Patent US4033805A successfully refreshed from Google Patents.
US4033805A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing an insulated electric coil
Assignee: Toshiba Corp
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Filing: 1976-02-24
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Granted: 1977-07-05
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Expires: 1996-02-24
Abstract
Abstract A compound mica sheet is prepared by bonding a mica sheet to a woven fabric through a powdered epoxy resin with curing agent. The mica sheet holds a cured thermosetting resin composition impregnated therein and has an uncured epoxy resin composition including a curing agent impregnated therein. When thermosetting resin is forcedly impregnated, through vacuum/pressure impregnation, into a coil wound with the compound mica sheet which is adapted for use in medium and high voltage electric apparatus, and then cured, an excellent insulated coil is obtained.
Inventors
- 👤 Hisayasu Mitsui
- 👤 Jun-ichi Kamiuchi
- 👤 Ryozi Kumazawa
- 👤 Kimikazu Umemoto
- 👤 Toshimitsu Yamada
- 👤 Katsuhiko Yoshida
- 👤 Taichi Takechi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:48
CPC Classifications
B; B32; B32B; B32B19/00; B32B19/06; B32B38/00; B32B38/08; H; H01; H01F; H01F41/00; H01F41/02; H01F41/04; H01F41/12; H01F41/127; B32B2038/0052; B32B2038/0076; B32B2260/00; B32B2260/04; B32B2260/046; B32B2307/00; B32B2307/20; B32B2307/206; B32B2315/00; B32B2315/08; B32B2315/085; B32B2315/10; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/251
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
127 words
A method of manufacturing an insulated electrical coil comprising the steps of: (a) bonding a mica sheet to a lining material to produce a compound mica sheet by (1) depositing a mixture of powdered epoxy resin and a curing agent onto the surface of a mica sheet to produce a coated mica sheet, (2) contacting the lining material with the coated mica sheet, and (3) subjecting the coated mica sheet and lining material together to a temperature and pressure sufficient to thermally fuse the powdered epoxy resin and bond the lining material to the mica sheet; (b) mechanically winding said compound mica sheet onto an electrical coil; (c) impregnating the coil wound with the compound mica sheet with a thermosetting resin; and (d) curing said impregnated coil.
Claim 2
Independent Claim
127 words
A method of manufacturing an insulated electrical coil comprising the steps of: (a) bonding a mica sheet to a lining material to produce a compound mica sheet by (1) depositing a mixture of powdered epoxy resin and a curing agent onto the surface of a mica sheet to produce a coated mica sheet, (2) contacting the lining material with the coated mica sheet, and (3) subjecting the coated mica sheet and lining material together to a temperature and pressure sufficient to thermally fuse the powdered epoxy resin and bond the lining material to the mica sheet; (b) mechanically winding said compound mica sheet onto an electrical coil; (c) impregnating the coil wound with the compound mica sheet with a thermosetting resin; and (d) curing said impregnated coil.
Claim 3
Dependent Claim
13 words
A method of claim 1, wherein the mica sheet is a mica paper.
Claim 4
Dependent Claim
35 words
A method of claim 2, wherein the amount of the mixture of powdered epoxy resin and curing agent is from about 0.5 to to about 8% by weight based on the weight of the mica.
Claim 5
Dependent Claim
12 words
A method of claim 1, wherein the mica sheet comprises flake mica.
Claim 6
Dependent Claim
33 words
A method of claim 4, wherein the amount of the mixture of powdered epoxy resin and curing agent is from about 0.5 to 6% by weight based on the weight of the mica.
Claim 7
Dependent Claim
35 words
A method of claim 1 wherein the temperature at which the powdered epoxy resin is thermally fused thereby bonding the lining material to the mica sheet is from about 100° C. to about 150° C.
Claim 8
Dependent Claim
22 words
A method of claim 1, wherein the lining material is selected from the group consisting of paper, woven fabrics and plastic film.
Claim 9
Dependent Claim
22 words
A method of claim 1, wherein the particle size of the powdered epoxy resin is from about 50 to about 500 mesh.
Claim 10
Independent Claim
156 words
A method of manufacturing an insulated electrical coil comprising the steps of (a) impregnating a mica sheet with a thermosetting resin; (b) curing the thermosetting resin impregnated therein to produce a cured mica sheet; (c) bonding the cured mica sheet to a woven fabric to produce a compound mica sheet by (1) depositing a mixture of a powdered epoxy resin and a curing agent onto the surface of the cured mica sheet to produce a coated cured mica sheet, (2) contacting the woven fabric with the coated cured mica sheet, and (3) subjecting the coated cured mica sheet and woven fabric together to a temperature and pressure sufficient to thermally fuse the powdered epoxy resin and bond the woven fabric to the cured mica sheet; (d) mechanically winding said compound mica sheet onto an electric coil; (e) impregnating the coil wound with the compound mica sheet with a thermosetting resin; and (f) curing said impregnated coil.
