Abstract: Multilingual computer-specified control messages are communicated to an operator in an operator-selected language by the combination of a message writer and a language changer. The language changer contains a set of message storage tables, each containing a set of control messages written in a particular language, and a set of message address tables, each message address table referencing a computer-generated message code indicative of a specific condition to a respective one of the control messages in an associated message location table. In accordance with an operator command indicative of a desired control message language, the language changer supplies the message writer with the corresponding message storage table and message address table.

Abstract: A vertical spindle numerically controlled machining center includes a stationary bed or base on which a workpiece holding table is slidably mounted for movement along a first axis. A vertically extending upright or column, having a vertically reciprocal spindlehead slidably mounted thereon, is slidably mounted on the bed for movement along a second axis perpendicular to the first axis so that the spindlehead overlies a portion of the table. Within the upright is a recess adjacent to the bed. A tool storage magazine is located in the recess and is slidably mounted on the bed for movement through the recess along an axis parallel to the second axis. During a tool change cycle, the toolholder then held in the spindle is returned to the tool storage magazine by first moving the spindlehead to the ready position and then moving the tool storage drum toward the spindlehead to engage the tool then held in the spindle.

Abstract: A spindle keylock for stopping and locking the spindle of a machine tool at a predetermined angular orientation to align the machine tool spindle key with the toolholder key to facilitate tool exchange includes a collar fastened about the spindle for co-joint rotation therewith. The collar has a helically cammed exterior surface into which an axially extending slot or channel is inscribed. A cam follower, pivotally mounted to the machine tool spindlehead so as to lie within a plane passing through the spindle axis which is at a predetermined angular orientation with respect to a reference plane passing through the spindle axis in alignment with the spindle key, is rotatable about an axis perpendicular to the axis of the spindle for engaging with the cammed collar surface.

Abstract: Apparatus for setting cutting tool length on numerically controlled machine tools includes a base having a leg extending perpendicularly therefrom. A rod is fastened to the base parallel to the leg. Overlying the end of the rod distal from the base is a cap which is reciprocal along the axis of the rod and which is biased away from the base by a spring interposed between the rod and the cap. A dial indicator gauge is fastened to the rod to abut the cap for indicating the displacement of the cap along the rod relative to the base. A setting block is pivotally mounted to the leg a known distance from the base and is rotatable about the axis of the leg for urging the cap against the spring so that the distance between the cap and the base corresponds to the known distance between the setting block and the base, to facilitate zeroing of the dial indicator gauge.

Abstract: An automatic tool changer for a machine tool having a rotary toolhead with cross-feed slide includes a tilt unit having a tool socket which is pivotal between a first position, parallel to the axis of a machine tool storage magazine to permit loading or unloading of a machine tool carrier into the tool socket from the tool storage magazine by a transfer arm, and a second position parallel to the axis of the rotary toolhead. A tool changer arm, having tool grippers at opposite ends, moves along and rotates about an axis parallel to the rotary toolhead to exchange the tool carrier in the tool socket of the tilt unit with the tool carrier in the rotary toolhead, thereby permitting a new machining operation to be performed by the machine tool as well as storage of the machine tool carrier previously held in the rotary toolhead.

Abstract: A combined tool storage and tool change arrangement for use with a machine tool of the type which includes a power driven rotatable spindle having a socket which receives a tool shank of a predetermined size. The tool storage arrangement comprises a main tool storage magazine with a plurality of tool receiving sockets sized to respectively receive a tool having a shank of said predetermined size. Means is provided for moving the main tool storage magazine whereby to present a predetermined tool receiving socket and the tool therein to a first tool transfer point. An auxiliary tool storage magazine is provided for receiving and storing a plurality of tools having shanks of a different size than said predetermined size. The auxiliary tool storage magazine has a shank of said predetermined size whereby the auxiliary tool storage magazine may be stored in a socket of the main tool storage magazine.

