Abstract: A method and apparatus for producing relative arcuate movement which may be greater than one quadrant for each input command by subdividing the movement into a plurality of sequential linear lengths of varying extent and proper direction. The extent of each length is defined by the number of steps of movement to be produced simultaneously over the same time interval on each of the pair of perpendicular axes. The extent of each length is determined to be that which both maintains the actual movement within a maximum deviation from the commanded path and is within the change of velocity limitation of the system thereby inherently providing acceleration and deceleration as well as not excessively exceeding any feed rate command.The method and system further selects the extent of the length from a group of possible extents by investigating which extent is most acceptable having regard to relative emphasis of path deviation and velocity error. The relative emphasis may be set by input commands.

Abstract: In a control apparatus for a machine tool, an interpolator circuit for determining whether or not one of the axis motors should be inhibited on the next step to maintain the tool closer to the desired circular path. The interpolator utilizes information as to the distance from the initial position of the tool to the center of the arc defining the path of travel and which axis is to be inhibited initially to determine when to inhibit. The main logic circuit in the control apparatus begins a move of the number of steps equal to the distance to be moved along the axis which represents the shorter distance between the initial point and the center of the arc. The interpolator presets a counter with that number of steps subtracted from the number of steps equal to the distance to be moved along the other axis and increments that counter by one each time the selected motor is inhibited.

Abstract: In infrared spectroscopy utilizing an interferometer, position stepping of the optical path difference in the interferometer must be accomplished quite rapidly in response to a drive signal applied to a moveable mirror in the interferometer which is proportional to the offset distance desired from the previous null point. As the mirror moves in response to this drive signal, effectively getting closer to the new null point, the drive signal is gradually reduced, in response to detected reference laser fringes. At the new null position, the drive signal will effectively be zero. A binary up/down counter drives a digital/analog converter (DAC). The output from the DAC is supplied to the mirror moving means. The fringes generated by a reference laser are detected as the mirror moves, causing the up/down counter to be decremented to its null count, thereby reducing the output of the DAC, as the mirror moves towards its new null position.

Abstract: An apparatus and method are disclosed for substantially improving the accuracy and surface finish quality of numerical control machine tool performance by generating velocity command signals for multiple axis drive systems based on the distance between the cutting tool and a point along the desired path, either the desired end point or a dynamic target which moves continuously along the desired cutting path ahead of the cutting tool.

Abstract: A computer numerical control system for controlling a lathe or similar machine tool in the cutting of threads. One computer is used as an interpolator to produce speed commands in real time for producing a smooth cutting tool motion. A second computer is used as an axis controller for receiving said speed commands and for controlling the servo circuits of up to six machine tool axes. A resolver attached to the rotating spindle is utilized to synthesize a tachonometric signal, and is also connected to an interrupt circuit to measure the spindle speed and position. The interpolator then uses this spindle information to synchronize the cutting tool motion with the spindle angular speed and position to enable multiple passes of the cutting tool along the same thread line.

Abstract: Input signals supplied for each block to an interpolator for a numerically controlled machine comprise displacement signals representative of conventional displacement data in terms of a conventional step size and a feed rate signal representative of a feed rate which, in turn, defines a conventional pulse distribution rate. The interpolator selects, in response to the feed rate signal, a working step size to be an integral multiple or an integral submultiple (exclusive of unity) of the conventional one, derives working displacement data and a working pulse distribution rate by dividing the conventional ones by the multiple or submultiple, and carries out pulse distribution in a conventional manner but by the use of the working displacement data and feed rate to produce those distribution signals at the working pulse distribution rate which make servos feed a machine tool relative to a workpiece with the working step size and at the feed rate.

Abstract: A numerical control system comprises a machine tool having two axially movable sections, a tape reader for instructing a movement path of the movable section, a sampling pulse generator for generating a pulse for each predetermined time period, a position detector for detecting the amount of movement of the movable section for each sampling time, a controller for calculating an instruction position increment value corresponding to the movement for the predetermined time period of the movable section of the machine tool based on a data from the tape reader, the sampling pulse from the sampling pulse generator and a position data from the position detector, a digital-analog converter for converting a digital output of the controller to an analog value, a servo amplifier for amplifying the output of the digital-analog converter and a servo motor driven by the output of the servo amplifier.

