Abstract: A device for securing blades on perforation and cutting cylinders for graphic arts machinery including two complementary rules which engage together and a pneumatic chamber arranged longitudinally between the two rules. The pneumatic chamber is inflated and causes the rules to separate slightly from each other and compress a blade arranged between at least one of the rules and the walls of a groove of the cylinder in which the device is situated. The pneumatic chamber is connected to a passageway through which a continuous supply of compressed air is provided in order to maintain the pressure in the pneumatic chamber. The device also includes elastic blocks which dampen impacts and noise, and other blocks to prevent regulation screws from loosening.

Abstract: The present invention includes a bi-directional hacksaw blade that bites into and saws an object and clears particulate from a cut being formed in the object in each of the forward and rearward sawing directions. Each of the blade embodiments disclosed include a blade with two sets of teeth. The teeth of the first set is a mirror image of the teeth of the second set so that one set saws the object and the other set clears particulate in one sawing direction. In the opposite sawing direction, the roles of the teeth are reversed.