Machine tool measurement system with scale and scanning device

摘要

The position measuring system has a measurement scale (1) and scanning device (A) to read the scale, where the measurement scale (1) is attached to the machine bed (2) and the scanner (A) is fixed to a longitudinally movable table (T) on the machine. The scale (1) is fixed to the machine bed (2) in th region of its mid point. the two elements (1,2) have differing coefficients of thermal expansion. The ends of the scale (1) are free to move longitudinally. Along the length of travel of the scanning device, holes (12) are located to supply lubricating air or fluid to support the scanning device.