Patent GB-1433420-A (GB)
Title: Apparatus for numerical control of automatic machine-tools
IPC: G05B19/414
Filed: 1973-08-06
Abstract: 1433420 Numerical control of machine tools LENINGRADSKY ORDEN LENINA POLITEKHNICHE INST IM MI KALININA and LENINGRAD ELEKTROMEKHANICHE ZAVOD LEMZ 6 Aug 1973 37267/73 Heading G3N In a numerical control apparatus for machine tools, a magnetic storage matrix 1 Fig. 1 owing to multi-functional usage of its components (squareloop hysteresis cores) provides the principal functional units of the apparatus i.e. a buffer storage 2, an operating register 3 and a computer 4. Input on punched tape at input unit 14 contains data of co-ordinates for moving working tools of an automatic metal cutting tool 13. The data is divided into portions forming frames each containing information about alteration of the position of tools between two reference points. Three programmes are introduced into the apparatus: the data input program, a program for computing the trajectory of movement of the tools, and a program for computing the co-ordinate correction of the final point of the trajectory of the working tools from a trajectory pre-set by the program to take into reduction in the radius of the cutting tools due to wear. The programmes are introduced into the magnetic matrix 1 for storage and conversion prior to the attachment of the apparatus to the machine tools 13, the buffer store 2 is used to store data about a subsequent frame while the operating registers 3 perform the storage function when the programmes are being computed by computer 4 which performs appropriate logical operations. In operation, an automatic control unit 11 is triggered by a current pulse from an output 18 of a control desk 17 and starts operating. The control unit 11 carries information contained in the buffer storage 2 into the operating registers 3 in a series of commands as part of the program for controlling the trajectory of movement of tools 13. In accordance with each command the address information is applied to reversible de-coders5, 6. Any command being fulfilled consists in exciting a series of current pulse signals from a multichannel output 28 of the tool control 11. These signals excite the de-coders5, 6, pulse shapers 7, regeneration register 10 and switching keys 9 in a required sequence. In addition a pulse from 28 is used to read information from a program control unit 15 and carry it to the matrix 1 via register 10 and to read information supplied from the control desk and carry it to the matrix via units 15 and 10. Words from the buffer storage 2 or operating registers 3 are rewritten into the lines of computer 4, the addresses of these lines having been previously introduced from output 26 of control 11 into the de-coders5, 6. The computer converts information fed thereto in accordance with an algorithm corresponding to the given command and expressed as elementary operations of conjunction, disjunction, inversion, shift and carry through. Data read from lines of the matrix 1 is recorded via reproduction amplifiers 8 into the regeneration register 10 or is transmitted into the tool control 11, feedrate setting unit 12 or into the machine tool unit 13. The feedrate setting unit 12 controls the time of shaping of control pulses by a unit 32 which pulses are used for controlling the drives (not shown) of the tools in the metal cutting machine tool 13. This determines the frequency of elementary movements of the tools, the pulses from 32 corresponding to co-ordinates of movement of the tools. The multiprogramming unit 20 is detailed in Fig. 2 (not shown) and the tool control 11 is detailed in Fig. 3 (not shown).