US3591960A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermostatic actuator
Assignee: National Aeronautics and Space Administration
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Filing: 1969-08-19
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Granted: 1971-07-13
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Expires: 1989-08-19
Abstract
Abstract A thermostatic actuator for imparting displacement to mechanical linkages and the like, having particular utility aboard spacecraft and characterized by the utilization of a rectilinearly reciprocating, spring-biased output shaft operatively coupled with a stack of superimposed individual bimetal disc members and a selectively operable electric heater including a resistance coil associated therewith adapted to heat the stack for achieving distortion of the individual disc members and an elongation of the stack to cause the output shaft to be axially extended against the bias of the spring and a bimetal latch coupled with the shaft adapted to latch the shaft against axial extension, at a first temperature, and to release the shaft for an extending displacement at elevated temperatures, whereby the actuator is selectively driven by energizing the heater.
Inventors
- 👤 Lloyd J Derr
- 👤 Robert A Tobias
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 00:27
CPC Classifications
B; B64; B64G; B64G1/00; B64G1/22; B64G1/66
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
135 words
A linear actuator including: A. an actuator housing; B. an actuator output shaft supported for rectilinear reciprocation relative to said housing; C. a heat-responsive drive means comprising a stack of superimposed and engaged bimetal members having an axial bore extended therethrough operatively coupled with the output shaft and adapted to respond to given changes in temperature for displacing the shaft in preselected directions; D. a heat-responsive latch coupled with said shaft and adapted to restrain the shaft against displacement at given temperatures and to respond to predetermined changes in temperature for releasing said shaft for linear displacement; and E. selectively operable heat transfer means, including a cylindrical resistance heater coil inserted within said bore, for selectively imparting changes in temperature to said latch and to said drive means for selectively achieving displacement of said shaft.
Claim 2
Dependent Claim
135 words
A linear actuator including: A. an actuator housing; B. an actuator output shaft supported for rectilinear reciprocation relative to said housing; C. a heat-responsive drive means comprising a stack of superimposed and engaged bimetal members having an axial bore extended therethrough operatively coupled with the output shaft and adapted to respond to given changes in temperature for displacing the shaft in preselected directions; D. a heat-responsive latch coupled with said shaft and adapted to restrain the shaft against displacement at given temperatures and to respond to predetermined changes in temperature for releasing said shaft for linear displacement; and E. selectively operable heat transfer means, including a cylindrical resistance heater coil inserted within said bore, for selectively imparting changes in temperature to said latch and to said drive means for selectively achieving displacement of said shaft.
Claim 3
Dependent Claim
89 words
The actuator of claim 1 wherein the latch comprises: A. a U-shaped member formed of a bimetal having a pair of legs spaced at a distance dictated by the temperature of the member and extended along opposite sides of the shaft; and B. means defining a stop surface formed on the housing near the distal ends of the legs in a manner such that the distal end surfaces are caused to engage the stop surface at a first temperature and to disengage the stop surface at a second temperature.
Claim 4
Dependent Claim
162 words
A linear actuator comprising: A. an actuator housing including means defining therein an annulus; B. an actuator output shaft supported for rectilinear, axial displacement within said annulus; C. a thermally responsive actuator stack, including a plurality of superimposed, thermally responsive bimetal plates seated within said housing and adapted to expand and contract as the temperature thereof is varied; D. coupling means operatively coupled with said shaft and with said stack adapted to respond to an expansion of said stack and impart axial displacement to said shaft; and E. a thermally responsive, shaft-restraining latch including a generally U-shaped member formed of a bimetal material having a transverse base and a pair of upstanding legs fixedly coupled with the shaft near one end thereof with the distance between the legs being a function of the temperature thereof for restraining the shaft against displacement at given temperatures and for releasing the shaft for axial displacement through said annulus in response to selected changes in temperature.
Claim 5
Dependent Claim
162 words
A linear actuator comprising: A. an actuator housing including means defining therein an annulus; B. an actuator output shaft supported for rectilinear, axial displacement within said annulus; C. a thermally responsive actuator stack, including a plurality of superimposed, thermally responsive bimetal plates seated within said housing and adapted to expand and contract as the temperature thereof is varied; D. coupling means operatively coupled with said shaft and with said stack adapted to respond to an expansion of said stack and impart axial displacement to said shaft; and E. a thermally responsive, shaft-restraining latch including a generally U-shaped member formed of a bimetal material having a transverse base and a pair of upstanding legs fixedly coupled with the shaft near one end thereof with the distance between the legs being a function of the temperature thereof for restraining the shaft against displacement at given temperatures and for releasing the shaft for axial displacement through said annulus in response to selected changes in temperature.
Claim 6
Dependent Claim
103 words
The actuator according to claim 3 wherein the latch further includes: A. means defining a pair of stop surfaces formed internally of said housing being engageable with distal end surfaces of said legs in the presence of predetermined temperature conditions; and B. means defining a pair of spaced openings adjacent said stop surfaces adapted to receive the distal ends of said legs for displacement therethrough in the presence of elevated temperature conditions, whereby the shaft is restrained against axial displacement when the latch is at a first given temperature and released for axial displacement when the latch is at a second given temperature.
Claim 7
Dependent Claim
62 words
The actuator accoRding to claim 4 wherein said coupling means comprises a rigid coupling member secured to said shaft and extending into engagement with the face portion of an adjacent bimetal plate of said stack, whereby as the stack is caused to expand, displacement is imparted to said coupling member for axially displacing said shaft through said bore in a shaft-extending direction.
Claim 8
Dependent Claim
23 words
The actuator according to claim 5 wherein biasing means operatively are coupled with said shaft for continuously urging the shaft in shaft-retracting displacement.
Claim 9
Dependent Claim
32 words
The actuator according to claim 6 further comprising a selectively operable heater coupled with said stack adapted to transfer heat to the bimetal plates and to the U-shaped member at selected rates.
Claim 10
Dependent Claim
40 words
The actuator according to claim 7 wherein the stack further includes means defining an axial bore extending therethrough and the heater includes a cylindrical, electrically energizable resistance coil extended into said bore and adapted to radiate heat at selected rates.
References Cited (Backward Citations)
US2879356A
Cited
US3205675A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-12 | 1975-01-11 | 1975-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-12 | 1979-01-11 | 1979-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-12 | 1983-01-11 | 1983-07-13 | $7700.00 | Window Closed / Lapsed |