PURPOSE: To obtain plural working functions in a small device by continuously restricting rotation of ring-like tools at both sides by linking the tools to a fixed guide standing on a base with stringy members.

CONSTITUTION: Ring-like tools 2, 4 at both sides are supported by bearings 9, 10 at a reversely eccentric position against that of a ring-like tool 3. Rotation of the tools 2, 4 is restricted by stringy members 14, 15. Therefore, rotation of a tube or bar stock is restricted by being brought into contact with inside faces A, C of the tolls 2, 4. Rotation of the stringy members 14, 15 is restricted by linking the tools 2, 4 with fixed guides 12, 13 and then with bases 11. In the illustration, movable members indicated by hatched lines are only driven by rotation of a gear 6, so that a device has a simple, small, and strong structure.