Patent ID: 7896163

Claim:
A sifter comprising: a receiver having a supply chamber for receiving an air-powder mixture to be sifted from an upstream via an inlet; a sieve assembly having a sieving chamber, said sieving chamber having an inner area and an outer area, said sieve assembly being coupled to and communicating with said supply chamber; a rotator having a rotating shaft laterally arranged to pass through said supply chamber and said sieving chamber; a cylindrical sieve located inside said sieving chamber and arranged coaxially with said rotating shaft; a hollow drum having an inner circumferential face and an outer circumferential face, having a circular cross-section, and having a larger diameter than the diameter of said rotating shaft, said hollow drum being extended in at least space of said sieving chamber and arranged coaxially with said cylindrical sieve in an axial direction of said rotating shaft, said hollow drum having a conical front portion having a front end, and said front end being connected to said rotating shaft; a stirring rotor located in said inner area of said sieving chamber inside said cylindrical sieve, said stirring rotor comprising a plurality of rotating blades attached to said rotating shaft to push the air-powder mixture to be sifted from said inner area to said outer area of said sieving chamber outside said cylindrical sieve, said stirring rotor being attached to said outer circumferential face of said hollow drum; an extraction member for enabling removal of oversize powder or foreign substances trapped by said cylindrical sieve from said inner area; and an outlet for discharging powder passing through said cylindrical sieve from said inner area to said outer area.