RING EXPANDING METHOD Russian patent published in 1998 - IPC

FIELD: plastic metal working, namely manufacture of rings by cold opened expansion. SUBSTANCE: ring is expanded at reducing its wall between drive outer roller and idle inner roller moved to side of outer one. Simultaneously ring is sized by diameter by means of one or more positively moved backup rollers. Each backup roller is moved in such a way that zone of its contact with ring is always arranged behind line passing through center of ring normally relative to direction of inner roller motion. EFFECT: enhanced efficiency due to increased separate reduction values as result of changing direction of sizing efforts created by backup rollers and acting upon ring. 1 dwg