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:
Feb. 26, 2013
Filed:
Oct. 03, 2008
Yoshiaki Aso, Kyoto, JP;
Yoshiaki Aso, Kyoto, JP;
Shimadzu Corporation, Kyoto, JP;
Abstract
A check valve capable of improving the tightness between a sphere and a valve seat and suppressing the sinking is provided, so as to provide a liquid chromatography infusion pump enabling a high precision infusion even if in a low flow rate region. On a surface, contacted with the sphere, on the valve seatof the check valve, a rimis disposed around a through holein the center of the valve seat. The rimis formed as a boundary between a concave spherical surface of a diameter Φand a concave spherical surface of a diameter Φdisposed as concentric circles with the through hole. When the sphere of a diameter ΦB abuts against the valve seat, the sphereabuts against the valve seatat the annular rimin a line contact according to a relation of Φ>ΦB>Φ