CRASH SENSOR

• US 3,673,367 A
• Filed: 11/04/1970
• Issued: 06/27/1972
• Est. Priority Date: 11/04/1970
• Status: Expired due to Term

• Current Assignee: TRW Vehicle Safety Systems Incorporated (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Hermann Kaiser
• Inventors: Kaiser, Hermann
• Primary Examiner(s): Schaefer, Robert K.
• Assistant Examiner(s): Ginsburg, M.
• Application Number:
  US05/086,683
• Time in Patent Office: 601 Days
• Field of Search: 200/61.45R,61.45M,61.53
• US Class Current: 200/61.45R
• CPC Class Codes: B60R 21/017 including arrangements for providing electric power to safety arrangements or their actuating means, e.g. to pyrotechnic fuses or electro-mechanic valves
• 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 improved sensor assembly for actuating a vehicle safety apparatus upon the occurrence of an accident includes a mass which is movable from an initial position to an actuated position in response to the occurrence of an accident. When the mass is in its actuated position, the safety apparatus is activated to protect the occupant of the vehicle. A plurality of spring contact fingers bias the mass toward its initial position. Cam means is associated with the contact fingers and act to apply a preload to the mass. As the mass moves toward its actuated position, the number of spring fingers which cooperate to bias the mass decreases and the biasing force exerted by the remaining spring fingers increases. Thus, the mass moves from its initial position to its actuated position against a biasing force which may be controlled by the configuration of the spring fingers and the cam member.

Claims

1. A sensor assembly comprising a housing, a mass located in said housing and movable between an initial position and an actuated position in response to an impulse of predetermined magnitude imposed upon said housing, contact means having open and closed conditions and being open when said mass is in said initial position and closing in response to said mass moving to said actuated position, and a plurality of spring fingers biasing said mass toward said initial position and applying a force to said mass which increases at a decreasing rate as said mass moves from said initial position toward said actuated position.

2. A sensor assembly as defined in claim 1 further including cam means mounted in said housing adjacent to said spring fingers for deflecting said spring fingers toward said mass to bias said mass toward the initial position.

3. A sensor assembly as defined in claim 2 wherein said spring fingers move in response to movement of said mass toward said actuated position, said cam means cooperating with said spring fingers upon movement of said mass toward said actuated position to decrease the effective length of said spring fingers as said mass moves toward said actuated position to thereby increase the spring rate of said spring fingers.

4. A sensor assembly as defined in claim 1 further including electrical circuitry associated with said contact means for actuating an explosive means upon closing of said contact means, and wherein said sensor assembly further includes means for grounding both sides of said explosive means when said mass is in said initial position to thereby prevent inadvertent actuation of said explosive means due to induced currents in said electricaL circuitry.

5. A sensor assembly as defined in claim 3 wherein the number of said spring fingers which apply a biasing force to said mass decreases as said mass moves toward said actuated position.

6. A sensor assembly for use in actuating a safety apparatus on a vehicle for protecting an occupant of a vehicle during an accident, said sensor assembly comprising a housing adapted to be mounted on a vehicle, a movable mass located in said housing and having an initial position and an actuated position to which said mass moves in response to the occurrence of an accident, contact means having open and closed conditions and being open when said mass is in said initial position and closing in response to said mass moving to said actuated position, said closing of said contact means effecting actuation of the safety apparatus, spring means for biasing said mass toward said initial position, and means for varying the spring rate of said spring means as said mass moves between said initial and said actuated positions.

7. A sensor assembly comprising a housing, a mass located in said housing and movable between an initial position and an actuated position in response to an impulse of predetermined magnitude imposed upon said housing, contact means having open and closed conditions and being open when said mass is in said initial position and closing in response to said mass moving to said actuated position, a plurality of spring fingers, and cam means for resiliently deflecting said spring fingers toward and into pressure engagement with said mass when said mass is in the initial position to apply a biasing force to said mass.

8. A sensor assembly as set forth in claim 7 wherein said contact means includes first contacts and second contacts on said spring fingers, said mass being movable under the influence of the impulse of predetermined magnitude and against the biasing force to further deflect the spring fingers and move said second contacts into initial engagement with said first contacts and to move said second contacts relative to said first contacts with a wiping action to promote the establishment of an electrical interconnection between said first and second contacts.