Control device for a hoist mechanism of a crane

US6079576A · kind A · utility

Assignee

• LIEBHERR-WERK EHINGEN GMBH · DE

Inventors

• Peter Bosler · Wassertrüdingen, DE
• Erwin Morath · Lauterach, DE

Key dates

• Filing date: Dec 12, 1996
• Grant date: Jun 27, 2000
• Expiry date: Dec 12, 2016

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B66D1/44
• WIPO field: Handling
• WIPO sector: Mechanical engineering

Abstract

The present invention relates to a control device for a hoist mechanism of a crane, preferably for a crane with a jib which can be varied in length and be luffed, with a hydraulic motor driving the hoist mechanism drum which motor forms a closed hydraulic circuit together with a hydraulic pump driven by a motor, preferably by a diesel engine, and with a locking brake for the hoist mechanism drum. In accordance with the invention in the high-pressure line of the hydraulic circuit a pressure gauge is positioned the signals of which are fed to a comparator unit, a unit for determining the moment of the hoist mechanism drum is provided the signals of which are fed to the comparator unit and the comparator unit together with a processing unit of the control unit adapts the pressure in the high-pressure line to the moment which must be applied by the hydraulic motor and which corresponds to the moment of the hoist mechanism drum by means of a corresponding increase or decrease of the pumping capacity in such a manner that a smooth holding, lifting or lowering of the load is possible when the locking brake is released.