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:
Mar. 23, 1976
Filed:
Dec. 20, 1974
Robert A Fritsch, Cedar Rapids, IA (US);
James C Mayo, Sr, Cedar Rapids, IA (US);
James N Johnson, Cedar Rapids, IA (US);
Harnischfeger Corporation, West Milwaukee, WI (US);
Abstract
A mobile crane has a multisection telescopic boom and an optionally useable lattice jib storable alongside the boom with the base end of the jib adjacent the point end of the boom. One side of the boom base section is provided with a pair of longitudinally spaced apart jib storage support assemblies to facilitate storing and installing the jib. The point end of the boom fly section and the base end of the jib are provided with cooperating disconnectable hinge members for attaching the jib to the boom so that the jib can be swung horizontally between stored and installed positions. The point end of the boom fly section and the base end of the jib are provided with connection means, including a cylindrical rod on the boom fly section and cooperating journal bearings on the jib, for securing the jib to the boom in either axial aligned position or in downwardly tilted position, and adjustable strut means is detachably connected between the boom and the jib to limit the extent to which the jib can tilt downwardly. The jib is provided with a self-storing and self-erecting jib mast which is pivotally mounted on the upper side of the jib and cooperates with guy lines to support the jib during set-up and operation of the crane. Releasable locking means are provided on the boom fly section and the next adjacent boom section to prevent the extended boom sections from accidentally telescoping under the weight of the jib in the event of a hydraulic system failure.