Patents by Inventor Tetsuhiro Harada

Tetsuhiro Harada 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: 8640789
    Abstract: According to an aspect of the invention, an oil pulse tool includes: a motor generating a driving force according to a driving voltage; an oil pulse unit driven by the driving force and generating a torque in a pulse-like shape when the motor passes a strike position on a shaft thereof; and an output shaft on which a front end tool is mounted, the output shaft being connected to the shaft, characterized in that the oil pulse tool further comprises driving adjusting means to control the driving voltage, the driving voltage is reduced during a given period including a timing when the torque is transmitted to the output shaft, and the reduced driving voltage is increased when the given period is finished.
    Type: Grant
    Filed: May 8, 2009
    Date of Patent: February 4, 2014
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Tetsuhiro Harada, Tomomasa Nishikawa, Kazutaka Iwata, Shiniki Otsu, Nobuhiro Takano
  • Publication number: 20130264087
    Abstract: A driving tool includes a motor, and an end-bit holding section. The motor includes an output shaft. The end-bit holding section is connected to and rotated by the motor and configured to hold an end-bit. The driving tool further includes a weight connected to the motor without a reduction mechanism and rotatable together with the motor and the end-bit holding section.
    Type: Application
    Filed: December 28, 2011
    Publication date: October 10, 2013
    Applicant: Hitachi Koki Co., Ltd.
    Inventors: Tetsuhiro Harada, Nobuhiro Takano, Tomomasa Nishikawa, Hironori Mashiko
  • Publication number: 20110214894
    Abstract: According to an aspect of the invention, an oil pulse tool includes: a motor generating a driving force according to a driving voltage; an oil pulse unit driven by the driving force and generating a torque in a pulse-like shape when the motor passes a strike position on a shaft thereof; and an output shaft on which a front end tool is mounted, the output shaft being connected to the shaft, characterized in that the oil pulse tool further comprises driving adjusting means to control the driving voltage, the driving voltage is reduced during a given period including a timing when the torque is transmitted to the output shaft, and the reduced driving voltage is increased when the given period is finished.
    Type: Application
    Filed: May 8, 2009
    Publication date: September 8, 2011
    Applicant: Hitachi Koki Co., Ltd.
    Inventors: Tetsuhiro Harada, Tomomasa NIshikawa, Kazutaka Iwata, Shinki Ohtsu, Nobuhiro Takano
  • Publication number: 20110203822
    Abstract: According to an aspect of the invention, an oil pulse tool includes: a motor generating a driving force; an oil pulse unit including a shaft, the oil pulse unit being driven by the motor and generating an impact torque on the shaft when the motor passes an impact position; and an output shaft on which a front end tool is attached, the output shaft being fixed to the shaft, wherein the oil pulse tool is provided with a rotational position detecting sensor of detecting a rotational position of the output shaft, and a torque detecting sensor of detecting generation of an impact torque, and the oil pulse tool is provided with detecting means for measuring a state required for reversely rotating the motor by generating an impact, and regularly rotating again the motor and passing a position of generating the impact, and detecting a reduction in a performance of the oil pulse unit by an aging change of the state.
    Type: Application
    Filed: May 8, 2009
    Publication date: August 25, 2011
    Inventors: Tetsuhiro Harada, Tomomasa Nishikawa, Kazutaka Iwata, Shiniki Otsu, Nobuhiro Takano