| 摘要 |
<p>The mobile stope support apparatus comprises a number of individual units (10) which are interconnected by hydraulic cylinders (12). Each of the units (10) has a series of upright, double-acting legs (20). The legs (20) have independent bases of rounded shape and they are pivoted to an overhead canopy (22) which can be raised and lowered by appropriate actuation of the legs. Each unit also has a fore-and-aft hydraulic cylinder (34) which is connected to a common rail (37), the cylinder (34) being pivotable, by the action of a cylinder (36) in an upright plane to raise and lower the rail. By appropriate sequential operation of the various cylinders, the units can be advanced in turn to advance the whole apparatus. In addition, by appropriate operation of the cylinder (36), the front legs (20) can be lifted off the footwall to facilitate movement of the unit over a rough or uneven footwall. <IMAGE></p> |
