US4356342A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fully-filled telecommunication cables
Assignee: Balfour Beatty PLC
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Filing: 1980-08-13
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Granted: 1982-10-26
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Expires: 2000-08-13
Abstract
Abstract Waterproof filling medium, used in telecommunication cables with cellular insulation of polyethylene or polypropylene, is based on a mineral oil (with or without a gelling agent such as microcrystalline wax) and includes two non-polar additives. The first is soluble and of low enough molecular weight to reduce significantly the osmotic pressure of the base, but does not diffuse into the insulation below 80° C.; and the second is polymeric and of high enough molecular weight to increase the resistance to flow to obtain the required non-draining property. Filling of cells in the insulation is inhibited.
Inventors
- 👤 Stefan Verne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:32
CPC Classifications
C; C10; C10M; C10M1/00; C10M1/08; H; H01; H01B; H01B3/00; H01B3/18; H01B3/20; H01B3/22; C10M2203/00; C10M2203/06; C10M2205/00; C10M2205/02; C10M2205/024; C10M2205/026; C10M2229/00; C10M2229/02; C10M2229/04; C10M2229/05; C10N; C10N2020/00; C10N2020/01; C10N2040/00; C10N2040/14; C10N2040/16; C10N2040/17
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
203 words
A fully-filled telecommunication cable comprising a multiplicity of conductors each insulated with cellular polymeric material selected from the group consisting of polyethylene and polypropylene and enclosed in a sheath, the interstices between the insulated conductors and between them and the sheath being filled with a waterproof filling medium having a base comprising a hydrocarbon oil, characterised by the use of two non-polar additives, namely: (i) a first additive which is soluble and consists substantially of molecules that are substantially incapable of diffusing into polyethylene or polypropylene at temperatures of up to 80° C. but having a low enough (number average) molecular weight to reduce significantly the osmotic pressure of the base, this additive having no appreciable useful effect on the composition's resistance to flow at temperatures in the range 50°-80° C.; and (ii) a second additive which is polymeric and has a high enough (viscosity average) molecular weight to raise the resistance to flow of the composition so that the cable will pass a water-penetration test as defined in Post Office Telecommunications Specification No. CW236 (issued by the Post Office Corporation in Great Britain) not only at room temperature but also at temperatures up to a limit that is higher than 50° C.
Claim 2
Dependent Claim
203 words
A fully-filled telecommunication cable comprising a multiplicity of conductors each insulated with cellular polymeric material selected from the group consisting of polyethylene and polypropylene and enclosed in a sheath, the interstices between the insulated conductors and between them and the sheath being filled with a waterproof filling medium having a base comprising a hydrocarbon oil, characterised by the use of two non-polar additives, namely: (i) a first additive which is soluble and consists substantially of molecules that are substantially incapable of diffusing into polyethylene or polypropylene at temperatures of up to 80° C. but having a low enough (number average) molecular weight to reduce significantly the osmotic pressure of the base, this additive having no appreciable useful effect on the composition's resistance to flow at temperatures in the range 50°-80° C.; and (ii) a second additive which is polymeric and has a high enough (viscosity average) molecular weight to raise the resistance to flow of the composition so that the cable will pass a water-penetration test as defined in Post Office Telecommunications Specification No. CW236 (issued by the Post Office Corporation in Great Britain) not only at room temperature but also at temperatures up to a limit that is higher than 50° C.
Claim 3
Dependent Claim
16 words
A cable as claimed in claim 1 in which the base also includes a gelling agent.
Claim 4
Dependent Claim
18 words
A cable as claimed in claim 1 or claim 2, characterised in that both additives are hydrocarbon polymers.
Claim 5
Dependent Claim
16 words
A cable as claimed in claim 1 characterised in that the first additive is polybutene oil.
Claim 6
Dependent Claim
17 words
A cable as claimed in claim 1 characterised in that the second additive is an amorphous polypropylene.
Claim 7
Dependent Claim
24 words
A cable as claimed in claim 1 characterised in that the second additive is selected from the group consisting of polyisobutylenes and butyl rubbers.
Claim 8
Dependent Claim
27 words
A cable as claimed in claim 1 characterised in that the second additive is selected from the group consisting of copolymers and terpolymers of ethylene and propylene.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-25 | 1986-04-26 | 1986-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-25 | 1990-04-26 | 1990-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-25 | 1994-04-26 | 1994-10-26 | $7700.00 | Window Closed / Lapsed |