Accelerometer
First Claim
1. A servoed accelerometer comprising:
- a housing configured in a generally cylindrical shape;
a one-piece support frame secured within said housing;
a pendulum;
support means secured to said support frame, including an axle, for supporting said pendulum generally parallel to the cylindrical axis of said housing wherein said axle is secured transversely to said pendulum;
position detecting means for generating a signal representing the rotational position of said pendulum in said housing with respect to the cylindrical axis of said housing;
restoring means, including a magnetic assembly secured to said support frame and a torque coil secured to said pendulum, for rotating said pendulum to a predetermined position generally parallel to the cylindrical axis of said housing;
a generally rectangular shaped circuit support member secured at each end within said support frame above and generally parallel to said pendulum; and
an electronic circuit secured to one side of said circuit support member and electrically connected to said position detecting means, said pendulum and said torque coil effective to generate a restoring current in said torque coil for moving said pendulum to said predetermined position when said pendulum has moved with respect to the cylindrical axis of said housing in response to an acceleration force.
2 Assignments
0 Petitions
Accused Products
Abstract
In order to facilitate construction of a compact, lightweight servoed accelerometer with capacitive pick-off, a one-piece support frame, adapted to be inserted within a cylindrical housing, is used to support a pair of capacitor plates and a lightweight longitudinally reinforced pendulum or seismic mass having a paddle on one end. Attached to the pendulum is an axle which in turn is supported between two flexures by means of jeweled pivoted bearings. Also attached to the pendulum is a torque coil which interacts with a magnetic assembly, secured to the support frame, to restore the paddle to the midpoint between the capacitor plates when the pendulum has been subjected to an acceleration force. Secured to the support frame above and parallel to the pendulum is a thick film circuit board containing an integrated circuit and associated hybrid elements for applying time varying voltages to each capacitor so that the currents flowing through the capacitors can be used as a measure of the difference in capacitance due to deflection of the paddle; and in response thereto, generate sufficient current in the torque coil to restore the paddle to the midway point between the capacitor plates.
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Citations
37 Claims
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1. A servoed accelerometer comprising:
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a housing configured in a generally cylindrical shape; a one-piece support frame secured within said housing; a pendulum; support means secured to said support frame, including an axle, for supporting said pendulum generally parallel to the cylindrical axis of said housing wherein said axle is secured transversely to said pendulum; position detecting means for generating a signal representing the rotational position of said pendulum in said housing with respect to the cylindrical axis of said housing; restoring means, including a magnetic assembly secured to said support frame and a torque coil secured to said pendulum, for rotating said pendulum to a predetermined position generally parallel to the cylindrical axis of said housing; a generally rectangular shaped circuit support member secured at each end within said support frame above and generally parallel to said pendulum; and an electronic circuit secured to one side of said circuit support member and electrically connected to said position detecting means, said pendulum and said torque coil effective to generate a restoring current in said torque coil for moving said pendulum to said predetermined position when said pendulum has moved with respect to the cylindrical axis of said housing in response to an acceleration force. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A servoed accelerometer comprising:
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a housing configured in a generally cylindrical shape; a one-piece support frame secured within said housing; a pendulum including a paddle at one end; support means secured to said support frame, including an axle, for supporting said pendulum generally parallel to the cylindrical axis of said housing wherein said axle is secured transversely to said pendulum; a pair of spaced parallel capacitor plates secured within said housing wherein said paddle is located in a space parallel relationship between said plates and movable transversely to the plane of said plates in response to acceleration forces perpendicular to the surface of said paddle; restoring means, including a magnetic assembly secured to said support frame and a torque coil secured to said pendulum, for moving said paddle to a predetermined position between said plates; a generally rectangular shaped circuit support member secured to each end within said support frame above and generally parallel to said pendulum; and an electronic circuit secured to one side of said circuit support member and electrically connected to said capacitor plates, said pendulum and said torque coil effective to generate a restoring current in said torque coil for moving said paddle to said predetermined position when said paddle has moved closer to one or another of said plates in response to an acceleration force. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A servoed accelerometer comprising:
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a cylindrically shaped housing configured with one end closed and the other end open; a one-piece support frame adapted for insertion within said housing; a pendulum including a beam and a paddle portion; an axle secured to said beam for rotatably supporting said pendulum; a pair of flexures secured to said support frame parallel to and on either side of said pendulum; a pair of bearings wherein one of said bearings is attached to each of said flexures effective to rotatably support said axle; means for adjusting pressure of said bearings on said axle; a pair of spaced apart capacitor plates secured to said frame wherein said paddle is located in a parallel relationship between said capacitor plates and wherein the two capacitors plates in cooperation with said paddle form two capacitors having a capacitance on the order of 2 picofarads; a torque coil secured to said pendulum beam between said paddle and said axle; a permanent magnet secured to said support frame; a pole piece secured to said permanent magnet and located within said torque coil; an additional portion of said one-piece support frame configured so as to provide a magnetic circuit from said permanent magnet to said torque coil; a thick film circuit board; a plurality of circuit board support portions configured from said one-piece support frame wherein said circuit board is secured to said support portions above and generally parallel to said pendulum; an electronic circuit secured to said circuit board including;
a circuit means for applying a time varying means to said capacitors;
a detector circuit for measuring the current through each of said capacitors and generating a signal representing the difference between said currents; and
an output circuit responsive to said difference signal for applying a restoring current to said torque coil wherein said output circuit includes a servo-compensation network; anda header member secured to said support frame effective to hermetically seal said open end of said housing. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
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Specification