Cord switch and pressure sensor

• US 6,078,014 A
• Filed: 01/16/1998
• Issued: 06/20/2000
• Est. Priority Date: 12/04/1995
• Status: Expired due to Term

• Current Assignee: ASMO Company Limited (DENSO Corporation), Hitachi Cable Limited (Proterial Ltd.)
• Original Assignee: ASMO Company Limited (DENSO Corporation), Hitachi Cable Limited (Proterial Ltd.)
• Inventors: Kikuta, Tomoyuki, Tanaka, Takeshi, Ishihara, Hidenori, Horii, Koji, Kashiwazaki, Shigeru, Yagyu, Hideki
• Primary Examiner(s): Luebke, Renee S.
• Application Number:
  US08/875,742
• Time in Patent Office: 886 Days
• Field of Search: 200/61.43, 200/61.44, 200/61.73, 200/61.82, 200/85 R, 200/508, 200/511, 200/512, 200/DIG. 10, 200/DIG. 37, 49/26-28
• US Class Current: 200/61.43
• CPC Class Codes: H01B 7/104 responsive to pressure
• CPC Class Codes: H01H 2003/143 provisions for avoiding the contact actuation when the elongated strip is bended
• CPC Class Codes: H01H 3/142 of the elongated strip type

Abstract

In order to provide a cord switch which can reliably carry ON/OFF operations, can cancel an erroneous operation by preventing contact between electrodes caused by bending of the cord switch, and have a positive sensitivity for pressurization in all directions and high reliability, at least two wire electrodes are spirally arranged along the inner surface of an insulator which is hollowed in cross section and comprises a restorative rubber or plastic material in the longitudinal direction. The wire electrodes are not electrically contacting each other, and the wire electrodes are fixed to the hollowed insulator such that the wire electrodes are projected from the insulator.

Claims

1. A cord switch characterized in that at least two wire electrodes are spirally arranged along an inner surface of an insulator hollowed in cross section, which comprises a restorative rubber or plastic material, in a longitudinal direction wherein said wire electrodes are not electrically contacting each other;

said wire electrodes are fixed to said hollowed insulator in a state where said wire electrodes are projected from said insulator, and said wire electrodes have a spiral lead length L in a range from Nφ

to 25 Nφ

, wherein N represents the number of the wire electrodes, and φ

represents an inside diameter of a circle inscribed by the wire electrodes arranged spirally.

2. The cord switch according to claim 1, wherein said spiral lead length L is in a range of 2 Nφ

to 10 Nφ

.

3. The cord switch, according to claim 1, wherein said wire electrodes project 5% or more, of an inside diameter of said insulator hollowed in cross section.

4. The cord switch, according to claim 1, wherein a part of each of said wire electrodes is embedded into said insulator hollowed in cross section.

5. The cord switch, according to claim 1, wherein each of said wire electrodes is a metal conductive wire.

6. The cord switch, according to claim 5, wherein said metal conductive wire is a metal strand formed by stranding plural metal wires.

7. The cord switch, according to claim 1, wherein each of said wire electrodes has a conductive rubber or plastic layer formed on an outer periphery of a metal conductive wire.

8. The cord switch, according to claim 7, wherein said metal conductive wire is a metal strand formed by stranding plural metal wires.

9. The cord switch, according to claim 7, wherein said conductive rubber or plastic layer has a cross-sectional area more than twice a cross-sectional area of said metal conductive wire.

10. The cord switch, according to claim 1, wherein said at least two wire electrodes comprise 4n in number, wherein n represents a positive integer.

11. The cord switch, according to claim 1, wherein said wire electrodes project ten percent or more of an inside diameter of said insulator hollowed in cross-section.