Combination arming/discriminating inertia switch
First Claim
1. A passive automotive vehicle occupant restraint system comprising an electrically-fired occupant restraint device which is deployed in response to the concurrence of the closure of an arming switch means and of the closure of a discriminating switch means in an electrical firing circuit for the restraint device, characterized in that said arming switch means comprises an arming switch which has normally closed contacts that are caused to be held open by the attraction of a magnetically responsive inertial sensing mass to a magnet means with respect to which said inertial sensing mass is relatively movable until velocity change sensed by said inertial sensing mass creates inertial force in a direction opposite that of the magnetic attraction of said inertial sensing mass to said magnet means to move said inertial sensing mass along a defined path of motion to a point beyond which said inertial sensing mass ceases to hold said contacts of said arming switch open, there is provided means to impose damping on motion of said inertial sensing mass along said path in said direction, and said discriminating switch means comprises a discriminating switch which has normally open contacts that remain open until closed by said inertial sensing mass having executed an amount of motion along said path in said direction sufficient to have caused said inertial sensing mass to cease holding said contacts of said arming switch open so that as a consequence concurrence of the closure of said contacts of said arming switch and of the closure of said contacts of said discriminating switch is attained upon said inertial sensing mass having executed said amount of motion along said path in said direction.
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Accused Products
Abstract
The switch assembly comprises a single inertial sensing mass which is magnetically biased to an initial position along a path of travel within an enclosure. In this position, the mass holds a normally closed arming switch open. A normally open discriminating switch is disposed in the path of travel of the mass to be closed by the mass upon the occurrence of a velocity change indicating that a passive occupant restraint device such as an air bag should be deployed. Travel of the mass from the initial position releases the arming switch before the discriminating switch closes.
38 Citations
6 Claims
- 1. A passive automotive vehicle occupant restraint system comprising an electrically-fired occupant restraint device which is deployed in response to the concurrence of the closure of an arming switch means and of the closure of a discriminating switch means in an electrical firing circuit for the restraint device, characterized in that said arming switch means comprises an arming switch which has normally closed contacts that are caused to be held open by the attraction of a magnetically responsive inertial sensing mass to a magnet means with respect to which said inertial sensing mass is relatively movable until velocity change sensed by said inertial sensing mass creates inertial force in a direction opposite that of the magnetic attraction of said inertial sensing mass to said magnet means to move said inertial sensing mass along a defined path of motion to a point beyond which said inertial sensing mass ceases to hold said contacts of said arming switch open, there is provided means to impose damping on motion of said inertial sensing mass along said path in said direction, and said discriminating switch means comprises a discriminating switch which has normally open contacts that remain open until closed by said inertial sensing mass having executed an amount of motion along said path in said direction sufficient to have caused said inertial sensing mass to cease holding said contacts of said arming switch open so that as a consequence concurrence of the closure of said contacts of said arming switch and of the closure of said contacts of said discriminating switch is attained upon said inertial sensing mass having executed said amount of motion along said path in said direction.
- 2. A passive automotive vehicle occupant restraint system comprising an electrically-fired occupant restraint device which is deployed in response to the concurrence of the closure of an arming switch means and of the closure of a discriminating switch means in an electrical firing circuit for the restraint device, characterized in that said discriminating switch means comprises a discriminating switch which has normally open contacts that remain open until caused to be closed by a magnetically responsive inertial sensing mass having executed, in response to certain velocity change, an amount of motion along a defined path in a direction opposite that of the attraction of said inertial sensing mass to a magnet with respect to which said inertial sensing mass is relatively movable, said arming switch means comprises an arming switch which has normally closed contacts that are caused to be held open by said inertial sensing mass until velocity change sensed by said inertial sensing mass creates inertial force in said direction to move said inertial sensing mass along said path to a point beyond which said inertial sensing mass ceases to hold said contacts of said arming switch open, there is provided means to impose damping on motion of said inertial sensing mass along said path in said direction, and the closure of said contacts of said discriminating switch caused by said inertial sensing mass having executed said amount of motion occurs after closure of said contacts of said arming switch so that as a consequence concurrence of the closure of said contacts of said arming switch and of the closure of said contacts of said discriminating switch is attained upon said inertial sensing mass having executed said amount of motion along said path in said direction.
- 3. An arming/discriminating inertia switch assembly comprising a switch enclosure, a magnetically responsive inertial sensing mass disposed for motion within said enclosure along a defined path of motion, means providing a magnetic restraining force urging said inertial sensing mass to an initial position along said path of motion, means for damping motion of said inertial sensing mass along said path in a direction away from said initial position, said inertial sensing mass occupying said initial position until said enclosure is subjected to velocity change causing said inertial sensing mass to move along said path of motion away from said initial position against said magnetic restraining force, said magnetic restraining force being sufficient to return said inertial sensing mass to said initial position upon sufficient timely attenuation of said velocity change, an arming switch that is disposed within said enclosure and that has normally closed contacts which are caused to be held open by said inertial sensing mass so long as said inertial sensing mass occupies said initial position and any position along said path within an initial segment of said path immediately contiguous said initial position and which cease to be held open by said inertial sensing mass whenever said inertial sensing mass occupies a position along said path that is beyond said initial segment, a discriminating switch that is disposed within said enclosure and that has normally open contacts which are caused to be closed by said inertial sensing mass whenever said inertial sensing mass occupies a position within a succeeding segment of said path that is beyond said initial segment of said path, and terminal means mounted on said enclosure providing for connection of said contacts of said arming and discriminating switches in an electric-firing circuit for deploying a passive automotive vehicle occupant restraint device upon concurrence of closure of said contacts of said arming switch and of closure of said contacts of said discriminating switch.
Specification