US3720107A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature responsive actuation
Assignee: Westinghouse Electric Corp
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Filing: 1971-08-02
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Granted: 1973-03-13
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Expires: 1991-08-02
Abstract
Abstract There is disclosed an actuator having a shaft which, responsive to temperature changes, is rotated by bi-metallic coiled members. The members are tightly coiled so that each produces a high spring torque. One member is coiled with the lower-thermalcoefficient-of-expansion layer radially inward and the higher coefficient-of-expansion layer radially outwardly; the other member is coiled with the higher thermal coefficient-of-expansion layer radially inward and the lower coefficient-of-expansion layer radially outward. The inner ends of the members are connected to the shaft and the outer ends to a fixed support; the members being positioned about the shaft with their coils wound oppositely so that the spring torques of the members counteract at any temperature but the torques produced by change in temperature act cumulatively.
Inventors
- 👤 B Shepard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:56
CPC Classifications
G; G01; G01K; G01K5/00; G01K5/48; G01K5/56; G01K5/62; G01K5/64; G01K5/68
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
201 words
A small-volume high-gain thermally responsive mechanical actuator including a supporting structure, a shaft rotatable relative to said supporting structure, a first coiled bi-metallic member having a fixed end connected to said supporting structure and a movable end in rotating engagement with said shaft, said member including a first strip having a lower thermal coefficient of expansion radially outward with respect to said shaft and a second strip of higher thermal coefficient of expansion radially inward with respect to said shaft, a second coiled bi-metallic member having a fixed end connected to said supporting structure and a movable end connected in rotating engagement with said shaft, said second member including a first strip of higher thermal coefficient of expansion radially outward with respect to said shaft and a second strip of lower thermal coefficient of expansion radially inward with respect to said shaft, one of said members being wound clockwise as viewed from one direction along said shaft and the other of said members being wound counterclockwise as viewed from said direction along only said shaft, said shaft being freely rotatable responsive to the sum of the torques exerted by said first and second members when the temperature of said strips changes.
Claim 2
Dependent Claim
201 words
A small-volume high-gain thermally responsive mechanical actuator including a supporting structure, a shaft rotatable relative to said supporting structure, a first coiled bi-metallic member having a fixed end connected to said supporting structure and a movable end in rotating engagement with said shaft, said member including a first strip having a lower thermal coefficient of expansion radially outward with respect to said shaft and a second strip of higher thermal coefficient of expansion radially inward with respect to said shaft, a second coiled bi-metallic member having a fixed end connected to said supporting structure and a movable end connected in rotating engagement with said shaft, said second member including a first strip of higher thermal coefficient of expansion radially outward with respect to said shaft and a second strip of lower thermal coefficient of expansion radially inward with respect to said shaft, one of said members being wound clockwise as viewed from one direction along said shaft and the other of said members being wound counterclockwise as viewed from said direction along only said shaft, said shaft being freely rotatable responsive to the sum of the torques exerted by said first and second members when the temperature of said strips changes.
Claim 3
Dependent Claim
201 words
A small-volume high-gain thermally responsive mechanical actuator including a supporting structure, a shaft rotatable relative to said supporting structure, a first coiled bi-metallic member having a fixed end connected to said supporting structure and a movable end in rotating engagement with said shaft, said member including a first strip having a lower thermal coefficient of expansion radially outward with respect to said shaft and a second strip of higher thermal coefficient of expansion radially inward with respect to said shaft, a second coiled bi-metallic member having a fixed end connected to said supporting structure and a movable end connected in rotating engagement with said shaft, said second member including a first strip of higher thermal coefficient of expansion radially outward with respect to said shaft and a second strip of lower thermal coefficient of expansion radially inward with respect to said shaft, one of said members being wound clockwise as viewed from one direction along said shaft and the other of said members being wound counterclockwise as viewed from said direction along only said shaft, said shaft being freely rotatable responsive to the sum of the torques exerted by said first and second members when the temperature of said strips changes.
Claim 4
Dependent Claim
201 words
A small-volume high-gain thermally responsive mechanical actuator including a supporting structure, a shaft rotatable relative to said supporting structure, a first coiled bi-metallic member having a fixed end connected to said supporting structure and a movable end in rotating engagement with said shaft, said member including a first strip having a lower thermal coefficient of expansion radially outward with respect to said shaft and a second strip of higher thermal coefficient of expansion radially inward with respect to said shaft, a second coiled bi-metallic member having a fixed end connected to said supporting structure and a movable end connected in rotating engagement with said shaft, said second member including a first strip of higher thermal coefficient of expansion radially outward with respect to said shaft and a second strip of lower thermal coefficient of expansion radially inward with respect to said shaft, one of said members being wound clockwise as viewed from one direction along said shaft and the other of said members being wound counterclockwise as viewed from said direction along only said shaft, said shaft being freely rotatable responsive to the sum of the torques exerted by said first and second members when the temperature of said strips changes.
