Foam forming liquid dispensing device

Abstract

A foam dispensing apparatus of the present invention includes a reservoir containing a foamable liquid, with a closed headspace above a surface of the liquid. The apparatus also includes a source of a gas disposed to impose a gas pressure higher than ambient atmospheric pressure into the closed headspace. There is a mixing chamber having an inside diameter, an inlet and an outlet open to the ambient atmosphere with a flow restricter having a plurality of openings therein in gaseous communication with the closed headspace. The flow restricter is positioned at the inlet of the mixing chamber and an elongate delivery tube with an open passageway therethrough that defines a longitudinal axis extending from the inlet of the mixing chamber to below the surface of the foamable liquid disposed so that an application of the gas having higher pressure than atmospheric pressure to the headspace causes the foamable liquid to flow through the tube past the flow restricter, to mix with the headspace gas having higher pressure than atmospheric pressure that flows from the openings in the flow restricter and then to expand to atmospheric pressure in the mixing chamber thereby to form a foam from the foamable liquid and discharge the foam from the outlet.