Gas damped acceleration switch
First Claim
1. An acceleration sensing apparatus comprising:
- a base, a movable mass, means supporting the mass from the base for movement along an axis, a force generating means urging the mass in one direction along said axis, damping means controlling movement of the mass against the urging of the force generating means, the damping means including a first member secured to the base and a second member secured to the mass, the two members having broad mating surfaces which are normally held in contact by the force generating means, the mating surfaces being moved apart by movement of the mass relative to the base along said axis, the second member comprising a thin plate having an outer periphery out of contact with any surrounding structure, one side of the plate forming said mating surface with the first member, the plate being moved by the mass free of any restraining forces other than viscous damping of any surrounding air.
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Accused Products
Abstract
A gas damped acceleration switch for use as a vehicle crash-sensing device. A mass is supported for movement along an axis against a spring, the mass actuating a switch only after moving a predetermined distance against the spring by an accelerating force. A gas damping system makes the device sensitive to the duration as well as the magnitude of the velocity change. Damping is provided by a plate movable with the mass having surfaces that are perpendicular to the axis of motion. The plate is normally pressed against a mating surface to exclude air. A seal is formed between the mating surfaces around the periphery so that a partial vacuum is formed as the mass moves the surfaces apart. When the surfaces move apart a predetermined distance, the seal is broken and the pressure equalizes. However, the moving plate still produces viscous damping as a function of velocity as it continues to be moved through the air by acceleration of the mass against the spring.
17 Citations
14 Claims
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1. An acceleration sensing apparatus comprising:
- a base, a movable mass, means supporting the mass from the base for movement along an axis, a force generating means urging the mass in one direction along said axis, damping means controlling movement of the mass against the urging of the force generating means, the damping means including a first member secured to the base and a second member secured to the mass, the two members having broad mating surfaces which are normally held in contact by the force generating means, the mating surfaces being moved apart by movement of the mass relative to the base along said axis, the second member comprising a thin plate having an outer periphery out of contact with any surrounding structure, one side of the plate forming said mating surface with the first member, the plate being moved by the mass free of any restraining forces other than viscous damping of any surrounding air.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A crash sensor for automobiles and other types of vehicles comprising:
a housing having a gas-filled chamber, a force generating means attached to the housing and extending into the chamber, force transmitting means secured to the force generating means, means supporting the force transmitting means in the chamber for movement along a longitudinal axis against the urging of the force generating means, switching means actuated by movement of the force transmitting means a predetermined distance along said axis, a damping member secured to the force transmitting means within the chamber, the damping member having a broad flat surface extending substantially transverse to said longitudinal axis, means secured to the housing forming a fixed broad flat surface normally held in contact with said flat surface of the damping member by the urging of the force generating means, and flexible sealing means extending around the periphery of said surfaces for restricting the flow of air into the space between the surfaces when the surfaces are slightly separated by movement of the force transmitting means toward the switching means. - View Dependent Claims (13, 14)
Specification