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:
Jul. 16, 1985
Filed:
Aug. 22, 1983
Charles L Wadsworth, Escanaba, MI (US);
Harnischfeger Corporation, Milwaukee, WI (US);
Abstract
The inner end of a tower crane boom is connected to the top of its tower by two lugs fixed on the tower, each having an upwardly opening slot, and two trunnions fixed on the inner end portion of the boom, one for each lug, each rotatably seatable in the rounded bottom of the slot in its lug. The slot bottom in one lug defines a first fixed axis, midway between the front and rear sides of the tower, about which the boom swings in its range of working positions; that in the other lug defines a second fixed axis, near the front side of the tower, about which the boom swings to and from an inoperative position wherein it extends along the front side of the tower. The distance between the trunnion axes equals the distance between the fixed axes. Links confine the boom against moving to a position in which neither trunnion is seated in the slot in its lug. Each link has a pivot connection with the tower at a fixed axis defined by one lug and a pivot connection with the boom at the axis defined by the trunnion for the other lug. Preferably, lugs, trunnions and links are duplicated at opposite sides of a vertical plane of symmetry.