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:
Nov. 03, 1981
Filed:
Feb. 19, 1980
Applicant:
Inventor:
Narahari Gattu, Cedar Rapids, IA (US);
Assignee:
Harnischfeger Corporation, W. Milwaukee, WI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B66C / ;
U.S. Cl.
CPC ...
212267 ; 212230 ; 212264 ;
Abstract
A telescopic boom comprises inner and outer boom sections; an elongated rotatable screw rotatably mounted on the outer section; a first thread on the screw engaged with a first nut on the inner boom section whereby screw rotation effects telescopic movement of the inner boom section and a second thread of smaller lead superimposed on the first thread and engaged with a second nut mounted on a support which is movably mounted on the outer boom section whereby screw rotation also effects axial movement of the support at a slower rate than telescopic movement of the boom sections to a position wherein it supports the mid-section of the screw.