Abstract: A broach for working the services of pre-cast or preformed pins on workpieces while the workpieces are rotating, including a broach body and having a number of sections including a roughing section provided with cutting elements including perforated reversible plates fastened therein. The cutting plates are formed of a hard cutting material and have cutting edges which converge toward each other in a pushing direction of the broach during working along lines defining opposites acute angles symmetrical with respect to the longitudinal axis of the broach.

Abstract: A drive unit for a rotary tool, which unit includes a housing, a drive shaft mounted in the housing for transferring rotational drive force from a rotary drive to the tool, and a clamping mechanism mounted in the housing for generating a tool clamping movement along the axis of the drive shaft. The drive shaft is a hollow shaft, the clamping mechanism includes a pull rod mounted in the drive shaft and coaxially positioned relative to the drive shaft, the pull rod being mounted to be axially displaceable and fixed against rotation relative to the drive shaft, and the unit further includes a blocking device operative between the drive shaft and the housing for permitting the drive shaft to rotate relative to the housing only when the drive shaft is coupled to the rotary drive.

Abstract: A composite tool unit comprising a tool shank, a tool head a chuck, a drawbar which is slidable in the longitudinal direction of the tool shank and a pulling shank which projects from the tool head. The drawbar and pulling shank are engaged around by the chuck, which is disposed in the tool shank axially to slide between an opening position and a closure position. The tool shank comprises an inner conical face which tapers in the direction of the drawbar and co-operates with outer conical segments disposed on the clamping jaws. The zones of the drawbar 8 and pulling shank 8 of the tool head engaged around by the chuck have respective projections.