CO-ORDINATE MEASURING DEVICE COMPRISING VISCOUS DAMPER AND A REDUCED INFLUENCE OF THERMAL EXPANSION

摘要

The invention relates to a co-ordinate measuring device with a scanning head which is used to scan an object, comprising a base (41) and a pair of parallel guiding rails (11), in addition to a bridge carrier extending transversally thereto and displaceably mounted therein in the longitudinal direction (y) thereof, the scanner head being arranged on said bridge carrier. Vertical support bars (61) provided in the form of viscous dampers for the guiding rails (11) are situated between the base and the guiding rails (11). Said support bars help to dampen the horizontal relative movements. Additionally, a scale (21) can be fixed to a guiding rail (11), said scale possessing a thermal coefficient of dilatation which is different from that of the guiding rail (11). A central area (125) of the scale (21) is fixed to the guiding rail (11) in the longitudinal direction (y) thereof, and the areas (121) of the scale (21) arranged at a distance from said central area (125) on both sides thereof can be displaced in relation to the guiding rail (11) in the longitudinal directional (y) of the scale.