Brewing unit for a coffee machine

Abstract

The invention relates to a brewing unit () for a coffee maker for brewing a ground coffee portion (), comprising a brewing unit housing (), an upper plunger () firmly connected to the brewing unit housing (), a holder () for receiving the ground coffee portion (), said holder being open at the top and closed at the bottom by a base (), and a brewing plunger () for compressing the ground coffee portion () in a brewing chamber (). The holder () and the brewing plunger () are disposed movably and pivotally in the brewing unit housing (). Mechanical operating elements are provided in the brewing unit housing () for raising, lowering, and pivoting the holder () and the plunger (). The brewing plunger () is hydraulically guided displaceably in the holder () relative to the holder (). Between the brewing plunger bottom side () and the base () of the holder () a lower chamber space () is provided, into which the hot water supply () opens. The brewing plunger () has a passage () for the hot water, said passage being provided with a valve () and connecting the lower chamber space () to the brewing chamber (). When supplying pressurized hot water via the hot water supply () in the lower chamber space (), overpressure is created there, by which the brewing plunger () can be hydraulically pressed in the direction of the brewing chamber ().