Abstract: The spindle of a machine-tool is mounted on a carriage movable along a horizontal transverse member which is carried by the columns of a part of the frame of the machine having the shape of a closed porch, and which is situated in front of these columns. This transverse member moves vertically along the columns. The workpiece-carrying table, which can rotate on itself, is mounted on a carriage movable in a direction parallel to the spindle axis on a portion of the frame situated in front of the porch. Thus, the machine is compact and, whatever the extreme positions of its movable elements might be, no cantilever condition is produced which could generate machine deformations.

Abstract: The invention is related to a device for determining the position of a structural element to which is affixed a scale composed of regularly spaced markings which are optically cast onto a line scanner containing regularly spaced photosensitive elements, the spacing between photosensitive elements being a subdivision of the distance between two adjacent markings of the scale. The output of the line scanner is coupled to a processing network which detects shifts in the shadows of the cast markings to evaluate the position of the element with precision. A pulse generator in the processing network provides pulses at a frequency which is a multiple of the rate of scanning of the photosensitive elements for measurement of a subdivision of the distance separating two photosensitive elements of the line scanner to obtain greater precision.