Dispenser having foamed output

A dispenser for dispensing liquids, the dispenser having:

• a housing including structure to change the pressure in the housing;
• a receptacle for liquid to be dispensed, the receptacle being positioned within the housing and having an opening at the bottom of the receptacle so that the liquid will exit the receptacle into the housing sufficient to form a pool having a predetermined level above the opening and thereby trap the remaining liquid in the receptacle with a negative pressure above the liquid in the receptacle in an equilibrium condition;
• and
• a discharge device having an inlet passage extending upwardly from below said level to convey liquid upwardly, a foamer chamber within the discharge chamber for receiving liquid from the inlet passage and having a tubular wall extending upwardly and defining very small openings about the wall and along the vertical extent of the wall spaced in the wall along the upward extent of the wall and located above said level, and an outlet passage leading from the foamer chamber and having an external outlet through which the foam is to be dispensed, whereby activating said structure to increase the pressure within the housing drives the liquid through the inlet passage into the foamer chamber and simultaneously force air through the holes to meet the rising liquid so that the rising liquid is exposed sequentially to individual streams of air passing through the holes thereby causing progressive foaming of the liquid as the progressively foamed liquid meets more holes in travelling vertically so that the foaming is enhanced as the progressively foamed liquid passes all of the holes resulting in a completed foam which is driven through the outlet passage and issues through the outlet.