| 摘要 |
A hydraulic drive for a hoist with telescopic boom lowered below the level, fitted with shut valves located in the below-piston branches of the boom raise actuators and in the boom telescopic action actuators, whereas those valves also brake the operation of the boom by a hydraulic method, whereas such operation movements are: lower the boom, shorten the telescope at a positive inclination angle, lengthen the telescope at a negative inclination angle, characterized in that the hydraulic brake unit has a single brake valve (9) for all the boom movements, whereas the valve inlet (7) is connected with the boom's telescopic operation actuator (2) via a distributor (10), and via a return valve (17) is connected with the shut valves (6) of the hoist actuators (1), whereas the brake valve outlet (9) is connected with the tank (18).<IMAGE>
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