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:
May. 29, 1990
Filed:
Mar. 22, 1989
Masanobu Nakamura, Kamakura, JP;
Mitsui & Co., Ltd., Tokyo, JP;
Kokan Kako Co., Ltd., Yokohama, JP;
Abstract
A method for forming projections on the periphery of a pipe in order to provide branch pipes, such as a manifold for automobiles, is characterized in that the branch pipes are formed by a bulging process to have a predetermined thickness without thinning. A first embodiment includes the step of indenting a pipe member by press work or the like, at locations close to the position of a projection which is to be formed, in a preliminary deforming process. The deformed pipe member is then placed in a bulge mold having a recess or space, with the pipe member being positioned so that the indentations in the pipe member lie adjacent the recess in the bulge mold. Pressurized fluid is then introduced into the interior of the pipe member to bulge the wall of the pipe member into the recess in the bulge mold. A second embodiment employs a bulge mold having fixed recesses or spaces and variable recesses or spaces for forming a plurality of projections. The second embodiment includes the step of bulging the pipe material into the fixed spaces while the variable spaces are occupied by detachable members, and the step of removing the detachable members from the mold and then bulging the pipe member again.