Acceleration sensor

• US 5,393,943 A
• Filed: 04/12/1994
• Issued: 02/28/1995
• Est. Priority Date: 08/25/1992
• Status: Expired due to Fees

• Current Assignee: Takata Corporation (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Takata Corporation (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Yoshimura, Kazuo, Furukawa, Koichi
• Primary Examiner(s): Scott, J. R.
• Application Number:
  US08/226,385
• Time in Patent Office: 322 Days
• Field of Search: 200/61.45 R, 200/61.45 M, 200/61.53, 335/205
• US Class Current: 200/61.45M
• CPC Class Codes: B24B 49/105 using eddy currents
• CPC Class Codes: H01H 1/50 Means for increasing contact pressure, preventing vibration of contacts, holding contacts together after engagement, or biasing contacts to the open position
• CPC Class Codes: H01H 2300/052 Controlling, signalling or testing correct functioning of a switch see also H01H2300/056 - H01H2300/066 and H01H11/0062
• CPC Class Codes: H01H 35/14 Switches operated by change of acceleration, e.g. by shock or vibration, inertia switch wherein the liquid constitutes a contact of the switch H01H29/002

Abstract

An acceleration sensor is formed of a housing, an inertia member located inside the housing so as to be freely movable in a longitudinal direction of the housing, a conductor provided on at least an end surface of the inertia member in the longitudinal direction of the housing, a pair of electrodes disposed at one end side of the longitudinal direction of the housing, and electrically connected together by a conductive bridging inertia member. An attractor is disposed at the other end side of the longitudinal direction of the housing and magnetically attracts the inertia member. A stopper is disposed at an opposite side of the inertia member with respect to the electrodes, and abuts against the tip surface of the inertia member when the inertia member moves forwardly. The stopper is disposed at a position which is located off-center with respect to or deviated from the axial center line of the housing.

Claims

1. An acceleration sensor, comprising:

a housing;

an inertia member mounted inside of said housing so as to be freely movable in a longitudinal direction of said housing;

a conductor provided on at least an end surface of said inertia member in the longitudinal direction of said housing;

a pair of electrodes disposed at one end side of the longitudinal direction of said housing, and being electrically connected together through said conductor when said conductor of said inertia member engages said electrodes;

an attractor disposed at the other end side of the longitudinal direction of said housing and magnetically attracting said inertia member; and

a stopper disposed at a side opposite to said inertia member with respect to said electrodes to abut against a tip surface of said inertia member when said inertia member moves forwardly, said stopper being disposed at a position deviated from an axial center line of said housing so that the inertia member inclines relative to the housing and frictionally engages the housing when the inertia member hits the stopper.

2. The acceleration sensor as claimed in claim 1, further comprising a contact holder provided at the one end of the longitudinal direction of said housing, wherein said contact holder is provided with a cylindrical vacant room disposed coaxially with said housing and intercommunicated to the inside of said housing, and said electrodes project from an inner surface of said vacant room of said contact holder.

3. The acceleration sensor as claimed in claim 2, wherein said stopper is projectingly provided at a position which is on a surface confronting the tip surface of said magnetized inertia member of the inner surface of said vacant room of said contact holder.

4. The acceleration sensor as claimed in claim 3, wherein said electrodes face each other in a radial direction of said vacant room, and end portions of the electrodes extend toward a lower surface of said vacant room.

5. The acceleration sensor as claimed in claim 1, wherein a gap is provided between an outer peripheral surface of said inertia member and an inner peripheral surface of said housing so that when said magnetized inertia member moves forwardly and abuts against said stopper, said inertia member is inclined in such a direction that the axial center line thereof intersects with the axial center line of said housing to push the inertia member against the inner peripheral surface of said housing, thereby increasing frictional force between said inertia member and the inner peripheral surface of said housing.