Claim 11
Independent Claim
156 words
A method of manufacturing an insulated electrical coil comprising the steps of (a) impregnating a mica sheet with a thermosetting resin; (b) curing the thermosetting resin impregnated therein to produce a cured mica sheet; (c) bonding the cured mica sheet to a woven fabric to produce a compound mica sheet by (1) depositing a mixture of a powdered epoxy resin and a curing agent onto the surface of the cured mica sheet to produce a coated cured mica sheet, (2) contacting the woven fabric with the coated cured mica sheet, and (3) subjecting the coated cured mica sheet and woven fabric together to a temperature and pressure sufficient to thermally fuse the powdered epoxy resin and bond the woven fabric to the cured mica sheet; (d) mechanically winding said compound mica sheet onto an electric coil; (e) impregnating the coil wound with the compound mica sheet with a thermosetting resin; and (f) curing said impregnated coil.
Claim 12
Dependent Claim
32 words
A method of claim 9, wherein the amount of thermosetting resin impregnated into the mica paper is from about 0.1 to about 1% by weight based on the weight of the mica.
Claim 13
Dependent Claim
35 words
A method of claim 9, wherein the temperature at which the powdered epoxy resin is thermally fused thereby bonding the woven fabric to the cured mica sheet is from about 100° to about 150° C.
Claim 14
Dependent Claim
13 words
A method of claim 9, wherein the woven fabric is a glass cloth.
Claim 15
Dependent Claim
22 words
A method of claim 9, wherein the particle size of the powdered epoxy resin is from about 50 to about 500 mesh.
Claim 16
Independent Claim
183 words
A method of manufacturing an insulated electrical coil comprising the steps of (a) impregnating a mica sheet with a thermosetting resin; (b) curing the thermosetting resin impregnated therein to produce a cured mica sheet; (c) impregnating said cured mica sheet with an epoxy resin composition containing a curing agent to produce an impregnated cured mica sheet; (d) bonding the impregnated cured mica sheet to a woven fabric to produce an integral compound mica sheet by (1) depositing a mixture of a powdered epoxy resin and a curing agent onto the surface of the woven fabric to produce a coated woven fabric, (2) contacting the coated woven fabric with the impregnated cured mica sheet, and (3) subjecting the impregnated cured mica sheet and coated woven fabric together to a temperature and pressure sufficient to thermally fuse the powdered epoxy resin and bond the woven fabric to the impregnated cured mica sheet; (e) mechanically winding said integral compound mica sheet onto an electric coil; (f) impregnating the coil wound with the integral compound mica sheet with a thermosetting resin; and (g) curing said impregnated coil.
Claim 17
Independent Claim
183 words
A method of manufacturing an insulated electrical coil comprising the steps of (a) impregnating a mica sheet with a thermosetting resin; (b) curing the thermosetting resin impregnated therein to produce a cured mica sheet; (c) impregnating said cured mica sheet with an epoxy resin composition containing a curing agent to produce an impregnated cured mica sheet; (d) bonding the impregnated cured mica sheet to a woven fabric to produce an integral compound mica sheet by (1) depositing a mixture of a powdered epoxy resin and a curing agent onto the surface of the woven fabric to produce a coated woven fabric, (2) contacting the coated woven fabric with the impregnated cured mica sheet, and (3) subjecting the impregnated cured mica sheet and coated woven fabric together to a temperature and pressure sufficient to thermally fuse the powdered epoxy resin and bond the woven fabric to the impregnated cured mica sheet; (e) mechanically winding said integral compound mica sheet onto an electric coil; (f) impregnating the coil wound with the integral compound mica sheet with a thermosetting resin; and (g) curing said impregnated coil.
Claim 18
Dependent Claim
13 words
A method of claim 14, wherein the mica sheet is a mica paper.
Claim 19
Dependent Claim
36 words
A method of claim 15, wherein the amount of the thermosetting resin of step (a) impregnated into the mica paper is from about 0.1 to about 1% by weight based on the weight of the mica.
Claim 20
Dependent Claim
37 words
A method of claim 15, wherein the amount of epoxy resin composition of step (c) impregnated into the cured mica sheet is from about 5 to about 20% by weight based on the weight of the mica.
Claim 21
Dependent Claim
36 words
A method of claim 14, wherein the temperature at which the powdered epoxy resin is thermally fused thereby bonding the woven fabric to the impregnated cured mica sheet is from about 100° to about 150° C.
Claim 22
Dependent Claim
13 words
A method of claim 14, wherein the woven fabric is a glass cloth.
Claim 23
Dependent Claim
22 words
A method of claim 14, wherein the particle size of the powdered epoxy resin is from about 50 to about 500 mesh.
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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) | 1980-07-04 | 1981-01-03 | 1981-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-04 | 1985-01-03 | 1985-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-04 | 1989-01-03 | 1989-07-05 | $7700.00 | Window Closed / Lapsed |