Abstract: A lathe for processing a workpiece into a nonaxisymmetric shape including a cutter to be always contacted with a workpiece surface at an almost fixed angle. A first support shaft is rotatably supported around a first axis mounted on a tool rest, and a second support shaft is rotatably supported around a second axis mounted on and off-centered from the first axis. Also, a third support shaft is rotatably supported around a third axis mounted on and off-centered from the second axis, and a holder for holding the cutter is secured to one end of the third support shaft. A controller controls the rotating angles of the support shafts to control the movement of the cutter forwards and rearwards and also its contact angle.

Abstract: The workpiece handling device includes a workpiece carrying arm and a workpiece support spaced from the lathe machine on which the workpiece carrying arm is pivotally provided. The workpiece carrying arm includes a gripping unit for holding the workpiece thereon. The workpiece carrying arm can turn within a 180 degree range.

Abstract: In summary, therefore, this invention is directed to a thermal growth detector and compensator for detecting and compensating for relative movement between a work holder of a machine tool and a tool holder, that includes an elongated rod made of a material having a coefficient of thermal expansion of substantially zero that is attached at one end thereof to a part of a machine tool, and is attached at another end thereof to a part of a work holder on the machine tool.

Abstract: In order to so improve a machine for the non-circular machining of workpieces comprising a machine frame, a workpiece spindle held on the machine frame for receiving a workpiece and having a C-axis sensor, a Z-slide displaceable parallel to the workpiece spindle and having a Z-axis sensor, an X-axis drive arranged on the Z-slide for advancing a tool towards the workpiece, an X-axis sensor for determining the position of the tool, and a control device, that it operates quickly and reliably, it is proposed that the control device comprise a numerical machine control system for activating the workpiece spindle and the Z-axis drive and include a numerical X-axis control system, that the X-axis control system activate the X-axis drive independently of the machine control system in accordance with the predetermined non-circular shape, and that a coordination take place between the machine control system and the X-axis control system after certain time intervals.

Abstract: In order to improve a device for the non-circular machining of workpieces comprising a machine frame, a workpiece spindle held on the machine frame and operated as C-axis for a workpiece to be machined, a Z-slide displaceable on the machine frame in the Z-direction in relation to the workpiece spindle and having a Z-axis drive, an X-axis drive in the form of a linear motor arranged on the Z-slide for advancing a tool in the X-direction towards the workpiece, and a numerical control system for activating the X-axis drive in correlation with the rotation of the workpiece spindle, such that more precise work results are obtained, it is proposed that the linear motor serving as X-axis drive be a three-phase asynchronous linear motor with a primary part fixedly arranged in the X-direction on the Z-slide and a secondary part movable relative to the primary part.

Abstract: An apparatus for machining a non-circular workpiece such as a piston wherein a tool is moved back and forth against the workpiece in accordance with profile data defining a desired final shape of the workpiece while the workpiece is rotated at a predetermined speed. The tool is moved by a composite movement of a linear motor driven in accordance with low frequency command values, and a piezoelectric actuator driven in accordance with high frequency command values. A numerical controller of the apparatus calculates the low frequency command values using a first Fourier series and the high frequency command values using a second Fourier series. Coefficients of the first and second Fourier series are determined using least square method in such a way that errors contained in the low and high frequency command values becomes within a predetermined limit.

Abstract: A process permitting a work to be machined alternately using two different spindles of a multi-spindle lathe is disclosed. A transfer process by which the work is transferred between spindles is further added to the automatic programming scheme. The automatic programming apparatus accepts the instructions and allows implementation through interpretation of the instructions and processing of data in the instruction and field and/or in a separate storage. Therefore, machining the work using two spindles and transferring the work enabled with a straightforward input that can be easily understood and through the use of a single program. Conventional machining can be effected without the programmer having to be constantly conscious of which head or spindle is being employed.

