Supporting-arm adjusting device for mining machines, in particular for shearer-loaders and selective-cut heading machines

摘要

The invention relates to an adjusting device for the supporting arm (2) of a mining machine, in particular of a shearer-loader (3) or a selective-cut heading machine (1). This device is equipped with at least one double-acting pressure cylinder (4) which produces the adjusting forces and holds the supporting arm (2) in its operating position when the piston (5) is secured at the end of the respective adjusting movement by the closing of both cylinder spaces (28a; 28b). In order to make the pressure-cylinder piston (5) less sensitive to external forces during the cutting operation of the shearer drum (3), which forces act on the shearer drum (3) or the supporting arm (2) or are caused by the weight of supporting arm (2) and/or shearer drum (3), it is proposed to constantly admit fluid to both sides of this piston (5) at least in its secured position and to put the fluid located on both piston sides (23a; 23b) under a pressure at which each change DELTA S of the piston travel is largely proportional to each change DELTA P of the pressurising. <IMAGE>