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. 19, 1988
Filed:
Nov. 04, 1986
James A Miller, Cedar Falls, IA (US);
Roger J Nelson, Cedar Falls, IA (US);
Bennie J Vaughn, Cedar Falls, IA (US);
Deere & Company, Moline, IL (US);
Abstract
A two stage brake valve for communicating fluid pressure to a brake assembly. The valve has a stepped cylinder formed therein in which a high volume piston and high pressure valve are slidably located. The piston and valve define high volume and high pressure chambers respectively. A set of passageways through the piston and valve communicate fluid pressure from the high volume chamber to the high pressure chamber and from the high volume chamber to a reservoir. Relief valve elements located in the passageways regulate fluid communication between the chambers and reservoir. A motion responsive relief valve comprising a ring and groove is also disclosed which provides an orifice function and facilitates refilling of the first chamber. One embodiment includes a highly compact relief assembly valve assembly having dual poppets which act to communicate fluid pressure from the first chamber to either the second chamber or the reservoir. The compact nature of the brake valve assembly will also permit incorporation of a differential lock valve assembly in the same valve body.