| 摘要 |
PURPOSE:To fix surely and stably a disk to the center of a rotary shaft regardless of some error in dimension about the diameter of the disk center hole, by providing a member having a taper-shaped outer circumferential surface which is fitted freely to the inner circumferential surface of the disk center hole. CONSTITUTION:When a cabinet 24 is opened upward, a disk holder member 20 moves up to produce a gap to a disk table 12. A disk 13 is inserted through said gap and the inner circumferential surface 13a of the center hole of the disk 13 is fitted to a taper-shaped outer circumferential surface 16a of a mobile member 16. Thus the disk 13 is set concentrically with the center of a rotary shaft 11. The disk 13 can always be set on the table 12 surely and concentrically with the center of the shaft 11 regardless of some variance in size of the center hole diameter of the disk 13 to the center diameter of the shaft 11 since a recess part 22 of a mobile member 16 is hooked to a hook part 21a of a magnetic member 21. When the cabinet 24 is closed, the member 20 moves down and attracted fixedly to the member 21 via a magnet 19. At the same time, the disk 13 is held and fixed between a friction member 23 and the table 12. |
