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EP0669229A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Membrane switch for use over a steering wheel airbag assembly

Assignee: Bergquist Co Inc
•
Filing: 1994-12-02
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Granted: —
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Expires: 2014-12-02
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Abstract

Abstract A low profile membrane switch adapted for use over an automobile steering wheel airbag assembly for actuating a horn. The low profile membrane switch is comprised of an opposing pair of flexible electrodes separated by a dielectric layer. The dielectric layer has a unique pattern defining opposing electrode contact portions. A plurality of integral outwardly-extending protrusions are screen printed on the exterior surface of each flexible electrode, one over each of the opposing contact portions. These protrusions help concentrate an applied force to bring the respective electrode contact portions together to make electrical contact with the other. The opposing contact portions are defined by the dielectric pattern, and have a high density to insure redundancy and closure of the switch when one depresses the membrane switch with one's hand, and to insure the switch does not inadvertently close when flexed. An applied force of as little as four pounds causes closure of the membrane switch, even when positioned over a resilient airbag device.

Inventors

  • 👤 Mark Green
  • 👤 Robert B. Hartline

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-04 03:20
CPC Classifications
B; B60; B60Q; B60Q5/00; B60Q5/001; B60Q5/003; B60R; B60R21/00; B60R21/02; B60R21/16; B60R21/20; B60R21/215; B60R21/2165; B60R21/21656; B60R21/21658; H; H01; H01H; H01H3/00; H01H3/02; H01H3/14; H01H3/141; H01H2203/00; H01H2203/036; H01H2203/054

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 110 words
A membrane switch, comprising: a pair of flexible, Opposing, planar conductive electrodes electrically isolated from one another, each said electrode having an outer surface and an inner surface, said inner surfaces opposing one another; a generally planar dielectric member disposed between said Opposing electrodes and having a pattern defining a plurality of opposing electrode contact portions which remain unobstructed by said dielectric member; and a plurality of outwardly extending protrusions defined on each said electrode outer surface, one said protrusion provided adjacent each said electrode contact portion, such that pressure exerted on said outwardly extending protrusion causes said corresponding, opposing, electrode contact portions to make electrical contact with one another.
Claim 2
Dependent Claim 110 words
A membrane switch, comprising: a pair of flexible, Opposing, planar conductive electrodes electrically isolated from one another, each said electrode having an outer surface and an inner surface, said inner surfaces opposing one another; a generally planar dielectric member disposed between said Opposing electrodes and having a pattern defining a plurality of opposing electrode contact portions which remain unobstructed by said dielectric member; and a plurality of outwardly extending protrusions defined on each said electrode outer surface, one said protrusion provided adjacent each said electrode contact portion, such that pressure exerted on said outwardly extending protrusion causes said corresponding, opposing, electrode contact portions to make electrical contact with one another.
Claim 3
Dependent Claim 33 words
The switch as specified in Claim 1 wherein said dielectric member pattern comprises a plurality of adjacent geometric shapes having a cavity, said electrode contact portions being defined within said geometric shape cavities.
Claim 4
Dependent Claim 15 words
The switch as specified in Claim 1 wherein said protrusion is comprised of a dot.
Claim 5
Dependent Claim 29 words
The switch of Claim 1, wherein said pattern defines a plurality of cavities between said pair of electrodes and opposing electrode contact portions are formed by the dielectric cavities.
Claim 6
Dependent Claim 33 words
The switch as specified in Claim 4 wherein said dielectric member pattern comprises a plurality of adjacent geometric shapes defining said cavities, said electrode contact portions being defined within said geometric shape cavities.
Claim 7
Dependent Claim 26 words
The switch as specified in Claim 4 or 5 wherein one said protrusion is defined on each said electrode outer surface adjacent said opposing contact portions.
Claim 8
Dependent Claim 27 words
The switch as specified in any one of Claims 2 to 6 wherein said dielectric member pattern comprises a plurality of hexagons to form a honeycomb-like pattern.
Claim 9
Dependent Claim 23 words
The switch as specified in any preceding claim wherein said protrusions are spaced no more than 5.1 mm (.20 inches) from one another.
Claim 10
Dependent Claim 46 words
A steering wheel having a resilient airbag assembly disposed therein, a resilient airbag cover for covering said airbag assembly, and a membrane switch disposed in a covering relation over said airbag assembly and under said airbag cover, said switch being constructed according to any preceding claim.
Claim 11
Dependent Claim 27 words
A horn for generating an audio output, and a switch coupled to said horn for activating said horn, said switch being constructed according to any preceding claim.

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