Abstract: Four carriers are disposed at 90.degree. intervals about the axis of rotation. A wound core formed on a mandrel is shifted to one of the carriers contacted with the mandrel. The carrier with the core is rotated through 90.degree. to reach a compression unit and the core is compressed through the movement of the carrier toward the unit, after which the compressed core is welded. When the carrier with the completed core faces a discharge channel through its intermittent rotation, the carrier moves into the channel. Then the carrier ascends to leave the core in the channel and is then rotated to oppose to the mandrel to repeat the above process. The remaining carriers are similarly operated.

Abstract: A magnetic strip is first driven around one end of a mandrel by a plurality of cam operated pins slidably extending through a rotary member and is then moved along a spiral guiding piece disposed around the mandrel until the strip passes through a cutter in its inoperative position. Then the strip enters a push plate slidably mounted on the mandrel and travels along a spiral path therein to be spirally wound around the mandrel. When a predetermined length of the strip passes through the cutter, the cutter cuts the strip and the push plate is moved along the mandrel to shift the wound strip to a carrier abutting against the mandrel for readiness for the next working operation.

Abstract: A stator core including a central cylindrical opening defined by a plurality of teeth consecutive through a circumferential continuous portion is prepared by winding a magnetic strip having a corresponding shape into a spiral. A forming cylindrical rod having a diameter larger than the inside diameter of the core is forced into that opening, and then a pressure is axially applied to the core to compress it to level the beginning and last edges of the strip. The rod is removed from the core and the pressure is released to complete the stator core having a predetermined inside diameter.

Abstract: A wound core is formed by forming a core element having slots for inserting a wire and teeth with equal spaces on one side of a band steel sheet; and winding the core element by engaging pins and applying local stress at the part of the slots to the opposite side to deform the core element to sequentially bend it in a multi-angle structure and to wind it helically.