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:
Jun. 18, 1985
Filed:
Aug. 31, 1984
Donald E Moore, Marion, IA (US);
David W Olsen, Palo, IA (US);
FMC Corporation, Chicago, IL (US);
Abstract
An improved anti-two block system having a boom hoist drum driven by a first hydraulic motor with a first variable displacement motor controlled by a first ram moveable in a given direction to supply fluid pressure for driving the boom drum to lower a boom and a hook block drum driven by a second hydraulic motor with a second variable displacement pump controlled by second ram moveable in a given direction to supply fluid pressure for driving the hook drum to raise a hook block. A differential mechanism sums the movement of the hook block and boom and activates a switch to energize solenoid valve means, when the hook block is a predetermined distance from the boom, to preclude movement of said rams in the given directions.