Abstract: A counterblow--tap hole--boring machine, especially for pneumatic rammer advance, combined with a counterblow device which serves as tapping equipment and a rotator for the actuation of a bar drill or a striking bar, consisting of sliding control valves which feed the main air to the consumer and back as exhaust, whereby an additional quick action ventilating valve quickly reduces the pressure of the used air, is provided with a mobile control piston (20) disposed on the distal end of the axially sliding control valve (15), which holds a valve disk (16) and controls the main air supply, between the housing (12) and the shaft of the sliding control valve (15), whereby a separate annular piston (18) alternatingly rests against the valve fitting surface (19) and a fitting surface (29) at the control piston (20).

Abstract: A housing of the grasping device is connected by way of a headpiece with a taphole drilling machine equipped with a counterblow hammer. A clamping mechanism which can be coupled in a force-locking fashion in the housing of the grasping device with the smooth-round end of the tapping rod by means of an operating device is provided, this mechanism being in operative connection with an installation enhancing the clamping force upon an increase in tensile force at the tapping rod. The clamping mechanism can be, for example, a tilting disk surrounding the smooth-round end of the tapping rod with a bore and being in operative connection on one side with a stop fixedly connected to the housing of the grasping device, this stop converting the tensile force at the tapping rod into a tilting moment at the tilting disk so that the clamping force is enhanced.