Patent ID: 7114929

Claim:
A reciprocating pump for delivering fluid comprising: a diaphragm that is reciprocated to deliver fluid; a diaphragm drive chamber provided therein with said diaphragm; and a drive-power supply member for supplying drive power for reciprocating said diaphragm; wherein check valves are respectively provided on the upstream side and downstream side of said diaphragm; and each of said check valves includes a valve body having a fluid communication passage, a valve element provided within said valve body so as to open and close said fluid communication passage, an upper guide member provided within said valve body for guiding said valve element within said valve body, and an urging member provided within said valve body so as to apply urging force to said upper guide member, in which said upper guide member to be urged by said urging member is provided so as to urge said valve element towards an inlet side through which fluid flows, and such a clearance as to have an end of said upper guide member positioned close to the surface of said valve element is created between said valve element and said upper guide member when said fluid communication passage has been closed by said valve element.