Patents by Inventor Keigo Naoi

Keigo Naoi 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).

  • Publication number: 20200093141
    Abstract: A knife having scales includes a U-shaped handle having a first shaft and a second shaft, a first fixed knife, which is coupled with the handle, a second movable knife, which is able to connect to and move along the first shaft in order to divide an object by a desired angle, and a protractor, which is possible to be put on the first shaft, and is used as a guide for dividing the object into desired numbers, each of which is equal amount, wherein scales are shown on the protractor, and wherein the scales are grouped in accordance with the number that the object is divided.
    Type: Application
    Filed: November 29, 2019
    Publication date: March 26, 2020
    Inventors: Ayame NARA, Yuki FUKUDA, Ayumi NISHIMINE, Kana NAGASAWA, Keigo NAOI, Kazuma FUJISAWA, Miho ISHIDA, Yuka YAMANAKA, Kai KOMIYA
  • Patent number: 5404717
    Abstract: The present invention relates to a control circuit for use in an internal combustion engine having a cranking device and an air pump driven by a starter motor. The control circuit comprises a first circuit for supplying a power to the starter motor and the cranking device, a second circuit for terminating power supply for the cranking device with maintaining power supply for the starter motor, and a control unit for selectively switching between the first and second circuits.
    Type: Grant
    Filed: March 1, 1993
    Date of Patent: April 11, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Toshiharu Nogi, Minoru Ohsuga, Jun'ichi Yamaguchi, Yoshiyuki Tanabe, Keigo Naoi, Masayuki Shizuka, Kazuo Tahara
  • Patent number: 5355749
    Abstract: A control apparatus of a motor drive vehicle includes a unit for generating a target vehicle speed; a speed instruction unit for generating a target motor rotational speed of the motor based upon a preset motor control pattern in response to the target vehicle speed; a power circuit for operating the motor at the target motor rotational speed upon receipt of the target motor rotational speed; a variable transmission unit for converting a drive output from the motor into a transmission ratio for instructing a rotational speed of the drive output, and transferring the converted transmission ratio to a drive shaft of the motor drive vehicle; and a transmission ratio calculating unit for determining the transmission gear ratio based on the target vehicle speed and the target motor rotational speed thereby to instruct the determined transmission gear ratio to the variable transmission unit.
    Type: Grant
    Filed: December 17, 1992
    Date of Patent: October 18, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Sanshiro Obara, Ryoso Masaki, Toshiaki Okuyama, Tsutomu Ohmae, Keigo Naoi, Makoto Shioya
  • Patent number: 4760323
    Abstract: A voltage regulator for a generator wherein a switching device connected in series to the field coil of the generator is adapted to be controlled in accordance with an output voltage of the generator and the ambient temperature at the voltage regulator so as not to exceed the junction temperature limit value of the switching means.
    Type: Grant
    Filed: July 22, 1985
    Date of Patent: July 26, 1988
    Assignee: Hitachi, Ltd.
    Inventor: Keigo Naoi
  • Patent number: 4563631
    Abstract: A voltage regulator for a charging generator comprising an a.c. generator, a rectifier for converting the a.c. output of the a.c. generator to a d.c., a battery connected to the output of the rectifier, comparison means for comparing the battery voltage with a reference voltage of a reference voltage generation circuit and a power transistor controlled by the output of the comparison means and controlling a current flowing through a field coil of the a.c. generator.The reference voltage generation circuit comprises a voltage divider connected to a constant voltage power source and providing its divided voltage as the reference voltage, a plurality of transistors connected in parallel with a part of the voltage divider, and conduction control means for controlling the transistor in accordance with the ambient temperature so that the reference voltage is determined in accordance with the ambient temperature.
    Type: Grant
    Filed: February 10, 1984
    Date of Patent: January 7, 1986
    Assignees: Hitachi, Ltd., Hitachi Automotive Eng. Co., Ltd.
    Inventors: Keiichi Mashino, Keigo Naoi, Kunio Kobayashi
  • Patent number: 4232238
    Abstract: There is disclosed a rectifier assembly for an AC generator for use with vehicles. The rectifier assembly comprises a single horseshoe heat radiating plate and electric circuit elements mounted thereon, and including at least one rectifier unit and two DC output conductor plates. The two d.c. output conductor plates are disposed in spaced relationship on one surface of the heat radiating plate with an intermediate insulating layer and electrically connected to output terminals of the rectifier unit. The assembly may be incorporated with a voltage regulator of an integrated circuit configuration for controlling the output voltage of the AC generator and a brush holder. The voltage regulator may be coplanar with the conductor plates.
    Type: Grant
    Filed: March 6, 1979
    Date of Patent: November 4, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Akihiro Saito, Keigo Naoi