Crash sensor with magnetic field sensor

• US 6,282,942 B1
• Filed: 01/19/2000
• Issued: 09/04/2001
• Est. Priority Date: 01/19/2000
• Status: Expired due to Fees

• Current Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Breed Automotive Technology, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Husby, Harald S.
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US09/487,987
• Time in Patent Office: 594 Days
• Field of Search: 73/120.1, 73/120.4, 734/88, 200/61.45
• US Class Current: 73/12.04
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• CPC Class Codes: G01P 15/105 by magnetically sensitive devices
• CPC Class Codes: H01H 2003/0293 with an integrated touch switch
• CPC Class Codes: H01H 35/142 Damping means to avoid unwanted response
• CPC Class Codes: H03K 17/9517 using galvanomagnetic devices

Abstract

A crash sensor comprising a magnetic field sensor with means for concentrating magnetic flux from the magnet, wherein the magnetic field sensor detects a change in magnetic field strength as the sensing mass moves causing a corresponding change in output voltage or current from the magnetic field sensor. The magnetic field sensor is used for determining crash severity for timely deployment of an occupant restraint system.

Claims

1. A crash sensor for sensing velocity changes comprising:

(a) a tubular passage having a first end and a second end;

(b) a magnetically permeable sensing mass which is a ball, arranged to move in said passage between the first end and the second end of the passage;

(c) a fluid located in the passage for dampening the movement of the sensing mass, wherein a tight clearance is provided between said sensing mass and said tubular passage and said tubular passage is substantially closed;

(d) a magnet, positioned about said second end of the passage;

(e) a flexible member in the passage for biasing said sensing mass toward said first end of the passage; and

(f) a magnetic field sensor, positioned about the second end of the passage, and spaced from the magnet wherein as said sensing mass moves towards said second end, the change in magnetic field reaching the magnetic field sensor causes a corresponding change in output voltage or current from the magnetic field sensor.