Patents by Inventor Kunio Hirasawa

Kunio Hirasawa 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: 5734140
    Abstract: A circuit breaker includes a tank grounded and filled with an insulating gas, a first electrical series-connected section having a main conductor and a main breaking section, and a second electrical series-connected section having a resistor and an advance closing contact device. The first electrical series-connected section is coupled electrically in parallel to the second electrical series-connected section. The fixed contact side of the main breaking section is supported by an insulating cylinder and the fixed contact side of the advance closing contact device is supported by an insulating plate from the fixed contact side of the main breaking section. A breaking unit, chiefly composed of the main breaking section and the advance closing contact device, is supported by insulating cylinders. A resistor unit is supported by an insulating cylinder.
    Type: Grant
    Filed: July 25, 1995
    Date of Patent: March 31, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Hiromichi Hokuto, Kunio Hirasawa, Masatomo Ohno, Manabu Takamoto, Hideo Kawamoto
  • Patent number: 5661282
    Abstract: Breaking poles (1) and (2) are respectively secured to respective conductor bodies (4) and (5) and electrically connected thereto, and the conductor bodies (4) and (5) are fixedly secured and connected to each other by an interpole insulating support body (3). Interpole capacitors (7) are accommodated in the respective side walls of the interpole insulating support body (3). These parts for the breaking portion are accommodated within a grounded metal container (19) together with insulating gas and are secured to an operating box (18) via an insulating support body (17). The breaking poles (1) and (2) are designed to be transmitted an actuating force from the operating box (18) via an actuating insulation rod (not shown) and perform a breaking/making operation.
    Type: Grant
    Filed: March 13, 1995
    Date of Patent: August 26, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Tsuchiya, Goro Daimon, Kunio Hirasawa, Yuuichirou Yamane
  • Patent number: 5563459
    Abstract: An apparatus for controlling a switching device provided for breaking or closing a power line connecting a power source to a load in an electric power system includes a switching timing control unit for controlling the timing to apply a breaking signal to said switching device in response to a breaking signal externally applied thereto so that the contacts of said switching device are opened during a period of time when the current flowing through said power line first reaches its peak value from a zero value and for controlling the timing of applying a closing signal to said switching device in response to a closing command preferably externally applied thereto so that the contacts of said switching device are closed when the voltage of said power source becomes a predetermined value depending upon whether said load is capacitive or inductive, and an operating unit for opening and closing said contacts of said switching device in response to said breaking and closing signals, respectively.
    Type: Grant
    Filed: November 15, 1990
    Date of Patent: October 8, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Yukio Kurosawa, Hiroshi Arita, Kunio Hirasawa, Tadashi Sato
  • Patent number: 5502290
    Abstract: A switching mechanism for use e.g. in a circuit breaker of an underground electric substation has a movable rod which causes opening and closing of an electrical contact and a hydraulic operating system. The hydraulic operating system uses a hydraulic fluid which has a high flammability temperature or is incombustible. Thus, even if such fluid leaks from the hydraulic operating system, the risk of fire or explosion is minimized. The hydraulic operating system may have a sealed tank for the fluid, preferably with a variable volume expansion chamber. In a further development, the hydraulic operating system and possibly parts of the movable rod, is enclosed in a casing which is sealed and is filled with a gas which does not support combustion therein. Thus, the risk of fire or explosion is further reduced. The casing may have a variable volume expansion chamber.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: March 26, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Osamu Koyanagi, Kunio Hirasawa, Masanori Tsukushi, Yukio Kurosawa, Tadashi Sato, Youichi Ohshita
  • Patent number: 5327355
    Abstract: In order to control a voltage using e.g. a tap transformer, the difference .DELTA.V between the actual voltage and a reference voltage is obtained and integrated over time. That integral is then modified by at least one parameter generated by fuzzy logic from control conditions of the voltage. In this way the fuzzy logic may find the optimum control strategy which keeps the actual voltage closest to the reference voltage without an excessive number of tap position changes. The reference voltage may vary with time, and therefore the control of the voltage with time may be evaluated, and the control conditions varied accordingly, e.g. by fuzzy logic, so that the control arrangement can exhibit learning. Normally, the integral is modified such that.intg..DELTA.Vdt.gtoreq.Bwhen B is the parameter determined by the fuzzy logic, but other control strategies may be used. The present invention is also applicable to control of reactive power.
    Type: Grant
    Filed: January 17, 1992
    Date of Patent: July 5, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Tomio Chiba, Mitsuyasu Kido, Junzo Kawakami, Kunio Hirasawa, Yoshiaki Matsui
  • Patent number: 5274205
    Abstract: A gas blast circuit breaker comprises an insulation nozzle for blowing extinguishing gas to an arc generated between a stationary contact and a movable contact. The nozzle has a throat section into and out of which one of the two contacts is movable and a divergent section provided downstream of the throat section. A slanting surface for increasing a reflectivity of energy intensity of the arc is formed on the divergent section of the nozzle. The nozzle is formed of a fluoroplastic material and boron nitride powder of not more than 15 vol. % is added as a filler.
