Coil assembly for magnetically-operated valve - has winding embedded in concentric tubular container

摘要

The assembly facilitates the mass prodn. of sealed windings. The sealing keeps out moisture. The coil (11) is wound with wire interspersed with insulation such that, when completed and pressed, a void-free assembly results. The coil is then placed in an insulation container comprising two concentric tubes (17,19) joined at one end by an integral flange (18). The space (20) between the coil and its case is filled with casting resin, and a seal (22) is fitted at the open end. The completed coil and case assembly is then placed in a rectangular metal housing (3). Typically, this housing is of folded material. The inner dimensions are such that the coil case bears against each side of the housing. The need to mfr. a hermetically-sealed housing is thus avoided.