Abstract: A working tool has a large number of cutter rings (2.1 to 2.3) on a curved guide rod (1) of circular cross section. The guide yoke (1) exhibits at least two helical grooves winding in opposite directions along its outer side, the cutter rings engaging into these grooves in each case with at least one guide element. Consecutive cutter rings (2.1, 2.2) engage with their guide elements in each case into contrarotating grooves.
Abstract: A working tool has a large number of cutter rings (2.1 to 2.3) on a curved guide rod (1) of circular cross section. The guide yoke (1) exhibits at least two helical grooves winding in opposite directions along its outer side, the cutter rings engaging into these grooves in each case with at least one guide element. Consecutive cutter rings (2.1, 2.2) engage with their guide elements in each case into contrarotating grooves. When the rings are driven forward during operation of the tool, consecutive cutter rings will rotate in opposite directions on account of the helical grooves (8, 9).