Abstract: An apparatus for machining a non-circular workpiece, wherein the profile data of plural sections of the workpiece stored in the profile data storage means are transformed into the frequency functions of 1 to n degree which is a function of the rotary angular velocity of the workpiece. The calculation means finds the amplitudes and the phases of each degree of the frequency function of each of plural intermediate sections by means of the interpolation according to the position between selected two sections based on the frequency functions of the selected two sections so as to obtain high frequency functions and low frequency functions which are then converted to high frequency and low frequency profile data. The machining apparatus actuates a linear motor in accordance with the high frequency profile data and actuates a PZT actuator in accordance with the low frequency profile data.

Abstract: The transverse cross section of a body is modified by the steps of: a) determining the extent to which the body has material in excess of a desired shape at a plurality of points, b) exposing the body to a local heat source having a temperature sufficiently high to remove material from the surface of the body, and c) moving the surface of the body in relation to the source at a speed which decreases in regions where the body has material in excess of the desired shape so as to remove more material from such regions than from other regions. In a preferred embodiment, the body is an optical fiber preform, the local heat source is the fireball of a plasma torch, and the body is moved relative to the torch by rotating the preform at a controllable angular velocity while the torch is translated along the length of the preform.

Abstract: An apparatus for machining a non-circular workpiece wherein a tool is moved by a composite movement given by a linear motor and a piezoelectric actuator. The linear motor is driven by the numerical controller in accordance with the low frequency components of profile data defining a position change of the tool with respect to angular position change of the spindle, while the piezoelectric actuator is driven by the numerical controller in accordance with the high frequency components of the profile data. Further, a positioning error of the tool due to reaction force generated by the piezoelectric actuator is detected by the numerical controller to compensate the high frequency components for the detected positioning error.

Abstract: The invention relates to a spindle drive controller for a machine tool such as a numerically controlled lathe of the two spindle type. According to the invention, a drive control unit is enabled to separately control the spindles, or jointly control both spindles simultaneously. A switchover unit controls whether one or both spindles is controlled, and changeover units are provided for selectively feeding back speed and position feedback signals from one or the other of the respective spindles, depending on which spindle is being driven at that time.

Abstract: An apparatus and method for forming aspherical lenses is provided in which a holder holds and rotates a predetermined lens workpiece, with a rotation detecting device provided for detecting the rotation angle of the workpiece. The cutting bit is mounted to swing about an axis perpendicular to the axis of rotation of the workpiece holder, with the cutting bit holder also linearly reciprocated. The swing angle and linear extent of the cutting bit or cutting bit holder are also detected, such that the swinging and reciprocating movement can be coordinated and controlled. The method and apparatus is particularly advantageous in forming aspherical and irregular lens shapes.

Abstract: A machine tooling system is provided, comprising a tooling machine having a plurality of adjustable cutting units installed at various locations therein, a collet for holding a workpiece to be tooled, and a presetter machine for adjusting the adjustable cutting units to within prescribed specifications when the adjustable cutting units are detached from the tooling machine. Each of the adjustable cutting units may be precisely positioned to contact the workpiece to be tooled, and each is provided with an identification device attached thereto. The identification devices provide (i) location information identifying a particular location on the tooling machining for which the cutting unit is precisely adjusted and (ii) adjustment information including the adjustment parameters at which the adjustable cutting unit is preset. A cutting unit identification subsystem reads and stores the location information and the adjustment information provided by the identification devices.

Abstract: A method for synchronously interlocking feed axes of a lathe is disclosed. In particular, a numerical controller (NC) controls the operation of a lathe by sending position command signals to servo amplifiers. The lathe turns a long workpiece chucked by two opposed headstocks which are driven synchronously. The servo amplifiers send signals to corresponding directional servo motors for moving the headstocks in respective directions. The present invention overcomes the problems of mechanical and workpiece displacement developed as loads on the servo motors by compensating for the positions of the feed axes by means of position offset values determined from the displacement of the machine or workpiece. Specifically, the displacements are detected in accordance with a difference between the torque of the two feed axes to be controlled for synchronous interlocking.

