Providing Locality Information to Smart Sensor Networks

The punch unit is comprised of a punch driver connected with a punch and has a base at its rear end. Securing members keep the punch and the punch driver free of relative rotation during the stroke of the punch. A pre-loaded compression spring can be compressed between the base and a guide bushing receiving the punch, so that it cannot be rotated during the stroke of the punch, but is axially displaceable. To make possible an adjustment of the total length of the punch in arbitrarily small steps, without weakening the connection between the punch and the punch driver, it is provided that the back end of the pressure spring is supported on a spring seat at the rear end of a sliding bushing which is maintained in the guide bushing and is axially displaceable with respect thereto, and that at least the rear part of the punch driver is connected indirectly or directly with the punch via an adjustment screw thread and is in engagement with the sliding bushing in a manner secure against relative rotation by means of releasable securing members.