EXTENSIBLE SUPPORT

摘要

The invention relates to a sliding- type extensible support. The cylinder (2) of a jack (1) is fixed to a box (4) which surrounds it and against the surface of which there slides a rigid rod (8) connected to the free end of the rod (3) of the jack (1). One end of a hauling chain (14) for a machine (10) is connected to a base plate (5) on the free end of the jack rod at (16) and the other end of the chain (14) is connected at (17) to the free end of the rigid rod (8). The chain (14) is mounted as a crossed loop on a return arrangement at both ends of the box (4) so that the chain remains tensioned during all jack positions. The chain is engaged by a drilling and bolting head driving pinion (19) for head transport. The complete assembly is locatable and adjustable by positioning jacks. The jack (1) operates to press the bottom of the assembly in a mine flow for drilling etc.