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:
Mar. 19, 1985
Filed:
Jul. 24, 1980
Lawrence S Kelly, Bolingbrook, IL (US);
Dean L Schaffran, Carol Stream, IL (US);
Donald S Nii, Arlington Heights, IL (US);
Graco Inc., Minneapolis, MN (US);
Abstract
A system for pumping liquid materials with reciprocating pumps driven by hydraulically operated motors, wherein the pressurized hydraulic oil which is used to drive the hydraulic motors is supplied via reciprocating proportioners. The reciprocating proportioners are driven by a reciprocating air motor operated under predetermined air pressure. The system operation is characterized in that, under blocked output pressure conditions, the air motor will inherently stall and thereby limit the pressure of the hydraulic oil acting to drive the hydraulic motors, which therefore limits the pumping pressure applied to the reciprocating pumps, and limits the output pressure of the pumped liquid materials.