Claim 5
Dependent Claim
46 words
The actuator of claim 1 wherein each member is wound into a tight coiled spring configuration, the spring of each member exerting a torque and exerted by the spring of one member counteracting the torque exerted by the spring of the other member at any temperature.
Claim 6
Dependent Claim
39 words
The actuator of claim 1 including means for maintaining the first and second members at a common temperature the shaft being rotatable in dependence upon the sum of the torques exerted by both members when the common temperature changes.
Claim 7
Dependent Claim
28 words
the actuator of claim 1 wherein the turns of the coiled members have low-friction surfaces so that friction between contiguous turns that may be in contact is minimized.
Claim 8
Dependent Claim
14 words
The actuator of claim 1 including means for restraining the members from bulging axially.
Claim 9
Dependent Claim
185 words
Apparatus responsive to the temperature of a region, including a supporting structure contiguous to said region, a shaft rotatable with respect to said supporting structure, first and second coiled bi-metallic members, both maintained at said temperature of said region, each said member having a fixed end connected to said supporting structure and a movable end connected in rotating engagement with said shaft, said first member including a first strip of lower thermal coefficient of expansion radially outward with respect to said shaft and a second strip of higher thermal coefficient of expansion radially inward with respect to said shaft, said second member having a first strip of higher thermal coefficient of expansion radially outward with respect to said shaft and a second strip of lower thermal coefficient of expansion radially inward with respect to said shaft, one of said members being coiled clockwise as viewed from one direction along said shaft and the other member being coiled counterclockwise as viewed from said direction, said shaft being freely rotatable by the sum of the torques exerted by said first and second members where said temperature changes.
Claim 10
Dependent Claim
185 words
Apparatus responsive to the temperature of a region, including a supporting structure contiguous to said region, a shaft rotatable with respect to said supporting structure, first and second coiled bi-metallic members, both maintained at said temperature of said region, each said member having a fixed end connected to said supporting structure and a movable end connected in rotating engagement with said shaft, said first member including a first strip of lower thermal coefficient of expansion radially outward with respect to said shaft and a second strip of higher thermal coefficient of expansion radially inward with respect to said shaft, said second member having a first strip of higher thermal coefficient of expansion radially outward with respect to said shaft and a second strip of lower thermal coefficient of expansion radially inward with respect to said shaft, one of said members being coiled clockwise as viewed from one direction along said shaft and the other member being coiled counterclockwise as viewed from said direction, said shaft being freely rotatable by the sum of the torques exerted by said first and second members where said temperature changes.
Claim 11
Independent Claim
229 words
The method of actuating a mechanism in dependence upon temperature by means of first and second coaxial coiled bi-metallic members, one of said members having a first strip of lower thermal coefficient of expansion radially inward and a second strip of higher thermal coefficient radially outward with respect to the axis and the other member having a strip of higher thermal coefficient of expansion radially inward and a second strip of lower thermal coefficient radially outward with respect to the axis, the said method comprising connecting one of said members to said mechanism so that from a given viewpoint it is coiled clockwise and exerts a spring torque tending to rotate said mechanism in one direction and responsive to a change in temperature of a given polarity exerts a torque rotating said mechanism in said one direction, connecting said other of said members to said mechanism so that from said viewpoint it is wound counterclockwise and exerts a spring torque counteracting the spring torque of said one member and responsive to said change of temperature of said given polarity exerts a torque rotating said mechanism in said one direction, and maintaining both said members at a common temperature whereby for any change in temperature said mechanism is caused to be rotated by the sum of the torques exerted by said members as a result of the change in temperature.
Claim 12
Independent Claim
229 words
The method of actuating a mechanism in dependence upon temperature by means of first and second coaxial coiled bi-metallic members, one of said members having a first strip of lower thermal coefficient of expansion radially inward and a second strip of higher thermal coefficient radially outward with respect to the axis and the other member having a strip of higher thermal coefficient of expansion radially inward and a second strip of lower thermal coefficient radially outward with respect to the axis, the said method comprising connecting one of said members to said mechanism so that from a given viewpoint it is coiled clockwise and exerts a spring torque tending to rotate said mechanism in one direction and responsive to a change in temperature of a given polarity exerts a torque rotating said mechanism in said one direction, connecting said other of said members to said mechanism so that from said viewpoint it is wound counterclockwise and exerts a spring torque counteracting the spring torque of said one member and responsive to said change of temperature of said given polarity exerts a torque rotating said mechanism in said one direction, and maintaining both said members at a common temperature whereby for any change in temperature said mechanism is caused to be rotated by the sum of the torques exerted by said members as a result of the change in temperature.
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) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |