Dispenser head for mixing separate pasty substances and a storage unit provided with such a dispenser head

A head for dispensing doses of a product of a pasty or viscous consistency resulting from the mixing in the head of two constituents stored in separate side-by-side reservoirs each provided with a dispensing outlet element, said head being comprised of a first and a second part fitted to each other, said first part having a pair of ejection ducts passing therethrough and being provided with means adapted to cooperate simultaneously with the two dispensing outlet elements for causing the ejection of the contents of the reservoirs into respective ones of said ejection ducts, said first and second parts having complementary means carried thereby to cooperate to define a mixing chamber in the assembled position of the two parts, said ejection ducts opening into said mixing chamber at spaced locations, and said mixing chamber having a single outlet opening for the dispensing of a mixture of material admitted to the chamber from the two ducts, said first and second parts having mutually facing respective walls integral with said respective part, one of said walls having a continuous rib carried thereon extending substantially perpendicular therefrom and the other of said walls having a groove formed therein of a shape complementing the external contour of said rib, said mixing chamber being located between said walls and said rib being received in said groove with said rib having a height from said respective wall such that said rib defines the side walls of said mixing chamber when said first and second parts are assembled.