Abstract: A machine tool employs a cam, driven in response to an angular position signal of a workpiece, to cyclically displace a cutting tool with respect to the workpiece.

Abstract: An attachment assembly for a multi-spindle screw machines which provides positive part recovery and increased back-machining capabilities. The attachment is fully integrated in the host multi-spindle machine to complete cut-off, back-machining operations, and part recovery within the cycle time of the host machine. The configuration and construction of the attachment assembly provides reliable operation with minimum adjustment and simplified trouble-shooting through a central processing display panel. The integration of the components also simplifies tool changes and adjustments for production of different parts. As a result, the cut-off and back-machining are accomplished within the limited cycle time of the multi-spindle machine while recovery of the finished part ensures diversion to the proper storage bin prior to return to the start position to pick-off the next production part.

Abstract: A screw cutting method for use with a numerically controlled machining system is improved by enabling finer finishing of the final screw surface. The invention allows the removal of scars formed during rough machining by offsetting the position of the rough machining passes in the direction of screw cutting, i.e., in the direction of movement of the tool during cutting, so that during the final finishing pass, more material is removed from the screw surface opposing the cutting direction. Surface finish is further improved by specifically controlling the cutting depth in the cutting passes just preceeding the final cutting pass.

Abstract: In the present invention, a machining range for each chucking can be determined automatically by inputting a final work shape and a starting material shape. Therefore, the burden on the operator can be reduced. That is, the present invention is a method for automatically determining a machining range, comprising the step of inputting a final work shape and a starting material shape for a lathe turning machining operation and automatically collectively determining one or more chucking places and corresponding lathe turning machining ranges which will result in the production the desired final work shape. Further, the present invention is an automatic programming system for controlling lathes, comprising a machining range determination portion that collectively determines one or more chucking places and corresponding lathe turning machining ranges, which will result in the production of the desired final work shape, on the basis of the final work shape and the starting material shape.

Abstract: A brake lathe for drum and disc rotor brakes for grinding the inside cylindrical surface of a brake drum and machining the opposite parallel surfaces of a disc rotor. The lathe includes rotating spindle output shaft extending along an axis of the lathe housing. The spindle is driven by a motor which translates an endless belt over a V-belt pulley. A pair of cog belts respectively connect an intermediate pulley to the V-belt pulley and a taper lock bushing mounted on the spindle shaft. This arrangement reduces the motor speed to the desired spindle output speed and eliminates the need for an idler shaft. A first cross-feed slide is mounted in a direction transverse to the axis of the brake housing on a first side thereof for advancing the inboard and outboard cutters toward and away from the opposite parallel surfaces of a disc rotor concentrically mounted on the output shaft.

Abstract: A CNC lathe comprising two opposed spindle stocks (2a, 2b) and two turret type tool rests (3a, 3b), in which a base (1) is of a slant type, the first spindle stock (2a) is secured to the base (1), the second spindle stock (2b) is provided to be capable of being moved and located only in a direction to the spindle, and both the tool rests (3a, 3b) are arranged in the deep side of the spindle stocks (2a, 2b). The CNC lathe having said construction in which both spindle stocks include an independent spindle motor (21), a spindle indexing and driving device (23) capable of mechanically releasing connection, and encoders (27, 26) on the side of the spindle, and the indexing and driving device wherein an index motor (40) is rotated on the basis of a phase difference detected by the encoder to match a phase when the spindle indexing and driving device (23) is connected to the spindle 11), so when a work (16) is delivered between both the spindles (2a, 2b).

Abstract: A brake is provided for a workpiece spindle for spindle control. The generation of position shear of a workpiece spindle due to the unbalanced contact of the brake is prevented by changing the clamping power before and after the contact with the workpiece spindle. After the clamping of the workpiece spindle, the servo controlling state of the workpiece spindle motor is maintained and the overheat of the motor is prevented by limiting the torque of the workpiece spindle motor.

