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:
May. 20, 2008
Filed:
Apr. 28, 2004
Hitoshi Kawamura, Sanda, JP;
Hitoshi Kawamura, Sanda, JP;
Nippon Pillar Packing Co., Ltd., Osaka, JP;
Abstract
A suction passage () and a discharge passage () for a to-be-transferred fluid are disposed in a pump body (). A bottomed cylindrical bellows () is integrally coupled to the axial rear side of the pump body to form a closed space (). The suction passage () has an upstream portion (A) having a larger diameter and a predetermined passage cross section area, and downstream portions (B) which are formed by branching the upstream portion into a bifurcated or Y-shape while reducing the passage cross section area. Two first small check valves () of the spring type in each of which the pressure receiving area is reduced in accordance with the reduced passage cross section areas of the smaller-diameter downstream portions (B) are attached respectively to outlet portions of the smaller-diameter down-stream portions (B) so as to be arranged in parallel. The outlets of the first check valves () are opened in the closed space ().