The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 03, 1989
Filed:
Dec. 23, 1986
Applicant:
Inventors:
Heikichi Kuwahara, Ibaraki, JP;
Kenji Takahashi, Abiko, JP;
Takehiko Yanagida, Tsuchiura, JP;
Wataru Nakayama, Kashiwa, JP;
Shigeo Sugimoto, Ibaraki, JP;
Kiyoshi Oizumi, Tsuchiura, JP;
Assignees:
Hitachi, Ltd., Tokyo, JP;
Hitachi Cable, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21D / ;
U.S. Cl.
CPC ...
72 78 ; 2915 / ;
Abstract
A method for producing a heat transfer tube for single-phase flow having rows of discontinuous projections formed on the inner surface thereof along one or more spiral curves. Each projection has a circular, elliptic or a similar cross-section constituted by smooth curves at any desired height including the bottom thereof. The cross-sectional area of the projection progressively decreases towards the top of the projection.