Abstract: A hook assembly includes a bearing rib on a bobbin case basket or at least a surface layer thereof composed of a synthetic resin, such as a liquid crystal polymer, which has properties such that the amount of the rotating friction generated between such surface layer and an inner surface layer of a groove shaped bearing raceway in which the bearing rib is fitted is lower, with no industrial sewing machine oil therebetween than such industrial sewing machine oil where to be provided therebetween. The hook assembly thus has good durability without any lubrication being provided. Accordingly, oil staining of threads and sewing materials by a lubricant is avoided, and sewing quality is enhanced.

Abstract: In order to equalize voltage shares of DC-side voltage dividing capacitors of a three-level power converting apparatus for converting a DC voltage to a three-level AC phase voltage, there is provided an arrangement for compensating for rising and falling instances of a three-level AC voltage pulse depending on a difference voltage between the two voltage dividing capacitors and the polarity of the AC current, thereby adjusting a zero-voltage period of the AC voltage.

Abstract: A blowing apparatus includes a suction passage having a suction chamber enclosed by rigid body surfaces, suction ports opening toward the suction chamber for sucking air from outside, and a fan suction port serving as a suction port for a blower, the suction ports, the suction chamber, and the fan suction port being arranged in nonlinear form. In such blowing apparatus, a doughnut-like straightening guide is arranged on an opening edge on the suction chamber side of the fan suction port. The straightening guide has a projection toward the suction chamber, an appropriate thickness in the radial direction, and a guide passage matching the fan suction port in the middle thereof.

Abstract: An electric power converting apparatus equipped with a 3-level PWM control in which the output voltage can be continuously and smoothly controlled from zero to a maximum voltage. The electric power converting apparatus includes a multi-pulse generating unit arranged for a dipolar modulation, a unipolar modulation, and an overmodulation; a 1-pulse generating means; and a unit for controlling the transfer operation among these modulation regions.

Abstract: An electric railway vehicle control system including a converter for converting a single-phase a.c. voltage to a d.c. voltage, a PWM inverter for inverting the d.c. output of the converter to a variable voltage, variable frequency a.c. voltage, and a three-phase induction motor supplied with the a.c. output voltage of the inverter to drive electric railway vehicles. The control system further includes a unit for controlling the output voltage of the inverter in a variable voltage, variable frequency mode for changing the output voltage substantially relative to a change in the output frequency thereof and in a constant voltage, variable frequency control mode for fixing the output voltage to a substantially constant value, and a unit for detecting a rectification ripple in a frequency band including a frequency double the frequency of the single-phase a.c. voltage included in the d.c. input voltage to the inverter.

Abstract: Disclosed is an apparatus for realizing a small apparatus by making element currents uniform in the dipolar modulation mode. The zero voltage period in the dipolar modulation period is made shorter than other voltage output periods. Accordingly, currents of switching elements constituting the main circuit of an inverter can be made uniform.

Abstract: The power converter of the invention relates to a small-sized highly efficient power converter for generating an a.c. voltage output of multiple levels with less harmonic content. In the power converter, a d.c. voltage source is separated into plural sections by series connected voltage dividing capacitors and multiple levels of a.c. output voltage are obtained from the divided d.c. voltage by on-off control of switching devices. The power converter has plural sets of the voltage dividing capacitors disposed separately adjacent to each switching devices, and series connection point of each set of the voltage dividing capacitors are connected to division points of the corresponding switching devices of each phase. The voltage dividing capacitors are connected with each other at their series connection points. Thereby, the arrangement makes wiring length short and equal between the switching devices and the voltage dividing capacitors for each phase and reduce a loss in the snubber circuit, resulting in an a.c.

Abstract: An electric power converting apparatus equipped with a 3-level PWM control in which the output voltage can be continuously and smoothly controlled from zero to a maximum voltage. The electric power converting apparatus includes a multi-pulse generating unit arranged for a dipolar modulation, a unipolar modulation, and an overmodulation; a 1-pulse generating means; and a unit for controlling the transfer operation among these modulation regions.

Abstract: A bobbin case holder body and a track projection portion are made of steel. A coating member of a liquid crystal polymer is integrally molded to the outer surface of the track projection portion so as to have a thickness t which is selected to be 0.3 to 0.5 mm. A part of the coating member is fitted into a groove formed in the track projection portion, thereby preventing the member from peeling off. In a loop spreading portion, the track projection portion made of steel is exposed from the coating member so that a so-called thread handing area is prevented from being formed. Therefore, wear resistance and durability are improved.

Abstract: The present invention relates to a group control elevator system which has been adjusted to operate in response to a state of utilizing elevator cars. In a group control elevator system which carries out a control of allocating elevator cars to elevator car calls for serving many floors by using an evaluation function having a plurality of variable parameters, targets for elevator control performance are inputted, a traffic flow to which elevator car demand belongs is judged, variable parameters to be adjusted which have been set in advance for each combination of said targets and traffic flows are stored, stored variable parameters are adjusted, adjustment sequence of variable parameters to be adjusted is stored, and a plurality of variable parameters are sequentially adjusted according to the stored sequence. By the above arrangement, only desired parameters to be adjusted are selected and adjusted out of a plurality of variable parameters for desired targets and traffic flows.

