Crane for lifting and depositing loads - has hydraulic crane cable actuator operative to compensate between two relatively vertically movable support surfaces e.g. dock and ship

摘要

The arrangement is for lifting a load and depositing it in a predetermined location, and inlcudes a crane (30) disposed between two supports (31,33) having relative vertical movement between them. One (31) support carries the crane. An hydraulic actuator (1) has its cylinder (2) fixed to the crane, with a piston dividing the cylinder in two. The piston rod operates a pulley (8). Another pulley (10) is connected to the other end of the cylinder, and both gullies act as returns for the crane cable (11). A high pressure fluid chamber is connected to one cylinder compartment. Controls detect the rod position and speed and release of cable pressure, and so deal with problems of the support (33) moving vertically.