Patents by Inventor Kazu Itoh, deceased

Kazu Itoh, deceased 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).

  • Closed circuit type respirator
    Patent number: 4633868
    Abstract: A closed-circuit type respirator includes an oxygen enriching valve provided in an exhalation system of the respirator, preferably at the lower front end of a respirator mask. This oxygen enriching valve comprises a housing having a passage communicating to the exhalation system and a passage communicating to the atmosphere, a first valve which is provided in the passage communicating to the exhalation system and opens only when pressurized for exhalation and a second valve which is provided in the passage communicating to the atmosphere and is opened for a desired period of time by an external force such as manual operation so that the space inside the housing communicates with the atmosphere.
    Type: Grant
    Filed: May 22, 1985
    Date of Patent: January 6, 1987
    Assignee: Itoh Seiki Kabushiki Kaisha
    Inventors: Kazu Itoh, deceased, Akira Itoh, legal representative