Machine for preparing coffee infusion

Claim 1

IN A MACHINE FOR PREPARING ESPRESSO COFFEE UPON PERCOLATION OF PRESSURIZED HOT WATER THROUGH A LAYER OF GROUND COFFEE METEREDLY LOCATED INTO HOLES PARAXIALLY PROVIDED INTO A DISCOIDAL ROTARY ELEMENT ARRANGED FOR INTERMITTENT ROTATION INTO A SPACE DEFINED BY OPPOSED FRAME WALLS AND TRANSISTORILY POSITIONED AT A BEVERAGE FORMING LOCATION BELOW A PERFORATED PRESSER FOOT AND ABOVE A COFFEE SCREENING PERFORATED FILTER SUPPORTED BY A MOVABLE PORTION OF SAID WALLS, A SOURCE OF RECIPROCATING MOTION, A PISTON RECIPROCABLE INTO A CYLINDER CHAMBER AND DRIVINGLY CONNECTED TO SAID SOURCE, HOT WATER SUPPLY DUCT MEANS HAVING AN OUTLET IN SAID CHAMBER AND LOCATED TO BE UNCOVERED BY SAID PISTON AS SAID PISTON IS RETREATED BY SAID SOURCE, A PASSAGE BETWEEN SAID CHAMBER AND UPSTREAM OF SAID PRESSER FOOT WHEREBY HOT WATER IS FORCIBLY PERCOLATED THROUGH SAID COFFEE LAYER THROUGH SAID PRESSER FOOT AND SAID FILTER AS SAID PISTON IS FORWARDED BY SAID SOURCE, A SECOND PISTON RECIPROCABLE INTO A SECOND CHAMBER IN FLUID COMMUNICATION WITH SAID CYLINDER CHAMBER, AND MEANS CONNECTING SAID SECOND PISTON TO SAID MOVABLE PORTION OF SAID WALLS TO DISPLACE SAID WALL PORTION TOWARDS SAID ROTARY ELEMENT TO TRANSITORILY PROVIDE A FLUID-TIGHT SEAL BETWEEN SAID ROTARY ELEMENT AND SAID WALLS AS SAID HOT WATER IS PRESSURIZED FOR PERCOLATION THEREOF THROUGH SAID LAYER.