Method of making seamless metal tubes
AssigneeKabel-und Metallwerke Gutehoffnungshutte Aktiengesellschaft
InventorsWalter Langhans, Otto Uhlmann, Norbert Stephan
Life of this patent
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Abstract
A seamless pipe made by extrusion or piercing and having eccentric interior has the outside of one of its ends turned to concentric dimensions with its interior and is pulled through a peeling and scraping tool affixed to a positioning die, and over a mandrel which widens the pipe particularly in the zone of peeling.
Claims6
In a method of making seamless tubes or pipes which have been made by extruding or piercing metal billets, the improvement comprising:
- turning a pipe at its end to obtain a relatively short end portion of exact concentricity of its outer dimensions with regard to the inner dimensions of the pipe;
- drawing the pipe through a positioning die and over a mandrel which is concentrically arranged to the die, beginning with the turned end;
- said mandrel centering, positioning and supporting the interior of the pipe also in relation to a concentric peeling and scraping tool disposed radially adjacent to the mandrel, outside of the pipe;
- and
- peeling and scraping at least a portion of the outer surface of the pipe by means of said tool, ahead of the die and adjacent to the mandrel.
A device for achieving concentricity along the entire length of a seamless tube or pipe which has been made by extruding or piercing a billet, the tube or pipe having an end turned to obtain a relatively short end postion of exact concentricity of its outer dimensions with regard to the inner dimensions of the tube or pipe, comprising a mandrel on a mandrel rod held in a particular position for insertion into the pipe and supporting the pipe from the inside;
- a positioning die disposed in radial alignment with the mandrel, the mandrel projecting somewhat from the die in the direction opposite the direction of drawing the pipe over the mandrel;
- and
- scraping blades disposed at the die, radially facing the projecting portion of the mandrel for peeling and scraping off a portion of the outer surface of a pipe when moved through the die, beginning adjacent the turned end.
Dependencies are inferred from the claim text.