together with the rotation of the ring the upper and lower tapered portions a 1 and a 2 of the periphery of the rotary body 1 are provided with a large number of inclined grooves c 1 c 2 respectively for improving the efficiency of exhausing dust from the entire surface of the spinning ring body according to the respective direction of rotation of the ring from the central portion a of the body 1 to the respective ends a 1 and a 2 thus when the body 1 is in a state wherein there is no admixture such as cotton dust or the like present in the inclined grooves c 1 and c sub 2 there will be no friction resistance on the rotary body as shown in fig2 thus the rotation of the spinning ring is increased in speed and air flow exhausted towards the respective ends a 39 1 and a 39 2 of the upper and lower tapered portions a 1 and a 2 is generated and thereby preventing the intrusion of dust from the upper and lower ends in this instance when fine dust or the like should stick or enter the admixture will be held in the small plays d 1 and d 2 between the ring rotary body 1.