Patents by Inventor Kazutaka Iwata

Kazutaka Iwata 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: 20100096155
    Abstract: An impact tool (100) includes a spindle (11), a motor (1), a rotational impact system (10), a current detecting unit (32), and a current control unit (31). The spindle extends in an axial direction thereof. The motor provides the spindle with a rotational power in accordance with a motor current flowing therethrough. The rotational power rotates the spindle about the axis at an rpm value. The rotational impact system provides the spindle with an impact force in the axial direction, thereby transmitting both the rotational power and the impact force to an end bit. The current detecting unit detects a current value of the motor current. The current control unit reduces the current value if the current value detected by the current detecting unit exceeds a predetermined value.
    Type: Application
    Filed: September 19, 2008
    Publication date: April 22, 2010
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Kazutaka Iwata, Shinji Watanabe, Nobuhiro Takano
  • Publication number: 20090096401
    Abstract: The controller determines the presence or absence of operation of the trigger switch according to an ON/OFF state of the main contact of the trigger switch and designating the rotation speed of the motor based on a signal outputted from the speed contact. The controller stops the rotation of the motor, after the trigger switch is activated and the main contact is turned ON and the motor is driven according to a signal outputted from the speed contact, when an OFF state of the main contact is detected, only in the case where a signal value outputted from the speed contact is a predetermined value or less.
    Type: Application
    Filed: September 19, 2008
    Publication date: April 16, 2009
    Inventors: Shinji Watabe, Kazutaka Iwata, Nobuhiro Takano
  • Publication number: 20080265695
    Abstract: A power tool includes a housing, a brushless motor, and a cover member. The housing has an air intake hole and an air exhaust hole formed therein, the housing having an inner surface. The brushless motor has an outer surface disposed in the housing, a first endface near the air intake hole, and a second endface near the air exhaust hole. The cover member covers at least one of the first endface and the second endface for preventing dust from entering the brushless motor. The inner surface of the housing and outer surface of the brushless motor define a circulation path providing communication between the air intake hole and the air exhaust hole.
    Type: Application
    Filed: April 17, 2008
    Publication date: October 30, 2008
    Inventors: Kenichirou Yoshida, Katsuhiro Oomori, Yoshihiro Komuro, Kazutaka Iwata
  • Patent number: 7330006
    Abstract: A power tool includes a brushless motor, a cooling fan, and a driving unit in a housing. The brushless motor is provided in the housing and having a rotary shaft. The cooling fan is attached to the rotary shaft in the housing, and rotatable together with the rotary shaft. The driving unit is provided in the housing for driving the motor. The driving unit includes an inverter circuit having a circuit board and a plurality of switching elements mounted on the circuit board. The circuit board is positioned on an opposite side to the motor with respect to the cooling fan. The plurality of switching elements is positioned around the cooling fan in a circumferential direction about the rotary shaft.
    Type: Grant
    Filed: April 19, 2006
    Date of Patent: February 12, 2008
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Kazutaka Iwata, Shinichi Sakamoto, Tomoyoshi Yokota, Kenichirou Yoshida, Tomomasa Nishikawa, Atsushi Nakagawa
  • Publication number: 20060255756
    Abstract: A power tool includes a brushless motor, a cooling fan, and a driving unit in a housing. The brushless motor is provided in the housing and having a rotary shaft. The cooling fan is attached to the rotary shaft in the housing, and rotatable together with the rotary shaft. The driving unit is provided in the housing for driving the motor. The driving unit includes an inverter circuit having a circuit board and a plurality of switching elements mounted on the circuit board. The circuit board is positioned on an opposite side to the motor with respect to the cooling fan. The plurality of switching elements is positioned around the cooling fan in a circumferential direction about the rotary shaft.
    Type: Application
    Filed: April 19, 2006
    Publication date: November 16, 2006
    Inventors: Kazutaka Iwata, Shinichi Sakamoto, Tomoyoshi Yokota, Kenichirou Yoshida, Tomomasa Nishikawa, Atsushi Nakagawa