Mine working area striding supports remote control - involves dual pressure valves conveying reversal impulse when two pressures are equal

摘要

Operative functions, such as setting, exploiting or advancing, are set in motion by control impulses. The system is used in connection with hydraulic main control valves for individual units, in a remote control system for support units in underground mine working areas. Twin pressure valves are incorporated into impulse leads leading to the main control valves. These convey the impulse to reverse the main control valve only when the same pressure is in force at both control inputs of the twin pressure valve. The twin pressure valves have control connections which may be interchangeable. For striding support systems, this makes it feasible for a number of units to be controlled from a single position.