Crane with self-raising mast

摘要

An apparatus and method of self-raising a mast for a crane having an upper works rotatably mounted on a lower works and a boom pivotally mounted on the upper works, the boom being supported by boom hoist rigging and a mast pivotally connected to the upper works. The crane further includes a self-raising mast assembly for controlling the position of the mast when the mast is not connected to the boom and is not supportable by the boom hoist rigging. The self-raising mast assembly comprises a mast raising yoke pivotally connected to the upper works, a hydraulic mast raise cylinder pivotally connected between the upper works and the mast raising yoke, and a hydraulic system for controlling the mast raise cylinder.