Patents by Inventor Kenichi Ohyabu

Kenichi Ohyabu 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).

  • Thread joint for tube
    Patent number: 5649725
    Abstract: A thread joint for a tube which suppresses galling without deteriorating its sealing performance since a sliding distance L.sub.S which expresses a quantity of spiral sliding of sealing portions relative to each other during a tightening period from the start of a contact between the sealing portions until shoulder portions abut each other satisfies the following relationship:Sliding Distance L.sub.S .ltoreq.-0.0093.times. (Tube Outer Diameter).sup.2 +4.73.times. (Tube Outer Diameter).To shorten the sliding distance L.sub.S, the sealing portion of a box portion is formed shorter than the sealing portion of a pin portion. In this case, a circumferential groove may be formed to discharge a dope. Conversely, the sealing portion of the pin portion is formed shorter than the sealing portion of the box portion. In this case, a precedent-stage unthread portion whose inclination is smaller than that of the sealing portion of the pin portion is formed between a male thread and the sealing portion of the pin portion.
    Type: Grant
    Filed: October 17, 1995
    Date of Patent: July 22, 1997
    Assignee: Sumitomo Metal Industries Limited
    Inventors: Shigeo Nagasaku, Kenichi Ohyabu, Jun Maeda, Akira Narita