Patent US3663839A successfully refreshed from Google Patents.
US3663839A
Expired / Lapsed
US
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Thermal motor
Assignee: National Aeronautics and Space Administration
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Filing: 1971-02-24
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Granted: 1972-05-16
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Expires: 1991-02-24
Abstract
Abstract An electrically powered actuator for providing a rotational or large linear motion, which is simple and highly reliable, including a bi-metallic strip with a slot extending along its length from one end to a position near the opposite end. In a rotational actuator, the strip is bent into a spiral, with the inner turn fixed to the shaft which is to be rotated and the outer turn fixed to a support and connected to electrical leads. Current passed through the leads and through the slotted strip heats it to make it uncoil or to make it coil further, the several rotations of the strip resulting in a large rotation of the shaft.
Inventors
- 👤 Lloyd J Derr
- 👤 Robert A Tobias
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:04
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; F; F03; F03G; F03G7/00; F03G7/06; F03G7/061; F03G7/0613; F03G7/063; F03G7/0633; F03G7/064; F03G7/0641; H01J3/00; H01J3/02; H01J3/028
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
153 words
A thermal motor for driving an output member comprising: an elongated sandwich of a plurality of materials of different thermal-expansion coefficients, at least one of said materials being electrically conducting, said sandwich having a slot along its length which forms a pair of parallel legs joined at their first ends by a base and having separated second ends, said legs being bent into a curve of at least one complete turn; support means for fixing the position of said second ends of said legs of said sandwich; a shaft mounted for pivoting about an axis which is fixed with respect to said support means, and said sandwich extending in a spiral of more than one complete turn between said support means and said shaft, and said base of said sandwich fixed to said shaft; and electrical conductors coupled to said second ends of said sandwich legs for applying heating currents through said sandwich.
Claim 2
Dependent Claim
153 words
A thermal motor for driving an output member comprising: an elongated sandwich of a plurality of materials of different thermal-expansion coefficients, at least one of said materials being electrically conducting, said sandwich having a slot along its length which forms a pair of parallel legs joined at their first ends by a base and having separated second ends, said legs being bent into a curve of at least one complete turn; support means for fixing the position of said second ends of said legs of said sandwich; a shaft mounted for pivoting about an axis which is fixed with respect to said support means, and said sandwich extending in a spiral of more than one complete turn between said support means and said shaft, and said base of said sandwich fixed to said shaft; and electrical conductors coupled to said second ends of said sandwich legs for applying heating currents through said sandwich.
Claim 3
Dependent Claim
82 words
A thermal motor comprising: a shaft; means for pivotally supporting said shaft; strip support means; and bi-metallic strip means having a slot therein extending From a first end thereof to a position spaced from a second end thereof, said strip means extending in a spiral with said first end mounted on said strip support means and with said second end fixed to said shaft, whereby heating currents fed serially through the separated portions of said first end causes pivoting of said shaft.
Claim 4
Dependent Claim
82 words
A thermal motor comprising: a shaft; means for pivotally supporting said shaft; strip support means; and bi-metallic strip means having a slot therein extending From a first end thereof to a position spaced from a second end thereof, said strip means extending in a spiral with said first end mounted on said strip support means and with said second end fixed to said shaft, whereby heating currents fed serially through the separated portions of said first end causes pivoting of said shaft.
Claim 5
Dependent Claim
71 words
The thermal motor described in claim 2 including: second bi-metallic strip means having a slot therein extending from a first end to a position spaced from a second end thereof, said first end fixed to said support means and said second end fastened to said shaft; and including means for electrically connecting together portions of said first ends of each of said strip means, to connect said strip means in series.
Claim 6
Dependent Claim
84 words
A thermal motor comprising: a support having a track; a glide mounted for movement along said track; and bi-metallic strip means having a slot therein extending from a first end thereof to a position spaced from a second end thereof, said strip means extending in a loop with said first end mounted on said support and said second end coupled to said glide, whereby heating currents fed serially through the separated portions of said first end causes movement of said glide along said track.
Claim 7
Dependent Claim
84 words
A thermal motor comprising: a support having a track; a glide mounted for movement along said track; and bi-metallic strip means having a slot therein extending from a first end thereof to a position spaced from a second end thereof, said strip means extending in a loop with said first end mounted on said support and said second end coupled to said glide, whereby heating currents fed serially through the separated portions of said first end causes movement of said glide along said track.
Claim 8
Dependent Claim
124 words
A thermal motor for driving an output member comprising: an elongated sandwich of a plurality of materials of different thermal-expansion coefficients at least one of said materials being electrically conducting, said sandwich having a slot along its length which forms a pair of parallel legs joined at their first ends by a base and having separated second ends, said legs being bent into a curve; support means for fixing the position of said second ends of said legs of said sandwich; a glide mounted on said base of said sandwich; a track engaged with said glide for confining said glide to motion along said track; and electrical conductors coupled to said second ends of said sandwich legs for applying heating currents through said sandwich.
Claim 9
Dependent Claim
124 words
A thermal motor for driving an output member comprising: an elongated sandwich of a plurality of materials of different thermal-expansion coefficients at least one of said materials being electrically conducting, said sandwich having a slot along its length which forms a pair of parallel legs joined at their first ends by a base and having separated second ends, said legs being bent into a curve; support means for fixing the position of said second ends of said legs of said sandwich; a glide mounted on said base of said sandwich; a track engaged with said glide for confining said glide to motion along said track; and electrical conductors coupled to said second ends of said sandwich legs for applying heating currents through said sandwich.
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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |