Patents by Inventor Akira Tatsumi

Akira Tatsumi 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: 6930895
    Abstract: An object of the present invention is to provide a computer power supply in which, by improving the circuit itself, internal heat loss can be reduced, thereby greatly improving efficiency. A partial resonance circuit 8 is constituted by a primary side winding N1 of a high frequency transformer 3, a resonance condenser 7, and two switching elements Q1, Q2, a secondary side output circuit 4 for driving a load is connected to a secondary side of the high frequency transformer 3 via a winding, and a reverse converter 11 for driving and halting the first switching element and second switching element by causing the respective phases thereof to differ on the basis of a driving signal is provided.
    Type: Grant
    Filed: October 2, 2003
    Date of Patent: August 16, 2005
    Assignee: Nipron Co., Ltd.
    Inventors: Tomiji Yamada, Akira Tatsumi
  • Publication number: 20040085054
    Abstract: An object of the present invention is to provide a computer power supply in which, by improving the circuit itself, internal heat loss can be reduced, thereby greatly improving efficiency. A partial resonance circuit 8 is constituted by a primary side winding N1 of a high frequency transformer 3, a resonance condenser 7, and two switching elements Q1, Q2, a secondary side output circuit 4 for driving a load is connected to a secondary side of the high frequency transformer 3 via a winding, and a reverse converter 11 for driving and halting the first switching element and second switching element by causing the respective phases thereof to differ on the basis of a driving signal is provided.
    Type: Application
    Filed: October 2, 2003
    Publication date: May 6, 2004
    Applicant: NIPRON CO., LTD.
    Inventors: Tomiji Yamada, Akira Tatsumi
  • Patent number: 5848831
    Abstract: The present invention relates to an illuminated umbrella intended to assure safety of the user of the umbrella in rainy weather, comprising a light source in a handle or a shaft, thereby illuminating at least part of the shaft coupled to the handle, and therefore the inside of the umbrella, and the face of the user or the vicinity are illuminated by illuminating the shaft itself which is near the face when using to notice the presence of man emphatically to others and drivers, so that the safety of the user in traffic may be enhanced.
    Type: Grant
    Filed: March 1, 1997
    Date of Patent: December 15, 1998
    Inventor: Akira Tatsumi
  • Patent number: 5803011
    Abstract: The invention relates to a vehicle with hull having a hull serving as a roof when mounted on a car detachably fixed on the upper part of a car body, and by detachably mounting and fixing the hull with the ship's bottom directed upward on the upper part of the car body of the vehicle from which the roof is removed, particular carriage is not needed when transporting the hull, and the Overall length is not extended when transporting the hull, and moreover the hull can be used as the roof when mounted on the car, and when dismounted,it can be used as the hull itself.
    Type: Grant
    Filed: November 10, 1997
    Date of Patent: September 8, 1998
    Inventor: Akira Tatsumi
  • Patent number: 5638677
    Abstract: The current operational condition is discriminated as being the vehicle propulsion condition or the performing work condition. When the vehicle propulsion operational condition is discriminated, the maximum engine revolution speed is limited to a first revolution speed and the maximum displacement is limited to a first displacement value. When the performing work condition is discriminated, the maximum engine revolution speed is limited to a second revolution speed equal to or lower than the first revolution speed and the maximum displacement is limited to a second displacement value higher than the first displacement value.
    Type: Grant
    Filed: April 8, 1994
    Date of Patent: June 17, 1997
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Junichi Hosono, Seiji Tamura, Hideaki Sayama, Mitsuo Kihara, Kazuo Asano, Saburo Yoshio, Akira Tatsumi, Kazuhiro Ichimura
  • Patent number: 5479778
    Abstract: When the pump pressure detected through a pressure detecting line 48 is raised higher than a first predetermined pressure Pd1, a recovery switching valve 44 is shifted to a valve-closed position to cease the recovery function. At this time, the pump delivery pressure detected through a pressure detecting line 51 is higher than a second predetermined pressure Pd1* close to the first predetermined pressure Pd1, and an engine speed increasing device 52 controls an engine controller 11 to increase the rotational speed of an engine 10, thereby increasing the pump delivery rate. Thus, it is possible to make small speed change of an actuator and to increase working efficiency with no deterioration in operability, even when a recovery function is ceased.
