US4765602A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite coil spring
Assignee: Boeing Co
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Filing: 1982-12-22
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Granted: 1988-08-23
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Expires: 2002-12-22
Abstract
Abstract A helical torsion spring (10) composed of unidirectional graphite fibers (26) encased in an epoxy resin matrix of rectangular cross section. The graphite fibers are longitudinally oriented relative to the core of the coil spring and can be located adjacent the inner and outer surfaces of each of the coils.
Inventors
- 👤 William G. Roeseler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:38
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/04; B29C70/06; B29C70/10; B29C70/16; B29C70/20; B29C70/205; B29C70/08; B29C70/083; B29C70/085; F; F16; F16F; F16F1/00; F16F1/36; F16F1/366; F16F1/3665; B29K; B29K2063/00; B29K2277/00; B29K2307/00; B29K2309/00; B29K2309/08; B29L; B29L2031/00; B29L2031/774; B29L2031/7742
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
130 words
A helical torsion spring comprising: a plurality of coils having a first end and a second end, said coils having an inner surface and an outer surface; and, a continuous core extending through said coils, said core being composed of a synthetic resin and unidirectional fibers oriented longitudinally relative to said core, said fibers being located adjacent said inner surface and said outer surface of said coils and in the central portion of said core, said fibers located adjacent said outer surface having a high tensile strength and being spaced radially outward from said fibers located adjacent said inner surface which have a high compressive strength, said fibers located adjacent said outer surface being aramid fibers, and said fibers located in the central portion of said core being aramid fibers.
Claim 2
Dependent Claim
130 words
A helical torsion spring comprising: a plurality of coils having a first end and a second end, said coils having an inner surface and an outer surface; and, a continuous core extending through said coils, said core being composed of a synthetic resin and unidirectional fibers oriented longitudinally relative to said core, said fibers being located adjacent said inner surface and said outer surface of said coils and in the central portion of said core, said fibers located adjacent said outer surface having a high tensile strength and being spaced radially outward from said fibers located adjacent said inner surface which have a high compressive strength, said fibers located adjacent said outer surface being aramid fibers, and said fibers located in the central portion of said core being aramid fibers.
Claim 3
Dependent Claim
14 words
The spring of claim 1 wherein said core has a generally rectangular cross section.
Claim 4
Dependent Claim
24 words
The spring of claim 1 further comprising: reinforcing fibers transversely disposed in said core at least adjacent said inner and said outer surface portions.
Claim 5
Dependent Claim
12 words
The spring of claim 1 wherein said resin comprises an epoxy resin.
Claim 6
Dependent Claim
18 words
The spring of claim 1 further comprising: reinforcing fibers transversely disposed in the central portion of said core.
Claim 7
Dependent Claim
13 words
The spring of claim 1 further comprising an antifriction coating surrounding said core.
Claim 8
Dependent Claim
14 words
The spring of claim 6 wherein said coating comprises a fluorinated ethylene polymer film.
Claim 9
Dependent Claim
13 words
The spring of claim 1 further comprising a fiberglass sheath surrounding said core.
Claim 10
Dependent Claim
14 words
The spring of claim 8 further comprising an antifriction coating surrounding said fiberglass sheath.
Claim 11
Dependent Claim
26 words
The spring of claim 1 further comprising an increased radius forming a portion of and integral with said core adjacent both said first and second ends.
Claim 12
Dependent Claim
15 words
The spring of claim 1 wherein the fibers adjacent said inner surface are graphite fibers.
Claim 13
Dependent Claim
131 words
A helical torsion spring comprising: a plurality of coils having a first end and a second end, said coils having an inner surface and an outer surface; and, a continuous core extending through said coils, said core being composed of a synthetic resin and unidirectional fibers oriented longitudinally relative to said core, said fibers being located adjacent said inner surface and said outer surface of said coils and in the central portion of said core, said fibers located adjacent said outer surface having a high tensile strength and being spaced radially outward from said fibers located adjacent said inner surface which have a high compressive strength, said fibers adjacent said inner and outer surfaces being graphite fibers, and said fibers located in the central portion of said core being aramid fibers.
Claim 14
Dependent Claim
131 words
A helical torsion spring comprising: a plurality of coils having a first end and a second end, said coils having an inner surface and an outer surface; and, a continuous core extending through said coils, said core being composed of a synthetic resin and unidirectional fibers oriented longitudinally relative to said core, said fibers being located adjacent said inner surface and said outer surface of said coils and in the central portion of said core, said fibers located adjacent said outer surface having a high tensile strength and being spaced radially outward from said fibers located adjacent said inner surface which have a high compressive strength, said fibers adjacent said inner and outer surfaces being graphite fibers, and said fibers located in the central portion of said core being aramid fibers.
Claim 15
Dependent Claim
24 words
The spring of claim 12 further comprising: reinforcing fibers transversely disposed in said core at least adjacent said inner and said outer surface portions.
Claim 16
Dependent Claim
14 words
The spring of claim 12 wherein said core has a generally rectangular cross section.
Claim 17
Dependent Claim
12 words
The spring of claim 12 wherein said resin comprises an epoxy resin.
Claim 18
Dependent Claim
18 words
The spring of claim 12 further comprising: reinforcing fibers transversely disposed in the central portion of said core.
Claim 19
Dependent Claim
13 words
The spring of claim 12 further comprising an antifriction coating surrounding said core.
Claim 20
Dependent Claim
14 words
The spring of claim 17 wherein said coating comprises a fluorinated ethylene polymer film.
Claim 21
Dependent Claim
13 words
The spring of claim 12 further comprising a fiberglass sheath surrounding said core.
Claim 22
Dependent Claim
14 words
The spring of claim 19 further comprising an antifriction coating surrounding said fiberglass sheath.
Claim 23
Dependent Claim
26 words
The spring of claim 12 further comprising an increased radius forming a portion of and integral with said core adjacent both said first and second ends.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-23 | 1992-02-22 | 1992-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-23 | 1996-02-22 | 1996-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-23 | 2000-02-22 | 2000-08-23 | $7700.00 | Window Closed / Lapsed |