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:
Aug. 12, 1997
Filed:
Dec. 07, 1995
Frederick W Cords, Le Sueur, MN (US);
David E Frye, North Mankato, MN (US);
Commercial Intertech Corp., Youngstown, OH (US);
Abstract
A brake system with a hydraulic pilot brake valve for use in connection with a vehicle requiring finite brake control with high volume pressure control. The brake system includes the hydraulic pilot brake valve, a main hydraulic system, a control hydraulic system, and hydraulic brakes. The main hydraulic system includes a belt-driven hydraulic pump, a tank of hydraulic fluid, and an accumulator. The control hydraulic system includes an electrically actuated hydraulic pump and a tank of hydraulic fluid. The pilot brake valve is designed to control the flow of hydraulic fluid from the main hydraulic system to the hydraulic brakes, and includes a modulator chamber and a primary chamber. The modulator chamber houses a modulator piston valve, and the primary chamber houses a primary input piston which extends into a sleeve chamber of a sleeve. The modulator piston valve controls a modulating fluid flow from the control hydraulic system to generate amplified input forces on the input piston in the primary chamber. These input forces urge the input piston and sleeve toward extended positions, which controls the flow of hydraulic fluid from the main system to the brakes. The modulator piston valve is comprised of a modulator piston and a primary control piston, both being movable between retracted and extended positions and biased toward the retracted position, and a secondary control piston, which is capable of motion between extended and retracted positions.