JPS6449158A - Centering pressing member - Google Patents

Abstract

PURPOSE:To obtain a centering pressing member having a superior roundness with no fear of biting the inner periphery of a center hole of an information recording disk due to burrs by forming projection pieces extending out from outer peripheral surfaces and integrally to segments on their slit forming side. CONSTITUTION:The projection pieces 20 are extendedly provided on the slit 2 side of the outer peripheral surfaces 4a and 4b which is the centering surface 4 of the individual segments 3 of a hub 1 in accordance with a curvature of the outer peripheral surfaces 4a and 4b. These projection pieces 20 are integrally and extendedly provided along the outer peripheral surfaces 4a and 4b in the circumferential direction and formed totally to be thin with their tip parts 21 being formed the thinner the nearer tips 21a as if their surfaces on their inner peripheral side where chamfered. Then, the tips 21a of the projection pieces 20, which are adjacent to each other are oppositely disposed under the state of being apart from each other with a gap G. By such a method of constitution, the centering pressing member with the superior roundness is obtained with no fear of biting the inner periphery of the center hole of an information recording disk by burrs produced during the forming process of the hub 1.