US5281757A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-layer power cable with metal sheath free to move relative to adjacent layers
Assignee: Pirelli Cable Corp
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Filing: 1992-08-25
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Granted: 1994-01-25
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Expires: 2012-08-25
Abstract
Abstract An electrical power cable with a stranded conductor, a semi-conductive stress control layer around the conductor, a layer of insulation around the stress control layer, a semi-conductive insulation shield layer around the layer of insulation, an imperforate metal strip with overlapping edge portions around the shield layer and a polymeric jacket around the metal strip. The strip is free to move with respect to the jacket and the shield layer with expansion and contraction of the cable elements with temperature changes, and the overlapping edge portions of the strip are bonded together by an adhesive which permits the edge portions to move relative to each other with such temperature changes without creating fluid passageways between the edge portions. A cushioning layer can be between the shield layer and the strip and preferably, the cable is water sealed.
Inventors
- 👤 Carlo Marin
- 👤 Fabrizio Marciano-Agostinelli
- 👤 Paul K. dePratter
- 👤 Frank L. Kuchta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:20
CPC Classifications
H; H01; H01B; H01B7/00; H01B7/17; H01B7/28; H01B7/282; H01B7/18; H01B7/189; H01B7/2813; H01B7/285; H01B7/288; H01B9/00; H01B9/02; H01B9/022
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
221 words
In an electrical power cable operable throughout a predetermined temperature range and comprising a stranded conductor formed by a plurality of wires stranded together and in conductive contact with adjacent wires, a semi-conductive stress control layer around said conductor, a layer of insulation around said stress control layer, a semi-conductive insulation shield layer around said layer of insulation, an imperforate metal shield around said shield layer, said metal shield being formed by a metal strip with overlapping edge portions, and a jacket of polymeric material around said metal shield, wherein the improvement comprises a metal shield which is free to move with respect to said insulation shield layer and said jacket with expansion and contraction of said metal shield, said semi-conductive stress control layer, said insulation, said insulation shield layer and said jacket when said cable is subjected to temperature changes in said predetermined range and an adhesive bonding said overlapping edge portions together, said adhesive permitting said edge portions to move relative to each other without causing a fluid passageway between said edge portions when said cable is subjected to temperature changes in said predetermined range whereby fluid is prevented from passing between said overlapping edge portions and buckling and fractures of said metal shield is prevented even though said cable is subjected to repeated temperature changes within said range.
Claim 2
Dependent Claim
221 words
In an electrical power cable operable throughout a predetermined temperature range and comprising a stranded conductor formed by a plurality of wires stranded together and in conductive contact with adjacent wires, a semi-conductive stress control layer around said conductor, a layer of insulation around said stress control layer, a semi-conductive insulation shield layer around said layer of insulation, an imperforate metal shield around said shield layer, said metal shield being formed by a metal strip with overlapping edge portions, and a jacket of polymeric material around said metal shield, wherein the improvement comprises a metal shield which is free to move with respect to said insulation shield layer and said jacket with expansion and contraction of said metal shield, said semi-conductive stress control layer, said insulation, said insulation shield layer and said jacket when said cable is subjected to temperature changes in said predetermined range and an adhesive bonding said overlapping edge portions together, said adhesive permitting said edge portions to move relative to each other without causing a fluid passageway between said edge portions when said cable is subjected to temperature changes in said predetermined range whereby fluid is prevented from passing between said overlapping edge portions and buckling and fractures of said metal shield is prevented even though said cable is subjected to repeated temperature changes within said range.
Claim 3
Dependent Claim
45 words
An electrical power cable as set forth in claim 1 wherein said metal shield is free of a bond with said jacket, whereby said jacket may be readily stripped from around said metal shield, and is free of a bond with said insulation shield layer.
Claim 4
Dependent Claim
44 words
An electrical power cable as set forth in claim 2 wherein said adhesive is a hot melt adhesive which has a predetermined softening temperature and an application temperature higher than said predetermined softening temperature and higher than the highest temperature in said predetermined range.
Claim 5
Dependent Claim
30 words
An electrical power cable as set forth in claim 1 wherein said metal strip is bare and is selected from the group of metals consisting of copper, aluminum and steel.
Claim 6
Dependent Claim
44 words
An electrical power cable as set forth in claim 4 wherein said adhesive is a hot melt adhesive which has a predetermined softening temperature and an application temperature higher than said predetermined softening temperature and higher than the highest temperature in said predetermined range.
Claim 7
Dependent Claim
51 words
An electrical power cable as set forth in claim 1 wherein said adhesive has the following properties: Viscosity: Min. 2000 mPas @ 175° C. Ultimate tensile strength: Min. 300 psi @ 25° C. Elongation: Min. 250% @ 25° C. Softening point without melting: 80° C. Application temperature: at least 130° C.
Claim 8
Dependent Claim
48 words
An electrical power cable as set forth in claim 1 wherein said adhesive has the following properties: Viscosity: 2000-7000 mPas in the range 175°-180° C. Ultimate tensile strength: 300-1100 psi @ 25° C. Elongation: 250-780% @ 25° C. Softening point without melting: 80°-205° C. Application temperature: 130°-265° C.
Claim 9
Dependent Claim
35 words
An electrical power cable as set forth in claim 1 wherein said adhesive has a softening temperature in said predetermined temperature range and a melting temperature and an application temperature above said predetermined temperature range.
Claim 10
Dependent Claim
24 words
An electrical pwoer cable as set forth in claim 1 wherein any otherwise empty spaces within said jacket are filled with water sealing material.
Claim 11
Dependent Claim
30 words
An electrical power cable as set forth in claim 1 further comprising a cushioning layer around said insulation shield layer and intermediate said insulation shield layer and said metal shield.
Claim 12
Dependent Claim
24 words
An electrical power cable as set forth in claim 10 wherein said cushioning layer is a layer of tape containing a water swellable material.
Claim 13
Dependent Claim
24 words
An electrical power cable as set forth in claim 1 further comprising water swellable particles intermediate said insulation shield layer and said metal shield.
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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) | 1997-01-24 | 1997-07-26 | 1998-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-24 | 2001-07-26 | 2002-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-24 | 2005-07-26 | 2006-01-25 | $7700.00 | Window Closed / Lapsed |