Patent US2635859A successfully refreshed from Google Patents.
Patent US4043204A successfully refreshed from Google Patents.
US4043204A
Expired / Lapsed
US
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Magnetic fluid bearing accelerometer
Assignee: United States Department of the Army
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Filing: 1976-08-16
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Granted: 1977-08-23
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Expires: 1996-08-16
Abstract
Abstract An accelerometer employing a magnetic fluid bearing which permits movementf a magnetic cylinder along a designated sensitive axis. The device is used to measure acceleration in such applications as inertial platform leveling, thrust termination, and inertial reference triads. The position of the magnetic cylinder (proof mass) is measured by a capacitance bridge network. The output of this capacitance network is a voltage which is proportional in direction and magnitude to the applied acceleration. This voltage will be amplified by an operational amplifier.
Inventors
- 👤 Joe S. Hunter
- 👤 Little J. Little
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:25
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/13; G01P15/132
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
155 words
A fluid accelerometer including: a. a non-magnetic housing having a cylindrical interior; b. A magnetic cylinder carried in said housing; c. a magnetic fluid carried in said housing about said magnetic cylinder; d. a capacitance bridge means cooperating with said magnetic cylinder for providing a voltage which is proportional in direction and magnitude to applied acceleration said bridge means including a first plate in the interior of said housing adjacent a first end thereof, a second plate in the interior of said housing adjacent a second end thereof, said first and second plates being disposed on one side of said magnetic cylinder, a common plate disposed in the interior of said housing substantially along the length thereof and on a second side of said magnetic cylinder which is opposite said first side; and, e. means for providing closed loop operation of said accelerometer by aiding or opposing the magnetic field associated with the magnetic cylinder.
Claim 2
Dependent Claim
155 words
A fluid accelerometer including: a. a non-magnetic housing having a cylindrical interior; b. A magnetic cylinder carried in said housing; c. a magnetic fluid carried in said housing about said magnetic cylinder; d. a capacitance bridge means cooperating with said magnetic cylinder for providing a voltage which is proportional in direction and magnitude to applied acceleration said bridge means including a first plate in the interior of said housing adjacent a first end thereof, a second plate in the interior of said housing adjacent a second end thereof, said first and second plates being disposed on one side of said magnetic cylinder, a common plate disposed in the interior of said housing substantially along the length thereof and on a second side of said magnetic cylinder which is opposite said first side; and, e. means for providing closed loop operation of said accelerometer by aiding or opposing the magnetic field associated with the magnetic cylinder.
Claim 3
Dependent Claim
62 words
An accelerometer as set forth in claim 1 wherein said means for providing closed loop operation includes a pair of electromagnets, each disposed adjacent opposite ends of said housing, a differential amplifier connected to said capacitance bridge and said electromagnets whereby the output of said differential amplifier is used as a feedback to energize said electromagnets to provide the closed loop operation.
Claim 4
Dependent Claim
28 words
A fluid amplifier as in claim 2 including a demodulator for demodulating the output of said differential amplifier and an amplifier for amplifying the output of said demodulator.
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) | 1980-08-22 | 1981-02-21 | 1981-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-22 | 1985-02-21 | 1985-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-22 | 1989-02-21 | 1989-08-23 | $7700.00 | Window Closed / Lapsed |