A positioning device having a plate-shaped carrier (5) which is displaceable in a horizontal plane and which is journalled on a table (1) and on which is exerted a pressure and tensile force, respectively, by means of at least two translation drives (11, 13). The translation drives (11, 13) are coupled...http://www.google.com.tw/patents/US4628238?utm_source=gb-gplus-share專利 US4628238 - Positioning device comprising pre-stressed contactless bearings
