A device for centering an object and rotating it to a desired angular position relative to a discerning feature. The centration device is particularly adapted for use as a station in a semiconductor wafer handling apparatus, and includes a rotatably driven chuck on which a wafer may be placed by a robot...http://www.google.co.uk/patents/US4880348?utm_source=gb-gplus-sharePatent US4880348 - Wafer centration device