Abstract: The voltage and frequency of an A.C. excitation signal applied to the stator windings of an A.C. induction motor are varied in proportion to the amplitude of current flowing in the stator windings. The stator current flow is sensed by a feedback resistor in series with the inverter which generates the A.C. excitation signal for the stator windings. The voltage drop aross the feedback resistor is summed with a VELOCITY COMMAND voltage which indicates the desired speed of the motor and the summed voltage controls the frequency and the amplitude of the A.C. excitation voltage in a constant volts per hertz manner. The stator current feedback holds the motor speed constant in spite of variations in the load on the motor.

Abstract: A tachometer is coupled to the rotor of an A.C. motor and generates an output voltage proportional to the rotor's speed. A VELOCITY COMMAND voltage is generated having an amplitude which specifies a desired rotor speed. The tachometer voltage is subtracted from the VELOCITY COMMAND voltage to produce a VELOCITY ERROR voltage. The output of a D.C. power source is chopped at a fixed frequency and variable pulse width, the pulse width being proportional at any time to the amplitude of the VELOCITY ERROR voltage. The chopped D.C. voltage is filtered to provide a variable D.C. voltage having an amplitude which is proportional to the amplitude of the VELOCITY ERROR voltage. The variable D.C. voltage is applied to an inverter which changes it into an A.C. voltage. The A.C. voltage is applied to the stator windings of the motor to drive the rotor thereof. The frequency of the A.C. voltage is variable and is proportional, at rotor speeds above 150 RPM, to the amplitude of the velocity command voltage.

Abstract: An automatic tool changer for transferring single tools and/or multiple spindle toolheads between a tool storage magazine and a horizontal spindle of a machine tool. A plurality of single tools and/or toolheads are stored in the tool storage magazine with their shanks in a vertical position. A first tool change arm transfers a selected tool or toolhead from the storage magazine to a tilt unit which tilts the shank of the tool or toolhead by 90.degree. from a vertical to a horizontal position parallel with the axis of the spindle. A second tool change arm removes the tools or toolheads from the tilt unit and spindle simultaneously, interchanges them, and inserts the interchanged tools or toolheads into the spindle and tilt unit. The tilt unit then tilts by 90.degree. back to the vertical position, and the first tool change arm returns the tool or toolhead in the tilt unit back to the tool storage magazine.

Abstract: The control valve for a hydrostatic bearing on a machine tool slide is opened when motion is commanded along the corresponding machine tool axis to eliminate sticking at the start of motion. The valve is closed when the velocity of motion exceeds a predetermined level and is opened again when the velocity drops below the predetermined value to eliminate sticking at the end of motion. The valve is closed again when the machine tool slide arrives at its commanded position.

Abstract: A numerically controlled machining center has a tool magazine, automatic tool changer, workpiece shuttle, and a workpiece magazine which holds enough workpieces for operation by the machining center for an entire shift of approximately eight hours. The numerical controls are programmed to perform predetermined machining operations on each workpiece, in turn, and to replace each finished workpiece with a fresh workpiece at the end of each machining program. A proximity switch is mounted on the machining center for checking tools to detect broken or incorrect tools. The tools are positioned adjacent to the proximity switch and are rotated while the output of the proximity switch is counted for one complete rotation of the tool to determine the number of radially extending teeth on the tool. If the tool has too few or too many teeth, thus indicating a broken or incorrect tool, it is replaced by another tool of the same type.

Abstract: The cutting force applied between the cutting tool and the workpiece of a machine tool is periodically pulsated to expedite removal of material from the workpiece. The periodic cutting force pulsation is produced by periodically varying the spindle speed or the feed rate or both. In one embodiment, the periodic speed variation is produced by universal joints in the spindle drive and worktable drive. In a second embodiment, the periodic speed variation is produced by elliptical gears in the spindle drive and worktable drive.

