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:
May. 07, 1996
Filed:
Jul. 01, 1994
Roger D Luebke, Hartford, WI (US);
Harnischfeger Corporation, Brookfield, WI (US);
Abstract
Lifting apparatus comprising first and second generally vertical masts, an assembly including a frame moveable along the masts, and a load engaging mechanism mounted on the frame, a first brake mechanism which, upon actuation, engages the first mast to prevent downward movement of the frame relative to the first mast, a second brake mechanism which, upon actuation, engages the second mast to prevent downward movement of the frame relative to the second mast, an overspeed mechanism for sensing the downward velocity of the assembly and for actuating the first brake mechanism when the overspeed mechanism senses that the downward velocity of the assembly exceeds a predetermined value, a first electrical device for providing an electrical signal when the first brake mechanism is actuated, and a second electrical device for actuating the second brake mechanism in response to the electrical signal.