Abstract: An apparatus for distributing drive pulses to drive servomechanisms in a numerical control system is provided with a clock pulse generator, presettable counters respectively associated with the servomechanisms, and a digital computer. Each counter generates an output command each time it receives from the pulse generator clock pulses of the same number as its preset value. The digital computer is programmed to calculate from numerical control data pulse distribution cycles for the respective servomechanisms, and is further programmed to distribute one drive pulse to the corresponding servomechanism, as well as supplying the period of the distribution cycle for the same servomechanism as a preset value to the counter when the output command is supplied from the same.

Abstract: A control system for positioning a machine member in accordance with a set of predetermined instructions corresponding to a prescribed path of movement of the machine member includes first and second motor driving means operative in two mutually perpendicular directions to drive the machine member, pulse generating means to actuate the motor driving means, and a contour logic circuit to enable operation of the motor driving means in such a way that the machine member follows a staircase path closely conforming to the prescribed path. Drive of the first motor driving means is continuously maintained and drive of the second motor driving means is permitted only when required, then drive of the second motor driving means is continuously maintained and drive of the first motor driving means is permitted only when required.

Abstract: A numerical control system for lathes includes a controller adapted to calculate a tool moving amount based on data from a tool moving mode-punched tape as read by a tape reader for each sampling time .DELTA.t when a pulse is generated from a sampling pulse generator and on spindle rotation position data detected by a spindle position detector, and executes a tool action instruction mode including a feed per minute instruction mode, feed per spindle revolution instruction mode and thread cutting instruction mode by operating a tool through a servo system in accordance with the tool action mode.

Abstract: An automatic milling or grinding machine provided with a rotationally and rectilinearly displaceable workpiece support is disclosed. Sets of information relating to the law of a camming surface to be formed on a workpiece and to workpiece-dependent parameters determining dimensional characteristics of the camming surface, respectively, are stored in the machine. Related items of information derived from each set are operatively associated with one another and a succession of angle information signals are generated, the succession defining a circular arc corresponding to one on which the axis of rotation of a given roller follower would move on following the camming surface. The machine provides pairs of co-ordinate displacement command signals in response to each angle information signal and applies the command signals to orthogonal co-ordinate drive means arranged to displace the workpiece support along the circular arc in a plane perpendicular to the rotational axis of the workpiece support.

Abstract: A numerical control system having both linear and circular interpolating capabilities is described. Data from a permanent storage medium such as tape are input to a preprocessor. The preprocesor processes the data into a form acceptable to the system logic and makes all parameters for both linear and circular interpolation available to the system logic. Because linear interpolation is used, straight lines as well as arbitrary curves which are simulated by a series of short straight line segments can be drawn or cut. Additionally, because circular interpolation is used, arbitrary curves can be simulated by a series of arcs, each of the arcs being a portion of a different circle and the various circles having varying radii in accordance with the dictates of the arbitrary curve being cut or drawn. The ability to use both circular and linear interpolation substantially reduces the data processing because the interpolation technique requiring the least definition can be conveniently employed.

Abstract: A method and apparatus are disclosed for controlling the initiation of cutting motions for cutting multiple start threads on a rotating workpiece held in a spindle of a numerically controlled machine. The numerical control contains an interpolator circuit responsive to a spindle feedback circuit connected to the spindle for generating a marker pulse and a predetermined number of spindle pulses for every revolution of the spindle. The apparatus provides input signals representing a particular threading start number relative to the total number of threading starts. Next, a control signal is generated which represents a number of spindle pulses as a function of the ratio of the particular threading start number to the total number of threading starts. Upon detecting an occurrence of a marker pulse which would normally initiate a threading motion, the apparatus is operative to inhibit a number of spindle pulses corresponding to the control signal.

Abstract: Apparatus for positioning a workpiece and tool in a precise location relative to each other by positioning in a predetermined site the workpiece, and then positioning the tool in a precise predetermined positon relative to the site in minimum total time. The apparatus comprises a closed loop position and velocity sensitive servo system connected to the workpiece, the servo system including positioning apparatus for positioning the workpiece in a predetermined site. A position indicator determines the actual position of the workpiece relative to a fixed reference and emits a signal output which is compared, in an error generator, with the desired position of the workpiece relative to the reference. The difference signal, from the error generator, is applied to the positioner and is used to bring the workpiece into the site. The positioner is provided with velocity feedback which cooperates with the positioning signal from the error generator to drive the workpiece into the predetermined site.

