| 摘要 |
<p>A pneumatic reversible percussion device comprises a casing (1) with a movable striker (2). A stepped sleeve (5) is secured inside the casing (1). The thicker part of the sleeve (5) enters into a hollow (4) of the stricker (20) and is provided with an opening (12) for distribution of the air and its supply to the hollow of the casing (1). A bush (14) is mounted inside the sleeve (5) and is provided with an opening (15) connected intermittently to the opening (12) of the sleeve (5) in one of its two positions. One of the butt-ends of the sleeve (5) is provided with a protrusion (13) in the form of a circular sector, whereas the bush (14) is provided with a radical protrusion (16) so that in the course of rotation of the bush (14) its protrusion (16) rests against one of the side walls of the protrusion (13) of the sleeve (5) thus taking one of its two positions.</p> |