    Type: Grant
    Filed: March 26, 1993
    Date of Patent: December 28, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Masanori Tsukushi, Akira Hashimoto, Minori Satoh, Yukio Kurosawa, Kunio Hirasawa, Fumihiro Endo, Tokio Yamagiwa
  • Patent number: 5153518
    Abstract: The invention relates to a synthetic equivalent test circuit which can generate a 4-parameter transient recovery voltage TRV, for verifying a large current breaking performance of a power circuit breaker. A current source current is supplied to only a testing circuit breaker which is to be tested and an auxiliary circuit breaker. A small current with respect to the current source current is transmitted to the first and second auxiliary switches from a power source. When the small current form the current source or the resonance circuit flows, the first auxiliary switch is opened almost simultaneously with the auxiliary circuit breaker, the testing circuit breaker and operates so as to break the current at the time point of the final zero point of the current source current.
    Type: Grant
    Filed: September 7, 1990
    Date of Patent: October 6, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Minori Satoh, Isao Takahashi, Yukio Kurosawa, Kastuichi Kashimura, Kunio Hirasawa
  • Patent number: 4847476
    Abstract: An ion source device comprises a plasma generating vessel for generating plasma therein, a plurality of magnets arranged on an outer periphery of the plasma generating vessel to establish a cusp field in the plasma generating vessel, means for supplying a power to generate the plasma in the plasma generating vessel, and an anode electrode arranged on an inner wall of the plasma generating vessel and adapted to be heated by electrons emitted from the plasma and maintain the heat.
    Type: Grant
    Filed: December 17, 1986
    Date of Patent: July 11, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Tadashi Sato, Yasunori Ohno, Tomoe Kurosawa, Nobuya Sekimoto, Yoshimi Hakamata, Yukio Kurosawa, Kunio Hirasawa
  • Patent number: 4739169
    Abstract: An ion beam for use in fabrication and processing of semiconductors, thin films or the like. For making uniform the radial distribution of an ion beam extracted from the ion source, a plasma chamber is formed by extending a plasma producing chamber in the direction in which microwave energy is introduced. The plasma chamber thus formed is provided with second magnetic means for generating a magnetic field of multicusp geometry.
    Type: Grant
    Filed: October 1, 1986
    Date of Patent: April 19, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Yukio Kurosawa, Yoshimi Hakamata, Yasunori Ohno, Kunio Hirasawa, Tadashi Sato
  • Patent number: 4578730
    Abstract: There is disclosed a high-voltage DC circuit breaker apparatus with reverse current insertion system by line voltage charge, which comprises a commutation switch, a series circuit of a capacitor, a reactor and a switch connected in parallel with the commutation switch, a resistor connected so as to charge the capacitor by a line voltage. The charging time constant of the capacitor determined by the capacity of the capacitor and the resistor is used as a reference in a manner so that the rise time constant of the line voltage is smaller than the charging time constant of the capacitor, and the rise time constant of the line current is larger than the charging time constant of the capacitor, thereby interrupting the fault current without fail.
    Type: Grant
    Filed: October 12, 1983
    Date of Patent: March 25, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Shunji Tokuyama, Kooji Suzuki, Kunio Hirasawa, Yoshio Yoshioka, Keiji Arimatsu
  • Patent number: 4562322
    Abstract: A SF.sub.6 gas insulating electric apparatus usable as a circuit breaker, etc., containing a SF.sub.6 gas insulator and a resin insulator, both of which insulators are present in an atmosphere to be exposed to arcs, characterized by making at least the surface portion to be exposed to arcs of the resin insulator from a polymer containing nitrogen atoms or a polyolefin resin, and if necessary together with an inorganic filler powder, is excellent in both surface and inner arc resistance and can maintain breaking performance for a long period of time.
    Type: Grant
    Filed: December 18, 1984
    Date of Patent: December 31, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Motoo Yamaguchi, Isamu Sone, Kunio Hirasawa, Yoshio Yoshioka, Akio Nishikawa, Hiroshi Suzuki, Mikio Sato, Masao Hosokawa
  • Patent number: 4442330
    Abstract: A puffer type current interrupter employing a pair of symmetric electrodes with contact bosses provided on their confronting surfaces. An insulator nozzle is arranged such that the throat section for providing a jet of arc blasting gas is located in the periphery of the bosses. The electrode structure provides a uniform electric field between the electrodes, thereby gaining the breakdown voltage.
    Type: Grant
    Filed: July 19, 1982
    Date of Patent: April 10, 1984
    Assignee: Hitachi, Ltd.