Abstract: A servo-controller, where, in order to enable a second mobile member to carry out a certain programmed sequence of operations corresponding to the moving position, speed, pressure, force or torque of a first mobile member, the said moving position speed, pressure, force or torque of the first mobile member is detected as an analog signal, which is compared with each of various level signals sorted stepwise and identified so as to operate the corresponding relays in succession; where the successive actions of these relays is such that control is effected by a first switch group (on a pin board connection panel), a second switch group (for carrying out switching operations for the step subsequent to each member of the first group) and a third switch group for selecting the said level signal; a remainder derived from the difference signal between set signals passed through these first and second switch groups, respectively, is multiplied by another remainder derived from the difference signal between the said an

Abstract: A converter converts numerical data of unit length indicating instructions for moving a component in directions of first and second coordinates to a number of pulses of minor resolution. An interpolator coupled to the converter interpolates the pulses of minor resolution to provide distribution pulses of minor resolution. A mover coupled to the interpolator moves the component in directions of one of the coordinates in minor resolution. A divider coupled to the interpolator converts the number of pulses of minor resolution to the lesser number of pulses of major resolution and a mover coupled to the divider moves the component in directions of the other of the coordinates in major resolution.

Abstract: A digital differential analyzer circuit is provided that depending on the embodiment chosen can carry out linear, parabolic, circular or cubic interpolation. In the embodiment for parabolic interpolations, the circuit provides pulse trains for the X and Y slide motors of a two-axis machine to effect tool motion along a parabolic path. The pulse trains are generated by the circuit in such a way that parabolic tool motion is obtained from information contained in only one block of binary input data. A part contour may be approximated by one or more parabolic arcs. Acceleration and initial velocity values from a data block are set in fixed bit size registers for each axis separately but simultaneously and the values are integrated to obtain the movement along the respective axis as a function of time. Integration is performed by continual addition at a specified rate of an integrand value stored in one register to the remainder temporarily stored in another identical size register.

Abstract: A lathe numerical control system for cutting a tapered thread by a cutting tool that is moved along a rotating workpiece in steps on both a lead axis and a radius axis. Synchronism of movement along both axes with the workpiece rotation is achieved by an encoder producing a set number of pulses per revolution of the workpiece and these pulses are directed simultaneously to a lead axis path and a radius axis path with each path effectively dividing its encoder pulses to produce the steps needed for the tool movement to produce a thread for each revolution.

Abstract: A circuit for analog adjustment of a machine including a programming means to generate a fixed number of discrete control voltages. Each programmed control voltage corresponds to the desired machine control voltage at a particular moment of time in the cycle of the controlled machine. A staircase voltage is generated during the time period between two successive moments in the machine cycle, i.e., a machine cycle interval at which the control voltage is defined. The staircase voltage starts during each machine interval at the programmed control voltage corresponding to one moment of time in the machine cycle at the beginning of a particular machine cycle interval and ending, at the beginning of the next machine cycle interval, at the programmed control voltage for the moment of time corresponding to the beginning of the next machine cycle interval.

Abstract: The invention is directed to a novel apparatus for milling Swiss-type screw machine cams. The invention provides a highly simplified and economical numerically controlled system enabling Swiss-type screw machine cams and similar articles to be milled with an ease and precision heretofore unattainable otherwise than with highly sophisticated and costly equipment.In its most typical application, the invention is utilized in the retro-fitting of an existing .Iadd.cutting machine, such as a shaping or .Iaddend.milling machine apparatus of otherwise conventional construction. Alternatively, the invention can be applied in the first instance in connection with the manufacture of modified milling machines incorporating the new control system.The system of the invention utilizes a conventional three axis .Iadd.cutting machine, such as a shaping or .Iaddend. milling machine, which is fitted out with a rotary table. Numerically controlled stepping motors are provided for the "X" and "Y" axes of the .[.milling.].