| 摘要 |
Hydraulic control comprises control valves (8, 9) divided into groups with each group connected to a hydraulic pressure pipe (16) by a supply pipe (18). The group connection can be closed by a check valve (20) according to the control valve operation when they are not closed. Preferred Features: The control valves of each support (1, 2, 3) form the groups of control valves which are connected to the pressure pipe by the group connection depending on the operation of the support in the non-operating state. |
