Patent ID: 6682681
Filing Date: 2004-01-27
Classification: B29C,H01F,Y10S

Abstract:
A method for producing an encapsulated transformer comprising:providing a transformer coil assembly that includes a core having a hollow interior, primary wire windings and secondary wire windings; placing a rigid core insert centrally in a mold cavity of a mold, said core insert including a base portion which has an end surface that rests on a bottom of the mold cavity, an upstanding portion extending from the base portion and a hole extending through the base portion and into the upstanding portion; positioning the transformer coil assembly in the mold cavity so that the transformer coil assembly rests on the base portion of the core insert and the upstanding portion of the core insert is positioned in the hollow interior of the core; closing the mold cavity; injecting thermoplastic rubber into the mold cavity to encapsulate the transformer coil assembly in a jacket of thermoplastic rubber and to bond the thermoplastic rubber to the base portion of the core insert; venting gas in the mold cavity during the injection step so that the gas flows through a groove formed in the end surface of the base portion of the core insert and through vent means located at least partially under the end surface of the base portion of the core insert; opening the mold cavity; and ejecting the encapsulated transformer coil assembly with the jacket of thermoplastic rubber from the mold cavity, thereby resulting in a completely waterproof encapsulated transformer.