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:
Sep. 12, 1978
Filed:
Aug. 26, 1977
Robert A Fritsch, Cedar Rapids, IA (US);
Narahari Gattu, Cedar Rapids, IA (US);
Lembit Vaerk, Cedar Rapids, IA (US);
Harnischfeger Corporation, W. Milwaukee, WI (US);
Abstract
A large light-weight deflection-resistant telescopic boom section of hollow rectangular cross-section comprises spaced apart top and bottom plates and spaced apart vertical side plates welded therebetween inwardly of the side edges thereof. Longitudinal corner stiffeners of angular cross-section are welded between the outwardly extending portion of the top and bottom plates and the associated vertical side plate to shorten the effective height of the side plate, to stiffen the top and bottom plates, to increase the mechanical section properties, and to provide a flat built-in slide pad bearing surface. Vertical side stiffeners of U-shaped cross-section are welded to the vertical side plates at intervals therealong and to the longitudinal corner stiffeners to provide the buckling resistance and increased shear load capacity of side plates.