    Type: Grant
    Filed: December 1, 1994
    Date of Patent: January 2, 1996
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Tsukasa Toyooka, Toichi Hirata, Genroku Sugiyama, Akira Tatsumi
  • Patent number: 5477679
    Abstract: A prime mover revolution speed control system for a hydraulically propelled vehicle controls the revolution speed of a prime mover to optimize vehicle acceleration in a vehicle propelling mode, and to optimize engine output and economy in a working mode. A vehicle equipped with the control system may include a hydraulic pump for discharging hydraulic fluid, the amount of fluid discharged depending on the revolution speed of the prime mover, a hydraulic motor for vehicle propulsion that is driven by hydraulic fluid discharged from the hydraulic pump, and an actuator for performing work that is also driven by hydraulic fluid discharged from the hydraulic pump. The revolution speed of the prime mover may be controlled according to a depression amount of a revolution speed control pedal. When the control system is in the working mode, the revolution speed of the prime mover is controlled in accordance with revolution speed characteristics suitable for a working operation.
    Type: Grant
    Filed: May 19, 1993
    Date of Patent: December 26, 1995
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Akira Tatsumi, Mitsuo Kihara, Seiji Tamura, Hideaki Sayama, Saburou Yoshio, Kazuo Asano, Junichi Hosono
  • Patent number: 5307631
    Abstract: The displacement of a variable displacement hydraulic pump (1) which is driven by a diesel engine (27) is so controlled as to be set to a first target displacement to keep a pump pressure higher than a load pressure by a predetermined target value, or a second target displacement to limit an input torque on the basis of the pump pressure. Provided is a stand-by flow rate control portion (65) which outputs a third target displacement larger than the minimum value of said first target displacement. The displacement of the pump (1) is controlled so as to be set to the third target displacement when the third target displacement is output from the stand-by flow rate control portion (65).
    Type: Grant
    Filed: October 29, 1992
    Date of Patent: May 3, 1994
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Akira Tatsumi, Seiji Tamura, Mitsuo Kihara, Kazuhiro Ichimura, Hiroshi Onoue, Shigetaka Nakamura
  • Patent number: 5277269
    Abstract: An engine revolution speed control device according to the present invention comprises: a hydraulic pump (1) which is driven by an engine (21); a hydraulic motor (4) for vehicle movement which is driven by oil expelled from the hydraulic pump (1) during vehicle movement; an actuator (52) for working which is driven by the oil expelled from the hydraulic pump (1) during the working state; a vehicle driving pedal (6) which during vehicle movement controls vehicle speed according to its amount of operation; a means (33) for speed reduction decision which makes a decision as to whether the amount by which the vehicle driving pedal (6) is depressed is being reduced; and a means for revolution speed control (33).
    Type: Grant
    Filed: November 17, 1992
    Date of Patent: January 11, 1994
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Kazuhiro Ichimura, Seiji Tamura, Akira Tatsumi, Mitsuo Kihara, Junichi Hosono, Kazuo Asano
  • Patent number: 5155996
    Abstract: A hydraulic drive system for a construction machine comprising a prime mover (1), a hydraulic pump (2) of variable displacement type driven by the prime mover, at least one hydraulic actuator (6) driven by a hydraulic fluid delivered from the hydraulic pump, control valves connected between the hydraulic pump and the actuator for controlling a flow rate of the hydraulic fluid supplied to the actuator dependent on the operation amount of control apparatus, pump control apparatus for controlling a displacement volume of the hydraulic pump dependent on the operation amount of the control apparatus such that the delivery rate of the hydraulic pump is increased with an increase in the operation amount, and prime mover control apparatus (29) for controlling a revolution speed of the prime mover.
    Type: Grant
    Filed: August 20, 1990
    Date of Patent: October 20, 1992
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Akira Tatsumi, Toichi Hirata, Masakazu Haga, Eiki Izumi
  • Patent number: 5036817
    Abstract: Disclosed is a remote control system which produces electric signals to be sent to a governor driving device from an operator's cabin for remote control of the governor mechanism. This remote control system essentially includes a detector for detecting the amount of control effected to the governor mechanism, and a control device which operates on detection signals from the detector and operation signals from an operating device in the operator's cabin. The control device is adapted to produce a stop signal to the driving device when the difference in control amount between two cyclic time points becomes smaller than a predetermined value, which is regarded as a limit of operation of the governor mechanism, thereby preventing impairment or damages of the governor mechanism and operating device.
    Type: Grant
    Filed: January 30, 1990
    Date of Patent: August 6, 1991
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Osamu Tomikawa, Touichi Hirata, Akira Tatsumi, Masakazu Haga, Masaki Egashira, Hiroshi Watanabe
  • Patent number: 4955344
    Abstract: A controller having an up/down switch for changing the rotational speed of a prime mover such as an engine, an actuator such as an electric motor for driving a governor on the basis of the operation of the up/down switch so as to control the rotational speed of the prime mover. A target speed is calculated on the basis of the operation of the up/down switch, and the prime mover speed is controlled by using the calculated value. Another switch is provided to immediately shift the prime mover speed to a speed previously set as desired. This shift switch is used to control the prime mover so that the prime mover rotates at the set speed, and this speed is adjusted by operating the up/down switch.
