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:
Feb. 20, 2001
Filed:
Mar. 12, 1999
Nicholas Colarelli, Creve Coeur, MO (US);
Paul W. Roloff, O'Fallon, MO (US);
Michael A. Olsen, Lake St. Louis, MO (US);
Hunter Engineering Company, Bridgeton, MO (US);
Abstract
A hydraulic control circuit comprises a power unit, a central processing unit, at least one feedback sensor, a valve manifold, and two or more hydraulic lifting cylinders interconnected with miscellaneous hydraulic hoses and electrical wiring. Basic lifting is regulated by a flow divider unit configured to distribute a flow of pressurized hydraulic fluid pumped from a fluid reservoir through the valve manifold to each of the lifting cylinders during a lifting operation. To compensate for any imbalance between the lifting cylinders, the central processing unit monitors the movement of the lifting cylinders, and is configured to divert, through a three-way valve in the valve manifold, an additional portion of the pressurized fluid flow to a lagging lifting cylinder. During decent operations, the central processing unit extracts an additional portion of the fluid return flow through the three-way valve from a lagging lift cylinder, such that at all times during either lifting or decent operations, each lifting cylinder and a supported runway are disposed in a substantially parallel configuration.