Cage for bending plate into U=section tapered web - uses cylindrical rollers with one smooth face and other with left and right hand spiral grooves

摘要

The two roller cage is produced using a bending process to fabricate a channel section with a tapered web (9a), each roller having a cylindrical working surface. The two surfaces combine to form a jig of varying section. One roller surface (2) is smooth whilst the other (4) incorporates left and right hand spiral grooves (6,7), the groove thickness being equal to that of the metal plate (8) and the groove depths being equal to the required flange widths (9b,9c). The angle of the spiral of one groove may vary along the roller axis and similarly one groove may run into a circumferential groove contained by a plane parallel to the direction of plate displacement.