Method of continuously processing metal bands into hollow rails

摘要

A method of continuously processing two bands of material into profiled rails, inserting insulating material adjacent their lateral longitudinal borders, and then connecting their lateral longitudinal borders through the insulating material. Initial corrugations are formed in each of the bands, and the bands are simultaneously passed between rotating pairs of forming rolls. The initial corrugations formed in the bands are increased so that the length of each enveloping line of each part of each band is longer than the enveloping line contemplated for the corresponding part. The longitudinal border of one of the rails is provided with projections, and the border of the other rail is provided with openings. Finally, the longitudinal border provided with projections is bent around the other longitudinal border, and its projections are forced through the strip of insulating material into the openings of the other longitudinal border. A tenoned folder connection of the longitudinal borders which is free from metallic contact between the rails is thus created.