| 摘要 |
FIELD: mining.SUBSTANCE: system of valves for a powered support unit in underground mines comprises the first and second unblocked check valves, besides, the first check valve is connected with a drop cylinder of a support unit, and the second check valve is connected with a lifting cylinder of a support unit, besides, both check valves are connected with each other. At the same time the control input of the second check valve is connected with the input of the piston surface of the first check valve, and the discharge input of the second check valve is connected to the input of the circular surface of the first check valve.EFFECT: making it possible to maintain pressure in a lifting hydraulic cylinder as a support unit moves.6 cl, 3 dwg |
