Dispenser unit with improved air supply

1. Dispenser unit suitable for a liquid container, comprising:

an air pump with an air cylinder and an air piston axially displaceable in the air cylinder,

an air space defined between the air cylinder and the air piston,

supply-closing means for closing an air supply to the air pump,

discharge-closing means for closing an air discharge from the air pump,

an axially displaceable activating element for activating the air pump, and

an air inlet opening in the activating element, wherein the air inlet opening debouches in the air space, characterized in that at least a part of the air piston forms the supply-closing means, said part being arranged against the inner wall of the activating element and over the air inlet opening, wherein the air piston is movable axially relative to the activating element;

a liquid pump with a liquid cylinder and a liquid piston, wherein a liquid chamber is defined between the liquid cylinder and the liquid piston; and

an insert which is connected to the activating element and which comprises a mixing chamber for mixing air from the air pump and liquid from the liquid pump.

2. Dispenser unit as claimed in claim 1 , wherein said part of the air piston forms a moving part of the supply-closing means.

3. Dispenser unit as claimed in any one of claim 1 or 2 , wherein the liquid piston is movable in axial direction relative to the activating element for the purpose of forming the discharge-closing means for air.

4. Dispenser unit as claimed in claim 3 , wherein the insert forms, together with the liquid piston axially movable relative thereto, the discharge-closing means for air.

5. Dispenser unit as claimed in any one of claim 1 , 2 , 3 , or 4 , wherein the liquid piston is connected to the activating element.

6. Dispenser unit as claimed in claim 5 , wherein the discharge-closing means comprise a pressure-controlled valve.

7. Dispenser unit as claimed in any one of the claim 1 , 2 , 3 , 4 , 5 , or 6 , wherein the air piston comprises a bottom edge part sealing the air cylinder, a top edge part sealing the air inlet opening, and a sleeve part extending substantially axially between the two edge parts.

8. Dispenser unit as claimed in any one of claim 1 , 2 , 3 , 4 , 5 , 6 , or 7 , wherein the activating element comprises a cover with a spout-like dispensing part.

9. Dispenser unit suitable for a liquid container, comprising:

an air pump with an air cylinder and an air piston axially displaceable in the air cylinder,

an air space defined between the air cylinder and the air piston,

supply-closing means for closing an air supply to the air pump,

discharge-closing means for closing an air discharge from the air pump,

an axially displaceable activating element for activating the air pump, and

an air inlet opening in the activating element, wherein the air inlet opening debouches in the air space, characterized in that at least a part of the air piston forms the supply-closing means, said part being arranged against the inner wall of the activating element and over the air inlet opening, wherein the air piston is movable axially relative to the activating element,

wherein opening and closing of the air supply with the supply-closing means and/or of the air discharge with the discharge-closing means is performed in actively controllable manner.

10. Dispenser unit as claimed in any one of the claim 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , or 9 , wherein the supply-closing means and/or the discharge-closing means comprise path-controlled valves.

11. Dispensing assembly comprising a liquid container and a dispenser unit as claimed in any one of the claim 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , or 10 connected thereto.

12. Use of a dispenser unit or dispensing assembly as claimed in any one of claim 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , or 11 .