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:
Mar. 06, 1979
Filed:
Sep. 12, 1977
Hitachi, Ltd., , JP;
Abstract
An internal groove forming apparatus for heat exchanging pipes, having a cylindrical holder adapted to be loosely fitted in a heat exchanging pipe in concentric relationship, and a plurality of groove forming rolling tools arranged on the holder in a plurality of axially spaced, circumferentially oriented rows and rotatably supported on the holder in such a manner that the rolling tools of one of the two adjacent rows are disposed in staggered relationship with respect to those of the other and an imaginary circle circumscribing the rolling tools is interposed between an outer peripheral surface and an inner peripheral surface of the heat exchanging pipe. Axial relative movements of the heat exchanging pipe and the holder enable the rolling tools to form a number of substantially axially oriented grooves on the inner peripheral surface of the heat exchanging pipe.