Disposable plastic liquid pump

Abstract From the Canadian patent

A disposable plastic pump for dispensing liquids is disclosed which comprises three basic unitary all plastic elements: a chamber forming body having an open outer end and an inner end in fluid communication with a liquid reservoir, a one-way valve located at the inner end of the chamber between the reservoir and the chamber permitting fluid flow only from the reservoir into the chamber, and a piston formed to slidably fit into the chamber. The piston comprises a stem on which is located an inwardly located flexing element serving as a one-way valve to permit fluid flow outwardly past the flexing element and a sealing element located outwardly of the flexing element. A channel is provided …