US3891880A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High voltage winding with protection against glow discharge
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1973-05-18
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Granted: 1975-06-24
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Expires: 1993-05-18
Abstract
Abstract An insulated high-voltage winding of an electrical machine is protected against glow discharge by application thereto of a wound-on tape of semi-conductive material which has been prestretched in its longitudinal direction and which is thereafter contracted by heat treatment. In one embodiment, the tape is a woven structure in which the warp threads consist of a prestretched, non-heat set polymer such as polyester and the weft threads being of the same material but dimensionally stable. In a modified embodiment for the woven tape, the weft threads consist of an inorganic material such as glass or asbestos. According to another embodiment the tape is constituted by sections cut from a foil which is pre-stretched in a longitudinal direction and nonheat-set, the foil being made from polymerous carbon fluoride, or polyester or polyvinylidenefluoride. The surface of the foil sections to be wound onto the winding insulation can be pretreated such as by cauterization or corona discharge to improve its adhesive character.
Inventors
- 👤 Helmut Britsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:03
CPC Classifications
H; H01; H01F; H01F5/00; H01F5/06; H02; H02K; H02K3/00; H02K3/32; H02K3/40; Y; Y10; Y10S; Y10S174/00; Y10S174/13; Y10S174/14; Y10S174/19; Y10S174/22; Y10S174/29; Y10T; Y10T442/00; Y10T442/30; Y10T442/3179; Y10T442/322; Y10T442/3228; Y10T442/3236; Y10T442/3252
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
94 words
An insulated high-voltage winding installed in the slots of the stator component of an electrical machine and wherein external glow-protection means are provided between the insulation on said winding and the slotted portion of said stator, said external glow-protection means being constituted by a wound-on impregnatable woven tape of an electrically semiconductive material covering the entire surface of said winding insulation, the warp threads of said woven tape consisting of a pre-stretched non-heat set and heat contractible filamentary material having an organic polymeric structure and the weft threads thereof consisting of dimensionally stable filaments.
Claim 2
Dependent Claim
94 words
An insulated high-voltage winding installed in the slots of the stator component of an electrical machine and wherein external glow-protection means are provided between the insulation on said winding and the slotted portion of said stator, said external glow-protection means being constituted by a wound-on impregnatable woven tape of an electrically semiconductive material covering the entire surface of said winding insulation, the warp threads of said woven tape consisting of a pre-stretched non-heat set and heat contractible filamentary material having an organic polymeric structure and the weft threads thereof consisting of dimensionally stable filaments.
Claim 3
Dependent Claim
36 words
A glow-protected insulated high-voltage winding as defined in claim 1 wherein the that contraction factor of wrap threads of said woven tape amounts to between 1 and 12 percent, and preferably between 2 and 5 percent.
Claim 4
Dependent Claim
42 words
An insulated glow-protected high-voltage stator winding as defined in claim 1 wherein the warp threads of said glow-protection woven tape are constituted by pre-stretched non-heat set filaments of polyester and the weft threads consist of dimensionally stable filaments of the same material.
Claim 5
Dependent Claim
28 words
An insulated glow-protected high-voltage stator winding as defined in claim 1 wherein the weft threads of said glow-protection tape consist of dimensionally stable filaments of an inorganic material.
Claim 6
Dependent Claim
26 words
An insulated glow-protected high-voltage stator winding as defined in claim 1 wherein the weft threads of said glow-protection tape consist of dimensionally stable filaments of glass.
Claim 7
Dependent Claim
26 words
An insulated glow-protected high-voltage stator winding as defined in claim 1 wherein the weft threads of said glow-protection tape consist of dimensionally stable filaments of asbestos.
Claim 8
Dependent Claim
89 words
An insulated high-voltage winding installed in the slots of the stator component of an electrical machine and wherein external glow-protection means are provided between the insulation on said winding and the slotted portion of said stator, said external glow-protection means being constituted by a wound-on impregnatable tape of an electrically semi-conductive material covering the entire surface of said winding insulation, said tape being constituted by sections taken from a foil of a non-heat set polymeric material which is pre-stretched in a longitudinal direction and heat contractible in such direction.
Claim 9
Dependent Claim
89 words
An insulated high-voltage winding installed in the slots of the stator component of an electrical machine and wherein external glow-protection means are provided between the insulation on said winding and the slotted portion of said stator, said external glow-protection means being constituted by a wound-on impregnatable tape of an electrically semi-conductive material covering the entire surface of said winding insulation, said tape being constituted by sections taken from a foil of a non-heat set polymeric material which is pre-stretched in a longitudinal direction and heat contractible in such direction.
Claim 10
Dependent Claim
20 words
An insulated glow-protected high-voltage stator winding as defined in claim 7 wherein said glow-protection foil consists of polymeric carbon fluoride.
Claim 11
Dependent Claim
18 words
An insulated glow-protected high-voltage stator winding as defined in claim 7 wherein said glow-protection foil consists of polyvinylidenfluoride.
Claim 12
Dependent Claim
18 words
An insulated glow-protected high-voltage stator winding as defined in claim 7 wherein said glow-protection foil consists of polyester.
Claim 13
Dependent Claim
54 words
An insulated glow-protected high-voltage stator winding as defined in claim 7 wherein the insulation on said winding consists of a glass-mica tape and wherein the surface of said glow-protection foil at the side thereof in contact with the glass-mica tape insulation on said winding is pre-treated to facilitate adhesion thereof to said tape insulation.
Claim 14
Dependent Claim
35 words
An insulated glow-protected high-voltage stator winding as defined in claim 11 wherein said glow-protection foil is constituted by fluorinated polymers and the surface thereof in contact with the glass-mica tape insulation is pre-treated by cauterization.
Claim 15
Dependent Claim
35 words
An insulated glow-protected high-voltage stator winding as defined in claim 11 wherein said glow-protection foil is constituted by polyester and the surface thereof in contact with the glass-mica tape insulation is pre-treated by a glowdischarge.
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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) | 1978-06-23 | 1978-12-23 | 1979-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |