Patent ID: 8677796

Claim:
A hemming station, for hemming a panel assembly including an outer panel having a hem flange defined by a hem edge and including an inner panel, comprising: a multi-level roller configured to fold the hem flange, wherein: the roller includes a first exterior level spaced by a first radius from a roller axis and a second exterior level being parallel to the first exterior level and spaced by a second radius from the roller axis; the first exterior level is a first hemming level configured and arranged in the hemming station to contact and hem, to a first desired resulting shape, a first section of the outer panel; the second exterior level is a second hemming level configured and arranged in the hemming station to contact and hem, to a second desired resulting shape, a second section of the outer panel; the first radius is less than the second radius; and the multi-level roller, in being configured to fold the hem flange, is configured to perform, simultaneously, functions comprising: folding, by the first hemming level of the roller, the first section of the outer panel to form a capture portion of the hem flange comprising a captured span of the inner panel captured by two capturing spans of the outer panel being parallel to each other and to the captured span of inner panel; and folding, by the second hemming level, the second section of the outer panel to form a flat portion of the hem flange wherein the outer panel is folded against itself so that an inside surface of the outer panel touches itself with is no intervening panel material between two directly-adjacent and parallel flat-portion spans of the outer panel, yielding a sharp hem edge having a minimum radius obtainable for the outer panel; a heating device configured to heat the hem edge; and a control unit configured to control the roller and the heating device such that the roller folds the hem flange when a temperature of the hem edge is in a predetermined temperature range.