US3733426A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and material for reclaiming waterlogged telephone cable and the like
Assignee: AT&T Inc
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Filing: 1971-12-15
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Granted: 1973-05-15
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Expires: 1991-12-15
Abstract
Abstract In-service PIC telephone cable that has become water-logged in places is reclaimed dielectrically by pumping in an aromatic solvent oil containing cross-linking agents that will gel the oil in a predetermined period preferably of the order 24 hours. A nongelling prepurgent miscible with both water and aromatic solvent oil may be pumped in before the gelling compound is introduced, to more completely purge the water.
Inventors
- 👤 S Kaufman
- 👤 R Sabia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:10
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/302; C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/30; C08G18/36; C08G18/67; C08G18/69; H01B7/00; H01B7/17; H01B7/28; H01B7/282; H01B7/285
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
127 words
In combination: an installed multipair sheathed plastic insulated conductor telephone cable with previously waterlogged interior voids filled by an initially liquid filler comprising a solvent oil gelled by in situ catalytic reaction of a hydroxyl terminated polybutadiene and a polyisocyanate prepolymer, the average functionality of the polyisocyanate prepolymer and the hydroxyl-terminated polybutadiene being sufficient to form a cross-linked urethane network that gells said oil, the solvent oil being the major fraction by weight of the filler, the properties of all said filler constituents being such that the viscosity of said filler when initially liquid is less than 100 cps at all temperatures between 35* F. and 90* F., and further being such that the filler when fully gelled has a dielectric constant of not more than 3.0.
Claim 2
Dependent Claim
127 words
In combination: an installed multipair sheathed plastic insulated conductor telephone cable with previously waterlogged interior voids filled by an initially liquid filler comprising a solvent oil gelled by in situ catalytic reaction of a hydroxyl terminated polybutadiene and a polyisocyanate prepolymer, the average functionality of the polyisocyanate prepolymer and the hydroxyl-terminated polybutadiene being sufficient to form a cross-linked urethane network that gells said oil, the solvent oil being the major fraction by weight of the filler, the properties of all said filler constituents being such that the viscosity of said filler when initially liquid is less than 100 cps at all temperatures between 35* F. and 90* F., and further being such that the filler when fully gelled has a dielectric constant of not more than 3.0.
Claim 3
Dependent Claim
60 words
The combination pursuant to claim 1 wherein said solvent oil is an aromatic solvent oil containing a major proportion of aromatic molecules; and wherein said polyisocyanate prepolymer is present in amounts of from 25 to 150 grams per liter and said hydroxyl-terminated polybutadiene is present in amounts of from 80 to 120 grams per liter of said initially liquid filler.
Claim 4
Dependent Claim
57 words
The combination pursuant to claim 2, wherein said isocyanate prepolymer is formed from toluene diisocyanate and castor oil and has a hydroxyl functionality of substantially 2.8 and an equivalent weight of approximately 288; and wherein said hydroxyl-terminated polybutadiene has a hydroxyl functionality between 2.2 and 2.4 and a hydroxyl content between 0.75 and 0.90 equivalents per kilogram.
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) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |