Patent US3637169A successfully refreshed from Google Patents.
US3637169A
Expired / Lapsed
US
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Variable parameter nutation damper
Assignee: United States Department of the Navy
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Filing: 1969-08-08
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Granted: 1972-01-25
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Expires: 1989-08-08
Abstract
Abstract An end-weighted pendulum is suspended on a torsion wire which extends parallel to the spin axis of a spacecraft and restrains the pendulum to swing in a plane normal to the spin axis, if the spacecraft is nutating. The end of the pendulum is a vane member formed of electrically conductive, nonmagnetic material which swings between the pole faces of a magnetic structure and creates eddy-current losses within the vane member to dissipate the nutation energy. Means are provided for changing both the eddycurrent damping coefficient and the mechanical resonance of the nutation damper structure so that the damper is effective in dissipating nutations at more than one spacecraft spin rate.
Inventors
- 👤 Barry E Tossman
- 👤 Frederick F Mobley
- 👤 Robert E Fischell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:45
CPC Classifications
B; B64; B64G; B64G1/00; B64G1/22; B64G1/24; B64G1/32; B64G1/28; B64G1/281; B64G1/38; Y; Y10; Y10T; Y10T74/00; Y10T74/12; Y10T74/1229; Y10T74/1257
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
104 words
A nutation damper for a spin-stabilized spacecraft comprising, a torsion wire assembly including a torsion wire extending parallel to and offset from the spin axis of said spacecraft, an arcuate vane member constructed on nonmagnetic, electrically conductive material supported by said torsion wire assembly and adapted to swing in a plane normal to said spin axis during nutations of said spacecraft, a magnetic structure including a pair of pole faces between which said vane member swings during nutations of said spacecraft and means for producing a magnetic field across said pole faces, and means for varying the torsion constant of said torsion wire assembly.
Claim 2
Dependent Claim
104 words
A nutation damper for a spin-stabilized spacecraft comprising, a torsion wire assembly including a torsion wire extending parallel to and offset from the spin axis of said spacecraft, an arcuate vane member constructed on nonmagnetic, electrically conductive material supported by said torsion wire assembly and adapted to swing in a plane normal to said spin axis during nutations of said spacecraft, a magnetic structure including a pair of pole faces between which said vane member swings during nutations of said spacecraft and means for producing a magnetic field across said pole faces, and means for varying the torsion constant of said torsion wire assembly.
Claim 3
Dependent Claim
65 words
The nutation damper specified in claim 1 wherein said means for varying the torsion constant of said torsion wire assembly comprises, a permanent magnet mounted on said torsion wire assembly adjacent said torsion wire to swing during nutations of said spacecraft, and an energizable coil mounted adjacent permanent magnet for producing a magnetic field directed opposite to the dipole moment sense of said permanent magnet.
Claim 4
Dependent Claim
42 words
THe nutation damper specified in claim 1 wherein said means for producing a magnetic field across said pole faces is capable of producing a variable magnetic field so as to vary the damping coefficient between said pole faces and said vane member.
Claim 5
Dependent Claim
51 words
The nutation damper specified in claim 3 wherein said variable magnetic field-producing means includes a permanent magnet for producing a magnetic field across said pole faces and an electromagnet adapted to be energized so as to increase and decrease the magnetic field produced across said pole faces by said permanent magnet.
Claim 6
Dependent Claim
62 words
The nutation damper specified in claim 4 wherein said magnetic structure comprises a substantially C-shaped magnetic core structure, one portion of said C-shaped magnetic core structure being permanently magnetized, and another portion of said C-shaped magnetic core structure being provided with a winding adapted to be selectively energized to add to and oppose the magnetic field produced by said permanently magnetized portion.
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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) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |