| 摘要 |
<p>A chuck assembly which can chuck thin and brittle workpieces that differ widely in size with high accuracy and reliability without warping them. The chuck assembly includes a tubular chuck body having three first cylinders and a plurality of second cylinders arranged along a circumference in a plane perpendicular to the axis of the chuck body at equal angular intervals. The cylinders have pistons adapted to protrude under oil pressure. The three first cylinders are also arranged at equal angular intervals. The chuck assembly further includes a pressure-biasing means for applying, independently of the oil pressure, pressure to the pistons of the first cylinders against a workpiece, so that the piston are less likely to be retracted by the reaction force from the workpiece. That is, this chuck assembly has a self-centering function. <IMAGE></p> |
