Rotary panel cutter

Claim 1

A ROTARY PANEL CUTTER FOR CUTTING SHEET MATERIAL COMPRISING A ROTATING MOUNTING CYLINDER, A CURVILINEAR SUBSTANTIALLY ELONGATED OVAL-SHAPED CUTTING KNIFE MOUNTED ON SAID CYLINDER AND HAVING ITS LONGITUDINAL AXIS OFFSET IN RESPECT TO THE LONGITUDINAL AXIS OF SAID MOUNTING CYLINDER, SAID CUTTING KNIFE BEING GROUND ALONG A CURVE HAVING A RADIUS OF CURVATURE SUBSTATIALLY LARGER THAN THE RADIUS FROM THE CENTER OF SAID MOUNTING CYLINDER TO AN EDGE OF SAID CUTTING KNIFE WHEREBY THE END PORTIONS OF SAID CUTTING KNIFE ARE SLIGHTLY UNDERCUT IN RESPECT TO THE SIDE ELONGATED PORTIONS, AND A BACKING ANVIL ROLLER COOPERATING WITH SAID CUTTING KNIFE AND ARRANGED WITH ITS OUTER SURFACE SPACED FROM THE ELONGATED SIDE CUTTING EDGES OF SAID CUTTING KNIFE AN AMOUNT LESS THAN THE THICKNESS OF THE SHEET MATERIAL BEING CUT WHEREBY COMPLETE PANELS ARE CUT OUT FROM THE SHEET MATERIAL AS IT IS ADVANCED BETWEEN SAID CUTTING KNIFE AND SAID BACKING ROLLER ANVIL AND THE END PORTIONS OF SAID CUTTING KNIFE ARE SUBJECT TO LESS CUTTING FORCE THAN THE ELONGATED SIDE PORTIONS.