System preventing load moving out of control if hose is broken - has connection conduit containing two hoses in parallel under control of three position switch-over valve

摘要

The hydraulic system prevents a load from moving out of control if a hose or corresponding conduit part is broken A connection conduit contains a first hose between a hydraulic pressure source and a load-supporting hydraulic motor such as a cylinder. A second hose is in parallel to the first. A first switch over valve connects one end of both hoses to the connection conduit portion attached to the motor. This switch over valve has three positions. a normal one in which both hoses are connected to the conduit, and first and second blocking positions in which the first or second hose respectively is disconnected and only the second or first hose respectively is connected to the connection conduit.