Patent US3937855A successfully refreshed from Google Patents.
US3937855A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of curing vacuum pressure impregnated coils
Assignee: General Electric Co
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Filing: 1974-06-21
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Granted: 1976-02-10
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Expires: 1994-06-21
Abstract
Abstract After vacuum pressure impregnating an insulated coil with liquid polyester resin the outer surface of the combination is treated to cause a quick low temperature gellation of an outer shell of the resin to thereby encapsulate the remaining liquid portion. A subsequent high temperature cure is imposed for a relatively long period of time to solidify the liquid inner portion and to fully cure the resin throughout the insulation.
Inventors
- 👤 Geza Gruenwald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:49
CPC Classifications
H; H02; H02K; H02K15/00; H02K15/12; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/42; H01B3/421; H01F; H01F41/00; H01F41/005
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
116 words
A method of insulating an electro-magnetic coil comprising the steps of: a. applying a permeable electrical insulating material to the coil; b. applying a first chemical catalyst throughout said material, said chemical catalyst being reactive with a resin at elevated temperatures but relatively unreactive therewith at room temperatures; c. vacuum pressure impregnating said material throughout with a liquid, chemically reactive, cross linkable resin; d. thereafter inducing a quick cure to solidify said resin on the surface of said impregnated material, thereby encapsulating the liquid resin which is in the bulk of said material; and e. subsequently exposing said material to elevated temperatures to cure said liquid resin and thereby form a solid structure throughout said material.
Claim 2
Independent Claim
116 words
A method of insulating an electro-magnetic coil comprising the steps of: a. applying a permeable electrical insulating material to the coil; b. applying a first chemical catalyst throughout said material, said chemical catalyst being reactive with a resin at elevated temperatures but relatively unreactive therewith at room temperatures; c. vacuum pressure impregnating said material throughout with a liquid, chemically reactive, cross linkable resin; d. thereafter inducing a quick cure to solidify said resin on the surface of said impregnated material, thereby encapsulating the liquid resin which is in the bulk of said material; and e. subsequently exposing said material to elevated temperatures to cure said liquid resin and thereby form a solid structure throughout said material.
Claim 3
Dependent Claim
42 words
A method of insulating an electro-magnetic coil as set forth in claim 1 wherein said first chemical catalyst is added to said liquid resin and the steps of applying said catalyst and of impregnating said material with said resin are accomplished concurrently.
Claim 4
Dependent Claim
22 words
A method of insulating an electro-magnetic coil as set forth in claim 1 wherein said cross linkable resin is a polyester resin.
Claim 5
Dependent Claim
37 words
A method of insulating an electro-magnetic coil as set forth in claim 1 wherein the step of inducing curing is accomplished by applying to the surface of the impregnated material a highly reactive chemical cross linking agent.
Claim 6
Dependent Claim
24 words
A method of insulating an electro-magnetic coil as set forth in claim 4 wherein said cross linking agent is of the class of peroxides.
Claim 7
Dependent Claim
33 words
A method of insulating an electro-magnetic coil as set forth in claim 1 wherein the step of inducing curing is accomplished by the ultra-violet irradiation of the outer surface of the impregnated material.
Claim 8
Dependent Claim
34 words
A method of insulating an electro-magnetic coil as set forth in claim 1 wherein the step of quick curing said resin on the surface is accomplished within a period of less than 3 minutes.
Claim 9
Dependent Claim
47 words
A process for treating the surface of an insulated coil impregnated with a polyester resin to prevent the resin from draining out during a subsequent heating process comprising: exposing the surface of the coil to an accelerator agent selected from the group consisting of peroxides and isocyanates.
Claim 10
Dependent Claim
47 words
A process for treating the surface of an insulated coil impregnated with a polyester resin to prevent the resin from draining out during a subsequent heating process comprising: exposing the surface of the coil to an accelerator agent selected from the group consisting of peroxides and isocyanates.
References Cited (Backward Citations)
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Cited
US2963747A
Cited
US2956613A
Cited
US3139657A
Cited
US3240848A
Cited
US3369947A
Cited
US3531699A
Cited
US3778536A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-09 | 1979-08-11 | 1980-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-09 | 1983-08-11 | 1984-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-09 | 1987-08-11 | 1988-02-10 | $7700.00 | Window Closed / Lapsed |