    Inventors: Youichi Oshita, Shunji Sato, Takeshi Takahashi, Kunio Hirasawa
  • Patent number: 4423298
    Abstract: Disclosed is a gas circuit breaker of resistance breaking type, which comprises a main breaking unit and a resistance contact mechanism electrically connected in parallel with the main breaking unit for resistively cutting off current. With the opening action of the main breaking unit, a spring used for opening the resistance contact mechanism is energized and the energized force of the spring is released by a releasing mechanism after the current in the main breaking unit is cut off, thereby to act as a drive force to open the resistance contact means.
    Type: Grant
    Filed: October 15, 1981
    Date of Patent: December 27, 1983
    Assignee: Hitachi, Ltd.
    Inventors: Masanori Tsukushi, Youichi Ohshita, Kunio Hirasawa, Takeshi Takahashi
  • Patent number: 4239948
    Abstract: A grounded support tank type gas circuit breaker comprising a cylindrical tank maintained at ground potential and filled with an arc-extinguishing gas, and a breaking unit disposed within the tank with its central axis extending along the axis of the tank. In the circuit breaker, a capacitor unit is disposed within the tank in axially aligned relation with the breaking unit with its axis extending along an extension of the central axis of the breaking unit, so that the capacitor unit can be easily incorporated in the circuit breaker by merely increasing the axial length of the tank.
    Type: Grant
    Filed: July 21, 1976
    Date of Patent: December 16, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Masanori Tsukushi, Kunio Hirasawa, Katsuichi Kashimura
  • Patent number: 4211903
    Abstract: An electromagnetic puffer type gas circuit breaker comprises two opposing puffer type gas circuit breaking units mounted on midway support means, actuating means for driving the circuit breaking units, an electromagnetic actuating unit drivingly coupled to the actuating means, and current transfer mechanism for transferring and applying the interrupting current to the electromagnetic actuating unit during a circuit breaking operation. The current transfer mechanism is located, in operative connection to the actuating means, at a point above the midway support means and in a spaced relation to the electromagnetic actuating unit. The contact surface area of the current-conducting path portion leading to the transfer mechanism is a fraction of that of another current-conducting path portion for the passage of most of the rated current. These features provide ease of inspection and replacement of the current transfer mechanism and reduces the operating force requirement of the breaker.
    Type: Grant
    Filed: June 9, 1977
    Date of Patent: July 8, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Masanori Tsukushi, Katsuichi Kashimura, Osamu Koyanagi, Yoshio Yoshioka, Kunio Hirasawa
  • Patent number: 4160888
    Abstract: A puffer type gas-blast circuit breaker includes at least one interrupting unit mounted in a vessel filled with an arc-extinguishing gas of a unitary pressure.
    Type: Grant
    Filed: June 2, 1977
    Date of Patent: July 10, 1979
    Assignee: Hitachi, Ltd.
    Inventors: Ken-ichi Natsui, Kunio Hirasawa, Yoshio Yoshioka, Hiroshi Chida
  • Patent number: 4105879
    Abstract: In a magnetic puffer type gas circuit breaker including an electromagnetic coil through which a current to be interrupted flows during the breaking operation, and an electromagnetic repulsive member which produces an electromagnetic repulsive force in cooperation with the electromagnetic coil and drives movable parts of a breaking portion of the apparatus, the electromagnetic repulsive member is so arranged that the electromagnetic neutral position of the electromagnetic repulsive member within the electromagnetic coil at the time when the breaking portion has been closed deviates on the closing side with respect to the electromagnetic center of the electromagnetic coil.
    Type: Grant
    Filed: March 7, 1977
    Date of Patent: August 8, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Masanori Tsukushi, Katsuichi Kashimura, Kunio Hirasawa, Yoshio Yoshioka
  • Patent number: 4059741
    Abstract: Two puffer type circuit breaking units are symmetrically disposed with respect to a bracket interposed therebetween. Linking means are mounted in the bracket, and one end of the linking means is connected to movable parts of the puffer type circuit breaking units and the other end is connected to operating means through an electrically insulated operating rod. An electromagnetic coil is disposed in the bracket and an electromagnetic repulsive member is electromagnetically connected to the electromagnetic coil to produce an electromagnetic repulsive force. During the breaking operation, current transferring means mounted in the puffer type breaking units are actuated to apply an electric current to the electromagnetic coil, and an electromagnetic repulsive force is imposed on the electromagnetic repulsive member to actuate the movable parts of the puffer type breaking units together with the operating means, whereby the breaking of a large current is made possible.
    Type: Grant
    Filed: February 24, 1976
    Date of Patent: November 22, 1977
    Assignee: Hitachi, Ltd.
    Inventors: Yoshio Yoshioka, Kunio Hirasawa, Masanori Tsukushi