Abstract: Method for forming a collar in a muffler shell including: providing a muffler shell made of a metal sheet and forming a muffler housing, the muffler shell having an exhaust gas opening, providing a collar forming head having a rotational axis and at least two movable expanders, introducing a collar forming head into a muffler housing, moving the expanders of the collar forming head introduced into the muffler shell radially away from the rotational axis of the collar forming head from a retracted position to an expanded position rotating the collar forming head around the of the collar forming head, bringing the rotating expanded collar forming head in contact with the metal sheet forming an outwardly projecting collar around the exhaust gas opening by flaring the edge of the metal sheet.

Abstract: Method for forming a collar in a muffler shell including: providing a muffler shell made of a metal sheet and forming a muffler housing, the muffler shell having an exhaust gas opening, providing a collar forming head having a rotational axis and at least two movable expanders, introducing a collar forming head into a muffler housing, moving the expanders of the collar forming head introduced into the muffler shell radially away from the rotational axis of the collar forming head from a retracted position to an expanded position rotating the collar forming head around the of the collar forming head, bringing the rotating expanded collar forming head in contact with the metal sheet forming an outwardly projecting collar around the exhaust gas opening by flaring the edge of the metal sheet.

Abstract: A changeover system for a metal forming mill, in particular for a tube-forming mill, comprises at least one pair of work modules, the work modules of which are adapted to be pivoted into and out of a line of work stations of the mill. Each work module has its own drive or drives. Within a pair of work modules the two work modules are arranged such, that when one work module is arranged in the line of work stations the other one is arranged off the line.

Abstract: A changeover system for a metal forming mill, in particular for a tube-forming mill, comprises at least one pair of work modules, the work modules of which are adapted to be pivoted into and out of a line of work stations of the mill. Each work module has its own drive or drives. Within a pair of work modules the two work modules are arranged such, that when one work module is arranged in the line of work stations the other one is arranged off the line.