Patents by Inventor Kazuo Tahara
Kazuo Tahara 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).
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Patent number: 5239490Abstract: This specification discloses inventions of a rotation detecting device for a rotary shaft and of a rotation controlling apparatus using this rotation detecting device. The rotation detecting device according to the invention comprises a signal generator for generating two signals vary their amplitude in accordance with the rotation angle of the rotary shaft and have a predetermined phase difference therebetween, part for correcting the respective center voltages output from the signal generator, part for correcting a deviation from the phase deviation between the two signals, and part for correcting the rotating amounts of the rotary shaft on the basis of the corrected two signal. The rotating amounts are represented in terms of rotating angles. A rotating torque can be obtained by calculating a difference between the rotating angles measured at two points apart from each other on the rotary shaft. The rotary shaft can be controlled in accordance with the rotating angle or the rotating torque.Type: GrantFiled: September 12, 1990Date of Patent: August 24, 1993Assignee: Hitachi, Ltd.Inventors: Ryoso Masaki, Toshiyuki Koterazawa, Kazuo Tahara, Kunio Miyashita, Yoshikazu Hoshi, Tadashi Takahashi, Shuichi Nakano
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Patent number: 5231344Abstract: A control device for an electric generator for use with a vehicle engine includes an armature winding (stator) and a field winding (rotor) driven by the vehicle engine. A chopper is provided for controlling the field current of the field winding and a pulse width modulator is provided for controlling the duty cycle of the chopper in response to the operating conditions of the engine. A voltage feedback loop is provided from a normally provided battery which loop incorporates a detector for detecting the actual battery voltage and a comparator for comparing the battery voltage with a predetermined set voltage so that the difference in voltage is rendered to zero. The invention additionally provides a current feedback loop for controlling a deviation between a current command value determining the duty of the chopper and an actual current flowing through the field winding so as to be substantially zero.Type: GrantFiled: July 20, 1992Date of Patent: July 27, 1993Assignee: Hitachi Ltd.Inventors: Katsuji Marumoto, Kunio Miyashita, Kazuo Tahara, Keiichi Mashino, Atsushi Kanke, Akihiro Saito
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Patent number: 5208502Abstract: Ceramics material are not resistant to tensile force, though they are resistant to compression force. Therefore, ceramics materials, when used as the material of a commutator of an electric rotary machine, tends to be cracked and broken due to tensile stress generated in the inner peripheral portion of the commutator when the latter is press-fitted on the rotor shaft of the machine. The invention is aimed at obviating the above-described problem, so as to make it possible to produce a sliding current collector of an electric rotary machine from a ceramics material. To this end, according to the invention, an annular gap is formed between the inner peripheral surface of the ceramics commutator and the other peripheral surface of the rotary shaft and the gap is filled with a resin such as a thermosetting resin which is then thermally set to form a resin layer by which the commutator is bonded to the rotor shaft.Type: GrantFiled: February 27, 1992Date of Patent: May 4, 1993Assignees: Hitachi, Ltd., Hitachi Koki Co., Ltd.Inventors: Nobuyuki Yamashita, Kazuo Tahara, Akio Chiba, Masahisa Sobue, Toshimi Abukawa, Shin'ichi Sakamoto, Shun Suzuki
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Patent number: 5166585Abstract: Method and apparatus for operating a vacuum cleaner in which by detecting a rotational speed of a variable speed fan motor adapted to give a suction force to the cleaner and its change range, the choking state of the filter and the state of the cleaned surface are discriminated, and a speed command of the fan motor is corrected on the basis of the result of the discrimination, and the comfortable cleaning can be performed by the optimum suction force.Type: GrantFiled: October 4, 1991Date of Patent: November 24, 1992Assignee: Hitachi, Ltd.Inventors: Haruo Koharagi, Kazuo Tahara, Tsunehiro Endo, Kunio Miyashita, Yoshitaro Ishii, Fumio Jyoraku, Syuji Watanabe, Hisanori Toyoshima, Kohichi Saito, Wakichiro Hishi, Koujirou Yamashita
