Improved foam pump

摘要

The present disclosure relates to a non-aerosol foam pump for use in association with an unpressurized liquid container and a foaming element comprising. The pump includes a liquid pump portion and an air pump portion. The liquid pump portion has a liquid chamber with a liquid internal volume and a shuttle liquid piston. The liquid chamber is in flow communication with the unpressurized liquid container and in flow communication with the foaming element. The air pump portion has an air chamber with an air internal volume. The air chamber is in flow communication with the foaming element. The liquid pump portion and the air pump portion have an activation stroke and a return stroke. During the activation stroke the air internal volume is reduced and during a beginning stage of the stroke the liquid internal volume remains the same and during a later stage the liquid internal volume is reduced.