Ciba-geigy Corporation

Ciba Specialty Chemicals Corporation

Vantico Limited

Felix Bleuel

Ulrich Weidmann

Philip David Willis

Dean Tallak Behm

Hans-Fred Buchmann

Dieter Glauch

Christian Bosshard

Process for impregnating electrical coils, and selected epoxy composition for carrying out the impregnation

A process for impregnating an electrical coil which comprises a winding comprising two or more layers consisting of more than one turn of an electrically conducting wire-form material with a polymer material which electrically insulates the individual turns of the wire-form material from one another with the aid of a thermally curable epoxy resin composition, which composition is solid at room temperature and comprises the following constituents:

Process for impregnating electrical coils

Two flanges form together with an outer tube a sealed-off casting mold for applying an envelope to a pipe at least part of which is lodged in the mold. The lower flange is equipped with a feed-in duct system and the upper flange with an air-escape and overflow duct. The flanges consist of a material of rubber-like elasticity. The duct system of the lower flange comprises a radially extending bore which opens in an annular distributory channel which merges with aerodynamic contours with a flow gap. The flow gap is of such configuration that it is closed when, and as long as, a higher pressure is exerted on the forward frontal face of the lower flange than prevails in the annular channel. The flanges are so shaped in the regions of their sealing faces that the contact pressure exerted on them increases proportionally with the pressure exerted on one of the frontal faces.

Flange having an outer and an inner circumferential sealing face and

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Basel, Switzerland

Felix Bleuel