Abstract: A sleeve is provided with a clamp for removably clamping the sleeve on a mandrel. A rigid ring is mounted inside of the sleeve at each end of the sleeve. Each ring has a generally cylindrical inside surface which includes a curved contact portion which extends for less than 180 degrees and which is engageable with the outside surface of the mandrel. A curved clamp arm is pivotally secured at one end thereof to each ring. An eccentric shaft extends through an opening in the other end of the clamp arm. Rotation of the eccentric shaft moves the clamp arm toward the contact portion of the ring so that the mandrel can be clamped between the clamp arm and the contact portion.