Pneumatic borehole driving drill reversible striker pin - has holed control slide on reversal unit acting with stepped slide socket and with exhaust apertures to align with openings

A striker pin in a housing unit transvers striking impulses to the housing as it moves to and fro under compressed air action. At the rear it has an open hollow with cross holes, regularly covered as it passed through a double-stepped slide socket connected to the air duct. The socket(3) has a recess(20) on its widened step(11), with one or more cross holes(13) in one half. The direction reverser has an adjustable control slide in the socket with a closed(21) and an open(22) half, and peripheral openings(14) for alignment with the cross holes. On the rear side the socket has exhaust apertures(18) which align with openings in the rear of the closed half of the slide, in one position.