Abstract: A system for numerically controlling a machine tool comprising a plurality of machine tools, a plurality of numerical control circuits and a computer as an entirely automatic operation commander device, for carrying out the control of the entire processes of said plurality of machine tools with a central control station.

Abstract: A control circuit for driving an induction motor wherein an AC voltage is converted into a direct current by a rectifying circuit and the direct current is converted into a signal having a variable voltage and frequency by a transistor inverter connected in parallel with a smoothing capacitor, and a regenerative circuit is connected in parallel with the inverter, and a circuit is provided for comparing the terminal voltage V.sub.C of the smoothing capacitor and a reference voltage V.sub.r when braking is to take place is disclosed. When condition V.sub.C .gtoreq.V.sub.r exists, the transistor inverter is disabled but the regenerative circuit is allowed to operate; when the condition V.sub.C <V.sub.r exists, the transistor inverter is operated in the regenerative braking mode.

Abstract: A wrist mechanism in an industrial robot comprises a wrist, a rotary type actuator which is rotatable in clockwise and counter-clockwise directions, a first positioning board which can define arbitrary angular stopping positions, sensing devices, and a second positioning board which is arranged facing the first positioning board, wherein the sensing devices detect the angular position of the wrist, which is driven by the rotary type actuator, the rotary type actuator is stopped by signals produced by the sensing devices, and the second positioning board with tapered receptacles is pressed to the first positioning board with tapered pins, whereby the positioning of the wrist mechanism is carried out.

Abstract: A power source arrangement for electric discharge machining in which a power source and a switching element are connected in parallel to an electrode and a workpiece and the switching element is driven by a pulse signal of a predetermined period to perform electric discharge machining of the workpiece, there being also provided a pulse signal generator for generating a pulse signal in which the ratio of the OFF interval to the ON interval gradually increases with the lapse of time and a detector for detecting the occurrence of an arc or short in the spark gap. Upon detection of arcing or shorting in the spark gap by the detector, the pulse signal generator is activated so that the pulse signal of the predetermined period to be applied to the switching element is gated by the output pulse signal from the pulse signal generator until the arc or short is removed.

Abstract: A wrist mechanism for an industrial robot having a robot casing, robot arms capable of extending from and contracting to the robot casing, a robot hand for gripping a workpiece, and a wrist arranged between the robot arms and the robot hand, comprises: two reduction gears with a high reduction ratio connected respectively to each of two high speed rotational driving motors, the two reduction gears cooperating with one another for generating two individual reduced rotational outputs, and; two transmitting mechanisms, connectable to the hand, for transmitting respectively the two reduced rotational outputs to the hand, thereby causing respectively rotational motion and swinging motion of the hand.

Abstract: A tracer control system which performs tracer control based on a displacement signal from a tracer head tracing the surface of a model and is equipped with the function of freely setting the infeed of a cutter for machining a workpiece. The tracer control system is provided with a first drive system for feeding the tracer head in the Z-axis direction, a second drive system for feeding the cutter head in the Z-axis direction, first and second position detectors for detecting the positions of the tracer head and the cutter head in the Z-axis direction, and a superimposing circuit for superimposing on each other a position detection signal from the first position detector and an infeed command signal for setting the infeed of the cutter head. The cutter head is fed by the second drive system in the Z-axis direction so that the difference between output signals from the superimposing circuit and the second position detector may be reduced to zero.

Abstract: A control circuit for driving an induction motor wherein an AC voltage is converted into a direct current by a rectifying circuit and the direct current is converted into a signal having a variable voltage and frequency by a transistor inverter connected in parallel with a smoothing capacitor, and a regenerative circuit is connected in parallel with the inverter, and a first monitoring circuit is provided for comparing the terminal voltage V.sub.C of the smoothing capacitor and a first reference voltage E.sub.1 when braking is to take place. When the condition V.sub.C .gtoreq.E.sub.1 exists, the transistor inverter is disabled but the regenerative circuit is allowed to operate. When the condition V.sub.C <E.sub.1 exists, the transistor inverter is operated in the regenerative braking region. A second monitoring circuit is provided for comparing the smoothing capacitor terminal voltage V.sub.C and a second reference voltage E.sub.2 (E.sub.2 >E.sub.1). When the condition V.sub.C .gtoreq.E.sub.

Abstract: In a tracer control system which controls tracing based on displacement signals from a tracer head tracing the surface of a model, there are provided position detectors for detecting the positions of a tracing machine along the X, Y and Z axes and angle correcting means. The difference between a set trace direction and the actual trace direction detected by the position detectors is obtained for every other fixed distance of movement along the X-axis or Y-axis direction and a trace velocity along the X-axis or Y-axis direction is corrected by the angle correcting means so that the above difference may be reduced to zero, thereby controlling tracing to be performed in the set trace direction.

