Abstract: A PWM converter apparatus having phase detection means including an error detection protection device for outputting an estimate value as a present phase signal when a phase signal in each computation cycle deviates for a predetermined value or more from the estimate value obtained according to the former phase signal, the frequency of a power voltage, and a computation cycle.

Abstract: In the control method for a PWM converter according to the present invention, an upper limit value of an inphase component of an instruction voltage for controlling an AC/DC converter is prescribed, and in the region where the upper limit value is exceeded, the inphase component of the instruction voltage is controlled to be within the prescribed upper limit value by setting a reactive component value corresponding to the exceeding quantity. This makes it possible to offer a low priced, stable control method for a PWM converter.

Abstract: In a tool exchange system, in which the selection of a tool (8) supported on a magazine (9) is done by the rotation of a main spindle (5) via a pair of gears (20) and (21), an elastic member (71) is provided so as to retain the magazine (9) in a machining position (pause position) which does not interfere with a machining operation. A first cam mechanism (11) is adapted to move the magazine (9) between a tool exchange position and the machining position in response to the vertical move of a Z-slider (3) moving along a column (1). A second cam mechanism (12) is adapted to operate a tool attachment/removal means (6).

Abstract: A power converter apparatus comprising an initial voltage-setting circuit by which a signal for generating a predetermined voltage on the alternating (A.C.) side of a converter is applied to a current negative-feedback circuit at the start of the converter.

Abstract: An optical star coupler having a biconically tapered optical star coupler suspensively inserted in a protection tube and the method for manufacturing the same are disclosed, and the manufacturing method is that an optical fiber bundle is inserted into a protection tube such as hollow glass tube, then the optical fiber bundle is twisted and pulled while it is indirectly heated through the protection tube, thereby to form a twisting, fusing and pulling portion, and both ends of the protection tube are sealed with an adhesive agent to fix the optical fiber bundle to the protection tube. This optical star coupler can be constructed so as to be connected in tandem without any splicing. The optical star coupler of the present invention, naturally in the case of an optical star coupler using multi-mode optical fiber, particularly in the case of one equally divided optical star coupler using single-mode optical fiber, also provides low insertion loss, less power deviation and low manufacturing cost.

Abstract: This invention relates to a device for removing short fibers from a mass of ibers. A pair of perforated cylindrical bodies are opposed to each other with a predetermined spacing defined therebetween, and static electricity is applied across the perforated cylindrical bodies. A suction-wise removing device is installed in at least one of the perforated cylindrical bodies. The initial end of a transfer conveyor is located on the surface of one perforated cylindrical body adjacent the opposed region. Short fibers contained in the mass of fibers fed to the opposed region by a feeding device are drawn into the suction-wise removing devices through the through holes in the cylindrical bodies by the action of electrostatic force and suction air currents. The mass of fibers having the short fibers removed therefrom are oriented by electrostatic force and transferred by the conveyor while being maintained in this oriented state.

Abstract: An interface signal produces in a phase modulation type fiber optic gyroscope is classified into odd and even groups at a synchronous detector. An angular velocity is processed by the signals of even groups and odd groups.

Abstract: The inventory management system comprises a central control unit, a number of parts terminal units deposed at each parts container, and some guide terminal units arranged at each parts container shelf. A worker goes to a parts container in accordance with the guidance on the guide terminal units, performs parts storing, parts collecting or stocktaking jobs in accordance with a job display and parts quantity display on the parts terminal unit and can also correct a displayed parts quantity if the quantity displayed is not correct.

Abstract: A spindle head unit having a bell crank lever (24) mounted pivotally on a spindle head (10) of a machining center to depress a drawbar (18) inserted through a spindle (14) mounted on the spindle head (10). One of arms of the bell crank lever (24) is located so as to be capable of being engaged with a guide cam (28) and a depressing end (24a) in the shape of a spherical protrusion which is not connected mechanically to an upper end (18a) of the drawbar (18) is formed in a free end of the other arm of the bell crank lever (24). The bell crank lever (24) is urged continuously by a spring means (32) so that the former arm is urged toward the guide cam (28).

Abstract: An optical star coupler having a biconically tapered optical star coupler inserted and suspended in a protection tube and the method for manufacturing the same are disclosed. The manufacturing method provides that an optical fiber bundle is inserted into a protection tube such as hollow glass tube, then the optical fiber bundle is twisted and pulled while it is indirectly heated through the protection tube, thereby forming a twisting, fusing and pulling portion. Both ends of the protection tube are then sealed with an adhesive agent to fix the optical fiber bundle to the protection tube. This optical star coupler can be constructed so as to be connected in tandem without any splicing. The optical star coupler of the present invention, in the case of an optical star coupler using multi-mode optical fibers, and particularly in the case of one equally divided optical star coupler using single-mode optical fiber, also provides low insertion loss, less power deviation and low manufacturing costs.

Abstract: A control apparatus for an A.C. elevator comprises resistances connected between an A.C. power source and a converter, a detection device to detect the build-up rate of the charged voltage of a smoothing capacitor, and control means to generate a signal for closing a contact interposed between the A.C. power source and the converter, when the output of the detection device is not greater than a predetermined value. The detection and control devices are preferably provided by a microcomputer.

Abstract: A method and apparatus used to compensate for thermal displacement and to correct a positional error caused by the thermally induced displacement of a spindle positioned in response to a numerical control system. The amount of thermally induced displacement of the spindle, at a predetermined point in time after application of electric power to the machine tool, is stored in a memory. When the spindle is to be positioned in response to numerical control data, the commanded amount of spindle movement is compensated by using the amount of thermally induced displacement stored in the memory, and the spindle is then positioned on the basis of the compensated commanded amount of movement.

Abstract: A motor having a clutch device which can provide a desired one of two (or more) rotating speeds of a rotor of the motor, comprising: an armature which is rotated by a driving shaft of said rotor and is slidable along the axis thereof; two rotating drive members which are rotatably supported by said driving shaft; electromagnetic exciting members which can attract said armature to a desired one of said rotating drive members, wherein a desired one of said rotating drive members produces rotational power due to the rotation of said driving shaft via said armature.