Patents by Inventor Yoshifumi Kuboto

Yoshifumi Kuboto 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).

  • Sintered alumina article with high flexural strength and process for producing same
    Patent number: 4996177
    Abstract: A sintered alumina article having an excellent flexural strength comprises numerous sintered plate crystalline corundum particles each having cleavage surface planes and accumulated on and bonded to each other in a manner such that the cleavage surface planes of the accumulated plate crystalline particles are substantially in parallel to each other and can be produced by forming the plate crystalline corundum particles into a predetermined shape so that the plate crystalline particles are accumulated in the above-mentioned manner; and by sintering the resultant precursory article at 1500.degree. C. or more under the ambient atmospheric pressure.
    Type: Grant
    Filed: July 22, 1988
    Date of Patent: February 26, 1991
    Assignee: Sumitomo Cement Co., Ltd.
    Inventors: Shigehide Takagi, Hideo Yano, Takashi Oku, Keijiro Shigeru, Yoshifumi Kuboto, Tsutomu Shishikura