The Manitowoc Company, Inc.

Manitowoc Crane Companies, Inc.

Manitowac Crane Group, Inc.

Terry S Casavant

Michael J Wanek

Paul M Pukita

Alan E Pleuss

Terry L Petzold

Thomas K Becker

P Ralph Helm

Art G Zuehlke

A drum tensioning method is provided for operating a crane having a continuously reeved load hoist line, with a first end of the load hoist line connected to a first drum and a second end of the load hoist line connected to a second drum, with the load hoist line reeved through boom sheaves and a hook block. The method includes the steps of applying a hold-back force to the second drum; applying a winding force to the first drum greater than the hold back force on the second drum; and applying the winding and hold back forces while limiting movement of the hook block, thereby spooling the load hoist line from the second drum through the boom sheaves and hook block to the first drum while maintaining tension in the load hoist line such that the load hoist line is wound under more tension on the first drum than it had previously been wound on the second drum.

Drum tensioning method and apparatus for load hoist wire rope

A crane boom top is disclosed in which a sheave assembly having a number of sheave sets is supported on the crane boom top by boom sheave supports. Each sheave set is mounted on an individual shaft and connectors connect the individual shafts to the boom sheave supports.

Easily removable sheave assembly

A luffing jib backstop assembly for limiting rotation between a luffing jib and a boom to which the luffing jib is attached is disclosed. The assembly comprises at least one backstop pendant attached at a first end to the luffing jib and at a second end to the boom, the pendant having a length sufficient to allow the luffing jib to be extended to an angle of 180.degree. with respect to the boom. The assembly further comprises a deployable member which engages the backstop pendant and which, upon full deployment, holds a portion of the backstop pendant away from the boom and luffing jib such that the pendant and deployable member prevent the luffing jib from rotating with respect to the boom beyond a permissible operating angle.

Luffing jib backstop assembly

A crane and an attachment comprising a counterweight support beam including a plurality of connected segments movable relative to each other, and having a fore end adapted to be connected to the crane upper works, and an aft end rearward from the rear portion of the upper works. The attachment also includes a moveable counterweight carrier adapted to carry a counterweight when the counterweight is supported thereon. The carrier is mounted on the support beam for movement along the length thereof. The attachment also includes a cylinder for selectively moving the counterweight carrier fore and aft along the beam, landing gear for normally supporting the aft end of the beam on the ground, and a backhitch pendant and a pendant cylinder interconnecting the aft end of the beam and the top of the mast for raising the landing gear from the ground incident to lifting a heavy load from the boom. The support beam is extendable by moving the connected segments relative to each other between a first position, wherein the aft end is spaced from the rear portion of the crane upper works, and a second position, wherein the aft end is spaced further from the rear portion of the crane upper works.

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Two Rivers, WI, United States of America

Terry S Casavant