Patent ID: 7048153

Claim:
A foam dispensing article comprising: a reservoir for receiving a liquid product, the reservoir having a closed and an open end; an operating unit for dispensing the foam as an air-liquid mixture at least partially positioned over the reservoir and the open end, the unit comprising: an air pump comprising an air piston slideably movable within an air cylinder; a liquid pump concentrically surrounded at least partially by the air pump comprising a liquid cylinder and a piston slideably movable within the liquid cylinder; an operating component positioned at least partially above the liquid and air pumps, the component comprising a foam forming screen device, a product outflow channel downstream and receiving foamed liquid from the screen device, the operating component by hand pressure being downwardly movable toward the reservoir thereby forcing the pistons to pump air and liquid product through the screen device; a spring system functioning to return both air and liquid pump pistons upward to an unactivated position, the system comprising an inner spring positioned internally concentric to the air piston; and wherein the improvement is characterized in the spring system having a return force of greater than 4 pounds (17.8 N), a lubricant being adjacent the air piston to assist movement against a wall of the air cylinder, the liquid product comprising a surfactant being present in a sufficient amount to at least partially dissolve the lubricant during repeated activation of the operating unit thereby causing the air piston to stick, and the spring system with a return force of greater than 4 pounds overcoming air piston stickage.