at least one first elongated electrical conductor and the weft filaments include at least one second elongated electrical conductor, said first conductor or conductors being crossed by said second conductor or conductors, said conductors being normally biased apart at a crossover point of said conductors with an air gap between them resulting from insulating fibres or filaments which bias the first and second conductors apart at the crossover point, whereby application of pressure in a direction substantially normal to a plane of the fabric causes the conductors to make contact.

2. A fabric according to claim 1, including a plurality of spaced first conductors and/or a plurality of spaced second conductors, forming a plurality of said crossover points.

3. A fabric according to claim 1 or 2, wherein each conductor comprises electrically conductive filaments or fibres.

4. A fabric according to any one of claims 1 to 3, which is woven, knitted, non-woven or plaited.

5. A fabric according to any preceding claim, wherein said biasing apart is effected by locating an electrical conductor of relatively smaller cross-section between insulating filaments or fibres of relatively larger cross-section.

6. A fabric according to any one of claims 1 to 4, wherein the weave includes warp and/or weft floats over more than one yarn to effect the biasing apart of first and second electrical conductors at the crossover point.

7. A fabric according to any one of claims 1 to 4, wherein said biasing apart is effected by employing, as at least one of the electrical conductors, an electrical conductor including insulating filament or fibre wound around it to leave the surface of the conductor exposed at the crossover point.

8. A fabric according to any one of claims 1 to 4, wherein said biasing apart is effected by twisting at least one of the electrical conductors together with insulating filament or fibre.

9. A fabric according to any one of claims 1 to 4, wherein said biasing apart is effected by employing, as at least one of the electrical conductors, an electrical conductor which is supported on and between deformable protuberances of an insulating filament or fibre.

10. A fabric according to any one of claims 1 to 4, wherein said biasing apart is effected by employing, as at least one of the electrical conductors, a fibre including an insulating yarn and a conductive yarn, the insulating yarn including portions extending beyond the conductive yarn.

11. A fabric according to claim 10, wherein there are provided two or more conductive yarns helically wound around the insulating yarn.

12. A fabric according to any preceding claim, wherein the electrical conductors have an electrical property which is proportional to the length of the conductor, whereby the length of a conductor or plurality of connecting conductors can be determined from measurement of that property.

13. A fabric according to claim 12, wherein the electrical property is electrical resistance.

14. A fabric according to any preceding claim, including at least one set of spaced electrical conductors, at least some of said set being electrically connected together to form at least one bus bar.

15. A fabric according to claim 14, wherein said set of spaced electrical conductors comprises electrically conductive filaments or fibres in the warp or weft of a woven construction and electrical connection between conductors of that set is provided by one or more electrically conducting filaments or fibres in the weft or warp, respectively.

16. A fabric according to claim 14, wherein set of spaced electrical conductors comprises electrically conductive filaments or fibres in the warp or weft of a woven construction and said electrical connection is effected after the weaving process.