Patent attributes
The invention provides a dispensing assembly to dispense a foam, comprising: ⋅—a double cylinder element (2) mounted or to be mounted in an opening of a container (100), comprising a liquid cylinder (3) and an air cylinder (4), wherein the liquid cylinder has a smaller diameter than the air cylinder, and wherein the liquid cylinder and the air cylinder are arranged substantially concentrically, and ⋅—a piston assembly (10) comprising a liquid piston (11) and an air piston (12) for reciprocal movements in the liquid cylinder and air cylinder, respectively, and a common operating part for operating the liquid piston and air piston, ⋅ wherein a liquid pump chamber (14) is at least delimited by the liquid cylinder and the liquid piston, said liquid pump chamber having a liquid inlet (15) and a liquid outlet (16), ⋅ wherein an air pump chamber (25) is at least delimited by the air cylinder, the air piston and the liquid piston, said air pump chamber having an air inlet (26) and an air outlet (27), ⋅ wherein the piston assembly (10) further comprises a dispensing channel (28) in fluid communication with the liquid outlet and the air outlet, wherein the dispensing channel ends in a dispensing opening (29), ⋅ characterized in that the air outlet (27) is provided in the liquid piston in a region of the air pump chamber opposite to the air piston (12).
