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:
Apr. 04, 1989
Filed:
Apr. 29, 1987
Ralph G Nasatka, Clinton, MD (US);
Michael Lippy, Herndon, VA (US);
Other;
Abstract
A hydraulic barricade comprising a support to which a barricade plate is pivotally attached. At least a first hydraulic cylinder and piston assembly is operably connected with the barricade plate for pivoting the barricade plate between an up and a down position. A pump supplies pressurized hydraulic fluid to a primary source and a secondary source of pressurized fluid. A directional control valve is interposed between the cylinder and piston assembly and the sources for causing operation of the cylinder and piston assembly and thereby pivoting of the barricade plate. A first check valve is interposed between the sources for permitting pressurized fluid to flow from the pump and the cylinder and piston assembly to the secondary source and for preventing fluid from flowing from the secondary source to the primary source. The secondary source includes an hydraulic accumulator for storing hydraulic fluid under pressure. An emergency valve is interposed between the secondary source and the directional control valve for supplying fluid from the accumulator to the directional control valve and the emergency valve includes a manual/remote operator for permitting selective operation thereof.