Frames for the backs of seats and the like and to their manufacture methods and devices

摘要

A rigid frame for use as framework in the back of a car seat is constituted by a shell which is itself built up by assembling together two half-shells (3) of stamped sheet metal along their juxtaposed edge flanges, which flanges extend respectively around an inside perimeter and an outer perimeter of each of the half-shells. A major portion at least of the length of the juxtaposed flanges of the half-shells is rolled up to form tubes (6, 7) of closed circular section.