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:
Sep. 01, 1998
Filed:
Feb. 28, 1997
Brian J Kurth, Lake Elsinore, CA (US);
Anil B Patel, La Crescenta, CA (US);
Shurflo Pump Manufacturing Co., Santa Ana, CA (US);
Abstract
A pump includes a housing having at least a first pumping chamber, an inlet, an inlet passage leading from the inlet to the pumping chamber, an outlet and an outlet passage leading from the pumping chamber to the outlet. A first pumping member is movable in the pumping chamber on an intake stroke whereby fluid from the inlet passage is drawn into the pumping chamber and on a discharge stroke whereby fluid in the pumping chamber is discharged into the outlet passage. A drive is provided for moving the pumping member on the intake and discharge strokes. A bypass passage leads from a location in the outlet passage to a location in the inlet passage. A bypass valve is provided and is movable in response to the pressure from the outlet passage and substantially independent of the pressure from the inlet passage between an open position in which fluid flows through the bypass passage and a closed position in which fluid is prevented from flowing through the bypass passage. Having a bypass valve movable only in response to the pressure from the outlet passage enhances the reliability and consistency of bypass valve operation.