APPARATUS FOR FORMING RING-SHAPED MEMBER.

摘要

An apparatus for forming a ring-shaped member comprising a main body of rotating drum having a rotary shaft; a drum driving device for rotating the main body of rotating drum about the rotary shaft; a plurality of movable members parallely provided in the circumferential direction of the main body of rotating drum and radially movably held by the main body of rotating drum; drum segments fixed to respective movable members and collectively forming the outer peripheral portion of the rotating drum; a stepless expanding-contracting device for simultaneously moving the movable members and the drum segments in the radial direction of the rotating drum to expand or contract the diameter of the rotating drum; and a switching device for switching this stepless expanding-contracting device between a movable state and a stationary state.