Patent ID: 6223421
Filing Date: 2001-05-01
Classification: B29C,B29L,Y10T

Abstract:
A method of manufacturing a transformer coil encapsulated in casting resin utilizing a disposable casting mold comprising the steps of:forming an annular inner mold of predetermined shape,placing the inner mold onto an expandable winding mandrel of a coil winding machine,winding a coil onto the inner mold,removing the inner mold and coil wound thereon from the winding machine,inserting inner support members within the inner mold to maintain the shape of the coil wound on the inner mold during encapsulation,forming an annular outer mold of predetermined shape having a mold dome,placing the outer mold over the coil,placing gasket material on the ends of the inner and outer molds,placing end plates against the gasket material on the ends of the inner and outer molds to form a casting mold,placing coil support plates at the top and each end of the mold dome of the outer mold to support the weight of the coil during encapsulation and curing processes,applying a predetermined compression force to the end plates of the casting mold,placing the casting mold containing the wound coil in a horizontal position in an evacuated chamber and pouring casting resin through an opening in the mold dome in the outer mold of the casting mold to encapsulate the coil,permitting the casting resin to harden on the coil, andremoving the encapsulated coil from the casting mold.