Mine support shield hydraulic setting cylinder control - has pressure regulated valve hydraulically locking cylinder

摘要

The prop-supported cap is hinged to a fracture shield, with one or more hydraulic cylinders hinged in between, on the shield support frame used in underground mining. The control system for the setting cylinder is dependent on pit setting pressure, and incorporates a pressure-regulated control member which hydraulically locks the cylinder in the mineral-working position. This can comprise a hydraulically activated valve sited in a line linking the cylinder with the return, and with regulating piston connected to the prop pressure space or setting-pressure lead. This ensures that the frame takes up fracture shield loading without loss of stability, and that correct position is taken up, even with uneven roofs.