Pneumatic chemical pump

Abstract

A pneumatic chemical pump includes a pump body having a base and a cover, and a bellows-type container. The base defines an inner receiving space, and is provided with two opposite one-way valves communicating with the receiving space. The bellows-type container is located in the receiving space in the pump body with a lower open end communicating with the two one-way valves. Multiple internal and external annular channels are alternately formed on a peripheral wall of the bellows-type container. Each of the internal annular channels has a lower surface radially inward and downward inclined toward to the lower open end. When the bellows-type container works to pump out a working fluid therein, the working fluid follows the inclined lower surfaces of the internal annular channels to completely flow out of the container without the risk of forming crystals to adversely affect the usable life of the bellows-type container.

1 . A pneumatic chemical pump, comprising:
 a pump body having a base and a cover; the base defining an inner receiving space and being provided at two opposite sides with a first and a second one-way valve communicating with the inner receiving space; and   a bellows-type container being located in the inner receiving space of the pump body with a lower open end of the container communicating with the first and the second one-way valve; a plurality of internal annular channels and a plurality of external annular channels being alternately formed on a peripheral wall of the bellows-type container, and each of the internal annular channels having a lower surface radially inward and downward inclined toward to the lower open end.   
   
   
       2 . The pneumatic chemical pump as claimed in  claim 1 , wherein the bellows-type container further includes a plurality of elastic members separately mounted around the external annular channels.