Power-driven chisel or drill hammer

摘要

To aerate and deaerate the piston space (8) during the idling of a chisel or drill hammer, the piston (5) has a lateral air passage (10) and the hammer tube (14) has an air passage (18). During the transition to the idling, the hammer tube (14) is displaced axially towards the tool holder (3) and simultaneously rotated, so that the air passages (10 and 18) coincide. The rotation of the hammer tube (14) is effected by a bolt (21) which is fixed therein and is guided in a groove (22) in the housing (1), running obliquely with respect to the axis of the percussion mechanism. By the rotation of the hammer tube (14), considerable shortening of the idling travel is achieved, with the result that the hammer is much more user-friendly. In the idling position, the percussion member (11) is held in a manner free from wear by an air spring in the space (33). <IMAGE>