Abstract: A system for controlling a plurality of microprocessors, comprising a common memory which can be selectively switched to exclusive buses which are connected to the plurality of microprocessors, respectively, and a priority control circuit which determines the priority of the microprocessors. According to the system of the present invention, it has a common memory that is selectively connected to the buses, data is transmitted without affecting the operation of the microprocessors on the receiving side, data transfer between the microprocessors having different cycle times is carried out at speeds that are adapted to the cycle times of the individual microprocessors, and the degree of the exclusive use of the bus by the microprocessor is prevented from being reduced when the direct memory access transfer is carried out. Consequently, a system for controlling a plurality of microprocessors having an improved performance is obtained in accordance with the present invention.

Abstract: A robot hand provided for an industrial robot used in association with a machine tool for carrying out a manipulating operation of attaching a workpiece to and detaching a workpiece from a workpiece chucking means of the machine tool, said robot hand being characterized by including means for removing chips and other foreign materials attached to the workpiece holding means during the manipulating operation.

Abstract: A method for rotating a workpiece at a constant peripheral speed when the workpiece is cut as on a lathe. Before a cutting tool is moved to a cutting position under a rapid-advance command, the number n of RPM for the spindle is computed from the following equation, based on the distance x between the cutting position and the axis of the spindle and based on the commanded periphery speed V for driving the spindle at the computed number of RPM thereof:n=V/2 xAccordingly, the actual peripheral speed of the spindle becomes the same as or approximates the commanded peripheral speed when the cutting tool reaches the cutting position.

Abstract: A programmable sequence controller which enables display of the contents of a storage means for storing input and output data to and from a machine, and which permits numerical values to be set in the storage device from an external unit. The programmable sequence controller utilizes a sending and receiving unit for an exchange of commands and other data with a numerical control device in order to transfer display content and numerical values which have been set. This allows the contents to be displayed on display means provided in the numerical control device, and permits the setting of numerical values which are entered from a data setting means provided in the numerical control device.

Abstract: In a wire-cut, electric discharge machine equipped with an automatic wire electrode threading mechanism, a straightening guide having a curved surface which guides thereacross a wire electrode while straightening it out. The straightening guide is positioned directly in front of feed-up rollers which grip the wire electrode released from a supply reel and guide it into a machining starting hole of a workpiece.

Abstract: Disclosed is a portable tape reader characterized in that a lid provided with a handle is integrally formed on the upper portion of a body provided with a reading head, the body is contained in a container box so that the body can be drawn out upwardly, and when the body is drawn out, the container box is held in the lower portion of the body and an opening of the container box is located below the reading head. In the portable tape reader having the above-mentioned structure, a tape which has been read is securely received and stored in the container box.

Abstract: An addressing system for use with a computer system having a plurality of processing units connected to independent address buses and a plurality of memories connectable to any of the address buses and given a series of addresses. Each processing unit is connected to an address modification register and an adder connected to its address bus. The address content outputted from the processing unit and the content of the address modification register are added together by the adder. The added output is sent on the address bus to address a desired one of the memories. This system permits easy modification of memory allocation and enhances the operation speed of each processing unit.

Abstract: A wire-cut, electric discharge machine which is provided with auxiliary wire feed means for feeding a wire in a backward direction when the wire is broken, and a wire detector for detecting, at a predetermined position, the extreme end of the broken wire fed in the backward direction. When detecting the extreme end of the broken wire by the wire detector, the feed of the broken wire by the auxiliary wire feed means is stopped to position the extreme end of the broken wire at a predetermined position.

Abstract: In a tracer control equipment which calculates a trace direction and a trace velocity using signals from a tracer head tracing the model surface and performs tracer control in accordance with the calculation results, there are provided a memory for storing numerical command data and means for reading out the numerical command data by a processor from the memory, whereby to add a numerical control function for positioning control to the tracer control equipment.

Abstract: A rotary electric motor of a sealed type comprising a heat pipe in a rotor shaft and a plurality of air vents in a stator. In the operation of this motor, a rotor mounted on the rotor shaft is cooled by the heat pipe and simultaneously, the stator is cooled directly by the air flowing therethrough.

Abstract: An industrial robot with a safeguard mechanism for mechanically preventing occurence of any uncontrolled movement of a movable part of the industrial robot, the safeguard mechanism having mechanical engagement means which provides a disengageable mechanical lock between the movable part of the industrial robot and the stationary part of the industrial robot or another stationary member different from the industrial robot.

Abstract: A system for stopping a spindle, which is provided in a machine tool, in such a manner that a specified point on the spindle is stopped at a predetermined rotational position. The system includes device for detecting the direction of spindle rotation. When the spindle arrives at a region where it is to be controlled in order to stop at the predetermined rotational position, a position deviation signal is applied as the input signal of a speed control loop for controlling the rotation of the spindle. This signal turns the specified point on the spindle to the predetermined rotational position, in the same direction in which the spindle is rotating, on the basis of the direction signal from the detecting means. That is, the specified point on the spindle is rotated to the predetermined rotational position in a direction which is the same as the direction of rotation during tool operation.