Patent ID: 6168392
Filing Date: 2001-01-02
Classification: A01K,F04B

Abstract:
An air pump, comprising: an outer casing; and a pump unit provided in said outer casing, wherein said pump unit includes:a diaphragm; a diaphragm-driving unit for driving said diaphragm; a pump casing to which said diaphragm is attached, said pump casing having an inside space which is divided into an air-inlet side chamber communicating with an inside space of said diaphragm via an inlet opening with an inlet valve and an air-outlet side chamber communicating with the inside space of said diaphragm via an outlet opening with an outlet valve; and a silencing unit provided in at least one of said chambers, wherein said silencing unit comprises an inner pipe having an opened tip end and an outer pipe having a closed bottom end, and wherein said outer pipe loosely covers said inner pipe with said closed bottom end facing said opened tip end, whereby air to be introduced into said diaphragm or to be sent out of said diaphragm flows through said silencing unit while changing a flow direction of the air at said closed bottom end of said outer pipe.