Patent ID: 8601845

Claim:
A method for forming, in a production line, profiles ( 50 ) with a cross-section that varies along the length thereof, said profiles being formed from a plane metal strip ( 10 ) that is unwound from a coil ( 9 ), said method employing edge cutters ( 14 ) and a plurality of roll-forming units ( 17 - 24 ), the edge cutters and the roll-forming units being individually displaceable sideways relative to the strip, the steps of said method comprising: controlling the edge cutters along a first pair of opposed curved lines ( 51 , 52 ) to sever opposed edges of said strip as said strip moves along the production line to provide the strip with curved opposed edges; thereafter controlling the roll-forming units along a second pair of opposed curved lines ( 53 , 56 ) for forming a first pair of corners ( 53 , 56 ) defining opposed flanges ( 79 , 80 ) to each side of the center of said metal strip ( 10 ) as said strip moves through a first roll-forming section of said production line, and thereafter controlling the roll-forming units along a third pair of opposed curved lines ( 54 , 58 ) for forming a second pair of corners ( 54 , 58 ) defining opposed sides ( 77 , 78 ) to each side of the center of said metal strip between said first corners, after said first corners have been formed, as said strip moves through a second roll-forming section of the production line, wherein the curvatures of the first, second, and third pairs of opposed curved lines vary the cross section of the profile formed from the strip along the length thereof.