Patent 8152524 was granted and assigned to Nakanishi on April, 2012 by the United States Patent and Trademark Office.
Two nozzles 37 in pair are provided along an inner circumferential surface 21a of a concavity 21, air is blown out in a space from a blowout hole 37a provided at a tip end portion of the nozzle from a side where the nozzle 37 is provided aiming at an opposite side along an inner circumferential surface of the space and a powder contained in the concavity 21 is caused to rise up in the space, whereby the condition of the powder mixed with the air within the space is improved.