Abstract: The disclosure relates to a ring-shaped tool for processing a work piece, wherein the tool has a fastening area for fastening onto a rotatable drive shaft, wherein the fastening area is centered with relation to the ring-shape of the tool, wherein the tool further has sprockets arranged around the circumference of the tool, wherein the sprockets are arranged on the head end of the tool, wherein the sprockets have an arc-shape seen in axial direction of the ring, the arc-shape having a summit, wherein the sprockets are formed in a mirror-symmetric manner relative to the ring surface of the tool which is cutting through the summit.

Abstract: A method and apparatus for monitoring the supply of cap members from a magazine or supply bin, via a channel, to the capping mechanism of a capping machine. At least one signal emitter, which is provided at the channel, generates an emitted signal that changes as the cap members move past, with a disruption signal being derived from the emitted signal if this emitted signal does not change during a specified time interval. A cycle signal is derived from the working or machine cycle of the capping machine. If no change of the emitted signal is determined in two successive cycles, the sum of which correspond to a full period of the cycle signal, the disruption signal is generated.