US3902334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant torque clutch
Assignee: Compensating Tension Controls Inc
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Filing: 1974-02-13
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Granted: 1975-09-02
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Expires: 1994-02-13
Abstract
Abstract The device comprises first and second clutch members rotatably mounted on a shaft to transmit torque therebetween. A spring washer urges the second member against the first member. A plate keyed to the shaft engages the spring washer and is moveable along the shaft to change the loading on the spring washer. A torsion spring is connected between the second clutch member and the plate to transmit torque to the shaft. The second clutch member rotates with respect to the shaft until the load on the torsion spring equals the frictional force between the clutch members. A camming arrangement between the spring washer and the second clutch member changes the loading on the washer in response to changes in the relative rotational position of the second clutch member to compensate for changes in the coefficient of friction between the clutch members. An annular nut rotatably mounted on the plate and an annular screw rotatably mounted on the shaft adjust the location of the plate to adjust the torque transmitted by the device.
Inventors
- 👤 Ralph L Ryan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:13
CPC Classifications
F; F16; F16D; F16D7/00; F16D7/02; F16D7/024; F16D7/025; F16D2300/00; F16D2300/02; F16D2300/021; F16D2300/0212; F16D2300/20; Y; Y10; Y10T; Y10T403/00; Y10T403/32; Y10T403/32008; Y10T403/32057
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
260 words
A device for transmitting a constant torque comprising a shaft, first and second clutch members rotatably mounted on said shaft, friction surfaces on said clutch members for interengagement to transmit a torque between said members which varies with the force normal to said surfaces pressing the surfaces together, resilient means for urging said second clutch member against said first clutch member, a torque altering member mounted to rotate with said shaft and to be movable axially with respect to said shaft to change the loading upon said resilient means, a torsion spring connected between said second clutch member and said altering member to transmit torque to said shaft, said second clutch member assuming a rotational position with respect to said shaft such that the loading on said torsion spring equals the frictional force between said surfaces, friction compensating means responsive to the relative position of said second clutch member with respect to said shaft for changing the loading on said resilient means to compensate for changes in the friction between said surfaces and maintain the transmitted torque constant, and adjusting means for moving said altering means axially with respect to said shaft for changing the torque transmitted by the device, said adjusting means including a screw member and a nut member threaded to said screw member, one of said adjusting members being locked against axial movement with respect to said shaft and the other of said adjusting members being locked against axial movement with respect to said torque altering member, both of said adjusting members being mounted for free rotation.
Claim 2
Independent Claim
260 words
A device for transmitting a constant torque comprising a shaft, first and second clutch members rotatably mounted on said shaft, friction surfaces on said clutch members for interengagement to transmit a torque between said members which varies with the force normal to said surfaces pressing the surfaces together, resilient means for urging said second clutch member against said first clutch member, a torque altering member mounted to rotate with said shaft and to be movable axially with respect to said shaft to change the loading upon said resilient means, a torsion spring connected between said second clutch member and said altering member to transmit torque to said shaft, said second clutch member assuming a rotational position with respect to said shaft such that the loading on said torsion spring equals the frictional force between said surfaces, friction compensating means responsive to the relative position of said second clutch member with respect to said shaft for changing the loading on said resilient means to compensate for changes in the friction between said surfaces and maintain the transmitted torque constant, and adjusting means for moving said altering means axially with respect to said shaft for changing the torque transmitted by the device, said adjusting means including a screw member and a nut member threaded to said screw member, one of said adjusting members being locked against axial movement with respect to said shaft and the other of said adjusting members being locked against axial movement with respect to said torque altering member, both of said adjusting members being mounted for free rotation.
Claim 3
Dependent Claim
17 words
A device according to claim 1 wherein both said adjusting members are annular and surround said shaft.
Claim 4
Dependent Claim
25 words
A device according to claim 2, wherein said screw member is mounted on said shaft and said nut member is mounted on said altering member.
Claim 5
Dependent Claim
51 words
A device according to claim 1, wherein said friction compensating means includes cam means having a first element mounted for rotation with said second clutch member and a second element mounted to rotate with said shaft, one of said elements being mounted to be moveable axially with respect to said shaft.
Claim 6
Dependent Claim
31 words
A device according to claim 4, wherein said first element is locked to said second clutch member and said second element is mounted on said shaft to be moveable axially therewith.
Claim 7
Dependent Claim
15 words
A device according to claim 5 wherein said altering member is keyed to said shaft.
Claim 8
Dependent Claim
20 words
A device according to claim 6, wherein said resilient means is positioned between said altering member and said second element.
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) | 1978-09-01 | 1979-03-03 | 1979-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-01 | 1983-03-03 | 1983-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-01 | 1987-03-03 | 1987-09-02 | $7700.00 | Window Closed / Lapsed |