US4079165A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite materials
Assignee: National Research Development Corp UK
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Filing: 1975-07-14
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Granted: 1978-03-14
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Expires: 1995-07-14
Abstract
Abstract A composite article comprising at least two load-bearing members one within the other and having mutually contacting surfaces adapted to generate a restraining force resisting relative axial movement of the members, wherein the members are constructed such that a local reduction in said restraining force takes place as the local tensile stress in the article increases.
Inventors
- 👤 John G. Morley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:27
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/04; B29C70/06; B29C70/08; B29C70/10; E; E04; E04C; E04C5/00; E04C5/01; E04C5/02; E04C5/03; E04C5/07; E04C5/073; E04C5/08; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/131; Y10T428/1314; Y10T428/1352; Y10T428/1355; Y10T428/1372; Y10T428/29; Y10T428/2913; Y10T428/2916; Y10T428/2918; Y10T428/292; Y10T428/2922; Y10T428/2925; Y10T428/2933; Y10T428/2935; Y10T428/2936; Y10T428/294; Y10T428/2964; Y10T428/2967; Y10T428/2969; Y10T428/2973; Y10T428/2975
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
212 words
A composite article comprising an elongated stiff outer member having at least one elongated bore therein and an inner member extending within at least part of said bore, said inner member serving to reinforce said outer member so that both said inner and outer members serve simultaneously to resist a tensile load applied to said composite article in substantially the direction of the longitudinal axis of said outer member, at least part of said inner member engaging the surface of said bore to engender frictional force tending to resist longitudinal movement of at least part of said inner member relative to said outer member, such that the application of a tensile stress to at least part of the article substantially in the direction of the longitudinal axis of said outer member causes a tensile stress to be transmitted to at least part of said inner member, the material of the outer member having an effective Poisson's ratio lower than the effective Poisson's ratio of the inner member, whereby said tensile stress caused in the inner member tends to reduce the resistive frictional force at at least another part of the inner member to zero, thereby permitting relative movement between said outer member to zero and said other part of the inner member.
Claim 2
Dependent Claim
212 words
A composite article comprising an elongated stiff outer member having at least one elongated bore therein and an inner member extending within at least part of said bore, said inner member serving to reinforce said outer member so that both said inner and outer members serve simultaneously to resist a tensile load applied to said composite article in substantially the direction of the longitudinal axis of said outer member, at least part of said inner member engaging the surface of said bore to engender frictional force tending to resist longitudinal movement of at least part of said inner member relative to said outer member, such that the application of a tensile stress to at least part of the article substantially in the direction of the longitudinal axis of said outer member causes a tensile stress to be transmitted to at least part of said inner member, the material of the outer member having an effective Poisson's ratio lower than the effective Poisson's ratio of the inner member, whereby said tensile stress caused in the inner member tends to reduce the resistive frictional force at at least another part of the inner member to zero, thereby permitting relative movement between said outer member to zero and said other part of the inner member.
Claim 3
Dependent Claim
14 words
A composite article according to claim 1 wherein the inner member is a fibre.
Claim 4
Dependent Claim
30 words
A composite article according to claim 1 in the form of a composite reinforcement element wherein the inner member is a fibre and the outer member is a tubular sheath.
Claim 5
Dependent Claim
38 words
A composite article according to claim 1 wherein a local reduction of said resistive force to zero takes place at a local tensile stress in the article just less than the ultimate tensile strength of the inner member.
Claim 6
Dependent Claim
16 words
A composite article according to claim 1 wherein the inner member is formed from stainless steel.
Claim 7
Dependent Claim
22 words
A composite article according to claim 1 wherein the inner member is formed from a polymeric resin having glass fibers embedded therein.
Claim 8
Dependent Claim
21 words
A composite article according to claim 1 wherein said inner member comprises a layer of soft metal surrounding a central core.
Claim 9
Dependent Claim
16 words
A composite article according to claim 1 wherein the outer member is provided with fibre reinforcement.
Claim 10
Dependent Claim
38 words
A composite article according to claim 1 wherein the outer member is formed from a polymerizable material and the inner member is an elongated fibre selected from the group consisting of carbon, boron, glass and high strength steel.
Claim 11
Dependent Claim
41 words
A composite article according to claim 1 wherein the outer member is concrete and the inner member is selected from the group consisting of steel in rod or bar form and bundles of glass or other fibres in a polymeric material.
