Impact sensor for vehicle safety restraint system
First Claim
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1. A vehicle restraint system that comprises:
- restraint means for positioning in a vehicle to restrain motion of an occupant upon operation of said restraint means,an impact sensor including means for sensing vehicle impact to provide an impact signal, said impact sensor including means of non-magnetic construction having an internal cavity, a permanent magnet movably mounted within said cavity, means for resiliently urging said magnet to a first position within said cavity, and a Hall sensor positioned adjacent to said cavity for sensing motion of said magnet against force of said urging means to generate said impact signal as an electrical signal having a magnitude that varies as a continuous monotonic analog function of position of said magnet within said cavity,means responsive to said impact signal for operation said restraint means, including means for analyzing rate of change of said analog electrical signal and operating said restraint means when said rate of change indicates a vehicle impact condition, andmeans for selectively adjusting sensitivity of said impact sensor by adjustably varying force urging said magnet to said first position, said selectively adjusting means comprising an electromagnet positioned axially externally adjacent to said cavity and means for selectively varying force of attraction/repulsion of said electromagnet on said magnet.
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Abstract
A vehicle restraint system that includes an impact sensor coupled by fiber optics to an igniter for inflating an air bag. The impact sensor includes a permanent magnet disposed within a cavity and biased by magnetic force toward one end of the cavity, motion of the magnet in the cavity being sensed by a weigand wire or Hall sensor for igniting the air bag. Facility is disposed externally of the cavity for selectively adjusting the bias of the sensor and/or moving the magnet into proximity with the Hall effect or weigand wire sensor to test operative condition of the sensor.
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Citations
24 Claims
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1. A vehicle restraint system that comprises:
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restraint means for positioning in a vehicle to restrain motion of an occupant upon operation of said restraint means, an impact sensor including means for sensing vehicle impact to provide an impact signal, said impact sensor including means of non-magnetic construction having an internal cavity, a permanent magnet movably mounted within said cavity, means for resiliently urging said magnet to a first position within said cavity, and a Hall sensor positioned adjacent to said cavity for sensing motion of said magnet against force of said urging means to generate said impact signal as an electrical signal having a magnitude that varies as a continuous monotonic analog function of position of said magnet within said cavity, means responsive to said impact signal for operation said restraint means, including means for analyzing rate of change of said analog electrical signal and operating said restraint means when said rate of change indicates a vehicle impact condition, and means for selectively adjusting sensitivity of said impact sensor by adjustably varying force urging said magnet to said first position, said selectively adjusting means comprising an electromagnet positioned axially externally adjacent to said cavity and means for selectively varying force of attraction/repulsion of said electromagnet on said magnet. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An acceleration sensor that comprises:
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a body of non-magnetic construction have an internal cavity, a first permanent magnet mounted within said cavity for movement therewithin between at least first and second positions spaced from each other longitudinally of said cavity, means for resiliently urging said magnet to said first position within said cavity, bistable magnetic flux-generating means carried by said body externally of said cavity, said flux generating means having first and second stable states of magnetic flux generated by said flux-generating means, and being responsive to proximity of a magnetic field of one polarity for switching from said first state to said second state, and to proximity of a magnetic field of polarity opposite to said one polarity for switching from said second state back to said first state, and means positioned adjacent to said flux-generating means, and responsive to switching of said magnetic flux-generating means from said first state to said second state as a result of motion of said magnet from said first position to said second position to generate a sensor output signal, said magnet, said cavity and said signal-generating means being constructed and arranged such that motion of said magnet from said first position to said second position switches said flux-generating means from said first state to said second state to generate said signal, and to motion of the same said magnet from said second position back to said first position under force of said resiliently urging means to switch said flux-generating means from said second state back to said first state. - View Dependent Claims (8, 9, 10, 12, 13, 14)
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15. A vehicle restraint system that comprises:
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restraint means for positioning in a vehicle to restrain motion of an occupant upon operation of said restraint means, an impact sensor including means for sensing vehicle impact to provide an impact signal, said impact sensor including means of non-magnetic construction having an internal cavity, a permanent magnet movably mounted within said cavity, means for resiliently urging said magnet to a first position within said cavity, and a Hall sensor positioned adjacent to said cavity for sensing motion of said magnet against force of said urging means to generate said impact signal as an electrical signal having a magnitude that varies as a continuous monotonic analog function of position of said magnet within said cavity, means responsive to said impact signal for operating said restraint means, including means for analyzing rate of change of said analog electrical signal and operating said restraint means when said rate of change indicates a vehicle impact condition, and means operatively coupled to said magnet for selectively testing operative condition of said impact sensor by urging said magnet into proximity with said magnetic sensing means so as to generate said electrical analog signal independent of a vehicle impact condition. - View Dependent Claims (16, 17, 18)
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19. A vehicle restraint system that comprises:
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an impact sensor including means for sensing vehicle impact to provide an impact signal, restraint means for positioning in a vehicle to restrain motion of an occupant upon operation of said restraint means, means responsive to said impact signal for operating said restraint means, fiber optic means interconnecting said sensor and said signal-responsive means for supplying said impact signal to said signal-responsive means, said impact sensor including means of non-magnetic construction having an internal cavity, a permanent magnet movably mounted within said cavity, means for resiliently urging said magnet to a first position within said cavity, and magnetic sensing means positioned adjacent to said cavity for sensing motion of said magnet against force of said urging means to generate said impact signal as an electrical signal, said magnetic sensing means comprising a Hall sensor for providing said electrical signal having a magnitude that varies as a continuous monotonic analog function of position of said magnet within said cavity, said means responsive to said impact signal including means for analyzing rate of change of said analog signal and operating said restraint means when said rate of change indicates a vehicle impact condition, said fiber optic means including a light emitter at said sensor responsive to said electrical signal to provide a light signal, a light sensor at said signal-responsive means for reconverting said light signal into an electrical signal, and a fiber optic connecting said light emitter to said light sensor, and means for selectively adjusting sensitivity of said impact sensor by adjustably varying force urging said magnet to said first position, said selectively adjusting means comprising an electromagnet positioned axially externally adjacent to said cavity and means for selectively varying force of attraction/repulsion of said electromagnet on said magnet. - View Dependent Claims (20, 21)
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22. A vehicle restrain system that comprises:
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an impact sensor including means for sensing vehicle impact to provide an impact signal, restrain means for positioning in a vehicle to restrain motion of an occupant upon operation of said restraint means, means responsive to said impact signal for operating said restraint means, fiber optic means interconnecting said sensor and said signal-responsive means for supplying said impact signal to said signal-responsive means, said impact sensor including means of non-magnetic construction having an internal cavity, a permanent magnet movably mounted within said cavity, means for resiliently urging said magnet to a first position within said cavity, and magnetic sensing means positioned adjacent to said cavity for sensing motion of said magnet against force of said urging means to generate said impact signal as an electrical signal, said magnetic sensing means comprising a Hall sensor for providing said electrical signal having a magnitude that varies as a continuous monotonic analog function of position of said magnet within said cavity, said means responsive to said impact signal including means for analyzing rate of change of said analog signal and operating said restraint means when said rate of change indicates a vehicle impact condition, said fiber optic means including a light emitter at said sensor responsive to said electrical signal to provide a light signal, a light sensor at said signal-responsive means for reconverting said light signal into an electrical signal, and a fiber optic connecting said light emitter to said light sensor, and means operatively coupled to said magnet for selectively testing operative condition of said impact sensor by urging said magnet into proximity with said magnetic sensing means. - View Dependent Claims (11, 23, 24)
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Specification