Patent ID: 7481151

Claim:
A beverage maker comprising: a water reservoir ( 2 ); a closed water boiler ( 5 ); a beverage brewing unit ( 8 ); a water supply channel ( 25 ) interconnecting the water reservoir ( 2 ) and the closed water boiler ( 5 ); a water discharge channel ( 19 ) interconnecting the boiler ( 5 ) and the beverage brewing unit ( 8 ); a pump ( 3 ) for pumping water from the boiler ( 5 ) to the beverage brewing unit ( 8 ); a return channel ( 25 ) interconnecting the reservoir ( 2 ) and the boiler ( 5 ); and a valve structure ( 7 ; 47 ; 107 ) having an inlet ( 9 109 ) connected for water inflow from the boiler ( 5 ) and the pump ( 3 ), a return outlet ( 16 ; 116 ) connected for returning water to the reservoir ( 2 ), and a discharge outlet ( 20 ; 120 ) connected for water outflow to the brewing unit ( 8 ), the valve structure ( 13 ; 43 ; 153 ) being adapted for: preventing water passage from said inlet ( 9 ; 109 ) to said return outlet ( 16 ; 116 ) if the water pressure at said inlet ( 9 ; 109 ) is below a relief pressure value; allowing water passage from said inlet ( 9 ; 109 ) to said return outlet ( 16 ; 116 ) if the water pressure at said inlet ( 9 ; 109 ) is above said relief pressure value and below a shut-off pressure; preventing water passage from said inlet ( 9 ; 109 ) to said return outlet ( 16 ; 116 ) if the water pressure at said inlet ( 9 ; 109 ) is above said shut-off pressure value; preventing water passage from said inlet ( 9 ; 109 ) to said discharge outlet ( 20 ; 120 ) if the water pressure at said inlet ( 9 ; 109 ) is below a discharge pressure value; and allowing water passage from said inlet ( 9 ; 109 ) to said discharge outlet ( 20 ; 120 ) if the water pressure at said inlet ( 9 ; 109 ) is above said discharge pressure value; wherein said relief pressure value, said shut-off pressure value, and said discharge pressure value are predetermined at least to the extent that: said relief pressure value is above atmospheric pressure; said relief pressure value is lower than each of said shut-off pressure value and said discharge pressure value; and said shut-off pressure value and said discharge pressure value are each lower than a pumping pressure at said inlet ( 9 ; 109 ) generated by said pump ( 3 ) when said pump is in operation.