Abstract: The worktable and pallet shuttle of a machine tool are driven by a common motor which is mounted on the worktable base. The motor is coupled to the worktable by gears which engage when the worktable is raised to be indexed and disengage when the worktable is lowered. The motor is coupled to the pallet shuttle by gears which engage when the worktable base is moved into the shuttle position and disengage when the worktable base is moved out of the shuttle position.

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 positon 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: A tool changer drum is rotatably mounted on a machine tool for rotation about an axis which is perpendicular to the spindle axis thereof. A plurality of tool changer arms are swingably mounted on the tool changer drum for swinging movement along radii of the drum between a storage position parallel to the central plane of the drum and a transfer position perpendicular to the central plane of the drum. A pneumatic cylinder is used to index the tool changer drum to place any selected tool changer arm in the ready position. Another pneumatic cylinder is used to swing the ready tool changer arm from its storage position to its transfer position to transfer a toolholder from storage to the spindle and later to swing the tool changer arm back to the storage position to return the toolholder to storage. Before the tool transfer operation, the spindle is moved to a tool transfer position in which the swinging movement of the tool changer arm either places a toolholder in the spindle or removes a toolholder therefrom.

Abstract: The tape in a tape reader is braked to a stop relatively slowly instead of being stopped on one character. Two sprocket reading photocells are mounted on the tape reader to provide quadrature sprocket waveforms which are applied to a bi-directional sprocket counter coupled to the address conductors of a buffer memory. The data read off the tape by the tape reader is written into the buffer memory at the addresses indicated by the sprocket counter. An output pointer counter is also coupled to the buffer memory address conductors in parallel with the sprocket counter through a time division multiplexer. During the time interval in which the output pointer counter is connected to the buffer memory address conductors, data can be read out of the buffer memory at the address indicated by the output pointer counter independently of the sprocket counter.

Abstract: An electronic data processing system which utilizes a variable timing period that is varied in accordance with the access time of the digital devices or circuits utilized in each step of the data processing program. In one embodiment, the data processing system is a computer which performs the basic arithmetic and logical operations. The computer utilizes three memories which have different access times. One memory stores instruction words specifying steps in a computer program for performing basic arithmetic and logical operations involving predetermined data words; another memory stores the data words; and, the third memory stores control words specifying the various machine operations required to execute the corresponding instruction. The three memories can be read out simultaneously, two at a time, or one at a time. In each case, the timing strobe which initiates the next step in the program is generated immediately after the slowest memory utilized in that step is ready for the next readout.

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 ring-shaped 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 ring-shaped secondary coil is coupled to the machine tool's NC circuits to indicate when the probe makes contact with the workpiece.

Abstract: A tool transfer arm is pivotally mounted on a tool transfer housing which is movable between a tool storage magazine and the spindle of a machine tool to transfer tools between the tool storage magazine and the spindle. The tool transfer arm has two pair of toolholder jaws, one pair on each end thereof. One toolholder jaw of each pair is movable and the other jaw is fixed. Each movable jaw is pivotable between an open and closed position by a clamp arm which is pivotally connected to the corresponding movable jaw and slidably engages an arcuate guide slot in the tool transfer arm. A cylindrical abutment on the spindle head near the spindle and on the tool storage magazine bears against the adjacent clamp arm when the tool transfer arm approaches either the tool storage magazine or the spindle in one angular orientation to close the corresponding movable jaw and clamp a toolholder in the jaws for removal from the tool storage magazine or spindle.

Abstract: Two transistors each have their emitter-collector circuits coupled in series between one end of a motor field winding and the opposite terminals of a D.C. voltage source to switch current flow in either direction through the winding. Two current sensors are provided, one coupled in series with each emitter-collector circuit. The voltage developed across each current sensor is applied through a driver circuit to the base of the other transistor so as to cut one transistor off when the other is conducting and vice versa, thereby eliminating the possibility of having both transistors conduct simultaneously which would short out the voltage source and burn out one or both transistors.

Abstract: A plurality of multiple spindle toolheads are stored in a carousel-type toolhead magazine on top of a machine tool which includes a toolhead driver for driving any selected one of the toolheads. The toolhead driver is mounted for movement along a Z axis toward and away from a worktable. A rotary toolhead changer arm for transferring toolheads from the toolhead magazine to the toolhead driver and vice versa is mounted on the machine for rotation about an axis which is inclined at an angle of 45.degree. to the Z axis. The toolhead changer arm has two diametrically opposed ends which are each inclined at an angle of 45.degree. to the rotary axis of the toolhead changer arm. Clamps are mounted on both ends of the toolhead changer arm for clamping toolheads thereto. When the toolhead changer arm is rotated through 180.degree.

Abstract: An electric motor driven drill and a battery therefor are mounted within a toolholder for a machine tool. The battery is coupled to the motor through a centrifugal switch which closes when the toolholder is rotated about its axis above a predetermined speed and opens when the rotary speed of the toolholder falls below the predetermined speed. The toolholder is mounted in the spindle of a machine tool and the drill turns on when the spindle is rotated and turns off when the spindle stops, the rotary speed of the spindle being added to the rotary speed of the drill in one direction of spindle rotation and subtracted from the rotary speed of the drill in the opposite direction of spindle rotation.