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:
Dec. 28, 1982
Filed:
Dec. 28, 1976
Wilburn K Brown, Morton Grove, IL (US);
Pettibone Corporation, Chicago, IL (US);
Abstract
The use of a lift fork for a boom swinging vertically over 240.degree. is made feasible by hanging the lift fork with freedom to pivot as gravity dictates when the angularity of the boom is changed, with a brake by which the angularity between boom and lift fork can be locked. The brake enables the boom to exert a strong forward thrust on the bottom of the lift fork when this is necessary for thrusting its tines under a load, and has other advantages. Proper positioning of the load on the forks will cause the forks to hang with the tines of the forks nearly level, or slightly tilted back if preferred. Prefably the fork-lift device also hangs conveniently close to this position when empty. Material handling programs which heretofore needed not only a crane operator but a crew for attaching the hoist line to the load and removing it, can be performed by the operator alone if the swinging but lockable lift fork is used with a three-part 'reach anywhere' articulated boom on a swinging crane.