Abstract: A ramming apparatus having a shortened length without sacrificing ramming power requirements is disclosed comprising a housing having a front end and a rear end, a pneumatically driven percussion piston having a front end and a rear end operatively mounted in the housing for oscillating movement between the front end and the rear end of the housing, a front pressure chamber provided in the front end of the housing, a rear pressure chamber provided in the rear end of the housing, a high pressure air supply line, a control device for controlling the application of pneumatic pressure on the percussion piston, the control device having a control piston extending axially from the rear end of the percussion piston into an opening of an end piece of the housing and having at least one radial control channel that is closable by the end piece, and an axial channel provided in the percussion piston, wherein when the percussion piston is in a forward position the axial channel communicates with the radial control channe

Abstract: A ram boring implement having a pneumatically or hydraulically driven percussion piston, movable axially in a reciprocating manner in a housing, and an axially movable bit which is connected to an end of the housing and acted upon directly or indirectly by the percussion piston, is of a structure which permits a restoring piston, connected to the bit, to be acted upon by the pneumatic or hydraulic pressure during the return stroke of the percussion piston.

Abstract: A ram boring implement has a pneumatically driven percussion piston (16), which is movable in the axial direction in a reciprocating manner in a housing (12), and a control sleeve (24) which is axially adjustable for reversing the direction of motion of the ram boring implement and is acted upon by the pressure in one (20) of the pressure chambers (18, 20) formed on both sides of the percussion piston (16). The control sleeve (24) can be adjusted by means of a spindle drive (30, 50) by turning a compressed air supply hose (26). According to the invention, the control sleeve is arranged on a core (30, 34), supported in an axially fixed manner on the housing (12), so that the control sleeve itself forms only a relatively small annular effective area (52) acted upon by pressure. This makes it possible for the control sleeve to be moved forward or toward the rear without the compressed air feed having to be interrupted.