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:
Jan. 07, 2003
Filed:
Jun. 22, 2001
Manfred Becker, Frankenthal, DE;
Deere & Company, Moline, IL (US);
Abstract
A two-stage brake valve, has a pair of stages with different effective areas which become effective in succession upon an actuation of the valve, including a larger area fill chamber and a smaller area pressure chamber. A fill stage pressure relief valve is connected between the fill chamber and a reservoir. The relief valve includes a valve element, which is exposed to the pressure in the reservoir and spring force, and which is exposed to pressure in the fill chamber, so that it opens upon a pre-set brake pressure existing in the fill chamber. The relief valve also includes a pressure relief piston which can be exposed to the pressure in the fill chamber, and which can be exposed to the pressure in the pressure chamber. The piston has a free end which engages the valve element, and forces the valve element in its opening direction with increasing pressure difference between the pressure chamber and the fill chamber.