Mounting-proofing machine

Abstract

A mounting-proofing machine to facilitate mounting of flexible printing plates on a plate cylinder preparatory to operation in a flexographic printing press and to obtain proofs from these plates, whereby the mounted plates may be checked for color registration and other factors. The machine includes a proofing cylinder cantilevered from and rotatable on the free end of a swing arm adapted to transfer the proofing cylinder from a forward-position proofing state in which it makes contact with the surface of a plate cylinder that has been elevated in a vertical plane intersecting the axes of rotation of both cylinders to effect such engagement, to a rear-position mounting state displaced from this plane. In the mounting state, an optical viewer adapted to observe the surfaces of both cylinders in superposed relation is brought into an operative position which is intersected by the vertical plane. In the course of its swing, the proofing cylinder is caused to undergo an angular displacement to an extent whereby a point printed on the proofing cylinder in the proofing state and corresponding to a contact point on the plate cylinder is phase-shifted to assume an observation position in the mounting state which, in the optical viewer, appears to be coincident with the contact point.

Dependencies are inferred from the claim text.