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US4038741A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of making electrical coils for dynamo-electric machines having band-formed insulation material

Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1976-01-13
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Granted: 1977-08-02
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Expires: 1996-01-13
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Abstract

Abstract A composite tape insulation for use in winding onto electrical conductors to be further processed for installation in an electrical machine comprises an internal insulation structure having a layer of glass cloth or polyester fleece and a layer of fine mica impregnated with a cured synthetic resin such as an epoxide resin, and outer facing layers of a synthetic material such as a polycarbonate resin bonded to opposite sides of the internal insulation structure by the impregnating resin. The composite tape insulation is made by passing the internal layer structure through a bath of the impregnating resin, thereafter applying the outer facing layers, heating the resulting composite structure so as to cure the impregnating resin to an intermediate B state, winding the composite structure onto the bare electrical conductor with an overlap of the order of 50%, cutting the conductor into lengths which are then shaped to the desired configuration, and then final pressing and heating the insulated and shaped conductor lengths to establish a final bond of all components and conversion of the impregnating resin to its C state.

Inventors

  • 👤 Roland Schuler

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 18:12
CPC Classifications
H; H02; H02K; H02K3/00; H02K3/32; H02K3/34; H02K15/00; H02K15/10; H02K15/105; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49009; Y10T29/4902; Y10T29/49071

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 85 words
The method of producing an electrical coil for installation in an electrical machine and wherein each turn of the coil is formed by a group of pre-insulated conductors which comprises the steps of: winding a composite insulating tape onto a bare conductor so as to completely cover the surface of the conductor, said composite tape including an inner layer of insulating material containing mica and facing layers of a polycarbonate foil secured to opposite sides thereof by an epoxy resin which impregnates the inner layer,
Claim 2
Independent Claim 85 words
The method of producing an electrical coil for installation in an electrical machine and wherein each turn of the coil is formed by a group of pre-insulated conductors which comprises the steps of: winding a composite insulating tape onto a bare conductor so as to completely cover the surface of the conductor, said composite tape including an inner layer of insulating material containing mica and facing layers of a polycarbonate foil secured to opposite sides thereof by an epoxy resin which impregnates the inner layer,
Claim 3
Dependent Claim 41 words
shaping and grouping conductors so pre-insulated into the form required for subsequent installation in the electrical machine, and subjecting the grouped and shaped pre-insulated conductors to heat and pressure thereby to cure the impregnating resin and glue the pre-insulated conductors together.
Claim 4
Dependent Claim 41 words
shaping and grouping conductors so pre-insulated into the form required for subsequent installation in the electrical machine, and subjecting the grouped and shaped pre-insulated conductors to heat and pressure thereby to cure the impregnating resin and glue the pre-insulated conductors together.
Claim 5
Dependent Claim 35 words
The method of producing an electrical coil as defined in claim 1 wherein the facing layers of polycarbonate foil are secured to the inner layer of insulating material by the epoxy resin in its B-state.
Claim 6
Dependent Claim 25 words
The method of producing an electrical coil as defined in claim 1 wherein the polycarbonate foil has a thickness ranging between 5 and 15 μm.
Claim 7
Dependent Claim 29 words
The method of producing an electrical coil as defined in claim 1 wherein said mica is in layer form and has a thickness ranging between 50 and 150 μm.
Claim 8
Dependent Claim 33 words
The method of producing an electrical coil as defined in claim 1 wherein the content of the epoxy resin ranges between 25 and 35% of the total weight of the composite insulating tape.
Claim 9
Dependent Claim 39 words
The method of producing an electrical coil as defined in claim 1 wherein the composite insulating tape is wound onto the bare conductor material with an overlap factor ranging between 40 to 60%, and preferably amounts to about 50%.

References Cited (Backward Citations)

US2656290A Cited
US2707204A Cited
US2917570A Cited
US3556925A Cited
US3695984A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1980-08-01 1981-01-31 1981-08-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-08-01 1985-01-31 1985-08-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-08-01 1989-01-31 1989-08-02 $7700.00 Window Closed / Lapsed

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