Patents by Inventor Tadayuki Miyagi

Tadayuki Miyagi 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).

  • Self-feeding mechanical pencil
    Patent number: 4411543
    Abstract: A mechanical pencil is of the type in which a writing lead can be advanced by the extent to which the lead has been worn without changing the writing posture of the pencil. The pencil has a lead holder slidably mounted lengthwise within a casing, a lead guide tube slidably mounted within the casing together with the lead holder, a lead feeding device mounted movably within the casing for feeding the lead into the lead guide tube, and a device mounted movably within the casing for locking rearward movement of the lead feeding device. The lead can be advanced by merely releasing a writing pressure which was applied by the writing tip onto a piece of writing paper.
    Type: Grant
    Filed: October 17, 1980
    Date of Patent: October 25, 1983
    Assignee: Pentel Kabushiki Kaisha
    Inventors: Junichi Hashimoto, Tadayuki Miyagi