Image Number 3 for United States Patent #5176946.
A method of manufacturing a core for an electrical inductive device. A blind hole is provided through a stack of laminations into which an oil or an epoxy resin adhesive is placed. The blind hole provides a slow release for the oil to the outer surfaces. This obviates the contamination of the outer surfaces of the coil during manufacture as in the case with a dipping procedure. When the epoxy resin adhesive is employed in the blind hole, a wicking action takes place for better fastening of the laminations together. In another embodiment of the fastening feature, epoxy resin adhesive is molded to the outside of the end piece laminations as well as through a passage in the laminations. An improved resulting core is also provided.