Abstract: A toolholder adapter has a cylindrical body, a cylindrical shank extending axially from one end of the body, a cylindrical flange extending radially from the body, a tapered socket within the body for receiving a tapered shank toolholder, and a clamping nut on the body which has inwardly projecting tabs that are positioned to bear against the flange of the tapered shank toolholder to clamp it in the socket. The toolholder adapter is dimensioned to fit in the tool storage magazine of a machine tool and to be handled by the automatic tool changer thereof.

Abstract: A tool storage drum which is adapted to receive and store a plurality of toolholders is rotatably mounted on top of the upright of a horizontal machining center behind the spindle thereof. A tool changer carriage carrying a tool change arm is pivotally mounted on the upright above the spindle and is pivotable between a parked position in which an end of the tool changer arm is adjacent to the tool storage drum and an exchange position in which an end of the tool changer arm is adjacent to the spindle. The tool changer arm is slidably mounted on the carriage for movement between an extended and a retracted position to remove toolholders from their sockets or insert them therein and is rotatable through 180.degree. to interchange its ends for the purpose of exchanging a tool in the spindle for a tool previously removed from the tool storage drum.

Abstract: Two pairs of crossed tool change arms are mounted adjacent to four spindles which are rotatably mounted on a common spindlehead. Each pair of crossed tool change arms is mounted on a common shaft which is rotatable and is movable along its axis and is positioned to simultaneously insert a pair of tools into or remove a pair of tools from the corresponding pair of spindles. A tool storage chain carrying a plurality of tool storage sockets is movably mounted on a frame in position to interact with the tool change arms which are operable to transfer tools from the tool storage sockets to the spindles and vice versa. Each tool storage socket is pivotally mounted for movement between a vertical storage position and a horizontal tool change position. Four tool storage sockets are pivoted from the vertical storage position to the horizontal tool change position for each tool change operation.

Abstract: A rotary table is driven by a pair of perpendicularly disposed linear slides which are each driven by a ballscrew drive. One of the linear slides is mounted on the movable member of the other linear slide and is coupled to the rotary table by a crank stud. The linear slides are driven at speeds which vary in accordance with the sine and cosine of the table angle to translate the linear slide motion into rotary motion.

Abstract: The feed rate of a computer controlled machine tool is periodically calculated every 9.6 milliseconds to produce a horsepower equal to a target horsepower at the cutting tool during a milling operation. When the feed rate rises above a predetermined level, the target horsepower is progressively lowered, and when the feed rate drops below a predetermined level, the target horsepower is progressively raised. The total amount of cutting time for each tool is measured and the amount of cutting time under increased target horsepower is also measured. When the amount of cutting time under increased target horsepower exceeds a predetermined percentage of the total cutting time for any given tool, a DULL TOOl signal is generated and the designated tool is subsequently replaced. If no cutting time is recorded, a BROKEN TOOL signal is generated and the broken tool is replaced.

Abstract: A probe is mounted on the nose of a toolholder which fits into the spindle of a numerically controlled machine tool. An oscillator is mounted within the toolholder and is powered by a battery within the toolholder. The output of the oscillator is coupled to a primary coil on the toolholder which is inductively coupled to a ringshaped secondary coil on the spindlehead of the machine tool. Switches within the toolholder are wired to the oscillator to cause it to shift frequency when the probe stylus makes contact with a workpiece when moving along any one of the X, Y or Z axes. The ringshaped secondary coil is coupled to the machine tool's NC circuits to indicate when the probe makes contact with the workpiece.

Abstract: A method and apparatus for transferring digital data between a mass memory and a random access memory. The mass memory has a plurality of memory loops, each having a plurality of memory cells, and a read/write device which either outputs data from the memory cells or inputs data to the memory cells. Each memory cell is identified by an address that specifies its place in the loop sequence starting from a reference cell. A loop position counter is set at zero when the reference cell of the selected memory loop is at the read/write device. The loop position counter is advanced by one count each time the next memory cell in the sequence is moved into operative relationship with the read/write device. Transfer of data between the mass memory and the random access memory is accomplished without any delay under the control of a random access memory address counter which is synchronized with the loop position counter.