US5006670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric power cable
Assignee: Phillips Cables Ltd
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Filing: 1989-11-20
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Granted: 1991-04-09
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Expires: 2009-11-20
Abstract
Abstract In a single core or multi-core electric power cable, the dielectric screen of the or each cable core is surrounded by a moisture barrier consisting of a composite tape comprising a carrier layer of plastics material which is sandwiched between radially inner and outer metal foils bonded to the major surfaces of the carrier layer and electrically connected together. The composite tape surrounds the dielectric screen with its longitudinally extending edges overlapping and secured to one another throughout their lengths to form a moisture-tight seal. The moisture barrier so formed effects electrical interconnection between the underlying dielectric screen and a surrounding neutral, earth or ground conductor of the core. The moisture barrier is less expensive than moisture barriers hitherto proposed and used.
Inventors
- 👤 Neil R. Plant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:12
CPC Classifications
B; B32; B32B; B32B15/00; B32B15/04; B32B15/08; B32B27/00; B32B27/32; B32B5/00; B32B5/02; B32B5/06; B32B7/00; B32B7/04; B32B7/12; H; H01; H01B; H01B7/00; H01B7/17; H01B7/28; H01B7/282; H01B7/2825; B32B2307/00; B32B2307/70; B32B2307/724; B32B2307/7242; B32B2311/00; B32B2311/12; B32B2311/24; B32B2323/00; B32B2323/04; B32B2323/10; B32B2367/00; Y; Y02; Y02A; Y02A30/00; Y02A30/14
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
161 words
An electric power cable comprising at least one cable core consisting of an electric conductor, a conductor screen surrounding the conductor, a dielectric wall of electrically insulating material surrounding the conductor screen, a dielectric screen surrounding the dielectric wall, a moisture-barrier surrounding the dielectric screen and, surrounding the moisture-barrier, a layer of metal or metal alloy, wherein the moisture-barrier of said at least one cable core consists of a composite tape comprising a carrier layer of plastics material which is sandwiched between radially inner and outer substantially fluid-impermeable foils of metal or metal alloy mechanically bonded to major surfaces of the carrier layer and electrically connected together, which composite tape surrounds the dielectric screen of the core with its longitudinally extending edges overlapping and secured to one another throughout their lengths to form a substantially moisture-tight seal between said overlapping edges, the moisture-barrier thereby effecting electrical interconnection between the underlying dielectric screen and the surrounding layer of metal or metal alloy.
Claim 2
Dependent Claim
161 words
An electric power cable comprising at least one cable core consisting of an electric conductor, a conductor screen surrounding the conductor, a dielectric wall of electrically insulating material surrounding the conductor screen, a dielectric screen surrounding the dielectric wall, a moisture-barrier surrounding the dielectric screen and, surrounding the moisture-barrier, a layer of metal or metal alloy, wherein the moisture-barrier of said at least one cable core consists of a composite tape comprising a carrier layer of plastics material which is sandwiched between radially inner and outer substantially fluid-impermeable foils of metal or metal alloy mechanically bonded to major surfaces of the carrier layer and electrically connected together, which composite tape surrounds the dielectric screen of the core with its longitudinally extending edges overlapping and secured to one another throughout their lengths to form a substantially moisture-tight seal between said overlapping edges, the moisture-barrier thereby effecting electrical interconnection between the underlying dielectric screen and the surrounding layer of metal or metal alloy.
Claim 3
Dependent Claim
97 words
An electric power cable as claimed in claim 1, wherein a longitudinally extending marginal portion of the composite tape of the moisture barrier is folded along two longitudinally extending, transversely spaced lines which define first and second portions of said marginal portion so that said first portion of said marginal portion of the composite tape including one of said longitudinally extending edges of said composite tape is sandwiched between said second portion of the marginal portion and a main portion of the composite tape, the two metal foils of the composite tape thereby being directly electrically connected.
Claim 4
Dependent Claim
28 words
An electric power cable as claimed in claim 1, wherein the overlapping edges of the composite tape are sealed together throughout their lengths by a hot melt adhesive.
Claim 5
Dependent Claim
26 words
An electric power cable as claimed in claim 1, wherein said longitudinally extending edges of said composite tape are secured to one another by adhesive tape.
Claim 6
Dependent Claim
45 words
An electric power cable as claimed in claim 1, wherein electrical connection between the metal foils of the composite tape of the moisture barrier is effected by using for the carrier layer a plastics material which is sufficiently semi-conductive to electrically interconnect the metal foils.
Claim 7
Dependent Claim
24 words
An electric power cable as claimed in claim 1, wherein the composite tape extends lengthwise along and is transversely folded around the dielectric screen.
Claim 8
Dependent Claim
36 words
An electric power cable is claimed in claim 1, wherein each metal foil of the composite tape is mechanically bonded to a major surface of the carrier layer by a substantially continuous layer of hot-melt adhesive.
Claim 9
Dependent Claim
23 words
An electric power cable as claimed in claim 1, wherein the plastics material of the carrier layer of the composite tape comprises polyethylene.
Claim 10
Dependent Claim
23 words
An electric power cable as claimed in claim 1, wherein each metal foil of the composite tape of the moisture barrier comprises aluminium.
Claim 11
Dependent Claim
30 words
An electric power cable as claimed in claim 1, wherein the composite tape has an overall thickness lying in the range of 1.5 to 5 mils (0.038 to 0.127 mm).
Claim 12
Dependent Claim
45 words
An electric power cable as claimed in claim 10, wherein each foil of the composite tape comprises aluminium and has a thickness of approximately 0.35 mils (0.009 mm) and the carrier layer of the composite tape has a thickness of approximately 2 mils (0.051 mm).
Claim 13
Dependent Claim
51 words
An electric power cable as claimed in claim 1 which has a single core, wherein an electrically conductive bedding layer is sandwiched between the moisture barrier and the surrounding layer of metal or metal alloy and wherein the layer of metal or metal alloy is a layer of helically wound wires.
Claim 14
Dependent Claim
40 words
An electric power cable as claimed in claim 1 which has at least two cable cores, wherein the layer of metal or metal alloy of each cable core comprises a layer of helically applied tape of metal or metal alloy.
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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) | 1994-04-08 | 1994-10-08 | 1995-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-08 | 1998-10-08 | 1999-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-08 | 2002-10-08 | 2003-04-09 | $7700.00 | Window Closed / Lapsed |