Patents by Inventor Masao Iwasa

Masao Iwasa 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: 10392709
    Abstract: A coated steel sheet includes a corrosion-resistant coating composed of at least one layer selected from the group consisting of a Ni layer, a Sn layer, an Fe—Ni alloy layer, an Fe—Sn alloy layer, and an Fe—Ni—Sn alloy layer disposed on at least one surface of a steel sheet, and an adhesive coating disposed on the corrosion-resistant coating, the adhesive coating containing Zr and further containing at least one metal element selected from the group consisting of Co, Fe, Ni, V, Cu, Mn, and Zn, in total, at a ratio by mass of 0.01 to 10 with respect to Zr. The coated steel sheet has excellent humid resin adhesion and corrosion resistance, in which streaky surface defects do not occur.
    Type: Grant
    Filed: March 31, 2017
    Date of Patent: August 27, 2019
    Assignee: JFE Steel Corporation
    Inventors: Yuka Miyamoto, Takeshi Suzuki, Hiroki Iwasa, Norihiko Nakamura, Masao Inose, Hisato Noro, Yoichi Tobiyama
  • Patent number: 6481533
    Abstract: A single inverter (8) provides variable frequency, variable voltage current output (11) to either a hoist motor (3) or a door motor (6), depending on the operating mode of the elevator car (1). A controller (9) provides an input signal (12) to an actuator (10) for switching the output current (11) between the motors (3, 6) by a relay switch (12). The controller (9) includes separate control profiles depending upon which motor (3, 6) is connected to the inverter (8).
    Type: Grant
    Filed: July 12, 2001
    Date of Patent: November 19, 2002
    Assignee: Otis Elevator Company
    Inventor: Masao Iwasa
  • Patent number: 5564530
    Abstract: A traction-type elevator includes a driving sheave (19) arranged in an upper portion of an elevator shaft, cage sheaves (6, 7) arranged at an angle with respect to the driving sheave (19) and mounted on a support beam (5), multiple (or turns of a rope) ropes (17) hung on the cage sheaves (6, 7) and the driving sheave (19), and a hanging rod (10) for hanging a cage from the support beam (5). In this traction-type elevator according to the invention, one torsion coil spring (16) is arranged between the cage side and the aforementioned support beam (5) appropriately so that the aforementioned hanging rod (10) is inserted through it; the two ends of torsion coil spring (16) are attached to a cage side and a side of the support beam (5), respectively. The support beam (5) can effectively rotate to relax torsion in the ropes (17), and it is possible to suppress generation of vibration by the torsion. Also, the torsion coil spring (16) can play the role in damping vibration without shifting outwardly.
    Type: Grant
    Filed: November 16, 1994
    Date of Patent: October 15, 1996
    Assignee: Otis Elevator Company
    Inventors: Atsushi Iwakiri, Masao Iwasa
  • Patent number: 5533595
    Abstract: In a traction-type elevator equipped with a driving sheave (16) positioned at the top of the shaft for ascent and descent (1), cage sheaves (4, 5) are attached to the upper section of the cage (2) and are inclined in relation to this driving sheave (16), and multiple ropes (12, 13, 14) are wound around the outer surface (4a) of this cage sheave and the outer surface (16a) of the above-mentioned driving sheave; the traction-type elevator is characterized in that along with making the outer surface (4a) of the above-mentioned cage sheave (4) parallel to the outer surface (16a) of the driving sheave (16), this cage sheave (4) is divided into multiple sheave pieces (17, 18, 19) according to the abovementioned ropes (12, 13, 14). The ropes (12, 13, 14) are pulled by the driving sheave (16), and even if the cage (2) is caused to move upwardly or downwardly at a high speed, there is essentially no more generation of vibration and noise, because none of the abovementioned ropes (12, 13, 14) twists undesirably.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: July 9, 1996
    Assignee: Otis Elevator Company
    Inventors: Eiji Narumi, Masao Iwasa
  • Patent number: 5247140
    Abstract: The current an inverter is used as a power source for a brake circuit. The brake circuit includes a current detector, a comparator for comparing the detected value with a dictated brake current pattern, and a switch which switches the brake current in accordance with the magnitude of the difference between the detected current value and the dictated value. The brake current is selected to smoothly increase and decrease the brake current to prevent vibration and noise.
