Long dwell crash sensor

• US 5,389,751 A
• Filed: 03/01/1993
• Issued: 02/14/1995
• Est. Priority Date: 04/17/1991
• Status: Expired due to Fees

• Current Assignee: American Vehicular Sciences LLC (Acacia Research Corporation)
• Original Assignee: Automotive Technologies International Incorporated
• Inventors: Breed, David S.
• Primary Examiner(s): SCOTT, JAMES R
• Application Number:
  US08/024,218
• Time in Patent Office: 715 Days
• Field of Search: 200/61.45 R-61.53, 200/61.45 M, 280/728-735
• US Class Current: 200/61.45R
• CPC Class Codes: B60R 21/01 Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents electrical circuits for transmission of signals between steering wheel and the vehicle itself B60R16/027; for electrically actuating belt retractor locking means B60R22/343
• 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: B60R 21/33 Arrangements for non-electric triggering of inflation electrical circuits for triggering safety arrangements B60R21/01
• CPC Class Codes: H01H 35/141 Details

Abstract

A vehicle crash detecting sensor having a pivoted sensing mass which rotates, in response to vehicle deceleration occurring in a crash of a vehicle, from an at-rest position through a second position of rotation at which time airbag deployment is enabled and then the mass is intentionally rotated through to a third (long dwell) position at a rotational angle much larger in magnitude and in the same direction as that of the second position. The sensing mass is spring biased to always bias the mass during rotation to the at-rest position regardless of the dwell angle of the mass during rotation. By appropriate configuration of the inner wall of the housing to which the other end of the spring, typically an elastica spring, is attached, the part of the spring which touches the wall can be controlled and thereby ensuring that the direction of the torque is always the same,- that is, towards the at-rest position.

Claims

1. In a vehicle having a deployable airbag, vehicle crash detecting sensor comprising:

a housing;

a switch means within said housing and operatively connected to said airbag;

a pivoted sensing mass within said housing, rotatably responsive to vehicle deceleration, having a first position where said mass is at rest in the absence of vehicle deceleration, a second position at a first rotation angle from said first position where said sensing mass is operatively adjacent said switch means, and a final position at a second rotation angle from said at-rest position, said second rotation angle having a magnitude of at least three times that of said first rotation angle;

a spring biasing means within said housing exerting a torque on said sensing mass urging it toward said first position;

and wherein said switch means enables deployment of said airbag in response to the motion of said sensing mass operating said switch means when in said second position.

2. The invention in accordance with claim 1 wherein said second rotation angle is at least 60 degrees.

3. The invention in accordance with claim 1 wherein said bias is created by an elastica spring.

4. The invention in accordance with claim 1 wherein said switch means comprises a Hall effect device.

5. The invention in accordance with claim 1 wherein said switch means comprises a reed switch.

6. The invention in accordance with claim 1 wherein said switch means comprises a Wiegand effect device.

7. In a vehicle having a deployable airbag, a vehicle crash detecting sensor comprising:

a housing;

a switch means within said housing and operatively connected to said airbag;

a sensing mass within said housing, whose movement is responsive to the deceleration of said vehicle, having a first at-rest position where said mass is at rest in the absence of vehicle deceleration and a second position at a rotational displacement from said at-rest position where said sensing mass is operatively adjacent said switch means;

a biasing means within said housing exerting a force on said sensing mass urging it toward said first at-rest position;

said switch means enabling deployment of said airbag in response to the motion of said sensing mass to said second position, said sensing mass operating said switch means when said mass is at said second position;

said switch means comprising electrical contact means; and

wherein

said contact means comprises a conductive coating comprising diamonds.

8. In a vehicle having a deployable airbag, a vehicle crash detecting sensor comprising:

a housing;

switch means within said housing and operatively connected to said airbag;

a pivoted sensing mass within said housing, rotatively responsive to vehicle deceleration, having a first at-rest position where said mass is at rest in the absence of vehicle deceleration, a second position at a first rotation angle from said first at-rest position and where said sensing mass is operatively adjacent said switch means, and a final position at a second rotation angle from said first at-rest position;

a biasing means within said housing exerting a torque on said sensing mass urging said mass toward said first at-rest position, said biasing means exerting a torque on said sensing mass at said final position, said torque having a magnitude less than one-half of the torque exerted by said biasing means on said sensing mass when said mass is at said at-rest position; and

wherein

said switch means enabling deployment of said airbag in response to the motion of said sensing mass to said second position;

said sensing mass operating said switch means when said mass is at said second position.

9. A vehicle crash detecting sensor comprising:

a housing;

an electrically conductive sensing mass within said housing, whose movement is responsive to the deceleration of said vehicle, having an at-rest position, a first triggering position and a second triggering position, said second triggering position located rotationally beyond said first triggering position;

said first triggering position located rotationally beyond said at-rest position;

a biasing means exerting a force on said sensing mass urging it toward said at-rest position;

a first pair of contacts having a first contact and a second contact, said first contact of said first pair(i) biased toward but held apart from said second contact of said first pair of contacts by said sensing mass when said sensing mass moves from said at-rest position to said first triggering position, and, (ii) released from said sensing mass thereby enabling engagement with the second contact of said first pair of contacts when said sensing mass moves beyond said first triggering position, thereby enabling the deployment of a first airbag; and

a second pair of contacts having a first contact and a second contact, said first contact of said second pair (i) biased toward but held apart from said second contact of said second pair of contacts by said sensing mass when said sensing mass moves from said at-rest position to said second triggering position, and, (ii) released from said sensing mass thereby enabling engagement with the second contact of said second pair of contacts when said sensing mass moves beyond said second triggering position, thereby enabling the deployment of a second airbag.

10. A method for producing an hermetically sealed deceleration sensor having a plastic housing and at least one metal conductor member with at least two ends with one end within said housing and one other end outside of said housing, said housing having at least one wall, said method comprising the steps of:

(a) coating said metallic conductor on the portion of said conductor which will pass through a wall of said housing with a heat activatable plastic coating; and

,

(b) insert-molding said metallic member into said wall of said housing at an elevated temperature, said elevated temperature activating said heat activatable plastic coating, bonding said metallic conductor to said housing.