Patent US3918310A successfully refreshed from Google Patents.
US3918310A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitive sensing system
Assignee: Kearfott Guidance and Navigation Corp
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Filing: 1974-06-14
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Granted: 1975-11-11
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Expires: 1994-06-14
Abstract
Abstract The angular deviation of relative alignment of a gyroscope rotor and stator about one or more axes is measured by a capacitance pickoff system. At least two pairs of separate capacitor plates are associated with the stator and positioned with respect to a portion of the rotor such that the latter forms the other plate of each capacitor. The capacitances of each pair are summed and the sum of one pair is then subtracted from the sum of the other pair. The values of the respective capacitors change with variations in relative angular alignments of rotor and stator which varies the effective overlap area of the capacitor plates. Positioning of the plates is such that when there is no angular deviation (i.e., rotor and stator axes are aligned) a null condition exists and the effective difference between opposed pairs of capacitors is zero. An additional capacitor is used to couple a drive signal from a sine wave oscillator to the rotor.
Inventors
- 👤 John L Evans
- 👤 Lincoln S Ferriss
- 👤 Jay Hoffmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:20
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/02; G01C19/04; G01C19/28; Y; Y10; Y10T; Y10T74/00; Y10T74/12; Y10T74/1261; Y10T74/1275
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
391 words
A gyroscope construction comprising a. a stator; b. a rotor supported for rotation about an axis with respect to said stator; c. at least two pairs of electrically conducting plates and fixedly positioned with respect to said stator and each having a continuous face, a portion of which is spaced a predetermined distance from and concentric with an electrically conducting portion of said rotor, said plates and said conducting portion forming individual capacitors having a capacitance variable in accordance with the area of said face which is spaced said predetermined distance from said conducting portion of said rotor; d. a first of said two pairs of plates being positioned on diametrically opposite siDes of said rotor and so positioned with respect to said conducting portion that relative angular displacement of said stator and rotor in a first direction about an axis perpendicular to said rotational axis increases said face area of both plates of said first pair by an equal amount, and relative angular displacement about said perpendicular axis in a second direction decreases said face area of both plates of said first pair by an equal amount; e. a second of said two pairs of plates being positioned on the same opposite sides of said rotor as respective plates of said first pair and so positioned with respect to said conducting portion that relative angular displacement of said stator and rotor about said perpendicular axis in said first direction decreases said face area of both plates of said second pair by an equal amount, and relative annular displacement about said perpendicular axis in said second direction increases said face area of both plates of said second pair by an equal amount; f. first and second operational amplifiers respectively connected to said first and second pairs of plates to add in parallel the individual capacitance of each pair formed thereby; g. a differential amplifier connected to both of said operational amplifiers to subtract the output of one from the other; h. an additional plate having a continuous face concentric with and spaced a predetermined distance from an electrically conduction portion of said rotor; i. an oscillator connected to said additional plate thereby coupling the oscillator''s signals to each of said individual capacitors whereby the signal output of said differential amplifier will be commensurate with the amount of said relative annular displacement.
Claim 2
Dependent Claim
391 words
A gyroscope construction comprising a. a stator; b. a rotor supported for rotation about an axis with respect to said stator; c. at least two pairs of electrically conducting plates and fixedly positioned with respect to said stator and each having a continuous face, a portion of which is spaced a predetermined distance from and concentric with an electrically conducting portion of said rotor, said plates and said conducting portion forming individual capacitors having a capacitance variable in accordance with the area of said face which is spaced said predetermined distance from said conducting portion of said rotor; d. a first of said two pairs of plates being positioned on diametrically opposite siDes of said rotor and so positioned with respect to said conducting portion that relative angular displacement of said stator and rotor in a first direction about an axis perpendicular to said rotational axis increases said face area of both plates of said first pair by an equal amount, and relative angular displacement about said perpendicular axis in a second direction decreases said face area of both plates of said first pair by an equal amount; e. a second of said two pairs of plates being positioned on the same opposite sides of said rotor as respective plates of said first pair and so positioned with respect to said conducting portion that relative angular displacement of said stator and rotor about said perpendicular axis in said first direction decreases said face area of both plates of said second pair by an equal amount, and relative annular displacement about said perpendicular axis in said second direction increases said face area of both plates of said second pair by an equal amount; f. first and second operational amplifiers respectively connected to said first and second pairs of plates to add in parallel the individual capacitance of each pair formed thereby; g. a differential amplifier connected to both of said operational amplifiers to subtract the output of one from the other; h. an additional plate having a continuous face concentric with and spaced a predetermined distance from an electrically conduction portion of said rotor; i. an oscillator connected to said additional plate thereby coupling the oscillator''s signals to each of said individual capacitors whereby the signal output of said differential amplifier will be commensurate with the amount of said relative annular displacement.
Claim 3
Dependent Claim
24 words
The invention according to claim 1 and further including a phase-sensitive demodulator connected to receive inputs from both said oscillator and said differential amplifier.
Claim 4
Dependent Claim
68 words
The invention according to claim 2 and further including a wave generator operating at a constant, predetermined frequency, and a comparator connected to receive inputs from both said demodulator and said wave generator, and having a digital output of a first value when the demodulator signal is greater than the wave generator signal, and a second value when said demodulator signal is less than said wave generator signal.
Claim 5
Dependent Claim
19 words
The invention according to claim 1 wherein said rotor includes an inertia rim which comprises said electrically conducting portion.
Claim 6
Dependent Claim
66 words
The invention according to claim 1 wherein said rotor is essentially spherical and includes a peripheral discontinuity adjacent the position of each of said plates and so positioned with respect thereto that said portion of each of said continuous faces is spaced said predetermined distance from said conducting portion at the juncture thereof with said discontinuity, the remainder of said continuous faces being opposite said discontinuity.
Claim 7
Dependent Claim
114 words
The invention according to claim 1 and further including third and fourth pairs of electrically conducting plates arranged with respect to one another and to said rotor the same as said first and second pairs, the centers of said third and fourth pairs being arranged at 90* intervals from the centers of said first and second pairs in a plane normal to said axis of rotation, whereby the individual capacitors formed by said third and fourth plates and said conducting portion of said rotor increase and decrease in value in response to relative angular displacement of said rotor and stator about a third axis perpendicular to both said rotational axis and said perpendicular axis.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |