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

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.

Dependencies are inferred from the claim text.