FOAM DISPENSING PUMP WITH DECOMPRESSION FEATURE

摘要

A dispenser comprises a liquid piston and a gas piston coupled for movement. The pistons are mounted for movement relative to one another to define a mixing chamber therebetween. An actuator simultaneously moves the pistons in a first direction such that the air piston delivers air from an air chamber to the mixing chamber and the liquid piston delivers a liquid from a liquid chamber to the mixing chamber where the air and liquid are mixed in the mixing chamber to create a foam. Movement of one of the air piston and the liquid piston is stopped such that the pistons move relative to one another such that only air is delivered to the mixing chamber. The movement of the pistons in a second direction draws residual foam from a delivery tube and delivers the residual foam to the air chamber.