Patent ID: 7712545
Filing Date: 2010-05-11
Classification: E21B

Abstract:
1. A telescopic feed beam for a rock drill comprising a lower beam and an upper beam, which are arranged in parallel and slidable with each other in the longitudinal direction, the rock drill being arranged to be movably installed in the upper beam in its longitudinal direction and a transfer cylinder connected to the upper beam and being arranged to act between the upper beam and the lower beam to move the upper beam and the lower beam with respect to each other in the longitudinal direction, wherein the lower beam has a cross section comprising a groove-like space at the bottom of the lower beam, that the transfer cylinder between the lower beam and the upper beam is mounted in the space so that it is protected from material falling from the top and sides of the feed beam and from impacts directed at the feed beam, a cradle coupled to move slidingly with respect to the lower beam in its longitudinal direction, a second transfer cylinder arranged to act between the cradle and the lower beam to move the cradle and the lower beam with respect to each other, wherein the feed beam comprises a first connection piece connected to the lower beam, that one end of the transfer cylinder between the lower beam and the upper beam is coupled to the upper beam via a second connection piece and the other end to the first connection piece, and that one end of the second transfer cylinder is correspondingly coupled to the first connection piece, and the other end to the cradle.