Patents by Inventor Nobukatsu Arai

Nobukatsu Arai 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: 4887577
    Abstract: A compact hot-wire type air flow meter for an internal combustion engine with a high measuring accuracy is provided with a primary flow path forming an intake air passage and an auxiliary flow path incorporating therein a hot-wire element for measuring the intake air. The auxiliary flow path is defined by a flow path in an axial direction of the primary flow path and a flow path in a radial direction of the primary flow path.
    Type: Grant
    Filed: June 16, 1988
    Date of Patent: December 19, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Nobukatsu Arai, Yoshihito Sekine, Tadao Osawa, Hiroatsu Tokuda, Toshifumi Usui, Mitsukuni Tsutsui
  • Patent number: 4735550
    Abstract: According to the turbo molecular pump of the present invention, a regenerative pump is constructed by arcuate eddy current grooves having a predetermined angle with respect to the surface of the outer periphery of a rotor and which are circumferentially engraved in array in the rotor and an arcuate ventilating channel engraved in the circumferential direction in a stator, and a partition is defined in the stator circumferentially partitioning the ventilating channel, so that the working range on the low vacuum side may be extended.
    Type: Grant
    Filed: July 30, 1986
    Date of Patent: April 5, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Takeshi Okawada, Shinjiro Ueda, Susumu Yamazaki, Masahiro Mase, Nobukatsu Arai, Kazuaki Nakamori
  • Patent number: 4522574
    Abstract: A balancing weight device for scroll-type fluid machine including a balancing weight rotatably secured to the orbital scroll member of the machine through a bearing, with the balancing weight producing a centrifugal force balancing the centrifugal force produced in the orbital scroll member during operation of the fluid machine.
    Type: Grant
    Filed: October 21, 1983
    Date of Patent: June 11, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Nobukatsu Arai, Naoki Maeda
  • Patent number: 4496296
    Abstract: A scroll type fluid machine having two scroll members each having an end plate and a spiral wrap formed on the end plate, the scroll members being coupled to each other such that the wraps thereof mate with each other. One of two scroll members being adapted to make an orbitary movement with respect to the other scroll member while being prevented from rotating around its own axis, so as to form at least one working chamber of different pressures between two scroll members. At least two pressing force imparting chambers are formed on the opposite side of the orbitary scroll member to the wrap.
    Type: Grant
    Filed: January 7, 1983
    Date of Patent: January 29, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Nobukatsu Arai, Shigeru Machida, Eiji Sato, Kenji Tojo, Naoshi Uchikawa
  • Patent number: 4326391
    Abstract: In a Rankine-cycle-engine-driven cooling-and-heating system comprising a power generating cycle including at least an expander, an oil separator, a condenser and a generator and a cooling-and-heating cycle including at least a compressor, an oil separator, a condenser, an expansion means and an evaporator, the housings of the expander and the compressor are so securely joined that a hermetically sealed space may be defined between them. This space is used as an oil separator which is common to both the cycles and is communicated with the outlet port of the expander and the discharge port of the compressor. As a result, the system can be made considerably compact in size as compared with the prior art systems in which the oil separator is disposed outside of the expander and the compressor.
    Type: Grant
    Filed: August 25, 1980
    Date of Patent: April 27, 1982
    Assignee: Hitachi, Ltd.
    Inventors: Eiji Sato, Nobukatsu Arai, Hideki Tanaka, Toshihiko Fukushima, Tadakatsu Nakajima
  • Patent number: 4216661
    Abstract: In a gas pressure increasing system for increasing the pressure of a refrigerant gas or air having a scroll compressor, a condenser, a pressure reducing means and an evaporator or a scroll compressor and a gas cooler, an exhaust gas released from the scroll compressor after having its pressure increased by the scroll compressor itself is cooled and expanded to reduce its pressure to an intermediate pressure level to produce a gas of an intermediate pressure having a cooling capability. The gas of the intermediate pressure is used to provide a force for axially sealing an orbiting scroll member of the scroll compressor as well as to cool the scroll compressor and a motor.
    Type: Grant
    Filed: December 8, 1978
    Date of Patent: August 12, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Tojo, Hirokatu Kousokabe, Nobukatsu Arai, Eiji Sato
  • Patent number: 4175416
    Abstract: An apparatus for manufacturing heat transfer tubes for use in evaporators and coolers for freezers, air conditioning units, refrigerators, and the like, with close machining tolerances. It forms cavities, with small openings communicating them with the outside, on the inside of a tube, through three steps of forming a multiplicity of alternate grooves and ribs in parallel on the inner surface of the tube, forming cuts in the concentrically directed crests of the ribs, and then forcing the crests sidewise so that the crest of each rib is bent down onto an intermediate part of the adjacent rib to form a cavity in between.
    Type: Grant
    Filed: January 11, 1978
    Date of Patent: November 27, 1979
    Assignee: Hitachi, Ltd.
    Inventors: Toshihiko Fukushima, Kunio Fujie, Akira Arai, Nobukatsu Arai, Kimio Kakizaki
  • Patent number: 4168743
    Abstract: A heat exchanging wall including a base member made of a material comprising graphite as its principal component and a resin as a binder, and a thin outer coat member made of similar material as the material for the base member and applied to one surface of the base member. The material for the base member is cast in a mold having a finely ribbed inner wall surface so that the base member may be formed in such one surface thereof with fine linear grooves. Portions of the thin outer coat member corresponding in position to the grooves in such one surface of the base member are formed with a multitude of small apertures. The heat exchanging wall constructed as aforementioned has high corrosion-resistant characteristics and high heat transfer capabilities, so that the wall is resistant to all corrosive fluids.
    Type: Grant
    Filed: January 27, 1977
    Date of Patent: September 25, 1979
    Assignees: Hitachi, Ltd., Hitachi Cable, Ltd.
    Inventors: Nobukatsu Arai, Kunio Fujie, Kimio Kakizaki