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Patent number: 5155885Abstract: An output of a electric driven blower in a cleaner main body is controlled in response to a detection value of a pressure sensor which detects an operation condition in the cleaner main body. A change-over level setting value is provided as a control value for the sensor so as to form a judgment point for changing over a control condition of the blower. A return level setting value is provided as a control value for the sensor so as to form a judgment point for returning to a previous control condition of the blower from a changed-over condition of the blower. When the detection value of the sensor is more than the change-over level setting value, the return level setting value is set higher than the change-over setting value, thereby the output of the blower is increased, or the return level setting value is set a lower than the change-over level setting value, thereby the output of the blower is decreased.Type: GrantFiled: October 3, 1989Date of Patent: October 20, 1992Assignee: Hitachi, Ltd.Inventors: Fumio Jyouraku, Yoshitaro Ishii, Hisao Suka, Kazuo Tahara, Haruo Koharagi
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Patent number: 5118960Abstract: An electromagnetic push-out unit which controls engagement and disengagement between a pinion gear and a ring gear for an engine in a starter device via a non-magnetic cylindrical member disposed concentrically with a pinion shaft mechanically coupled to an electrical motor.Type: GrantFiled: May 23, 1991Date of Patent: June 2, 1992Assignee: Hitachi, Ltd.Inventors: Hisaya Sasamoto, Kazuo Tahara
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Patent number: 5089737Abstract: A novel DC rotary electric machine of permanent magnet field type is disclosed, in which a plurality of permanent field magnets having an auxiliary pole of magnetic material are arranged alternately with a plurality of field magnets including only a magnetic material along the peripheral direction. The field magnets with the auxiliary poles are arranged adjacently with the field magnets of magnetic material with through bolts extending therebetween.Type: GrantFiled: April 24, 1989Date of Patent: February 18, 1992Assignee: Hitachi, Ltd.Inventors: Toshimi Abukawa, Kazuo Tahara, Noriyoshi Takahashi, Toshio Tomite
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Patent number: 5075607Abstract: Method and apparatus for operating a vacuum cleaner in which by detecting a rotational speed of a variable speed fan motor adapted to give a suction force to the cleaner and its change range, the choking state of the filter and the state of the cleaned surface are discriminated, and a speed command of the fan motor is corrected on the basis of the result of the discrimination, and the comfortable cleaning can be performed by the optimum suction force.Type: GrantFiled: October 4, 1990Date of Patent: December 24, 1991Assignee: Hitachi, Ltd.Inventors: Haruo Koharagi, Kazuo Tahara, Tsunehiro Endo, Kunio Miyashita, Yoshitaro Ishii, Fumio Jyoraku, Syuji Watanabe, Hisanori Toyoshima, Kohichi Saito, Wakichiro Hishi, Koujirou Yamashita
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Patent number: 5033565Abstract: A generator generates two voltage outputs which have different voltage levels. One voltage output from the generator is used for operating a power steering apparatus. Another voltage output from the generator is used for charging a battery which supplies current to other loads.Type: GrantFiled: October 18, 1989Date of Patent: July 23, 1991Assignees: Hitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.Inventors: Toshimi Abukawa, Toshiaki Okuyama, Kazuo Tahara, Katsuji Marumoto, Toshiyuki Koterazawa, Mitsuyuki Hombu, Tadashi Takahashi, Hisatugu Ishikura, Hiroshisa Yamamura, Toru Tatsuzaki, Tsutomu Omae, Shuichi Takamatsu
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Patent number: 5015905Abstract: A DC dynamoelectric machine with interpoles between field poles operable in sparkles even under heavy operating conditions comprising a solid soft iron magnetic flux bypassing members, each disposed between respective field poles and interpoles at their ends near its armature with an air gap between the field pole for controlling interpole magnetic flux, the solid soft iron magnetic flux bypassing member suppresses sudden change of magnetic flux flowing therethough by permitting flow of eddy current therethrough and maintains the interpole magnetic flux at a desired amount even during a sudden change of load current.Type: GrantFiled: May 17, 1989Date of Patent: May 14, 1991Assignees: Hitachi, Ltd., Hitachi Setsubi Engineering Co., Ltd.Inventors: Haruo Koharagi, Kazuo Tahara, Mitsuhiro Nitobe, Nobutaka Suzuki
