Abstract: A machine to facilitate the mounting of flexographic printing plates and for obtaining proofs thereof. The machine includes an impression cylinder supported for rotation at a fixed position, the impression cylinder making contact with printing plates on a plate cylinder and rotating concurrently therewith to print a proof secured to the impression cylinder. The plate cylinder is movable in a vertical plane from a proofing state in which it makes contact with the impression cylinder to a mounting state in which it is separated therefrom. A viewer is provided which is operative in the mounting state to show the operator both the plate he is mounting on the plate cylinder and the image reflected from the proof sheet on the impression cylinder.

Abstract: A carrier sleeve for supporting flexible printing plates, the sleeve having a limited circumferential resilience, whereby when subjected to air jets emitted from the apertures in the wall of a printing cylinder, the sleeve is dilated to facilitate the application of the sleeve to the cylinder or its removal therefrom. The sleeve is constituted by three interlaminated layers, each formed by a helix of synthetic plastic tape. Two layers of the sleeve are wound at the same helix angle but are phase displaced relative to each other, whereby the air gap between the convolutions of one layer is bridged by the convolutions of the other, thereby sealing the gap and rendering the sleeve impermeable to air. The remaining layer is wound at an angle opposed to the helix angle of the other two, thereby strengthening and rigidifying the structure of the sleeve.

Abstract: A machine for rolling and curving a metal backed rubber printing plate to conform it to the circumference of a printing cylinder. The machine includes a deflection bar having a longitudinal groove therein which accommodates and partly recesses a forming roller of small diameter. The bar is supported between a pair of clamping blocks which are pivotally mounted, means being provided to simultaneously swing the blocks to a predetermined degree to bow the bar and the roller held thereby. Cooperating with the forming roller is a large diameter driven roller of elastomeric material whose position relative to the forming roller is adjustable to define a nip for receiving the plate to be curved and for pressing the plate against the forming roller as it is conveyed through the nip to impart a desired curvature thereto, the bow formation of the forming roller producing a radius of curvature in the plate which gradually increases as one goes from the center to the outer edge thereof.