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. 20, 1988
Filed:
Sep. 09, 1987
Applicant:
Inventors:
Daniel J Kvinge, St. Louis Park, MN (US);
Frederick A Powers, Maple Grove, MN (US);
Assignee:
Graco Inc., Minneapolis, MN (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B / ; F01L / ;
U.S. Cl.
CPC ...
417404 ; 91346 ;
Abstract
The hydraulically powered fluid pump has a spool valve which controls the direction of travel of the pump. The spool valve is designed to switch between positions relatively slowly so that in between pump cycles, the ball checks associated with the pump may return under the force of gravity to their seats. This natural gravity return produces greatly decreased noise levels and increased seat life compared with the slamming action present in current pumps. The spool valve is viscous damped and of a closed centered construction to allow the relatively slow switchover to take place.