SENSOR SWITCH FOR OCCUPANT RESTRAINT SYSTEM WITH SPRING FRACTURE DETECTION MEANS

• US 3,832,507 A
• Filed: 06/26/1973
• Issued: 08/27/1974
• Est. Priority Date: 10/22/1971
• Status: Expired due to Term

• Current Assignee: James F. Marquardt, Vincent A. Orlando
• Original Assignee: James F. Marquardt, Vincent A. Orlando
• Inventors: Marquardt, James F., Orlando, Vincent A.
• Primary Examiner(s): Scott, James R.
• Application Number:
  US05/373,684
• Time in Patent Office: 427 Days
• Field of Search: 200/61.45,61.53,153R,166BB,DIG.45 280/15AB 180/91
• 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: 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 47/002 Monitoring or fail-safe circuits

Abstract

A vehicle includes a bumper or other portion which experiences a rapid change in velocity upon vehicle impact with an obstacle, an occupant compartment, an inflatable occupant restraint cushion within the compartment, and a source of pressure fluid for inflating the cushion. A sensor primarily responsive to the change in velocity of the bumper or other portion of the vehicle includes a housing of dielectric material having a sector-shaped recess, a spool-shaped mass of electrically conductive material slidable within the recess, and a pair of tension springs of electrically conductive material which are hooked between the mass and the housing to maintain the mass in unactuated position in engagement with the side walls of the recess adjacent the apical end thereof. The sensor is mounted on the bumper or other portion and is subjected to the velocity change thereof upon vehicle impact with an obstacle. The time for the mass to travel to actuated position is comparable within an order of magnitude to the deceleration time period of the sensor whereby movement of the mass to actuated position is responsive to the occurrence of a change in vehicle velocity above a predetermined value. When the mass moves to actuated position, it completes an electrical circuit across a pair of contacts located adjacent the basal end of the recess to initiate release of the pressure fluid to the cushion for inflation thereof. The springs and mass and the spring anchors to the housing are connected across a source of power in a diagnostic circuit so that any fracture of either spring can be detected.

Claims

1. A sensor comprising, in combination, a housing including a mass receiving recess, a mass slidably received in the recess for movement between unactuated and actuated positions, and a pair of springs respectively anchored at one end to the housing and secured at their other ends to the mass to locate the mass in unactuated position, the springs and mass being of electrically conductive material and closing a monitor circuit between the spring anchors to the housing across a source of power to test the continuity of the springs.

2. A sensor comprising, in combination, a housing including a mass receiving recess having spaced generally parallel planar walls, a mass received in the recess and including spaced generally parallel planar walls slidably engaging respective walls of the recess for movement between unactuated and actuated positions, and a pair of springs, each having one end respectively anchored to the housing and the other end secured to the mass intermediate the walls thereof to locate the mass in unactuated position, the springs and mass being of electrically conductive material and closing a monitor circuit between the spring anchors to the housing across a source of power to test the continuity of the springs.

3. A sensor comprising, in combination, a housing including a mass receiving recess having spaced parallel planar walls, a generally spool-shaped mass received in the recess with the end plates thereof slidably engaging respective planar walls of the housing for movement of the mass between unactuated and actuated positions, and a pair of tension springs, each having one end respectively anchored to the housing to one side of the recess and the other end secured to the axle of the mass to hold the mass in unactuated position against movement to actuated position, the springs and mass being of electrically conductive material and closing a monitor circuit between the spring anchors to the housing across a source of power to test the continuity of the springs.

4. A sensor comprising, in combination, a housing including a mass receiving recess of generally sector shape having spaced parallel planar base walls and a sector-shaped side wall joining the base walls to define the recess therewith, a generally spool-shaped mass having the end plates thereof slidably engaging respective base walls of the recess for movement between unactuated and actuated positions, and a pair of tension springs, each having one end thereof respectively anchored to the housing adjacent the apical end of the recess and the other end thereof secured to the axle of the mass intermediate the end plates thereof to exert a preload force on the mass holding the mass in the unactuated position with the end plates thereof in engagement with the side wall of the recess adjacent the apical end thereof, the springs and mass being of electrically conductive material and closing a monitor circuit between the spring anchors across a source of power to test the continuity of the springs.

5. A sensor comprising, in combination, a housing including a generally sector-shaped mass receiving recess having generally parallel planar spaced base walls joined by side walls defining an included angle and an arcuate end wall at the proximal ends of the side walls, a generally spool-shaped mass received within the recess and including circular end plates slidably engaging the base walls of the recess for movement of the mass between an unactuated position wherein the end plates tangentially engage the side walls and engage the end wall, and an actuated position adjacent the distal ends of the side walls, a pair of tension springs, each having one end thereof respectively anchored to the housing adjacent the proximal end wall of the recess and the other ends thereof secured to the axle of the mass intermediate the end plates to hold the mass in unactuated position, the springs and mass being of electrically conductive material and closing a first circuit across a source of power between the spring anchors to the housing, the lines of force of the springs lying in planes intersecting at the mass axis and passing through the points of tangency of the mass end plates with the recess side walls, and spaced contact means adjacent the distal ends of the side walls engageable by the end plates of the mass upon movement of the mass to actuated position to close a second circuit across a source of power between the contact means.

6. The combination recited in claim 3 wherein the end plates of the mass include recessed outer surfaces bounded by an axially extending lip slidably engaging respective planar walls to thereby reduce friction between the end plateS and the walls to a minimum.

7. The combination recited in claim 4 including spaced deflectable contact means adjacent the basal end of the recess slidably engageable by the end plates upon movement of the mass to actuated position and deflectable relative to each other upon such engagement, the contact means and mass closing a second circuit across the source of power.

8. The combination recited in claim 5 wherein the contact means are cantilever mounted on the housing and are deflectable relative to each other upon engagement with the end plates of the mass.

9. The combination recited in claim 5 wherein the contact means each include at least one cantilever spring finger having an integral angular terminal, and means on the housing slidably engageable with the angular terminals to deflect the spring fingers relative to each other to a position in the path of movement of the mass for slidable engagement with a respective end plate.