Patents by Inventor Masazumi Yahata

Masazumi Yahata 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).

  • Powder pump and image forming apparatus having the powder pump and method therefor
    Patent number: 5950055
    Abstract: A powder pump includes a case, a diaphragm, a working chamber which is partitioned with the case and the diaphragm, a powder inlet formed on the case for flowing the powder into the working chamber, a powder outlet formed on the case for flowing the powder in the working chamber out of the powder outlet, an inlet valve which opens the powder inlet when pressure in the working chamber is decreased by an operation of the diaphragm so that the powder flows into the working chamber from the powder inlet and shuts the powder inlet when the pressure in the working chamber is raised by the operation of the diaphragm, and an outlet valve which opens an outlet when the pressure in the working chamber is raised by the operation of the diaphragm, so as to let the powder flow through the powder outlet outside of the working chamber and shuts the powder outlet when the pressure in the working chamber is lowered by the operation of the diaphragm.
    Type: Grant
    Filed: April 17, 1998
    Date of Patent: September 7, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Masazumi Yahata, Shunji Katoh, Yuuji Kitajima, Masakuni Konja, Satoshi Takano, Fumihito Itoh