Stretching of oval metal tubes by drawing

摘要

A process is claimed for the mechanical stretching of metal tubes of oval cross-section by drawing. Some stretching elements (2) are drawn in a single sense into the tubes (3) with the aid of traction elements (1). The stretching elements are fixed to the traction elements by means of coupling devices having a contour in the shape of a hammer. The traction elements are advantageously in the form of bars. The mechanical stretching device used in this process is also claimed and is made up of at least one traction bar fitted with a stretching element and with at least one restraining device incorporating an entry funnel and a stop as well as some lateral flexible guides.