A device for measuring the shape of a three-dimensional object comprises a movable arm composed of a plurality of movable arm members and a probe coupled to a forward end of the movable arm by a universal joint. At each of the movable arm members and probe, there is provided an angle-of-rotation encoder...http://www.google.com/patents/US4703443?utm_source=gb-gplus-sharePatent US4703443 - Device for measuring the shape of a three-dimensional object
