Abstract: The invention provides a coffee machine, with a housing, a fresh water supply reservoir mounted therein, a heating means adapted to heat the fresh water and a feeding pump to supply the heated fresh water to a brewing chamber under pressure. The brewing chamber comprises a closure means and an inlet for coffee powder as well as an outlet for coffee. If appropriate, an installation for pushing out and removing, respectively, the leached-out coffee powder out of the brewing chamber and from the brewing chamber, respectively, may be provided. All parts of the apparatus which are subjected to contamination by the coffee powder or by the coffee, namely the brewing chamber, the closure element, the coffee powder inlet, the coffee outlet and eventually the installation for pushing-out and removing the coffee powder, are combined to a modular unit, which is removably inserted into the housing of the apparatus.

Abstract: A coffee machine includes a grinding mill, a proportioning chamber arranged adjacent to the outlet of the grinding mill and a processing chamber, into which the coffee powder from the proportioning chamber is discharged. The coffee powder coming from the grinding mill is thrown into the proportioning chamber, which includes a pressure sensitive, elastically resilient wall element with a signal generator connected thereto. As soon as the proportioning chamber is filled with coffee powder, a dynamic pressure is built-up within the proportioning chamber due to the overpressure caused by the grinding mill, which forces the wall element to a displacement, whereby the signal generator is operated. Subsequently, on the one hand, the motor of the grinding mill is switched off and, on the other hand, a bottom wall part of the proportioning chamber is unlocked, whereby the milled product, assisted by the elastically resilient wall element, is discharged from the proportioning chamber.