Patent US3797320A successfully refreshed from Google Patents.
US3797320A
Expired / Lapsed
US
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Electronic dither circuit for a mechanical bearing assembly and method and accelerometer using the same
Assignee: NEW SD Inc A CORP OF
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Filing: 1972-11-29
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Granted: 1974-03-19
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Expires: 1992-11-29
Abstract
Abstract Electronic dither circuit for a mechanical bearing assembly having a housing with a member disposed in the housing. Means is provided in the form of a mechanical bearing assembly for pivotally mounting the member in the housing for movement about a pivot axis. Means is mounted in the housing forming a magnetic field in the housing. A torque coil is connected to the member and is disposed in the magnetic field. Electronic means is provided for supplying electrical energy to the torque coil. The electronic means includes a damped closed loop servo system and means for removing the damping from the closed loop servo to cause the servo loop to oscillate to thereby supply oscillatory electrical energy to said torque coil to cause the torque coil to oscillate and to thereby minimize the effects of friction. In the method, the damping is removed from the closed loop servo for a predetermined period of time to permit the servo loop to oscillate. The damping is gradually restored to the servo loop over a predetermined period of time. The electronic dither circuit and method are particularly useful in connection with accelerometers.
Inventors
- 👤 R Clampitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:39
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/13
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
155 words
In an electronic dither circuit for a mechanical bearing assembly, a housing, a member disposed in the housing, means in the housing in the form of a mechanical bearing assembly for pivotally mounting the member in the housing for movement about a pivot axis, means mounted in the housing forming a magnetic field, a torque coil connected to the member and disposed in the magnetic field in the housing, electronic means for supplying electrical energy to said torque coil, said electronic means including a closed loop servo system, a damping circuit coupled to said system to provide damping for said system, and means for removing said damping from said system upon application of electrical power after the existence of an unenergized state to induce oscillatory instability in said servo system to thereby cause oscillatory movement of the torque coil and the member connected thereto to minimize the effects of friction in the mechanical bearing assembly.
Claim 2
Dependent Claim
155 words
In an electronic dither circuit for a mechanical bearing assembly, a housing, a member disposed in the housing, means in the housing in the form of a mechanical bearing assembly for pivotally mounting the member in the housing for movement about a pivot axis, means mounted in the housing forming a magnetic field, a torque coil connected to the member and disposed in the magnetic field in the housing, electronic means for supplying electrical energy to said torque coil, said electronic means including a closed loop servo system, a damping circuit coupled to said system to provide damping for said system, and means for removing said damping from said system upon application of electrical power after the existence of an unenergized state to induce oscillatory instability in said servo system to thereby cause oscillatory movement of the torque coil and the member connected thereto to minimize the effects of friction in the mechanical bearing assembly.
Claim 3
Dependent Claim
19 words
A circuit as in claim 1 together with means for restoring the damping to the closed loop servo system.
Claim 4
Dependent Claim
25 words
A circuit as in claim 2 wherein said means for restoring the damping to the closed loop servo includes means for gradually restoring the damping.
Claim 5
Dependent Claim
27 words
A circuit as in claim 3 wherein said means for gradually restoring the damping includes means for causing the damping to asymptotically approach stability and full damping.
Claim 6
Dependent Claim
16 words
A circuit as in claim 2 wherein said means for restoring the damping includes timing means.
Claim 7
Dependent Claim
50 words
A circuit as in claim 1 wherein said closed loop servo system includes an amplifier and means for forming a phase-lead network around the amplifier and wherein said means for removing said damping circuit from the closed loop servo system includes means for removing the phase lead from the amplifier.
Claim 8
Dependent Claim
19 words
A circuit as in claim 6 together with means for inserting a phase lag as the phase-lead is removed.
Claim 9
Dependent Claim
25 words
A circuit as in claim 1 wherein said means for removing said damping circuit from the servo system includes means for sudden removal of damping.
Claim 10
Dependent Claim
23 words
A circuit as in claim 5 together with means for resetting the timing means upon removal of electrical power to the electronic means.
Claim 11
Dependent Claim
118 words
In a method for electronically supplying dither to a mechanical bearing assembly of the type in which the bearing assembly is mounted within a housing and carries a member pivotally mounted in the mechanical bearing assembly for movement about a pivot axis, forming a closed loop servo system for maintaining said member in a predetermined position, damping said servo system to provide stability, removing the damping suddenly from the servo loop upon application of electrical power after the existence of an unenergized state to cause the servo loop to become unstable and oscillate to thereby cause oscillatory movement of the member to minimize friction in the mechanical bearing assembly, and gradually restoring the damping to the servo loop.
Claim 12
Dependent Claim
118 words
In a method for electronically supplying dither to a mechanical bearing assembly of the type in which the bearing assembly is mounted within a housing and carries a member pivotally mounted in the mechanical bearing assembly for movement about a pivot axis, forming a closed loop servo system for maintaining said member in a predetermined position, damping said servo system to provide stability, removing the damping suddenly from the servo loop upon application of electrical power after the existence of an unenergized state to cause the servo loop to become unstable and oscillate to thereby cause oscillatory movement of the member to minimize friction in the mechanical bearing assembly, and gradually restoring the damping to the servo loop.
Claim 13
Dependent Claim
20 words
A method as in claim 10 together with the step of restoring said damping over a predetermined period of time.
Claim 14
Dependent Claim
26 words
A method as in claim 11 wherein the step of restoring said damping is performed so that the servo loop asymptotically approaches stability and full damping.
Claim 15
Dependent Claim
134 words
In an accelerometer, a housing, a pendulous member disposed in the housing, means in the form of a mechanical bearing assembly pivotally mounting the pendulous member in the housing for movement about a pivot axis, means in the housing forming a magnetic field, a torque coil connected to the member and disposed in the magnetic field, pickoff means for sensing the position of the member, electronic means connected to the pickoff means for supplying energy to the torque coil, said electronic means including a damped closed loop servo system and means for removing damping from the servo loop to cause the servo loop to oscillate to thereby supply oscillatory electrical energy to the torque coil to cause the torque coil to oscillate to thereby minimize the effects of friction in the mechanical bearing assembly.
Claim 16
Dependent Claim
134 words
In an accelerometer, a housing, a pendulous member disposed in the housing, means in the form of a mechanical bearing assembly pivotally mounting the pendulous member in the housing for movement about a pivot axis, means in the housing forming a magnetic field, a torque coil connected to the member and disposed in the magnetic field, pickoff means for sensing the position of the member, electronic means connected to the pickoff means for supplying energy to the torque coil, said electronic means including a damped closed loop servo system and means for removing damping from the servo loop to cause the servo loop to oscillate to thereby supply oscillatory electrical energy to the torque coil to cause the torque coil to oscillate to thereby minimize the effects of friction in the mechanical bearing assembly.
Claim 17
Dependent Claim
23 words
An accelerometer as in claim 13 together with means for restoring the damping to the servo loop after the damping has been removed.
Claim 18
Dependent Claim
19 words
An accelerometer as in claim 14 together with timing means for gradually restoring the damping to the servo loop.
Claim 19
Dependent Claim
27 words
An accelerometer as in claim 13 together with means for sudden removal of damping upon application of electrical power to accelerometer after existence of an unenergized state.
Claim 20
Dependent Claim
22 words
An accelerometer as in claim 13 together with means for resetting the timing means upon removal of electrical power to the accelerometer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |