Device and method for forming coils of rolled or drawn long products

Method for coiling a long metal product, performed by means of a coiling device which includes a mandrel having a substantially circular transverse section and rotating around a horizontal, vertical or inclined axis, a containing element to contain said metal product, arranged at one end of said mandrel and including at least a lateral wall at least partly extending substantially orthogonal to said axis, and at least one guide and containing device, able to be driven between a first working position in which said guide and containing device cooperates with said mandrel, and a second inactive position in which said guide and containing device is arranged distant from said mandrel, said method comprising the following steps:

• a first step wherein a leading end of said metal product is inserted into a groove of said guide and containing device arranged in said first working position to guide said metal product along an outer circumference of said mandrel;
• a second step wherein said metal product is guided by said groove inside an annular channel defined between said lateral wall of said containing element and an outer surface of said mandrel and coaxially with said axis of rotation of said mandrel;
• a third step wherein an initial segment of said metal product is gripped and clamped in said annular channel by means of friction forces generated between said metal product and the walls of said annular channel;
• a fourth step wherein said metal product is wound onto said mandrel for a pre-determined segment of length;
• a fifth step wherein said guide and containing device is taken from said first working position to said second inactive position;
• and
• a sixth step wherein said metal product is wound for the remainder of its length;
• further comprising applying a flange on said containing element substantially perpendicular to said mandrel and shaped so as to have an annular tooth substantially coaxial with said mandrel, said annular tooth defining said annular channel at a lower part of said containing element.