Abstract: A method is specified for reversing a compressed air-driven ramming device for its control positions of forward running and rearward running in the earth, wherein, for reversal, a turning is performed against a relatively small detaining force and the force of the operational compressed air is used for locking the control device in the individual control positions and for damping the vibration propagation from a ram housing to the control device. As a result, a reversing of the ramming device during the admission of operational compressed air is reliably prevented.

Abstract: A forward and rearward running ramming device includes: a housing having a percussion head in which a percussion piston a axially displaced by compressed air; a control device for controlling the compressed air so that, during forward running the percussion piston strikes a front side of the housing, and during rearward running the percussion piston strikes a rear side of the housing, the control device interacting with control openings in the percussion piston, which control advancing movement and returning movement of the percussion piston, the control device being seated in a the housing and being connected, through the housing, to an air supply hose; an arresting device, which fixes the control device relative to the housing in individual switching positions, which are set by turning the air supply hose, wherein the arresting device is also a damping device, at least one air chamber, variable in size, being provided as arresting and damping element, the air chamber being bounded at end faces by rear and f

Abstract: In a device for controlling a pneumatic pile-driving or ram drilling apparatus having an internal, reciprocating ram, the control is effected in a forward stroke phase, a reverse stroke phase, and a subsidiary phase for the supply of air via a control device to a ram. The subsidiary control phase is a delay phase, in which subsidiary compressed air is fed to the front of the ram via time-delay means to take effect with an interval after that flow begins whereby to be substantially effective only in extending the reverse stroke of the ram. An apparatus is provided having a housing, in which the ram is reciprocated and compressed air admission is controlled by the control device which projects into the rear face of the ram and cooperates with the control ports in the ram to control the forward and reverse stroke movements of the ram. At least one supplementary control port, provides a time-delay device with which subsidiary compressed air is additionally fed on to the front of the ram.