Patent ID: 9560933
Date: 2017-02-07
CPC Classifications: A47J

Claim:
1. A brewing device for an espresso maker having a brewing chamber for receiving grounds, a pressing ram mounted movably along a path of travel extending between a top position and a bottom compaction position in which it penetrates into said brewing chamber to form a cake of compacted grounds, a hydraulic drive mechanism for the pressing ram having a hydraulic pump and means for measuring the volume of hydraulic fluid injected into the drive mechanism, wherein the brewing device has a control circuit which determines the height of the cake of compacted grounds from signals delivered by the volume measurement means during the travel of the pressing ram, and wherein the volume measurement means has a flow meter and the brewing device comprises a calibrating device for calibrating the flow meter in relation to a portion of the path of travel of the pressing ram, and wherein the calibration device has a switch and a ruler displaceable with the pressing ram in which the ruler is equipped with two projections cooperating with the switch, the distance between the two projections corresponding to the portion of the path of travel of the pressing ram.