Patent ID: 7886938

Claim:
A powder and granular material feeder, comprising: a bottom plate; an outer tube located upright on the bottom plate; an inner tube spaced from an upper end portion of the outer tube and sharing a center line with the outer tube; an ascendable/descendable height adjusting tube defining a material passage clearance between a lower end of the inner tube and the bottom plate for adjusting height of the clearance; a rotation shaft located on the bottom plate and extending along the center line; a plurality of spokes located on the rotation shaft; a ring located at distal ends of the plurality of spokes and extending along an inner peripheral surface of the outer tube; a plurality of inward claws located on the ring and between the spokes; a fall opening in the bottom plate and open to a space between the inner tube and the outer tube and having an arcuate configuration; a small cylinder comprising a center corresponding to a center of curvature of the fall opening, having an arcuate configuration ends reaching the inner tube or an inner side of the inner tube from an outer side of the outer tube, and an upper end connected to the bottom plate; a rotor sharing a center line with the small cylinder; a scraping plate located on the rotor, wherein the scraping plate and the spokes rotate in opposite directions from each other at a portion of the fall opening, and powder and granular material discharged from a discharge clearance at the lower end of the inner tube into the space and transferred into the fall opening from the bottom plate facing the spaced by the spokes and the inward claws is discharged in a direction opposite to the direction of transfer by the scraping plate while being leveled by a lower edge of the outer tube; an annular horizontal disk above the fall opening; and a cover on a discharge port in the small cylinder or in a lower end plate of the small cylinder, wherein both the annular horizontal disk and the cover include a ventilation hole and a plug for the ventilation hole.