Patents by Inventor Kazuya Kumei

Kazuya Kumei 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).

  • Publication number: 20200307312
    Abstract: A drive shaft is configured by joining solid stub shafts formed of a medium carbon steel to both ends of a hollow tubular body formed of a medium carbon steel. When expressed as grain size number, the grain size of the hollow tubular body at joint parts where the hollow tubular body and the solid stub shafts are joined together ranges from #5 to #9, and the grain size of the solid stub shafts at the joint parts ranges from #10 to #12.
    Type: Application
    Filed: March 24, 2020
    Publication date: October 1, 2020
    Inventors: Mitsuru Kamikawa, Naoto Shibata, Ko Sugai, Masafumi Yamamoto, Takafumi Murakami, Kazuya Kumei, Yutaka Takeuchi, Masaki Kawamura