    Type: Grant
    Filed: July 3, 1989
    Date of Patent: September 11, 1990
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Akira Tatsumi, Toichi Hirata, Masaki Egashira, Osamu Tomikawa, Hiroshi Watanabe
  • Patent number: 4942737
    Abstract: A drive control system for a hydraulic construction machine, comprises a prime mover driven by a hydraulic pump, at least one hydraulic actuator driven by hydraulic fluid discharge from the hydraulic pump, first rotational speed setting arrangement including a first operating arrangement for setting rotational speed of the prime mover, and a second operating arranngement for controlling operation of the hydraulic actuator (3).
    Type: Grant
    Filed: May 31, 1988
    Date of Patent: July 24, 1990
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventor: Akira Tatsumi
  • Patent number: 4726186
    Abstract: A control system of hydraulic construction machinery includes a prime mover, at least one variable displacement pump driven by the prime mover, at least one actuator hydraulically driven by the pump, maximum revolution number altering device for the prime mover, maximum displacment volume altering device for the pump and an information provider device for providing information on the operation mode of the actuator, whereby the maximum revolution number altering means and maximum displacement volume altering means are controlled by the information provider device to provide a maximum number of revolutions and a maximum displacement volume which suit the operation mode indicated by the output signal.
    Type: Grant
    Filed: December 29, 1986
    Date of Patent: February 23, 1988
    Assignee: Hitachi, Construction Machinery Co.
    Inventors: Akira Tatsumi, Nobuya Okabe, Mitsuo Kihara, Seiji Tamura
  • Patent number: 4697418
    Abstract: A control system for a hydraulic excavator having a prime mover, revolution number control device for the prime mover, at least one variable displacement hydraulic pump driven by the prime mover, displacement volume control device for the pump, actuators driven by pressurized fluid discharged from the pump and working elements driven by the respective actuators. The control system includes maximum revolution number altering device for the prime mover associated with the revolution number control device, maximum displacement volume altering device for the pump associated with the displacement volume control devices, devices for sensing the operation condition of the actuators, devices for selecting an operation mode for each working element and control devices.
    Type: Grant
    Filed: September 5, 1986
    Date of Patent: October 6, 1987
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Nobuya Okabe, Toichi Hirata, Kuniaki Yoshida, Genroku Sugiyama, Masakazu Haga, Hideaki Tanaka, Akira Tatsumi
  • Patent number: 4658315
    Abstract: A magnetic head mounting device of a magnetic recording apparatus including a carriage, a first magnetic head supported by the carriage, a head arm supported by the carriage for movement in a vertical direction, and a second magnetic head supported by the head arm and disposed in spaced juxtaposed relation to the first magnetic head, wherein both or one of the first magnetic head and second magnetic head is mounted on the carriage or head arm through a gimbal. The gimbal includes a head mounting section for mounting the first magnetic head or second magnetic head thereto, and a supported section disposed outwardly of the head mounting section and partly supported by projections located at the carriage or head arm, the head mounting section and supported section being partly connected together through a plurality of connections.
    Type: Grant
    Filed: October 10, 1984
    Date of Patent: April 14, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Gen Seki, Seiichi Hayashi, Haruyuki Kaito, Akira Tatsumi
  • Patent number: 4365542
    Abstract: An electric fan having a rotary grille provided with a plurality of inclined grille plates and a small-sized reversibly rotatable synchronous electric motor adapted to rotatively drive the rotary grille. A plurality of pairs of projections are formed on a peripheral portion of the rotary grille at different distances from the center of the rotary grille and at different angular intervals. A slidable stopper is mounted on the frame of the electric fan. The stopper is adjustably positionable so as to enable engagement with selected one of the pairs of projections or to a position where it does not contact the projections, so that the rotary grille is reciprocatingly rotated within an angular range limited by the projections or rotated continuously in one direction to vary the area or region of application of an air flow.
    Type: Grant
    Filed: March 17, 1981
    Date of Patent: December 28, 1982
    Assignee: Hitachi, Ltd.
    Inventors: Kenichi Watanabe, Hiroshi Kinoshita, Akira Tatsumi, Koichi Goto
  • Patent number: D788838
    Type: Grant
    Filed: July 7, 2015
    Date of Patent: June 6, 2017
    Inventor: Akira Tatsumi
  • Patent number: D973347
    Type: Grant
    Filed: February 6, 2020
    Date of Patent: December 27, 2022
    Assignee: TATSUMI GAKKI INC.
    Inventor: Akira Tatsumi