The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 03, 1996
Filed:
Mar. 18, 1994
Arthur G Zuehlke, Manitowoc, WI (US);
David J Pech, Manitowoc, WI (US);
Manitowoc Engineering Company, Manitowoc, WI (US);
Abstract
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.