Manitowoc Crane Companies, Inc.

The Manitowoc Company, Inc.

Manitowoc Crane Group, LLC

Manitowoc Engineering Company

Arthur G Zuehlke

David J Pech

Charles R Wernecke

John William Taylor

An improved method and system for a liftcrane in which a load is lifted through the combined action of first and second hoist drums. The method and system use a first rope wound on one hoist drum and a second rope wound on the second hoist drum. The ends of the ropes opposite the hoist drums are linked together to transmit tension between them. The load is coupled to the ropes. If the take up speed of one of the ropes exceeds the take up speed of the other, the linked ends of the ropes will shift. This condition is detected and the operation of at least one of the first and second hoist drums is modified to bring the take up rates into balance. This system is advantageously used with a hoist block sheave arrangement. This system can also be used with a single rope in which each of the ends of the single rope are wound on a separate one of the hoist drums and the load is coupled to the middle of the rope.

Liftcrane with synchronous rope operation

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.

Crane with self-raising mast

A crane having an upper works rotatably mounted on a lower works and a boom pivotally mounted on the upper works includes a hydraulic boom hoist cylinder and a hydraulic circuit for controlling the hydraulic boom hoist cylinder. The hydraulic cylinder is pivotally connected to a mast on the upper works and pendently connected to the boom. The boom hoist cylinder preferably comprises two double-acting hydraulic cylinders. The hydraulic circuit includes a closed loop pump and a hydraulic controller connecting the closed loop pump and the double-acting cylinders such that fluid from the pump can be directed either to extend or retract the cylinders, with the hydraulic fluid exiting the cylinders being directed to return to the pump.

Hydraulic system for boom hoist cylinder crane

A control system for a liftcrane that utilizes a closed loop hydraulic system that utilizes feed back and feed forward control architecture to provide responsiveness normally associated with systems that do not require feedback.

Control and hydraulic system for a liftcrane

An improved control system for operation of a liftcrane having mechanical subsystems powered by a engine and connected thereto by a closed loop hydraulic system with one or more individual closed hydraulic loops. The liftcrane includes controls for outputting signals for operation of the mechanical subsystems and a programmable controller connected and responsive to the controls and connected to the mechanical subsystems. The programmable controller is capable of running a routine for controlling the mechanical subsystems. A first set of sensors is operable to sense the pressure in the closed loop hydraulic system at each of the mechanical subsystems in a first set of mechanical subsystems and provide an output to the programmable controller indicative of the hydraulic pressure sensed. A second set of sensors is operable to sense the position or speed of each of the mechanical subsystems in a second set of mechanical subsystems and provide an output to the programmable controller indicative of the position sensed.

Control and hydraulic system for liftcrane

A control system for a liftcrane powered by a closed loop hydraulic system. In a liftcrane that includes controls by which an operator can run the liftcrane and mechanical subsystems each powered by a closed loop hydraulic system having a pump and an actuator, the present invention provides a controller responsive to the controls and connected to the mechanical subsystems, and further in which the controller is capable of running a routine for controlling said mechanical subsystems to define operation of the liftcrane.

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Manitowoc, WI, United States of America

Arthur G Zuehlke