Dispositif de commande automatique de machine-outil

摘要

922,542. Numerical control systems; electric selective signalling systems. SOC. GENEVOISE D'INSTRUMENTS DI PHYSIQUE. Feb. 23, 1961 [Feb. 24, 1960], No. 6698/61. Classes 38 (6) and 40 (1). In a punched-tape controlled numerical positioning system, tape errors are checked by duplicating the tape and the associated command signal circuits. A first binary coded tape 11 is read at 13, the resulting signal converted to six digit decimal at 14, and this is stored at 15 on telephone selectors before being converted at 16 to phase modulated A.C. signals. The three signals representing the three most significant digits are applied to three synchros 17 which are appropriately geared to a leadscrew 19 to measure the position of the worktable 10, and any error is amplified at 26 to control a servomotor 25. The signals representing the three least significant digits are applied to two (see below) synchros 18 which are appropriately geared to a lead-screw 20 to measure the position of a photo-electric microscope 29, and any error is amplified at 23 to control a servomotor 24 so that the microscope is moved the fine distance which is a fraction of one of the divisions of a scale 27 which is attached to the table 10. The output of the photo-cell is then applied via switch 28 to the amplifier 26 so as to move the table until the appropriate scale division, which can be checked visually, is centred beneath the microscope. The digital to analogue converter 16 consists of five synchros to the stators of which voltages are applied from five tapped transformers in respect of the first five digits of the decimal command signal, the final, least significant digit controlling the tappings of a sixth transformer which adds a signal to the rotor of the 5th synchro, Fig. 3 (not shown), so that five output lines carry the six digits. The second, checking tape 111 is similarly read and decoded, and the resulting phase-modulated signals are compared with the outputs of either the banks of synchros 17, 18 or with duplicate banks of synchros 171, 181. If, when the table is finally positioned, the second channel shows an error signal, unspecified devices 43, 44 cause a warning lamp to light, or stop the cutting tool. Specifications 684,435, 686,274, 864,049 and 864,050 are referred to.