Tragbare Schlagbohrmaschine in Zweischalenbauweise

A synthetic plastic housing of a hammer-drill has an output shaft for coupling with the drill bit, the output shaft being mounted in the housing for rotary and reciprocable displacement. A drive drives the output shaft in rotation and the inner end of the output shaft carries a disc which is normally in engagement with a juxtaposed but fixed disc, with the two discs having respectively engaging projections so configurated that when the disc on the output shaft rotates with the latter, it will alternately be urged away from and be allowed to move closer to the fixed disc so that the output shaft reciprocates axially. A cylindrical control element extends transversely of the axis of the output shaft in the region of the rear end thereof, having at least two surfaces which extend in parallelism with the axis of the cylindrical control member but are located at different distances from this axis. The control member is turnable so that, when the surface located closer to this axis is juxtaposed with the inner end of the output shaft, there is no contact with the latter, whereas when the surface which is farther from the axis of the control member is juxtaposed with the inner end of the output shaft it presses against the latter, urging the same and thereby the disc thereon away from and out of engagement with the fixed disc so that the output shaft will only rotate but not reciprocate.