Construction equipment with self-raising mast and method therefor

摘要

An apparatus and method of self-raising a mast (34) for a crane having an upper works (12) rotatably mounted on a lower works (16) and a boom (26) pivotally mounted on the upper works, the boom being supported by boom hoist rigging (36,38) and a mast pivotally connected to the upper works. The crane further includes a self-raising mast assembly (64) 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 (66) pivotally connected to the upper works, a hydraulic mast raise cylinder (88) pivotally connected between the upper works and the mast raising yoke, and a hydraulic system for controlling the mast raise cylinder. <IMAGE>