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:
Dec. 06, 1983
Filed:
Sep. 26, 1980
Applicant:
Inventor:
Ronnie F Burk, Waterloo, IA (US);
Assignee:
Deere & Company, Moline, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F04B / ;
U.S. Cl.
CPC ...
417396 ; 91291 ;
Abstract
A fluid supply system includes a pump body having a main bore connectible through inlet check valves to draw fluid from a fluid reservoir and through outlet check valves to supply low pressure fluid to a low pressure function upon reciprocation of a free piston in the main bore. The free piston includes a pair of coaxial driving pistons on either side which extend into main passages which are alternately connected to a high pressure source to cause reciprocation of the free piston. A first spool valve which responds to the completion of a free piston stroke activates a second spool valve which changes the high pressure source connections to the driving pistons.