Method of making a transformer core from strips of amorphous steel

Abstract

This method employs a rotatable mandrel having a circular outer peripheral portion comprising a section that is removably held in place within the peripheral portion and has an arcuate outer surface forming a part of said circular outer peripheral portion. As the mandrel is rotated, there is formed about the circular outer peripheral portion a toroidal core form that comprises laminations of amorphous steel strip having ends that meet in a joint region that extends angularly about a restricted zone of the toroidal core form. This forming step is so controlled that said restricted zone angularly aligns with the removable section of the mandrel. After the core-forming step, the removable section is removed from the mandrel thereby exposing an inner peripheral portion of the toroidal core form that angularly aligns with said restricted zone. Then, into the space vacated by removal of the removable section, there is inserted a forming member having a generally flat surface that aligns with and faces said exposed inner peripheral portion of the toroidal core form. Then, the portion of the core form in said joint region is clamped to said flat surface of the forming member with a clamping mechanism applied in said joint region, following which the core form together with the applied clamping mechanism is removed from the mandrel. Thereafter, the core form is shaped into a rectangular configuration.