anordning foer haoldrivning i haorda bergarter.

摘要

A device for working out drifts in hard rock comprises a movable base (1) with a boom (2) carrying a frame (4) in which an operative unit (9) with a striker (10) is mounted on fingers (8). The fingers (8) are provided with support elements (7) interacting with rods (12) of damping arrangements (11) in the form of cylinders. Each arrangement (11) has a cavity filled with a compressible fluid medium with the end-portion of the rod (12) entering it, as well as a first and second damping cavity filled with an incompressible fluid medium and interconnected via a throttle means. The rod (12) is provided with a piston-like protrusion which forces the incompressible fluid medium to pass through the throttle means between the first and the second damping cavities during displacement of the rod (12).