Abstract: An information transfer system in which an information transfer control arrangement including information transfer control and reference information storage is provided in a system having at least three subsystems communicating with each other using transfer information which contains an information unit common to all information handled by the subsystems. The information transfer control refers to information in the reference information storage, and rearranges the information arrangement from the transferer subsystem to an information arrangement suitable for the transferee subsystem, if necessary, followed by transferring it. The subsystem can be changed easily by adding, deleting or correcting the reference information in the reference information storage. The configuration of the transfer control system is therefore flexible.

Abstract: An elevator system which is provided with power converters, electric motors supplied with power from the power converters, and a torque distributing section having functions for determining allocation of output power from the power converters on the basis of a required torque, by which an elevator is operated on the basis of functions selected in accordance with the operation mode. The system is able to save power in the elevator operation and also improve control functions and increase system capacity.

Abstract: An electrical power converter having a phase converter constituted by positive side semiconductor switching elements connected in series and negative side semiconductor switching elements connected in series which converts a DC voltage to an AC output phase voltage having at least three potential levels, resulting in three possible modulation modes: dipolar, partial dipolar and unipolar. Dipolar modulation is realized by alternating positive and negative output pulses. Unipolar modulation is realized by output pulses having only the same polarity as the corresponding fundamental modulation wave. Transition is accomplished via partial dipolar modulation which is realized by alternating positive and negative output pulses in a first period of a half cycle by outputting alternating positive and negative pulses and in a second period by outputting pulses having only the same polarity as the corresponding fundamental modulation wave.

Abstract: An apparatus for a three-level DC/AC converter, in which the width of output pulse having the same polarity as the fundamental wave of the converter output phase voltage is adjusted depending upon the DC component of a differential voltage between two DC voltages in a dipolar modulation system of the converter. Whereby, the imbalance of DC components between the two DC voltages is easily and effectively suppressed.

Abstract: The present invention relates to a control apparatus of a three-level inverter and intends to provide a control apparatus of simplified construction which can suppress a fluctuation in neutral point voltage effectively. Only a third harmonic component which is particularly large in the fluctuation in neutral point voltage is suppressed, a third harmonic component for suppression has a ratio of amplitude to that of a fundamental wave and a phase which are set to be constant regardless of the inverter frequency, and this third harmonic component is applied to a command of the fundamental wave.

Abstract: Elevator group supervisory control method and system for group supervisory control of a plurality of elevators serving a plurality of floors. The method and apparatus of the invention permits the inputting of qualitative requests (guidance), from the user, concerning elevator operation into the group supervisory control system. Qualitative requests concerning elevator operation are set in the form of guidance (or request) targets. The thus set request, targets are converted into control targets for the elevators. Actual group supervisory control is executed using the control targets.

Abstract: An apparatus for detecting people waiting for an elevator. A detecting unit detects the number of people waiting on the basis of an image from an image pickup unit and delivers that number to a corresponding second people waiting detecting unit. The apparatus includes a unit which generates a coefficient depending on a percentage of overlap of the field of view of a reference image pickup unit, which is one of several image pickup units, with the field of view of a different image pickup unit on the basis of data on the allocation of an elevator, and calculates the number of waiting people in the overall hall from the respective numbers of waiting people output from the plurality of image pickup units and those coefficients. The coefficient generating unit generates a maximum coefficient for the reference image pickup unit and a smaller coefficient for any remaining image pickup unit based on the of overlap of the field of view of the respective image pickup units.

Abstract: An elevator control system for controlling movement of cages up and down in accordance with the situation of waiting persons in landing places or passengers in the cages detected by image pickup devices and other detecting devices includes first and second image processors, the image processing level of the second image processor being not lower than that of the first image processor. The system further includes an elevator controller for controlling movement of the cages up and down, the elevator controller including a device for applying the result of image processing performed by the first image processor to the control of the cages, and a device for applying the result of image processing performed by the second image processor to the control of the cages when the image processing is carried out based on the result of image processing performed by the first image processor and other information pertaining to passengers and waiting persons detected by the other detecting devices.

Abstract: In an inverter control apparatus including a pulse width modulation inverter supplied with power from a d.c. power source to generate an a.c. output, a frequency control unit controlling the output frequency of the inverter, and a voltage control unit controlling the output voltage of the inverter, a frequency adjusting unit is provided to adjust the operating frequency of the inverter so that the product of voltage and time in each positive half cycle of the output voltage of the inverter becomes equal to that in the next adjacent negative half cycle of the output voltage of the inverter.

Abstract: An electron gun in which at least two of a plurality of electrodes constituting the electron gun are endowed with structures for generating rotationally-asymmetric electric fields, in electron-beam apertures of the electrodes or around the electron-beam apertures, and a cathode-ray tube which comprises the electron gun can enhance focus characteristics and attain favorable resolutions over the whole area of a screen and in all the current ranges of electron beams, and they do not give rise to moire in the small current range of the electron beams, without supplying a dynamic focus voltage.