| 摘要 |
PURPOSE:To prevent the increase of diameter for the center hole of a disk and to ensure the highly precise centering of the disk, by positioning the disk by means of a conical surface of a center table which can freely move toward a driving shaft with a limited degree of projection. CONSTITUTION:When a loading member 8 is moved down, a contact face part 10a of a loading member 10 energized with a spring 11 touches a disk hub 2 which is reinforced by a metallic material, etc. of a disk 1. Thus a center table 6 is pushed down. The table 6 can move freely to a driving shaft 4 of a turntable 3 with application of the energy of a spring 7 and has its degree of projection limited via a stop ring 5. Then the center hole 1a of the hub 2 is fitted to the conical face part of the table, and the centering is carried out for the disk 1. When the member 8 is moved down further, the hub 2 is held between the tip edge face 3a of the table 3 and the face 10a. Thus the disk 1 is held. In such constitution, the increase is prevented for the diameter of the disk center hole and the centering of the disk can be performed with high precision and without causing any deformation, etc. |
