Patent US4307756A successfully refreshed from Google Patents.
US4307756A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermally insulated tubing
Assignee: KM Kabelmetal AG
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Filing: 1979-09-27
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Granted: 1981-12-29
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Expires: 1999-09-27
Abstract
Abstract A spacer is coiled about a drawn, seamless copper tube, and a metal foil or metallized paper ribbon is folded around the coiled spacer. A blend for foaming is injected into the unoccupied space between the folded foil or ribbon and the inner tube, to generate a cyanurate-modified polyurethane foam network in which phosphorous or halogen molecules are embedded by chemical bond. A flame-resistant ribbon is folded about the metal tube. The resulting product and further details of the process are described.
Inventors
- 👤 Hermann-Uwe Voigt
- 👤 Horst Matzat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:03
CPC Classifications
F; F16; F16L; F16L59/00; F16L59/14; F16L59/145; B; B29; B29C; B29C44/00; B29C44/20; B29C44/32; B29C44/322; B29C44/324; F16L59/04; F16L59/143; Y; Y10; Y10S; Y10S138/00; Y10S138/09; Y10S428/00; Y10S428/92; Y10S428/921; Y10T; Y10T428/00; Y10T428/13; Y10T428/1303; Y10T428/1352; Y10T428/1355; Y10T428/1359
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
151 words
Thermally insulated tube for installation in buildings, or the like, comprising: a metal inner tube; a metal foil or ribbon of at least 0.05 mm thickness, having been formed into an outer tube and disposed coaxially about the said inner tube and having overlapping interconnected edges; spacer means on the inner tube and supporting the outer tube, there being space left between the inner and outer tubes not occupied by the spacer means; a foam in said space being comprised of an isocyanurate-modified polyurethane network which includes urethane groups and primarily isocyanurate units, resulting from and being the reaction product of an aromatic polyisocyanate, and of a polyether polyol in chemical bond with molecules of a flame-resisting substance, in the presence of a catalyst blend which includes a trimerizing catalyst for the isocyanurate reaction; and a synthetic flame-resisting envelope on the metal foil tube, in intimate contact but without interconnection therewith.
Claim 2
Dependent Claim
151 words
Thermally insulated tube for installation in buildings, or the like, comprising: a metal inner tube; a metal foil or ribbon of at least 0.05 mm thickness, having been formed into an outer tube and disposed coaxially about the said inner tube and having overlapping interconnected edges; spacer means on the inner tube and supporting the outer tube, there being space left between the inner and outer tubes not occupied by the spacer means; a foam in said space being comprised of an isocyanurate-modified polyurethane network which includes urethane groups and primarily isocyanurate units, resulting from and being the reaction product of an aromatic polyisocyanate, and of a polyether polyol in chemical bond with molecules of a flame-resisting substance, in the presence of a catalyst blend which includes a trimerizing catalyst for the isocyanurate reaction; and a synthetic flame-resisting envelope on the metal foil tube, in intimate contact but without interconnection therewith.
Claim 3
Dependent Claim
16 words
Tube as in claim 1, said modified polyether polyol being a halogenized or phosphorylated polyether polyol.
Claim 4
Dependent Claim
15 words
Tube as in claim 1, said metal foil having a thickness not exceeding 0.5 mm.
Claim 5
Dependent Claim
17 words
Tube as in claim 3, said metal foil having a thickness between 0.1 mm and 0.2 mm.
Claim 6
Dependent Claim
17 words
Tube as in claim 1, said foil being established by an aluminum coating on a paper backing.
Claim 7
Dependent Claim
19 words
Tube as in claim 1 or 2, said envelope being a longitudinally folded ribbon with overlapping and interconnected edges.
Claim 8
Dependent Claim
15 words
Tube as in claim 6, said synthetic envelope being a rigid polyvinylchloride treated with antimony.
Claim 9
Dependent Claim
22 words
Tube as in claim 1, said envelope being made of polyvinylchloride to which antimony trioxide or a phosporous compound has been added.
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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) | 1984-12-28 | 1985-06-29 | 1985-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-28 | 1989-06-29 | 1989-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-28 | 1993-06-29 | 1993-12-29 | $7700.00 | Window Closed / Lapsed |