US3567846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metallic sheathed cables with roam cellular polyolefin insulation and method of making
Assignee: General Cable Corp
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Filing: 1968-05-31
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Granted: 1971-03-02
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Expires: 1988-05-31
Abstract
Abstract The metallic sheathed electrical cables of this invention have foamed cellular polyolefin dielectric insulation which is fusionbonded to the inside of an annealed sheath to obtain better electrical and mechanical characteristics. The sheath is applied to a foam-insulated core and then sunk down by drawing through a die or reducing rolls to make the tube fit the insulated core snugly. Controlled heating of the sheathing melts the part of the insulation, or adhesive material, when used, which is in contact with the sheath to produce the fusion bond. The heating period is short and is followed by a quench. This controlled heating and cooling is also used to anneal the metallic sheath.
Inventors
- 👤 William J Brorein
- 👤 Fred F Polizzano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:53
CPC Classifications
H; H01; H01B; H01B11/00; H01B11/18; H01B11/1834; H01B11/1839; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49123; Y10T74/00; Y10T74/20; Y10T74/20396; Y10T74/20402; Y10T74/20456
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
29 words
The electrical cable described in claim 1 characterized by the insulation being a cellular-foamed polyolefin and a hermetic seal is formed between the cellular-foamed polyolefin and the metallic sheath.
Claim 2
Dependent Claim
34 words
The electrical cable described in claim 1 characterized by the insulation being from the group consisting of foamed polyethylene and foamed polypropylene, and the sheath being from the group consisting of aluminum and copper.
Claim 3
Dependent Claim
58 words
The electrical cable described in claim 1 characterized by the fusion bond of the insulation to the sheath including a thin layer of insulation denser than the underlying foam and filling in irregularities in the inside surface of the sheath the fused insulation being less than 20 percent of the radial thickness of all of the foam insulation.
Claim 4
Dependent Claim
52 words
The electrical cable described in claim 1 characterized by the foam being in two layers including an inner layer and an overlying outer layer that has a softer foam than the inner layer to minimize the effects of sheath compression and to achieve more uniform bonding and hermetic sealing to the sheathing.
Claim 5
Dependent Claim
47 words
The electrical cable described in claim 1 characterized by the bond of the foam to the sheath including an outer layer of adhesion-promoting material that bonds the foam insulation to the inside surface of the sheath at a temperature lower than the fusion temperature of the foam.
Claim 6
Dependent Claim
60 words
An electrical cable including a conductor core, insulation surrounding the core, including a foamed dielectric, a metal sheath surrounding the insulation and holding the foamed dielectric under some compression, and a thin layer of adhesion-promoting material on the outside of the foamed insulation between the foam and the metal sheath and bonded to both the foam and the metal sheath.
Claim 7
Dependent Claim
30 words
The electrical cable described in claim 7 characterized by the adhesion-promoting material being from the group consisting of amorphous polypropylene and polypropylene copolymers, and copolymers of polyolefin and acrylic acid.
Claim 8
Dependent Claim
24 words
The electriCal cable described in claim 1 characterized by the metal sheath being annealed and being from the group consisting of aluminum and copper.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |