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:
Oct. 31, 1978
Filed:
Apr. 21, 1977
Wataru Midzutani, Kitakyshu, JP;
Koe Nakajima, Nakama, JP;
Toshio Kikuma, Onga, JP;
Keitaku Ondo, Kitakyushu, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
In a method and an apparatus for manufacturing a metal pipe wherein a flat strip or skelp is formed into a cylindrical pipe while being fed in its longitudinal direction by a forming mill having a prefinishing stand, a train of forming stands for forming the skelp with a U-shaped cross section, and a train of finishing stands, the improvement wherein both edge surfaces of the skelp are caused to contact in substantially point contact recess-defining surfaces of concave V-shaped recess in pairs of forming rolls, the respective rolls which are disposed symmetrically in a plane normal to the pass line as the skelp moves through the train of forming stands along the line, and the skelp has a bending load applied by the forming rolls so as to form the skelp into a U-shaped skelp. According to this method and apparatus, there is no need to change the forming rolls even if the diameter or wall thickness of the pipe to be manufactured are changed, and also since the skelp edge is held, during the forming process, at positions in a plane normal to the pass direction by the surfaces of the concave recesses, the skelp is not twisted around the pass line so that threading of the forming mill can be carried out accurately and easily.