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Patent number: 4983895Abstract: Method and apparatus for operating a vacuum cleaner in which by detecting a rotational speed of a variable speed fan motor adapted to give a suction force to the cleaner and its change range, the choking state of the filter and the state of the cleaner surface are discriminated, and a speed command of the fan motor is corrected on the basis of the result of the discrimination, and the comfortable cleaning can be performed by the optimum suction force.Type: GrantFiled: June 13, 1989Date of Patent: January 8, 1991Assignee: Hitachi, Ltd.Inventors: Haruo Koharagi, Kazuo Tahara, Tsunehiro Endo, Kunio Miyashita, Yoshitaro Ishii, Fumio Jyoraku, Syuji Watanabe, Hisanori Toyoshima, Kohichi Saito, Wakichiro Hishi, Koujirou Yamashita
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Patent number: 4960178Abstract: A generator generates two voltage outputs which have different voltage levels. One voltage output from the generator is used for operating a power steering apparatus. Another voltage output from the generator is used for charging a battery which supplies current to other loads.Type: GrantFiled: September 22, 1988Date of Patent: October 2, 1990Assignees: Hitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.Inventors: Toshimi Abukawa, Toshiaki Okuyama, Kazuo Tahara, Katsuji Marumoto, Toshiyuki Koterazawa, Mitsuyuki Hombu, Tadashi Takahashi, Hisatugu Ishikura, Hirohisa Yamamura, Toru Tatsuzaki, Tsutomu Omae, Shuichi Takamatsu
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Patent number: 4958406Abstract: In a vacuum cleaner comprising an electric blower and a speed control unit to operate the electric blower at a variable speed, a plurality of kinds of operation control rules of the electric blower are previously stored in the speed control unit, a load current value of the electric blower is continuously detected during the cleaning and the type of the surface to be cleaned is estimated from the load current value. Thereafter, the operation control rule suitable for the estimated cleaning surface is selected from the operation control rules stored in the speed control unit and the electric blower is driven on the basis of the selected operation control rule.Type: GrantFiled: December 14, 1988Date of Patent: September 25, 1990Assignee: Hitachi, Ltd.Inventors: Hisanori Toyoshima, Fumio Jyoraku, Yoshitaro Ishii, Kazuo Tahara, Haruo Koharagi, Syuji Watanabe, Kouichi Saito, Kunio Miyashita, Tunehiro Endo, Wakichiro Hishi
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Patent number: 4926960Abstract: An electric power steering apparatus for a vehicle comprises a steering shaft, an electric motor operable to generate an auxiliary steering force having a magnitude corresponding to a value of electric current supplied thereto, a steering toque sensor for detecting a steering torque applied to the steering shaft, a vehicle weight sensor for detecting a vehicle weight, and a control device. The control device is constituted to increase and decrease the value of electric current to be supplied to the electric motor in accordance with not only the increase and decrease of the value detected by the steering torque sensor but also the increase and decrease of the value detected by the vehicle weight sensor.Type: GrantFiled: September 16, 1988Date of Patent: May 22, 1990Assignees: Hitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.Inventors: Hisatugu Ishikura, Kazuo Tahara, Toshimi Abukawa, Katsuji Marumoto, Toshiyuki Koterazaka, Mitsuyuki Hombu, Tadashi Takahashi, Hirohisa Yamamura, Toru Tatsuzaki, Tsutomu Ohmae, Shuichi Takamatsu
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Patent number: 4880474Abstract: Method and apparatus for operating a vacuum cleaner in which by detecting a rotational speed of a variable speed fan motor adapted to give a suction force to the cleaner and its change range, the choking state of the filter and the state of the cleaned surface are discriminated, and a speed command of the fan motor is corrected on the basis of the result of the discrimination, and the comfortable cleaning can be performed by the optimum suction force.Type: GrantFiled: October 8, 1987Date of Patent: November 14, 1989Assignee: Hitachi, Ltd.Inventors: Haruo Koharagi, Kazuo Tahara, Tsunehiro Endo, Kunio Miyashita, Yoshitaro Ishii, Fumio Jyoraku, Syuji Watanabe, Hisanori Toyoshima, Kohichi Saito, Wakichiro Hishi, Koujirou Yamashita