Claim 12
Dependent Claim
66 words
A composite article according to claim 1 wherein the ultimate tensile strength of the said inner member is just greater than the tensile force required to be applied to a part of said inner member to reduce the frictional force between said inner member part and said outer member sufficiently to permit relative longitudinal movement between that part of said inner member and said outer member.
Claim 13
Dependent Claim
29 words
A composite article according to claim 1 wherein the outer member is formed from a polymerizable material containing particulate fillers to increase the elastic modules of said outer member.
Claim 14
Dependent Claim
15 words
A composite article according to claim 1 wherein the inner member is of convoluted form.
Claim 15
Dependent Claim
19 words
A composite article according to claim 13 wherein spaces at the interfacial region are filled with a viscous medium.
Claim 16
Dependent Claim
20 words
A composite article according to claim 1 wherein the outer member is reinforced to inhibit inward contraction under tensile load.
Claim 17
Dependent Claim
39 words
A composite article according to claim 15 wherein said reinforcement is effected by means of a closely-wound helix of reinforcing fibres, thinner than the inner member, wound round the inner member, and defining said bore in the outer member.
Claim 18
Dependent Claim
20 words
A composite article according to claim 1 wherein the surface of the inner member is treated to reduce surface irregularities.
Claim 19
Dependent Claim
16 words
A composite article according to claim 17 wherein said surface irregularities are reduced by chemical etching.
Claim 20
Dependent Claim
24 words
A composite article according to claim 18 wherein said etching is applied to a precursor textile fibre before pyrolysis to form a carbon fibre.
Claim 21
Dependent Claim
17 words
A composite article according to claim 18 wherein said etching is effected by oxidation at elevated temperature.
Claim 22
Dependent Claim
22 words
A composite article according to claim 17 wherein said surface irregularities are reduced by depositing a physical interlayer on the inner member.
Claim 23
Dependent Claim
15 words
A composite article according to claim 21 wherein said interlayer acts as a dry lubricant.
Claim 24
Dependent Claim
13 words
A composite article according to claim 22 wherein said interlayer comprises pyrolytic graphite.
Claim 25
Dependent Claim
16 words
A composite article according to claim 23 wherein said interlayer is applied by gas phase deposition.
Claim 26
Dependent Claim
26 words
A composite article according to claim 23 wherein said interlayer is applied by pyrolytic conversion of a polymer film deposited on a carbon substrate inner member.
Claim 27
Dependent Claim
170 words
A composite article comprising an elongated outer member which is substantially inelastic, said outer member having at least one longitudinal bore therein, and an elongated inner member within said bore, said inner member being substantially inelastic, so that both said inner and outer members serve to simultaneously resist a tensile load applied to the composite article in a longitudinal direction, said inner member engaging the surface of said bore to engender a frictional force tending to resist relative longitudinal movement between said outer and inner members, and the material of said outer member defining said bore having an effective Poisson's Ratio lower than the effective Poisson's Ratio of said inner member, whereby application to the composite article of a longitudinal tensile load above some minimum value causes a reduction in the frictional force between a part of said inner member and said outer member, and increasing values of such longitudinal tensile load cause progressive reduction of the frictional force between successive parts of said inner member and said outer member.
Claim 28
Dependent Claim
170 words
A composite article comprising an elongated outer member which is substantially inelastic, said outer member having at least one longitudinal bore therein, and an elongated inner member within said bore, said inner member being substantially inelastic, so that both said inner and outer members serve to simultaneously resist a tensile load applied to the composite article in a longitudinal direction, said inner member engaging the surface of said bore to engender a frictional force tending to resist relative longitudinal movement between said outer and inner members, and the material of said outer member defining said bore having an effective Poisson's Ratio lower than the effective Poisson's Ratio of said inner member, whereby application to the composite article of a longitudinal tensile load above some minimum value causes a reduction in the frictional force between a part of said inner member and said outer member, and increasing values of such longitudinal tensile load cause progressive reduction of the frictional force between successive parts of said inner member and said outer member.
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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) | 1981-03-13 | 1981-09-12 | 1982-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-13 | 1985-09-12 | 1986-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-13 | 1989-09-12 | 1990-03-14 | $7700.00 | Window Closed / Lapsed |