Abstract: A machine tool has a main slide movable along a first path and a cross-slide assembly movable perpendicular to the path of the main slide. The cross-slide assembly has a first slide unit which is directly driven by a primary servo control. The cross-slide assembly has a second slide unit driven by the first slide unit through a spring-loaded follower acting against a cam which can transmit numerically-controlled offset to the second slide unit such that both slide units will follow identical paths. The cam is adjustable to enable correction of the offset. Each slide unit carries a cutting tool. The invention is applicable to multiple spindle machines having two or more spindles.

Abstract: A complex machine tool has a single frame having a chip collecting space at a center portion thereof, first and second spindle stocks on the frame, relatively free to move and drive in a Z axis direction and holding the chip collecting space therebetween, workpiece spindles on the spindle stocks free to rotate and drive and facing each other, and tool rests. The tool rests have turrets and can assume various kinds of movement. Complicated and varied types of machining can be performed combining the rotation control of the workpiece spindles and the spindle stocks.

Abstract: The present invention relates to a machine for the machining of a metal bk, especially for boring and facing.The machine according to the invention comprises a laser sighting system making it possible to bring the component to be machined into coincidence with an axis (X) or a reference plane (XY). This system makes it possible, by means of removable optoelectronic sensors, to obtain a control signal allowing the holding table to be positioned in an assisted manual way or automatically, for example with a numerical control.

Abstract: A method for compensating thermally induced displacement between a workpiece clamped for machining relative to a tool arranged on a tool holder of an automatically controlled machine tool, such as a lathe, where use is made of mechanical sensors to sense and correct deviations between programmed and actual tool positions relative to the workpiece. With the workpiece clamped in place, a mechanical workpiece sensor clamped in a work holder is adjusted to make mechanical contact with the workpiece in the actual position in which the workpiece is to be machined or has been previously machined. Adjustment to a thermally compensating position of a tool measuring device coupled to a mechanical tool sensor is made via the adjusted mechanical workpiece sensor.

Abstract: A machine tool has first and second spindles provided so as to face each other. The first and the second spindles are synchronously rotated without stopping their rotation. A machined workpiece, after a first machining routine, in a state of rotation is directly delivered from the first spindle to the second spindle, and a second routine of machining is immediately performed.

Abstract: A machine tool for processing a work piece into a non-circular cross-sectional configuration according to the invention precisely processes, for example, a piston cylinder into a non-circular cross-sectional configuration by inputting simplified data.That is to say, a tool thereof is moved in a direction (X axis) perpendicular to an axis of the work piece by means of two servo motors. A first X axis servo motor operates to position the tool roughly in the X direction according to the size of the work piece. A second X axis servo motor finely vibrates the tool at high speed on the basis of program data.

Abstract: A system for machining a piston blank to a predetermined profile includes means for rotating a blank at a predetermined speed and means for moving a tool axially with reference to the blank. Digital processing means receives input data defining the required profile (or part only of the profile if the profile is symmetrical). In response to this data, to digital information on a channel corresponding to the instantaneous angular position of the blank, and to digital data on another channel corresponding to the instantaneous axial position of the tool, the processor outputs digital data defining the required position of the tool in the direction perpendicular to the surface of the blank in order to produce the required profile. The actuator control processor outputs a corresponding digital signal which, via a digital-to-analog converter, drives a tool actuator so as to position the tool correspondingly.

Abstract: An apparatus which moves a tool back and forth in synchronism with rotation of a workpiece with respect to the workpiece to machine the workpiece into a non-circular shape. The tool is attached to a tool mount placed on a tool mount table which is connected to be moved in a direction perpendicular to the axis of a spindle by a motor. The tool is connected to be moved in a direction perpendicular to the axis of the spindle with respect to the tool mount by a high speed actuator. Profile generating movement of the tool is thus provided by a combination of movement provided by the motor and movement provided by the high speed actuator. The high speed actuator is controlled in accordance with high frequency components included in profile data while the motor is driven in accordance with low frequency components included in the profile data. As a result, the responsiveness in profile generating movement of the tool is improved, and high speed machining of a non-circular workpiece is enabled.

