Switching valve for release of rope crane - has piston with leakage connection for releasing crane after stopping

摘要

The switching valve cylinder accommodates a moving spring loaded piston and has connections for a fluid and is used in a timed releasing device of a blocking arrangement of a rope crane. This arrests the crane support rope at a specified point for lifting a load vertically. The timed release is operated independently of outside energy sources. A piston (7) can be brought into two positions in each of which all fluid flow connectors are connected to each other. A leak connector is connected to a return connection. The pump connection is directly to the load connection. When the rope crane travels then a pump is actuated for holding switching valve piston in the first position. The pump is stopped when crane travel stops.