| 摘要 |
<p>The machine housing contg. the striker piston has a front part in which a drill casing is rotated by a motor and a gearwheel which engages cogs on the casing. The casing extends out of the housing, and at its front end is threaded for connecting the casing to a tube constituting its extension. This tube is connected to a set of tubes by threaded union. A drill crown is coupled by a splined union to the front end of the tube set. A bar is slidably arranged in the drill casing to transmit striker piston energy to a set of bars axially movable in the tubes. The bars transmit the piston energy to the drill crown via a further bar adjacent to the crown. The crown has a wash channel which only extends axially in the shaft, and the bar next to the crown has an axial flow channel which connects to the channel in the crown.</p> |
