ANORDNING FOR ATT TILLVERKA ETT ROR MED STOR DIAMETER, SERSKILT EN SILO

摘要

An apparatus for helically winding a strip of sheet metal into a large diameter pipe and connecting the edges of the strip by preforming and rabbeting. The edge bending for the rabbet is done in a preforming station and a rabbeting station in which the bends are sequentially and increasingly formed with multiple units at each station. Adjacent units are hinged and devices for adjusting the angular relationship between adjacent units are provided, including spacers and adjustable threaded devices. Gears permit driving multiple units at various adjustment angles.