| 摘要 |
A hub is disclosed for mounting the spindle of a rotary tool, particularly a grinding or polishing wheel for ophthalmic lenses. The hub comprises a cylindrical bore and a plurality of radial centering arms arranged around the bore with their free ends lying in a common circle concentric with the axis of the bore. The centering arms each have a hinge or pivot which may be formed by a portion of reduced section at their bases. The pivot or hinge axes of the centering arms are tangent to another common circle concentric with the bore. Each of the centering arms is of elastically deformable construction fixed, or formed in one piece, with the rest of the hub. The hub is divided by a radial groove into a rigid, one-piece part and a deformable flange formed by the centering arms. A tightening ring with a preferably planar thrust or engagement face is adapted to apply an axial force against the centering arms so that they come into retaining engagement with the spindle. |
