Patent US337885A successfully refreshed from Google Patents.
Patent US3662461A successfully refreshed from Google Patents.
US3662461A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making dry insulated inductive coil
Assignee: Chemetron Corp
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Filing: 1970-05-04
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Granted: 1972-05-16
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Expires: 1990-05-04
Abstract
Abstract A high voltage dry-insulated transformer includes a primary coil having a multiple turn, multiple layer winding constructed by alternately winding a coil layer and then insulation sheets or tape on a winding form. The insulation sheet is a non-woven glass filament cloth which is impregnated with a semi-cured epoxy resin. A plurality of insulating cloth layers are wrapped about the primary coil to define the necessary intercoil insulation. The secondary coil is then similarly formed. The interlayer and intercoil insulating cloth extends beyond the axial end faces of the coils and the space is filled by wrapping of a corresponding tape between the two extended layers. The cloth is applied under tension and heat and the exterior of each layer is rolled to exclude air and cause the resin to flow into the voids and crevices. After the formation of each coil or coils, the assembly is cured by heating under pressure and vacuum. The exterior is wrapped with a shrink type Mylar and the ends of the assembly are capped to confine the insulating resin during the curing and processing cycle.
Inventors
- 👤 Glen W Lake
- 👤 Myron D Coerper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:12
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/02; H01F41/04; H01F41/12; H01F41/125; H01F27/00; H01F27/28; H01F27/32; H01F27/327; H01F41/122; Y; Y10; Y10S; Y10S174/00; Y10S174/08; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49071
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
47 words
The method of claim 1 wherein said coil includes encapsulating insulation of said cloth material and terminal means projecting outwardly of said insulation, and including the step of forming a stress cone about the terminal means and integral with the encapsulating insulation to reduce dielectric stress concentration.
Claim 2
Dependent Claim
42 words
The method of claim 1 including the steps of wrapping a heat shrink cover about the insulating layer, and heating said wrapped coil thereby causing said cover to shrink and force said resin into voids and crevices within the conducting coil layer.
Claim 3
Dependent Claim
36 words
The method of claim 1 wherein said cloth material is a cloth sheet and wherein said physical working includes the further step of applying tension to each sheet as it is wrapped about each coil layer.
Claim 4
Dependent Claim
29 words
The method of claim 4 wherein the physical working of the cloth material includes the step of rolling a cylindrical member upon the outer surface of the insulating layer.
Claim 5
Dependent Claim
61 words
The method of claim 1 including the steps of forming additional interconnected conducting coil layers concentrically about the first coil layer, applying a cloth material as an integral sheet impregnated with the resin about each layer, wrapping the periphery with a heat shrink material and thereafter heating said coil and material to cure said resin, and removing said heat shrink material.
Claim 6
Dependent Claim
114 words
The method of claim 1 wherein a plurality of concentric multiple layer windings are formed with a heavy intercoil insulation therebetween and including the steps of winding a plurality of superimposed layers of said cloth material about the processed coil to define said intercoil insulation, heating said coil and superimposed layers to cure the resin in the intercoil insulation, winding additional interconnected coil layers concentrically about the intercoil insulation and applying said nonwoven cloth material about each layer and about the outermost layer, and wrapping a heat shrink material about said outermost insulating cloth, heating the wrapped assembly to cure the resin and shrink said heat shrink material, and removing the heat shrink material.
Claim 7
Dependent Claim
135 words
The method of claim 1 wherein said method includes the steps of forming a self-supporting winding tube of a non-woven glass filament cloth impregnated with a semi-cured epoxy resin, wrapping a glass filament film-like cloth impregnated with a semi-cured resin about said tube, winding a first coil layer upon said film-like cloth with end-turns spaced inwardly from the tube ends to define end insulating spaces, wrapping a tape of said film-like cloth about the tube to fill said end insulating spacing, and forming succeeding concentric winding layers by successive wrapping said film-like cloth of a depth corresponding to said winding tube depth about the preceding coil layer and the succeeding coil layers upon said cloth, wrapping the winding with a heat shrink cover to force the resin into voids and the like within the coil.
Claim 8
Dependent Claim
145 words
The method of claim 1 wherein said method includes the steps of forming a self-supporting winding tube of an insulating material, wrapping film-like sheets of the cloth material about said tube impregnated with a thermoset resin, winding a first coil layer upon said film-like sheet with end-turns spaced inwardly from the tube ends to define end insulating spacing, and forming succeeding concentric winding layers by successive wrapping said film-like cloth material of a depth corresponding to said winding tube depth about the preceding coil layer and the succeeding coil layers upon said cloth, and filling the end insulating spaces with said film-like cloth material to form a coil winding, wrapping the winding with a heat shrink cover, and heating the wrapped winding to cure the resin and simultaneously contract said heat shrink cover to force the resin into voids and the like within the winding.
Claim 9
Dependent Claim
27 words
The method of claim 9 including the step of working the film-like sheets during the application to exclude air and voids in the forming of the coil.
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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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |