A hemming machine is provided with a frame, a hemming tool support
structure and a swinging drive structure. The hemming tool support
structure is rotatably coupled to the frame to rotate about a center
rotation axis. The hemming tool support structure includes a hemming tool
disposed at a first location such that the hemming tool moves towards and
away from an edge part of a workpiece that is supported on a die upon
rotation of the hemming tool support structure. The swinging drive
structure transmits a rotational driving force to the hemming tool
support structure via a releasable connection located on a side of the
center rotation axis that is opposite of the hemming tool. The releasable
connection is configured to release the swinging drive structure to allow
further rotational movement of the hemming tool away from the die.