Patents by Inventor Yoshikatsu Arayama

Yoshikatsu Arayama 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).

  • Heat transfer tube having grooved inner surface and production method therefor
    Patent number: 5704424
    Abstract: The object of the present invention is to offer a heat transfer tube having a grooved inner surface, wherein the side edges of the board material do not form a waved shape and cracks do not form during tube expansion. In order to achieve this object, the grooved-inner-surface heat transfer tube of the present invention has a metallic tube with an inner circumferential surface, on which are formed a weld portion which extends in an axial direction of this metallic tube, a pair of projecting strip portions formed parallel to and separate from this weld portion, and a plurality of fins formed in an area between these projecting strip portions. The fins are formed with a constant angle with respect to the tube axis, and the ends of these fins are connected with the projecting strip portions. The thickness of the metallic tube within the grooves formed between the fins is made to increase in approaching the weld portion within an area surrounding the weld portion wherein the central angle is within 30.degree..
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: January 6, 1998
    Assignee: Mitsubishi Shindowh Co., Ltd.
    Inventors: Haruo Kohno, Takashi Kazama, Makoto Miyauchi, Yoshikatsu Arayama, Kohtaroh Nagahara, Shunroku Sukumoda