PNEUMATIC APPARATUS OF THE PERCUSSIVE TYPE

摘要

PNEUMATIC APPARATUS OF THE PERCUSSIVE TYPE The apparatus has a pointed-nose hollow cylindrical body with a closed back disposed wherein with provision for reciprocation and rotation about the axis of the body is a step?? striker which can also be locked against rotation about the axis of the body in two positions corresponding to the advance and of the apparatus. For the purpose of admitting compressed air into a forward working chamber, the striker is provided with a central passage permanently connected to a rearward working chamber as well as with at least two radial passages opening into that central passage and onto a cylindrical surface of a greater step of the striker, said radial passages being displaced relative to each other both circumferentially and longitudinally along the axis of the body, and the body is provided with grooves in an inside surface of its forward portio which form, in conjunction with an outside cylindrical surfac of a greater step of the striker, passages so arranged that one of the radial passages of the striker is connected to the when the striker is in said locked positions. For the purpose of discharging spent air from the forwar working chamber into the atmosphere, the striker is provided with longitudinal grooves in the outside surface of its greater step within the forward portion which form, in conjunctio with the body, passages opening into the forward working cha ber, and the body is provided with ports which recurrently connect the forward working chamber to the atmosphere through these passages.