Patents by Inventor Toru Tanahashi

Toru Tanahashi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6349796
    Abstract: A drive machine for elevators includes a rotatable drive sheave over which a main cable for hanging an elevator cage is wound, a stationary shaft for supporting rotation of the drive sheave and bearing a load applied to the drive sheave by the main cable, a field magnet attached to the drive sheave, constituting a part of an electric motor, and including at least one pair of magnetic poles, an armature attached to the stationary shaft facing the field magnet and constituting another part of the motor, and a field magnetic pole detector for detecting a magnetic pole of the field magnet rotating together with the drive sheave.
    Type: Grant
    Filed: August 15, 2001
    Date of Patent: February 26, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigeaki Tauchi, Toru Tanahashi
  • Patent number: 6344089
    Abstract: A drive machine for elevators includes a rotatable drive sheave over which a main cable for hanging an elevator cage is wound, a stationary shaft for supporting rotation of the drive sheave and bearing a load applied to the drive sheave by the main cable, a field magnet attached to the drive sheave, constituting a part of an electric motor, and including at least one pair of magnetic poles, an armature attached to the stationary shaft facing the field magnet and constituting another part of the motor, and a field magnetic pole detector for detecting a magnetic pole of the field magnet rotating together with the drive sheave.
    Type: Grant
    Filed: August 15, 2001
    Date of Patent: February 5, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigeaki Tauchi, Toru Tanahashi
  • Patent number: 6328136
    Abstract: A drive machine for elevators includes a rotatable drive sheave over which a main cable for hanging an elevator cage is wound, a stationary shaft for supporting rotation of the drive sheave and bearing a load applied to the drive sheave from the main cable, a field magnet attached to the drive sheave, constituting a part of an electric motor, and including at least one pair of magnetic poles, an armature attached to the stationary shaft facing the field magnet and constituting another part of the motor, and a field magnetic pole detector for detecting a magnetic pole of the field magnet rotating together with the drive sheave.
    Type: Grant
    Filed: September 17, 1999
    Date of Patent: December 11, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigeaki Tauchi, Toru Tanahashi
  • Patent number: 6064084
    Abstract: A fabrication process of a semiconductor device includes a step of forming a conductive overhang structure at a top part of a contact hole in continuation with a thin conductive film covering an exposed bottom surface and an inner surface of said contact hole.
    Type: Grant
    Filed: March 21, 1997
    Date of Patent: May 16, 2000
    Assignee: Fujitsu Limited
    Inventor: Toru Tanahashi
  • Patent number: 5698823
    Abstract: An elevator control system employs dynamic braking and achieves reduced energy consumption as compared to known elevator control systems. A synchronous motor using a permanent magnet is used as a hoist machine. A contactor short circuits the input terminals of the synchronous motor via a resistor. If an emergency stop is triggered while an elevator car is opened for passengers to enter or exit, the contactor short circuits the input terminals of the synchronous motor.
    Type: Grant
    Filed: December 21, 1995
    Date of Patent: December 16, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toru Tanahashi
  • Patent number: 5460244
    Abstract: The present invention provides an elevator speed control system in one mode, including: a plurality of converters connected in parallel for converting an AC voltage to a DC voltage by means of controllable devices; a capacitor for smoothing output voltages of the plural converters; a plurality of inverters connected in parallel which convert the voltages smoothed by means of the capacitors to an AC voltage whose magnitude and frequency are controllable, and which further supply the resulting AC voltage to a hoisting induction motor; current detectors for detecting the currents in each phase of the plural converters and inverters; a control means which calculates the sum of the resulting currents of the plural converters and inverters and which further controls the output voltages of plural converters and inverters so that the resulting sum is minimized.
    Type: Grant
    Filed: March 4, 1993
    Date of Patent: October 24, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toru Tanahashi
  • Patent number: 5414333
    Abstract: A speed control apparatus for an elevator using V.V.V.F. control including a power conversion device, an induction motor and a control device. The control device detects a secondary magnetic flux value from an output current of the power conversion device and generates a control command value for smooth operation of the elevator based on the velocity of the motor and the secondary magnetic flux value.
    Type: Grant
    Filed: September 12, 1994
    Date of Patent: May 9, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toru Tanahashi
  • Patent number: 5270498
    Abstract: An elevator speed control apparatus includes an inverter connected to an AC power source so as to supply an induction motor for driving an elevator with a variable-voltage, variable-frequency AC. A contactor provided between the invertor and the AC power source. A magnetic flux computing device computes residual value of secondary magnetic flux of the induction motor while the contactor is closed. A control device divides a primary current of the induction motor into an exciting current component and a torque current component so as to perform vector control, this control device being also used to generate a forcing pattern for the exciting current component in accordance with an output of the magnetic flux computing means when the contactor is closed.
    Type: Grant
    Filed: May 22, 1991
    Date of Patent: December 14, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toru Tanahashi
  • Patent number: 4602701
    Abstract: An apparatus for controlling the speed of an elevator, which controls an AC electric motor that drives the cage, by using a power rectifier made up of thyristors and a power inverter made up of a transistor and a diode. A speed instruction for the cage is compared with a detected speed to produce an output instruction signal for said power rectifier and a slip frequency instruction signal for said power inverter. A control circuit controls the phase of said power rectifier relying upon the output instruction signal and controls the pulse-width modulation of said power inverter relying upon said slip frequency instruction signal, the control circuit comprises a voltage detector that detects the voltage of the AC power source, and a minimum value select circuit that receives the output of said voltage detector as a first input, that receives said output instruction signal as a second input, that compares these inputs, and that produces a signal of the same level as the signal of the lower level.
    Type: Grant
    Filed: November 20, 1984
    Date of Patent: July 29, 1986
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toru Tanahashi
  • Patent number: 4519479
    Abstract: In an elevator having a converter which changes an A.C. output from an A.C. power source into a D.C. output, an inverter which changes the D.C. output of the converter into an A.C. output, a current detector which detects an output current of the inverter, and an inverter controller which controls the inverter on the basis of the detected current value of the current detector and a command current value, a hoist motor being driven by the A.C. output of the inverter; the operation of the inverter being stopped when a difference between the detected current value and command current value of the current detector for detecting the output current of the inverter exceeds a preset value. Accordingly, a current detector for detecting current flowing through the inverter is dispensed with, to realize a simple arrangement and a low cost.
    Type: Grant
    Filed: June 12, 1984
    Date of Patent: May 28, 1985
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toru Tanahashi
  • Patent number: 4452341
    Abstract: A floor relay contact 15 is connected between an elevator cage load detecting device 14 and a memory circuit 16. Just before the cage 7 reaches a desired floor the relay contact is closed to apply the output of the load detecting device 14 to a traction motor current control circuit 12 via the memory. This minimizes any acceleration-deceleration bumps and eliminates any vertical gap between the accessed floor sill and the stopped position of the cage when passengers exit before the cage comes to a complete halt.
    Type: Grant
    Filed: February 9, 1982
    Date of Patent: June 5, 1984
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toru Tanahashi