MACHINE FOR DRIVING WORKINGS IN HARD ROCKS

摘要

A machine for driving workings in hard works comprises a movable carrier having a boom to which is secured a frame. An implement having a hammer piston is mounted in the frame by means of pins. The pins have support members cooperating with piston rods of shock -absorbing means comprising cylinders. Each shock-ab- sorbing means has a space filled with a compressible fluid in which the end face of the piston rod is received, and a first and a second dashpot spaces filled with a non-compressible fluid which communicate with one another through a throttling means, The piston rod has an enlarged piston-like portion which forces the non-compressible fluid to overflow through the throttling means between the first and second dashpot spaces during movement of the piston rod.