US3987880A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wrap around spring clutch
Assignee: Wincor Nixdorf International GmbH
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Filing: 1975-04-23
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Granted: 1976-10-26
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Expires: 1995-04-23
Abstract
Abstract A spring clutch for a step drive, such as for form feeds in office machines, comprising drive and driven hubs rotatable about a common axis and having respective axially adjacent parts surrounded by a coil torsion spring which, in an unstressed condition, has a diameter greater than that of the hub parts, the spring having one end anchored for rotation with the drive hub, and the other end coupled to a clutch actuating member through the intermediary of a slip clutch mechanism having a slip torque which is greater than the torque required to wind the coil torsion spring onto the hub parts.
Inventors
- 👤 Gunter Holland-Letz
- 👤 Hermann Kohlhage
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:21
CPC Classifications
F; F16; F16D; F16D27/00; F16D27/10; F16D27/105; B; B41; B41J; B41J29/00; B41J29/38; F16D41/00; F16D41/20; F16D41/206
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
128 words
A spring clutch for a step drive, such as for form feeds in office machines, comprising drive and driven hubs rotatable about a common axis and having respective axially adjacent parts surrounded by a coil torsion spring which, in an unstressed condition, has a diameter greater than that of the hub parts, the spring having one end anchored for rotation with the drive hub, and the other end coupled to a clutch actuating member through the intermediary of a slip clutch mechanism having a slip torque which is greater than the torque required to wind up the coil torsion spring onto the hub parts said slip clutch mechanism comprising two concentric sleeve elements surrounding the spring which elements are frictionally coupled by a pre-loaded compression spring acting therebetween.
Claim 2
Dependent Claim
128 words
A spring clutch for a step drive, such as for form feeds in office machines, comprising drive and driven hubs rotatable about a common axis and having respective axially adjacent parts surrounded by a coil torsion spring which, in an unstressed condition, has a diameter greater than that of the hub parts, the spring having one end anchored for rotation with the drive hub, and the other end coupled to a clutch actuating member through the intermediary of a slip clutch mechanism having a slip torque which is greater than the torque required to wind up the coil torsion spring onto the hub parts said slip clutch mechanism comprising two concentric sleeve elements surrounding the spring which elements are frictionally coupled by a pre-loaded compression spring acting therebetween.
Claim 3
Dependent Claim
35 words
A spring clutch according to claim 1, wherein one of the sleeve elements is provided with several radially extending recesses, the said other end of the spring being removably located in one of the slots.
Claim 4
Dependent Claim
38 words
A spring clutch according to claim 1 wherein one sleeve element is connected to the said other end of the torsion spring and the other sleeve element has a toothed flange with which the actuating element can cooperate.
Claim 5
Dependent Claim
34 words
A spring clutch according to claim 1, wherein the driven hub carries a stop wheel for rotation therewith, for use in stopping the driven hub in predetermined angular positions when the clutch is disengaged.
Claim 6
Dependent Claim
52 words
A spring clutch according to claim 4, wherein an electromagnetically controlled actuating device is provided, which device has a stop element which is engageable with the stop wheel and an actuating element which moves out of engagement with a toothed flange on one of said sleeve elements when the electromagnet is de-energized.
Claim 7
Dependent Claim
30 words
A spring clutch according to claim 1, wherein the driven hub is provided with a return stop mechanism for preventing rotation of the driven hub when the clutch is disengaged.
Claim 8
Dependent Claim
27 words
A spring clutch according to claim 6, wherein the return stop mechanism includes a coil torsion spring which surrounds the driven hub and is held against rotation.
References Cited (Backward Citations)
US3376963A
Cited
US3425526A
Cited
US3559781A
Cited
US3648810A
Cited
US3797618A
Cited
US3876184A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-10-26 | 1980-04-26 | 1980-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-26 | 1984-04-26 | 1984-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-26 | 1988-04-26 | 1988-10-26 | $7700.00 | Window Closed / Lapsed |