Patents by Inventor Kozo Nishizaki

Kozo Nishizaki 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).

  • Patent number: 4097074
    Abstract: A slip-on type pipe joint construction wherein an annular sealing rubber packing is fitted in an annular recess formed in the inner peripheral surface of the socket of a pipe and the spigot end of another pipe is inserted in the socket, whereby the pipes are connected together. The shapes and sizes of the packing and annular recess are controlled so as to assure firm connection without the danger of the packing dragged during insertion of the spigot even in the case of large and medium diameter pipes. Further, in some cases a split lock ring engageable with a projection on the inner peripheral surface of the socket is fitted in an annular groove in the outer peripheral surface of the spigot so as to prevent slipping-off of the spigot.
    Type: Grant
    Filed: May 23, 1977
    Date of Patent: June 27, 1978
    Assignee: Kubota, Ltd.
    Inventors: Shozo Nagao, Junkichi Iwamatsu, Hiroshi Kitsukawa, Kozo Nishizaki, Yuichi Watanabe, Yasunori Okamoto