Patent ID: 8240245

Claim:
A brewing unit ( 1 ) for a beverage preparing machine, comprising: a brewing chamber ( 2 ), a first piston ( 5 ) providing a mobile wall ( 3 ) of said chamber, said mobile wall ( 3 ) having a delivery outlet ( 12 ) for delivering the beverage from said brewing chamber ( 2 ), a valve assembly ( 13 ) for opening/closing said delivery outlet, a second piston ( 6 ) for supporting said first piston ( 5 ) and said valve assembly ( 13 ), said second piston ( 6 ) being movable with said first piston ( 5 ) with respect to said brewing chamber ( 2 ) and being also movable with said valve assembly ( 13 ) with respect to said first piston ( 5 ) for actuating said valve assembly ( 13 ) to respectively open or close said delivery outlet ( 12 ) on said piston ( 5 ).