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Patent number: 4875539Abstract: An electric power steering control system includes an electric motor for producing an assisting torque for the vehicle steering system through a reduction gear, a steering torque sensor fitted on the steering shaft, a controller for controlling the input to the motor in accordance with the torque sensor output, a battery for supplying power to the controller, and a voltage step-up circuit connected to the battery for driving the motor at a voltage higher than the battery voltage. The controller drives the motor at a high voltage.Type: GrantFiled: March 31, 1988Date of Patent: October 24, 1989Assignees: Hitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.Inventors: Toshimi Abukawa, Kazuo Tahara, Katsuji Murumoto, Toshiyuki Koterazawa, Mitsuyuki Hombu, Tadashi Takahashi, Shuichi Takamatsu, Hisatugu Ishikura, Hiroshisa Yamamura, Toru Tatsuzaki, Tsutomu Ohmae, Toshiaki Okuyama, Seizi Yamashita, Shigeki Saito, Masato Sakai
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Patent number: 4865148Abstract: A vehicle height control apparatus responsive to power steering operation is disclosed in which a torque signal indicative of the steering torque imparted to the steering wheel by a driver's operation thereof is used for controlling the power steering system and also for controlling the operation of actuators for adjusting damping force of shock absorber provided to each wheel thereby controlling the height of the vehicle.Type: GrantFiled: August 9, 1988Date of Patent: September 12, 1989Assignees: Hitachi, Ltd., Hitachi Automotive Engineer Co., Ltd.Inventors: Katsuji Marumoto, Kazuo Tahara, Hisatugu Ishikura, Hirohisa Yamamura, Toru Tatsuzaki, Toshimi Abukawa, Toshiyuki Koterazawa, Mitsuyuki Honbu, Tadashi Takahashi, Shuichi Takamatsu, Tsutomu Ohmae
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Patent number: 4823037Abstract: A DC electric motor which comprises: a reversibly rotatable rotor having an armature core, an armature winding and a commutator; a stator having a yoke and a plurality of field poles provided on an inner circumference of the yoke and each having a permanent magnet and an auxiliary pole; and brush means including a plurality of brushes arranged to be slidably electrically conductively in contact with the commutator; in which the auxiliary pole of each of the field poles is disposed at an exit side of the field pole in the normal foward rotating direction of the rotor; each of the brushes is held movably between a first position corresponding to a position near a geometrically neutral point between a pair of adjacent field poles and a second position corresponding to a position separated at the maximum by an electrical angle of 90 degrees from the geometrically neutral point reversely to the normal rotating direction, and each of the brushes is fixed in the vicinity of the second position in normal use.Type: GrantFiled: October 28, 1987Date of Patent: April 18, 1989Assignee: Hitachi, Ltd.Inventors: Toshimi Abukawa, Kazuo Tahara, Noriyoshi Takahashi, Toshio Tomite
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Patent number: 4794291Abstract: A permanent magnet field DC machine comprises a rotor and a stator. The rotor comprises an armature core (3), an armature winding (4), and a commutator (2). The stator comprises a yoke (7), permanent magnets (8) disposed on the inner periphery of the yoke (7), and magnetic pole pieces (9) interposed between the yoke (7) and a portion of each magnetic pole (8). The magnetic pole pieces (8) are made of a material the permeability of which is greater than that of the permanent magnets.Type: GrantFiled: March 16, 1987Date of Patent: December 27, 1988Assignee: Hitachi, Ltd.Inventors: Toshimi Abukawa, Kazuo Tahara, Noriyoshi Takahashi, Toshio Tomite
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Patent number: RE34286Abstract: In a vacuum cleaner comprising an electric blower and a speed control unit to operate the electric blower at a variable speed, a plurality of kinds of operation control rules of the electric blower are previously stored in the speed control unit, a load current value of the electric blower is continuously detected during the cleaning and the type of the surface to be cleaned is estimated from the load current value. Thereafter, the operation control rule suitable for the estimated cleaning surface is selected from the operation control rules stored in the speed control unit and the electric blower is driven on the basis of the selected operation control rule.Type: GrantFiled: September 11, 1991Date of Patent: June 22, 1993Assignee: Hitachi, Ltd.Inventors: Hisanori Toyoshima, Fumio Jyoraku, Yoshitaro Ishii, Kazuo Tahara, Haruo Koharagi, Syuji Watanabe, Kouichi Saito, Kunio Miyashita, Tunehiro Endo, Wakichiro Hishi