Abstract: A system for locking thin flexible printing plates on to rotary printing press saddles includes securing means positioned along a first longitudinal side edge of such a saddle and a support member rotatably journaled along a second longitudinal side edge of the saddle and biased longitudinally away from the first transverse side. Pins are secured to the support member to register with corresponding openings in such a flexible printing plate. A rotation tool with openings formed along an edge to coact with said register pins is operable to rotate the support member to secure such a flexible printing plate. A locking means is provided to prevent support member rotation when such a flexible printing plate is secured to such a saddle.

Abstract: A clamping device for securing a thin flexible printing plate with longitudinally extending first and second opposite side edges to the cylinder of a rotary printing press, said clamping device including a semi-cylindrically shaped saddle adapted to be fixedly secured to said rotary press cylinder and to support said flexible printing plate on the saddle's outside face between the first and second longitudinally extending side edges of said saddle, securing means positioned along the first side edge of said saddle for securing the first side edge of the flexible printing plate to said saddle, a rotatable support member journaled to and along the second side edge of said saddle, a plurality of outwardly extending register pins secured to said support member to coact with openings formed along the second side edge of said flexible plate, and a lever secured to said support member for rotating said member to a position such that the register pins extend outwardly away from the second side edge of the saddle to l