Patent Number: 6,168,392

Title: Air pump

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

Inventors: Takano; Yoji (Osaka, JP)

Assignee: Kabushiki Kaisha Tominaga Jyushi Kogyosho

International Classification: A01K 63/04 (20060101); F04B 35/00 (20060101); F04B 39/00 (20060101); F04B 43/02 (20060101); F04B 35/04 (20060101); F04B 039/00 (); F04B 053/00 ()

Expiration Date: 01/02/2018