Abstract: Apparatus for positioning a block which may be used as a charger for a lathe. The apparatus includes opposed primary chucks, each taking the form of a tapered receptacle for receiving the end of a block. The primary chucks are each displaceable in x and y directions extending laterally of a rotation axis, to position a block in an optimum position for peeling veneer therefrom. A secondary chuck is associated with each primary chuck which extensible to grip a block independently of the primary chuck.

Abstract: Two preferred embodiments of an apparatus are disclosed for imparting combined synchronous reciprocating and oscillatory motions to a cutting tool of the type used with an engine lathe to cut a continuous circumferential serpentine-patterned groove in the surface of a workpiece held and rotated about an axis of rotation by the lathe. The tool is axially journaled and mounted on a slide block permitting oscillatory and reciprocating motions of the tool relative to the rotating workpiece. Direct inflexible drive mechanisms impart the reciprocating and oscillatory motions, where the motions are synchronous with each other and are timed so as to define an integral number of waves around the circumference of the workpiece. The first embodiment employs a cam, cam followers, and direct mechanical or hydraulic linkages therefrom utilizing a minimum of parts to impart the motions. The second embodiment employs two separate servo motors to impart the motions.

Abstract: When round screw thread machining is performed with a tool (TL) having a radius smaller than a circular arc radius of a threaded portion (RST), data necessary for deciding (i) tool path patterns of round screw threading cycles (PLi) and (ii) a starting point (Pi) of each round screw threading cycle are commanded and incorporated in NC command data of the round screw threading cycles, the cycle starting point (Pi) of each round screw threading cycle (PLi) is obtained along the circular arc profile of the round screw thread using the data, and round screw thread machining is performed by repeatedly executing the threading cycles while successively shifting the cycle starting point.

Abstract: An apparatus for manufacturing a body provided at one end with a surface of revolution. The axis of the apparatus is aligned with a predetermined longitudinal axis of the body. The apparatus including a mechanism for the compensation of the oscillations of the free end of the body. The apparatus is disposed around an assembly comprising a mandrel at the end of a flexible rotatable shaft, the mechanism including a bearing surrounding a component of the assembly. A plurality of means generating oscillating mechanical forces against the bearing means are guided by signals derived from rotation of the shaft to provide phase and amplitude synchronization and compensation of the oscillations of the free end of the body.

Abstract: A lens generator device is provided with a dynamic electronic braking circuit for instantaneously interrupting operation of the lens generated under certain conditions to prevent injury to an operator. The lens generator includes a chamber structure having an access cover and having a power driven grinding tool therein. A photoelectric switch is mounted on the tailstock in confronting relation with the chamber structure cover and is operable when the cover is raised or when the tailstock is retracted to operate the dynamic braking circuit and instantaneously stop operation of the grinding tool.

Abstract: The invention relates to a machine tool having two spindles driven and controlled by servomotors (1), (2) by supplying velocity control circuits (3), (4) with velocity commands (Vcmd.sub.1), (Vcmd.sub.2) for independently controlling the rotational velocities of first and second spindles. The spindles of a machine tool such as a lathe are controlled for synchronous operation so that the two spindles can be controlled in order to machine a workpiece efficiently. According to the invention, synchronous operation is executed efficiently upon achieving coincidence between the rotational angles of the spindles so that a workpiece can be regripped during rotation.

