Velocity change sensor with improved spring bias

• US 5,098,122 A
• Filed: 09/24/1990
• Issued: 03/24/1992
• Est. Priority Date: 12/06/1989
• Status: Expired due to Term

• Current Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Breed Automotive Corporation
• Inventors: Breed, Allen, Grossi, Carl, Thuen, Ted
• Primary Examiner(s): Rice, Kenneth R.
• Assistant Examiner(s): Tyson, Karin
• Application Number:
  US07/587,262
• Time in Patent Office: 547 Days
• Field of Search: 280/735, 280/734, 180/282, 200/61.45 R, 200/61.48, 200/61.49, 200/61.51, 200/61.53
• US Class Current: 280/735
• CPC Class Codes: G01P 15/135 by making use of contacts which are actuated by a movable inertial mass
• 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
• CPC Class Codes: H01H 35/142 Damping means to avoid unwanted response

Abstract

An accelerometer for a passenger restrain system in a motor vehicle includes a housing with a path for an inertial element, and a coil spring member for urging the inertial element toward a preselected position. When the vehicle decelerates at a rate higher than a preset rate, the ball moves away from the preselected position and closes an electrical contact.

Claims

1. In a passenger restraint system for a motor vehicle, an accelerometer comprising:

a. a housing;

b. an inertial element;

c. path means disposed in said housing for defining a path for said inertial element;

d. contact means disposed in said housing; and

e. spring coil means for urging said inertial element toward a preselected position on said path, said path being arranged and constructed to allow said inertial element to move away from said preselected position in the presence of a deceleration of said motor vehicle, said spring coil means including a blade attached to a spring coil, said blade having pivoted by the movement of said inertial element to contact said contact means.

2. The accelerometer of claim 1 further including indicating means disposed in said housing for indicating the position of said inertial element within said path.

3. The accelerometer of claim 2 wherein said indicating means include a pair of electrical contacts having an open and a closed contact position, said contact positions being defined by the position of said inertial element.

4. The accelerometer of claim 1 wherein said path means includes a chamber housing said inertial element.

5. An accelerometer for a passenger restraint system in a motor vehicle comprising:

a housing;

an inertial element disposed within said housing;

c. path means for defining a path of movement for said inertial element;

d. contact means disposed in said housing; and

e. spring coil means for biasing said inertial element, said spring coil means including a flexible blade attached to a spring coil and arranged to urge said inertial element toward a rest position, said blade being pivoted by the movement of said inertial element to contact said contact means when said motor vehicle undergoes an acceleration.

6. The accelerometer of claim 5 further comprising indicating means for indicating the position of said inertial element within said housing.

7. The accelerometer of claim 5 wherein said contact means comprises a second blade.

8. The accelerometer of claim 7 wherein said first and second blades cooperate for slowing said inertial element down after contact is made between said first and said second blades.

9. The accelerometer of claim 5 wherein said path means comprises a tubular chamber holding said inertial element and a gas for dampening the movement of said inertial element.

10. A passenger restraint system for a motor vehicle comprising:

a. an air bag arranged and disposed for restraining a passenger when the motor vehicle experiences a deceleration;

b. air bag inflating means for inflating said air bag; and

c. an accelerometer for sensing said deceleration for activating said air bag inflating means, said accelerometer comprising;

(i) a housing;

(ii) an inertial element disposed in said housing;

(iii) path means for defining a path of movement for said inertial element within said housing; and

(iv) coil spring means disposed in said housing for urging said inertial element toward a first position in the absence of said deceleration, said coil spring means including a first blade disposed in said housing and extending into said path.

11. The system of claim 10 further comprising a contact means disposed within said housing for contacting first blade as said inertial element moves from said first to a second position along said path.

12. The system of claim 11 wherein said contacting means comprises a second blade.

13. The system of claim 10 wherein said path means consists of a plurality of ribs extending within said housing.

14. The system of claim 13 wherein said ribs define a chamber, wherein said chamber has a lateral slot, and wherein said spring means extends into said chamber through said slot.