Patent ID: 7850049

Claim:
A foam pump comprising: (a) a piston housing including (i) a base wall, (ii) at least one sidewall extending from said base wall, (iii) a liquid tube extending from said base wall interiorly of said at least one sidewall, (iv) an inlet communicating with said liquid tube through said base wall; and (v) a liquid inlet valve regulating flow through said inlet; (b) a piston assembly received in said piston housing, said piston assembly including (i) a liquid piston sealed to said liquid tube of said piston housing to define a collapsible liquid chamber containing a foamable liquid, and (ii) an air piston sealed to said sidewall of said piston housing to define a collapsible air chamber containing air, said liquid piston being positioned in said collapsible air chamber and secured to said air piston to move therewith, said piston assembly including a premix chamber separated from both said collapsible liquid chamber and said collapsible air chamber by a premix chamber wall and fluidly communicating with both said collapsible liquid chamber and said collapsible air chamber through a mix aperture in said premix chamber wall, (c) a biasing member urging said piston assembly to a non-actuated position, wherein the foam pump is actuated by urging said piston assembly against said biasing member to an actuated position in which said collapsible air chamber and said collapsible liquid chamber are reduced in volume such that air is expelled from said collapsible air chamber and through said mix aperture while at the same time foamable liquid is expelled from said collapsible liquid chamber through said mix aperture, with the simultaneous movement of said air and foamable liquid through said mix aperture causing a turbulent mixing thereof into said premix chamber the foam pump characterized in that said air piston includes ribs spaced from one another, and said liquid piston includes a bracket extending to secure said liquid piston to said air piston at said ribs such that the spacing between the ribs provides air channels that permit the passage of air past said bracket and toward said mix aperture.