Patent ID: 8382980

Claim:
Household water filter comprising: a cylindrical housing coaxially surrounding a vertical axis and having an upper end with an inlet opening and an outlet opening and a closed bottom end; an upper distribution grid positioned spaced below the inlet and outlet openings, wherein the upper distribution grid is substantially flat and has a circular shape with a peripheral edge contacting the cylindrical inner surface of the housing; a lower distribution grid positioned below the upper distribution grid and spaced above the closed bottom end of the housing, wherein the lower distribution grid is substantially flat and has a circular shape with a peripheral edge contacting the cylindrical inner surface of the housing; a helical partition and a granular filter held between the upper distribution grid and the lower distribution grid; wherein the helical partition is made of a single twisted band having a longitudinal center axis twisted around the vertical axis of said housing to define a single partition having a helical shape, wherein side edges of the twisted band form blades that tightly contact a cylindrical inner surface of the housing along its entire length, wherein an upper end edge of the twisted band tightly contacts a lower surface of the upper distribution grid and the lower end edge of the twisted band contacts an upper surface of the lower distribution grid, wherein the granular filter material is arranged helically between the partition and the cylindrical inner surface of the housing; and one flat rectangular partition positioned between the inlet and outlet openings, said partition having a lower edge extending through the upper distribution grid and abutting an upper edge of the twisted band, a pair of side edges tightly contacting the cylindrical inner surface of the housing, and an upper edge tightly contacting the upper end of the housing.