HYDRAULIC CIRCUIT FOR LONGWALL SUPPORT

摘要

A hydraulic circuit for longwall support for use in underground mining for supporting a longwall by means of a plurality of support shields comprises in the annular piston line of each cylinder/piston unit a pressure sensor. Said pressure sensor upon reaching a predetermined maximum pressure activates a pressure deviation signal, which causes the entire longwall to be depressurized by means of a longwall shut-off valve. The pressure deviation signal is blocked for one of the hydraulic valves against each triggering signal.