Switching apparatus

• US 3,952,173 A
• Filed: 10/22/1974
• Issued: 04/20/1976
• Est. Priority Date: 11/09/1973
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho
• Original Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho
• Inventors: Takagi, Katsuyuki, Tsuji, Takehiro
• Primary Examiner(s): Hohauser, Herman J.
• Application Number:
  US05/516,924
• Time in Patent Office: 546 Days
• Field of Search: 200/264, 200/159 B, 200/159 R, 338/100, 338/114, 338/118, 338/2
• US Class Current: 200/511
• CPC Class Codes: H01H 1/029 comprising conducting material dispersed in an elastic support or binding material
• CPC Class Codes: H01H 13/64 wherein the switch has more than two electrically distinguishable positions, e.g. multi-position push-button switches

Abstract

A two-stroke switch to be actuated by two stroke operations comprises a first stationary terminal, a second stationary terminal, a contact element of conductive elastomeric material for establishing a current path between the first and second terminals, and an actuating member provided with a moving terminal for imparting a compressing force to the contact element. When the actuating member is first manipulated to compress the contact element axially thereof, the contact element is rendered electrically conductive, and when the actuating member is secondly manipulated to further compress the contact element which is then enlarged radially thereof, the contact element may be electrically connected to the first and/or second terminals thereby turning on the switch.

Claims

1. A switching apparatus operative to complete at least two different circuit paths in a predetermined operating sequence comprising a holder fixedly attached to a cylindrical stem member, electrical insulating means supported by said holder and defining an opening of hollow cylindrical shape positioned in coaxial relation to said stem member adjacent one end of said stem member, a first stationary electrode disposed at the end of said cylindrical opening remote from said one end of said stem member, a first terminal connected to said first electrode for connecting said first electrode to an external circuit, a second stationary electrode of cylindrical shape disposed along the sidewall portion of said cylindrical opening, said second electrode being positioned in spaced, electrically separate relationship to said first stationary electrode, a second terminal connected to said second electrode for connecting said second electrode to an external circuit, a cylindrical contact element disposed within said cylindrical opening in coaxial relation thereto, said contact element comprising a compressible elastomeric material constructed to be substantially nonconductive in its noncompressed state and to be electrically conductive when compressed, one end of said cylindrical contact element being in engagement with said first stationary electrode, the diameter of said contact element in its noncompressed state being less than the diameter of said second electrode whereby said contact element is normally maintained at a predetermined distance from said second stationary electrode, a moving electrode positioned adjacent the other end of said contact element for movement along the axial direction of said contact element to axially compress said contact element, a third terminal connected to said moving electrode for connecting said moving electrode to an external circuit, and an actuating member fixedly connected to said moving electrode and slidably disposed within said stem member for selectively compressing said contact element, movement of said actuating member and moving electrode toward said first electrode to a first stroke position being operative to partially compress said contact element to complete a conductive path between said first terminal and said third terminal via said contact element, the enlarged diameter of said contact element in its said partially compressed state still being less than the diameter of said second electrode to maintain an open circuit to said second terminal when said actuating element is in its first stroke position, further movement of said actuating element toward said first electrode to a second stroke position being operative to further compress said contact element and increase its diameter sufficiently to engage said second electrode thereby to complete a further conductive path between said first and second terminals via said contact element at said second stroke position of said actuating member.

2. The switching apparatus of claim 1 wherein said electrical insulating means comprises an elastic mat of electrical insulating material provided with a central opening centrally thereof for receiving at least one of said electrodes.

3. The switching apparatus of claim 1 wherein said actuating member includes spring means which normally urges said moving electrode toward a noncompressing position relative to said contact element.

4. The switching apparatus of claim 1 wherein said moving electrode includes a portion positioned to engage said second electrode when said actuating member reaches said second stroke position thereby to complete a conductive path between said second terminal and said third terminal.

5. The switching apparatus of claim 4 wherein said moving electrode portion comprises a conductive disk having a diameter at least equal to the diameter of said second electrode, said moving electrode including a further portion projecting from said first-mentioned portion and having a diameter less than that of said second electrode for imparting a compressing force to said contact element.