Abstract: A tool head (12) through which work bars (35) to be machined can be pushed and which is adapted to be driven in rotation is supported on a head stock (11). The head stock (11) is disposed between a rear feeding means (57) and a front chuck means (25). The rear feeding means (57) is designed for steadily advancing one work bar (35) at a time up to the chuck means (25) and is movable into a position ready to take up another work bar (35) before the preceding work bar (35) has been used up. The front chuck means (25) is designed to grip a portion of the work bar (35) pushed through the head stock (11) and the tool head (12) and to exert forwardly directed axial pull on the same, and it can be pushed axially back and forth by its own feed drive means (27) independently of the rear feeding means (57). That makes it possible to replace a used up work bar (35) by a new one in simple manner, in little time, and without any risk of an accident.

Abstract: The invention is a method and apparatus for sawing bar-shaped workpieces o slices by means of an annular saw. The saw blade deviation, from its nominal position in the axial direction during the sawing operation, is compensated for. According to the invention, the deviation can be compensated for by the workpiece and the clamping system of the saw blade performing an appropriate relative translatory axial movement in accordance with the measured deviation. This movement is conveniently controlled by a computer, which compares the actual and nominal position of the saw blade with one another. The method can be used especially in the sawing of semiconductor bars.

Abstract: Execution format data required by a specific C-axis machining function such as a lead machining function are prepared by a custom macro, which has been stored in a ROM (102), based on data set by an operator through use of setting means such as a keyboard (104), and high-speed distribution data for controlling the machine tool are provided whenever necessary by setting parameters similar to those in ordinary milling. This makes it possible to realize a specific machining function which requires high-speed interpolation for machine movement command data.

Abstract: An auxiliary shaft (16) mounted coaxially with a main shaft (5) has at the top an eccentric (17) operatively connected via grooving (20, 21) to a tool-fastening plate (13). At the bottom of the auxiliary shaft is a wheel (19) fixed to the eccentric and provided with a recess (18). The recess can engage a fixed lug cam so that a feed motor can cause both the rotary movement of the ball turner and a tool correction effected by a relative rotary movement between the main shaft and the auxiliary shaft. For the sake of accuracy, the angular displacement is limited to an area in which the displacement of the tool-fastening plate caused by the eccentric is substantially linear with the angular displacement. All rotary motions are measured during the operation by a shaft encoder (9) and communicated to a CNC system.

Abstract: The present invention relates to a clamping device for clamping a mandrel to an elbow or pipe as well as to a torque-reacting device between a power unit housing and the mandrel. The torque reacting device has a pair of torque reacting keys mounted in a non-rotatable portion of the power unit housing, each of the keys having an end portion with converging opposite sides. The end portions of the torque reacting keys extend into correspondingly shaped, axially extending grooves formed in opposite sides of the mandrel. The opposite sides of the grooves are outwardly diverging and define an included angle approximately equal to the angle between the converging sides of the torque reacting keys. Adjusting screws are provided for each of the torque reacting keys. The clamping device has a plurality of clamping pins, each pin having a generally cylindrical shape with a hemispherical end portion defining a plurality of concentric ridges.

Abstract: A method and means for accurately positioning a tool slide in an automatic machining apparatus. Said method and means utilizing a fluid operated drive means, a linear position detecting means, an encoder means operatively associated with said linear position detecting means, means for controlling fluid flow to said fluid operated drive means and a programmable controller means for receiving and storing control data information and for receiving coded information for comparison to said control data information and for outputting a signal to control the operation of said fluid drive means.

Abstract: An auxiliary-function hydraulic system is provided for a computerized numerical control (CNC) machine tooling unit. Hydraulic power is provided for locking collet or chuck to an open or closed position and providing an affirmative collet-open and/or collet-closed signal to communicate the collet position to the host computer. The tailstock can be brought gently forward to contact a workpiece and can be returned rapidly to the home position, with a break-away pressure feature being employed to overcome initial static friction. A pressure switch indicates that the tailstock is in position against the workpiece. A spindle brake applies braking to the spindle to stop the same from high speed either on command or in the event of system failure. In the latter case, braking occurs prior to loss of pressure to the collet closer cylinder. Also, a turret clamp locks and unlocks a tool changer turret.

