Cord switch and pressure sensor

• US 6,316,846 B1
• Filed: 11/19/1999
• Issued: 11/13/2001
• 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): Ballato, Josie
• Assistant Examiner(s): RIOS CUEVAS, ROBERTO JOSE
• Application Number:
  US09/443,887
• Time in Patent Office: 725 Days
• Field of Search: 307/116, 307/119, 200/61.43, 200/61.44, 200/61.73, 200/61.81, 200/61.82, 200/85.R, 200/508, 200/511, 200/512, 200/DIG.10, 200/DIG.37, 49/26, 49/27, 49/28
• US Class Current: 307/119
• 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 securely catch the ON/OFF operations, can cancel an erroneous operation by preventing the contact between electrodes caused by bending of the cord switch, and have a positive sensibility for the pressurization in all directions and a high reliability, at least two wire electrodes are spirally arranged along the inner surface of an insulator which is hollowed in the cross section and comprises a restorative rubber or plastic material in the longitudinal direction in a situation where the wire electrodes are not electrically contacted each other, and the wire electrodes are fixed to the hollowed insulator in a state where the wire electrodes are projected from the insulator.

Claims

1. A pressure sensor characterized in that a cord switch is used in which 4n wire electrodes (n represents a positive integer) are spirally arranged along the inner surface of an insulator hollowed in the cross section, which comprises a restorative rubber or plastic material, in the longitudinal direction in a situation where said wire electrodes are not electrically contacted each other, and said wire electrodes are fixed to said hollowed insulator in a state where the wire electrodes are projected from said insulator;

in one end of said cord switch, a power supply is connected between said two wire electrodes, and a current adjusting resistor is connected between other two said wire electrodes;

in other end of said cord switch, said wire electrodes are connected each other to form a serial circuit comprising said power supply, said current adjusting resistor and said wire electrodes.

2. A pressure sensor according to claim 1 wherein a part of said respective wire electrodes are embedded into said insulator hollowed in the cross section.