| 摘要 |
<p>A channel containing a column of liq. is incorporated in a drilling rod system, with a rear end striker device imparting blows onto a drilling tool at the front end, in a percussion drilling appliance as used in mining. The striker device strikes onto the rear end of the column of liquid, transmitting its blows to the drilling tool. There is pref. a piston acting on a striker piece sealing workface connected to a gas pressure reservoir via a lead.</p> |