Abstract: An improved apparatus and method are provided for cutting a tire surface to remove selected portions of rubber from the tire surface while the tire is rotating. The apparatus and method are especially useful in removing tread material from the tire to improve the force variation and runout characteristics of the tire. The material is removed by a cutting device such as a grinding wheel and a positioning device which holds the cutting device in a fixed cutting position for an incremental period of time while a corresponding incremental segment of the tire circumference, for instance a segment equal to 1/100 of the circumference (3.6.degree.), passes by the cutter. A sensing device measures a characteristic of the tire, such as its radial forced variation, and radial run-out of the tire is also measured.

Abstract: A method of making self-tensioning rings, including the steps of circumferentially machining an out-of-round ring blank on inner and outer surfaces thereof and subsequently cutting a ring segment out of the ring for obtaining a ring gap therein; measuring a circumferential contour of the ring subsequent to the machining step; and calculating the circumferential length of the ring segment and a cutting angle for removing the ring segment from the ring as a function of data obtained in the measuring step.

Abstract: A machine tool having a work spindle with an electrically actuated clamping unit including a three-phase motor with a stationary stator. The motor is supplied with electricity from a control unit operating with frequency conversion, and the control unit is alternatingly also used for triggering a spindle drive motor. A sensor detects clamping force applied to a workpiece, and produces a signal used to reduce motor speed of the three-phase motor until a predetermined clamping force is achieved.

Abstract: When NC programs of a simultaneous four-axis lathe have been prepared, a processor (11) obtains the machining times T.sub.1i, T.sub.2i of synchronized processes for each tool rest and obtains total machining time T.sub.m for machining performed by the simultaneous four-axis lathe by using the longer of the machining times for those synchronized processes carried out simultaneously by the tool rests. Next, the total machining time T.sub.m is divided by the number of characters C in the horizontal direction of a CRT (16d) used in displaying bar graphs, to calculate machining time t per character. The machining time of each synchronized process is divided by the obtained machining time t per character, to determine the number of characters necessary for displaying each machining time.

Abstract: A numerical control machine comprises a headstock rotatably supporting a spindle for a workpiece and a tool rest assembly in front of the headstock. The tool rest assembly includes a first pair of tool rests which are disposed on both sides of the longitudinal axis of the headstock spindle and are simultaneously movable in a first direction perpendicular to the spindle axis, and a second tool rest which is movable in both second and third directions perpendicular to the spindle axis. Either the headstock or the tool rest assembly is movable in a fourth direction along the spindle axis. The movement of the first pair of tool rests in the first direction, the movement of the second tool rest in the second and third directions, and the movement of either the headstock or the tool rest assembly in the fourth direction are carried out under the control of a numerical control unit.

Abstract: A machine tool has a workpiece which is rotated by a motor. The tool is moved by a tool drive to machine a required surface profile on the workpiece and is also indexed on a carriage. The stepping signals for the workpiece motor are produced by a control system and, for each workpiece step, the control system also produces from a data store, a signal which moves the tool to the required tool position for machining the workpiece profile at the angular position corresponding to the stepped position of the workpiece motor. After each revolution of the workpiece motor, the carriage is indexed. Thus, the control system also controls the rotation of the workpiece and so no feedback of the workpiece position is required. This means that, during the machining cycle, the control system is involved solely with the supply of data from the store and does not conduct any calculation.

Abstract: A turning machine is characterized by a new and improved control and mechanism for positioning the turning tool on the head. A CNC control issues command signals for selectively positioning the tool on the head. These signals are developed from an encoder which provides the instantaneous position of the rotating part being turned and from a program in the CNC containing information about the part. A closed loop control system receives these command signals and converts same into a control current for a linear motor which is the prime mover controlling the positioning of the tool on the head. The linear motor operates a carriage on the head and the cutting tool mounts on the carriage opposite the connection of the linear motor to the carriage. The carriage is a hollow bar guided on the head by sets of rollers which are cooperatively arranged to provide yieldably forceful constraint of the bar.