Abstract: A device for cooling a reversible motor comprising: a plurality of blade-type cooling fins (17) attached to the protrusion (13b) of a rotary shaft (13) which protrusion is protruded into a cooling chamber (5) formed on the outside of a motor case (10); an exhaust blower (25) provided on the outer side of the cooling chamber (5) in the axial direction to expel the cooling air, and; a fixed rectifying vane (29), consisting of a plurality of radially arrayed guide vanes (29a), provided in the exhaust space (28) between the blade-type cooling fins (17) and the exhaust blower. In the cooling device, the cooling air stream, moving in a spiral manner, passes through the blade-type cooling fins (17), is rectified in the axial direction via the fixed rectifying vane (29) and is expelled by the exhaust blower (25), when the motor runs in both the forward and the reverse directions.

Abstract: A circuit for controlling a D.C. electromagnetic brake, in which a series circuit consisting of a solenoid 35 for the electromagnetic brake and a transistor 52 for controlling the current that flows into the solenoid is connected to a D.C. power source 8 and wherein a varistor 4 is connected in parallel between the emitter and the collector of the transistor 52 which controls current that flows into the solenoid, in order to clamp the counter electromotive force that generates across the emitter and the collector of the transistor when the current flowing through the solenoid is interrupted.

Abstract: A method and apparatus for circular interpolation on the basis of a given arc center O, arc starting point P.sub.s and arc end point P.sub.e. In a case where the given arc end point P.sub.e does not lie on an arc of center O passing through the given arc starting point P.sub.s, a new center O.sub.N of an arc passing through the points P.sub.s, P.sub.e is computed, and circular interpolation is performed on the basis of the computed center O.sub.N, the given starting point P.sub.s and the given end point P.sub.e.

Abstract: Disclosed is an industrial robot having a function for controlling a current of a motor for driving, which comprises a circuit (41) for summing a plurality of input signals to which input signals of speed command, speed feedback, current command and current feedback are supplied, a switching circuit (23) for selectively switching the input of speed command to the inputs of current command and current feedback by a switching command signal and an operational amplifier (38) to which the switched signal is supplied. In this industrial robot, the position control is switched over to the current control by a switching command signal from a robot control device (22), and by the position control, an article to be held is shifted to a predetermined position and by the current control, driving electric motors (Mr, M.theta.

Abstract: In a system which performs tracer control by calculating the direction and velocity of tracing using signals from a tracer head tracing the model surface, there are provided an input unit for entering data defining the tracing operation, a memory for storing the data and a processor for reading out the data from the memory to control respective parts of a control device. Of the data defining the tracing operation, stored in the memory, data concerning the reference displacement of the tracer head is read out by the processor to change the reference displacement for each profile modeling operation, thereby automatically performing repetitive tracing.

Abstract: A speed control circuit and position control circuit are connected to a spindle drive motor in a machine tool or the like in order to drive the spindle at a predetermined speed and stop the spindle at a predetermined angular position. When an orientation command is issued while the spindle is being rotated at the predetermined speed by a speed control loop, a speed command signal from a speed command circuit is interrupted, the speed reduced to zero, and an initially set voltage is then employed as a speed command to rotate the spindle by a predetermined amount. Next, a integral value of the actual spindle speed is employed as the speed command to further rotate the spindle by a predetermined amount. When this has been accomplished, a constant bias voltage of a low level replaces the speed command, thereby to rotate the spindle still further by a predetermined amount until a specified portion of the spindle approaches extremely close to the predetermined angular position.

Abstract: A discharging circuit for a power source device with a rectifier circuit used in an power source for driving a motor in which when the alternating current power source is turned off and the load is electrically separated, the voltage of a time constant selection circuit (22, 23) falls rapidly, the voltage across a diode (25) rises, a Schmitt circuit (24) is activated, the circuit consisted of a transistor (27) and a resistor (26) is conducted, and a smoothing capacitor (28) is discharged, and hence the heat generation at the resistor is decreased and the concern over unsafety due to delayed discharge of the capacitor is eliminated.

Abstract: A method and system for rewriting data in a non-volatile memory in which the rewriting of one access unit of stored data is executed by erase and write cycles, the stored data being protected in the event of an interruption in electric power. In rewriting into second data the first data which is stored in a data storage area of the non-volatile memory, either the first or the second data is stored in a save area of the non-volatile memory, after which the first data in the data storage area is erased, followed by the writing of the second data in the data storage region to complete the rewrite operation.

Abstract: A method of adjusting for a shift of the position of a stylus tip and a deviation of the zero point of a displacement detector which are caused by an exchange of a stylus of a tracer head. The shift of the position of the stylus tip and the deviation of the zero point of the displacement detector are electrically or mechanically read out as displacement. In accordance with the displacement, the tracer head assembly is moved relative to a machine frame to adjust the tip of the stylus to its reference position.

Abstract: A portable bubble memory apparatus having a bubble memory cassette for accommodating a bubble memory element, and a portable cassette adapter provided with a cassette holder for loading and unloading the bubble memory cassette, the portable cassette adapter housing a control circuit and peripheral circuitry for the bubble memory element. A signal generator generates a signal to indicate whether the bubble memory cassette has been loaded at the correct position within the cassette holder. If the bubble memory cassette is displaced from the correct position, the generated signal causes the exchange of information between the bubble memory cassette and an external unit to cease.

Abstract: In a transmission system employing a plurality of parallel lines for transmitting serial digital signals, means are provided in each line for detecting and disconnecting any line on which transmission is interrupted comprising a converter for producing two signals of opposite polarity, a receiver for reconverting the signals connected to the converter by a pair of transmission lines, an exclusive OR gate connected to the pair of transmission lines for providing an output when normal signals of opposite polarity are present, and a switch comprising an AND gate converted to the receiver and to the exclusive OR gate which disconnects the receiver when no output is received from the exclusive OR gate. The received signals from each line are combined through a common OR gate.

Abstract: A direct current motor comprising: a yoke; an armature; a plurality of main magnetic poles equidistantly spaced around the inner circumference of the yoke, and each of which has a wide portion and a narrow portion, the air-gap between the armature and the main magnetic poles being narrow at the center and ends of the wide portion, and at the center of the narrow portion, and being wide at the intermediate of the wide portion, and at the ends of the narrow portion, and a plurality of interpoles, such as E-shaped interpoles, which are disposed at positions located between the adjacent narrow portions of the main magnetic poles.

Abstract: A wire-cut, electric discharge machining method in which a wire is inserted into a machining start hole made in a workpiece to start electric discharge machining from the machining start hole, a bushing of a conductive material is pressed into a hole made in the workpiece to provide the machining start hole.

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 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 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 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.