    Type: Grant
    Filed: August 7, 1991
    Date of Patent: September 21, 1993
    Assignee: Otis Elevator Company
    Inventors: Masao Iwasa, Koji Yamada, Hirofumi Sugiura
  • Patent number: 5105352
    Abstract: The DC offset in a current control system for a PWM inverter drive is corrected by integrating a DC component of a current control signal provided by a current control amplifier and feedback controlling the current control amplifier to reduce the DC component to zero.
    Type: Grant
    Filed: October 31, 1990
    Date of Patent: April 14, 1992
    Assignee: Otis Elevator Company
    Inventors: Masao Iwasa, Hirofumi Sugiura
  • Patent number: 5070426
    Abstract: A clipper circuit includes an auxiliary diode connected between a capacitor and diode, themselves forming a clipper circuit. The auxiliary diode thus forms an auxiliary clipper circuit taking the capacitor as a common capacitor. The clipper circuit diodes shunt current from the capacitor into first and second currents through the diodes. This obviates the necessity for a snubber circuit and power source clipper circuit as employed in the prior art.
    Type: Grant
    Filed: February 28, 1990
    Date of Patent: December 3, 1991
    Assignee: Otis Elevator Company
    Inventors: Masao Iwasa, Yasutami Kito
  • Patent number: 5070290
    Abstract: A control system for an alternating current motor, such as an elevator hoisting induction motor, in response to failure of power supply, such as service interruption, phase open and so forth, performs in a first emergency control mode and in a second emergency control mode. In the first emergency control mode operation, dynamic braking is used to decelerate the motor. On the other hand, in the second emergency mode, triggered while the motor is driven in regeneration mode to recirculate regenerated power to decelerate the motor, a mechanical brake is applied. During second emergency control mode operation, power supply condition is monitored to detect failure of the power supply for switching control mode from the second emergency control mode to the first emergency control mode.
    Type: Grant
    Filed: March 13, 1989
    Date of Patent: December 3, 1991
    Assignee: Otis Elevator Company
    Inventors: Masao Iwasa, Masayuki Mori
  • Patent number: 5058710
    Abstract: A simplified elevator power system using an AC-DC converter, both to convert AC to DC during normal operation and to convert stored DC power to AC during power failures. A power source monitoring relay monitors AC power coming from a utility, and upon power failure, switches a battery from a charging mode to a power source mode wherein DC power is supplied, not only to an inverter for driving a motor, but also to a converter hooked up to run as an inverter during such power failure in order to provide stepped-up AC voltage to elevator control devices. In this way, the prior art addition of an extra inverter is avoided.
    Type: Grant
    Filed: August 14, 1990
    Date of Patent: October 22, 1991
    Assignee: Otis Elevator Company
    Inventor: Masao Iwasa
  • Patent number: 4994951
    Abstract: The present invention is achieved with a control unit for a PWM inverter for comparing (8) a voltage command signal (7) with the fundamental of the inverter's output voltage waveform and for comparing (11) the result with a carrier signal (10) and using that result to keep the output voltage waveform equal to the voltage command signal. The use of the output's fundamental for feedback eliminates the prior art need to use slight delays in the inverter's switching stage thereby removing the prior art torque ripple and consequent vibration problems particularly at low speed and furthermore enables smoother stopping and starting control using variable speed ranges of several hundred to one.
    Type: Grant
    Filed: April 20, 1989
    Date of Patent: February 19, 1991
    Assignee: Otis Elevator Company
    Inventors: Masao Iwasa, Yasutami Kito
  • Patent number: 4870334
    Abstract: An apparatus for controlling an adjustable-speed electric motor. The actual motor speed is sensed and compared with a commanded motor speed. A speed error signal, which depends on the difference between the actual and desired values of motor speed, is derived and applied to a proportional-plus-integral control circuit which converts it into a first torque command signal. The speed command signal is converted into a second torque command signal proportional to the rate of change of the speed command signal. The second torque command signal is added to the first torque command signal to provide a torque command signal. A control circuit responds to the torque command signal by controlling the operation of the motor in accordance with the torque command signal.
    Type: Grant
    Filed: June 6, 1988
    Date of Patent: September 26, 1989
    Assignee: Otis Elevator Company
    Inventors: Masao Iwasa, Yasutami Kito, Masayuki Mori