Patent ID: 7878099

Claim:
A rotary cutting unit for trimming sheet material, comprising: a support plate for receiving the sheet material; a rotary cutting device is joined to the support plate; the rotary cutting device comprises a guide bar; a knife carriage is guided on and displaceable along the guide bar; a rotary knife is rotatably mounted on the knife carriage; the guide bar is held at one end by a first guidance device and at a second end by a second guidance device; the guide bar is guided in the guidance devices movably between an initial position raised with respect to the support plate and a clamping position lowered in a direction toward the support plate; the guide bar comprises a lower side which acts as a clamping surface for contact against the sheet material; a first spring device acts on the guide bar in a direction toward the initial position; an actuation device for moving the guide bar out of the initial position into the clamping position; the actuation device is movable between a starting position in which the guide bar is in the initial position, and a final position in which the guide bar is in the clamping position; the actuation device comprises an immobilization device that releasably immobilizes the actuation device in the final position, wherein the guide bar is clamped in vertically movable fashion between the first spring device and a second spring device; the second spring device has a spring action directed oppositely to the first spring device; the actuation device acts on the guide bar by means of the second spring device.