| 摘要 |
<p>A rock breaker comprising a tool insertable in a hole in a rock and fed through a supply line (52) with an incompressible liquid to maintain a column of the liquid in the hole, and means (60,61) to apply to the liquid a shock means sufficiently high to fracture the rock. The tool comprises a hollow stem having an expansible collet (5) to lock the tool in a hole and a resilient sealing member (15) to form a liquid seal forthe tool in the hole. In order to provide a simple arrangement which can readily be locked in and released from the hole, the tool has a sleeve (14,16) which is forced axially along the hollow stem of the tool to act on the sealing member (15) and collet (5) by a nut (11) screwed on to the upper end of the stem and bearing on the upper end of the sleeve (14). The nut is turned by a handle (10) acting on the nutthrough a ratchetto force the sleeve downwardly and thereby expand the colletand sealing member.</p> |
