Patent ID: 8690641

Claim:
An apparatus for supplying a constant amount of abrasive which supplies a mixed fluid composed of a compressed gas and the abrasive, comprising: a rotating disc which rotates in a horizontal direction and has a plurality of measuring holes having the same diameter, formed in such a manner as to pass through the rotating disc in a thickness direction of the rotating disc, and disposed at equal intervals along a circumferential direction; an abrasive charge section for allowing the abrasive to fall therethrough without application of pressure so as to charge the abrasive into the measuring holes of the rotating disc; and an abrasive mixing section disposed in such a manner as to straddle the rotating disc from opposite sides of the rotating disc at a position corresponding to a rotation orbit where the measuring holes are formed, and adapted to mix the compressed gas from a compressed-gas supply source and the abrasive contained in each of the measuring holes and to deliver the resultant mixed fluid to an abrasive transport path; wherein the abrasive mixing section includes a cylinder which opens toward one surface of the rotating disc at the position where the measuring holes are formed; a piston inserted into the cylinder; and a fluid channel which opens toward the cylinder through the intermediary of the rotating disc and whose opening rim is in sliding contact with another surface of the rotating disc; and one of the cylinder and the fluid channel communicates with a compressed-gas supply source through the intermediary of a compressed-gas introduction path; the other one of the cylinder and the fluid channel communicates with the abrasive transport path; and the piston has a through-hole passing therethrough in such a manner as to coincide with the position where the measuring holes are formed.