Metering device for at least one medium

1. A metering device for at least one medium, with a medium storage unit, and with a pumping system connected to the medium storage unit, said medium storage unit or said pumping system comprising a venting valve that is held in the closed position by elastic force, wherein a control member is assigned to the venting valve in such a way that the control member opens the venting valve in the event of a pumping movement of the pumping system, wherein the venting valve and the control member are provided with mutually corresponding control surfaces that are brought into contact with one another for opening the venting valve, wherein the venting valve comprises a tubular cuff which, coaxially with respect to a pump axis, encloses a rotationally symmetrical pump section, and wherein the control surfaces are oriented at an inclination with respect to the pump axis in such a way that, during a pumping movement, a radial movement component directed outward from the pump axis is applied to the tubular cuff to open the venting valve.

2. The metering device as claimed in claim 1 , wherein the control member is arranged on an actuating part which belongs to the pumping system and which is movable in a reciprocating motion relative to the venting valve, and in that the venting valve, in an unloaded state of the pumping system, is arranged at an axial distance from the control member relative to the pump axis, that is smaller than an actuating stroke of the actuating part.

3. The metering device as claimed in claim 1 , wherein the control surfaces are formed by mutually facing conical-ring surfaces arranged on the actuating part of the pumping system and on the tubular cuff.

4. A metering device for at least one medium comprising:

a pumping system connected to a medium storage unit, said pumping system comprising a piston pump including a rotationally symmetrical pump section having a pump axis;

a venting valve comprising an elastic tubular cuff having a tubular cuff control surface, the tubular cuff being disposed coaxially with respect to the pump axis and enclosing the pump section, the tubular cuff being elastically maintained in a closed position at rest to seal a radially opening venting bore formed within the pump section; and

a control member axially spaced from the tubular cuff and having a control member control surface, the control member being axially movable in the event of a pumping movement of the pumping system, wherein the control member control surface and the tubular cuff control surface are oriented at an inclination with respect to the pump axis, and wherein a pumping movement of the pumping section axially moves the control member so that the control member control surface contacts the tubular cuff control surface in such a way that a radial movement component directed outward from the pump axis is applied to the elastic tubular cuff to open the venting bore.

5. The metering device as claimed in claim 4 , wherein the control member control surface and the cuff control surface are formed by mutually facing conical-ring surfaces, the control member comprising an actuating part of the pumping system.

6. The metering device as claimed in claim 4 , wherein the control member is arranged on an actuating part of the pumping system and is movable in a reciprocating manner relative to the tubular cuff, and in an unloaded state of the pumping system, the control member is spaced an axial distance from the tubular cuff.

7. The metering device as claimed in claim 4 , wherein the control member has an inner face in contact with an outer sleeve of the pump section.

8. The metering device as claimed in claim 4 , wherein the tubular cuff includes a sealing lip defining an L-shaped cross section, the sealing lip contacting an annular shoulder of a lower part of the piston pump.

9. The metering device as claimed in claim 8 , wherein the inclination of the tubular cuff control surface of the tubular cuff is inclined at an acute angle, with an outer edge of the cuff control surface projecting outwardly and upwardly from an inner edge of the cuff control surface disposed in contact with the pump section.