US3788631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spiral springs and methods of making them
Assignee: Tensator Ltd
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Filing: 1972-06-16
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Granted: 1974-01-29
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Expires: 1992-06-16
Abstract
Abstract A method of making a spiral spring from a strip of spring material comprises the steps of forming an end portion of the strip of spring material so that the end portion is set to form a spiral coil and the remainder of the strip is substantially straight or is set to coil spirally around the said coiled end portion with a radius of curvature substantially greater than that of the coiled end portion, and then backwinding at least the said coiled end portion.
Inventors
- 👤 D Aldous
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:14
CPC Classifications
F; F16; F16F; F16F1/00; F16F1/02; F16F1/04; F16F1/10; B; B21; B21D; B21D11/00; B21D11/06; B21F; B21F3/00; B21F3/08; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49609
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
75 words
A method of making a spiral spring from a strip of spring material comprising the steps of forming an end portion only of the strip of spring material so that the end portion is set to form a close wound spiral coil, and then winding the whole length of the strip in a direction whereby the previously set end portion is backwound and the remainder of the strip is wound around the backwound end portion.
Claim 2
Independent Claim
75 words
A method of making a spiral spring from a strip of spring material comprising the steps of forming an end portion only of the strip of spring material so that the end portion is set to form a close wound spiral coil, and then winding the whole length of the strip in a direction whereby the previously set end portion is backwound and the remainder of the strip is wound around the backwound end portion.
Claim 3
Dependent Claim
60 words
A method as claimed in claim 1 in which the backwinding of said coiled end portion is carried out so that the spring material is stressed beyond its elastic limit so as to be permanently deformed whereby at least some of the coils take up a curvature in the reverse direction to that in which the coils were initially set.
Claim 4
Dependent Claim
26 words
A method as claimed in claim 1 in which the said end portion of the strip comprises less than half the total length of the strip.
Claim 5
Dependent Claim
23 words
A method as claimed in claim 5 in which the said end portion of the strip comprises one quarter of the total length.
Claim 6
Dependent Claim
12 words
A spiral spring when made by the method claimed in claim 1.
Claim 7
Dependent Claim
25 words
A spiral spring as claimed in claim 5 arranged in a spiral coil about an arbor, with the said one end attached to the arbor.
Claim 8
Independent Claim
83 words
A method of making a spiral spring from a strip of spring material comprising the steps of forming an end portion only of the strip of spring material so that the end portion is set to form a close wound spiral coil, the remainder of the strip being substantially straight, and then winding the whole length of the strip in a direction whereby the previously set end portion is backwound and the remainder of the strip is wound around the backwound end portion.
Claim 9
Independent Claim
83 words
A method of making a spiral spring from a strip of spring material comprising the steps of forming an end portion only of the strip of spring material so that the end portion is set to form a close wound spiral coil, the remainder of the strip being substantially straight, and then winding the whole length of the strip in a direction whereby the previously set end portion is backwound and the remainder of the strip is wound around the backwound end portion.
Claim 10
Independent Claim
101 words
A method of making a spiral spring from a strip of spring material comprising the steps of forming an end portion only of the strip of spring material so that the end portion is set to form a close wound spiral coil, forming the remainder of the strip so that it is set to coil around said coiled end portion with a radius of curvature substantially greater than that of the coiled end portion, and then backwinding the whole length of the strip, said remainder of the strip still having a radius of curvature substantially greater than said coiled end portion.
Claim 11
Independent Claim
101 words
A method of making a spiral spring from a strip of spring material comprising the steps of forming an end portion only of the strip of spring material so that the end portion is set to form a close wound spiral coil, forming the remainder of the strip so that it is set to coil around said coiled end portion with a radius of curvature substantially greater than that of the coiled end portion, and then backwinding the whole length of the strip, said remainder of the strip still having a radius of curvature substantially greater than said coiled end portion.
Claim 12
Dependent Claim
39 words
A method as claimed in claim 1 in which the step of forming the said coiled end portion before it is backwound acts to impart beneficial residual stresses of a tensile and compressive nature to the said end portion.
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) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |