Apparatus for etching curved metal plates

Claim 1

IN AN APPARATUS FOR ETCHING CURVED PRINTING PLATES, A VERTICAL SHAFT, A PLATE MOUNT CARRIED BY THE SHAFT AND ADAPTED TO SUPPORT A CURVED PLATE IN CONCENTRIC FASION WITH RESPECT TO THE SHAFT, SPACED PERFORATE AND IMPERFORATE SHELLS POSITIONED IN CONCENTRIC RELATION TO SAID VERTICAL SHAFT, SAID PERFORATE SHELL SURROUNDING SAID CURVED PRINTING PLATE, MEANS FOR PUMPING ETCHING FLUID IN THE SPACE BETWEEN THE SHELLS AND THROUGH THE PERFORATIONS IN THE PERFORATE SHELL TO FORM SPRAY STREAMS CONVERGING GENERALLY ON SIAD VERTICAL SHAFT AND CURVED PLATE, AND MEANS EFFECTING SIMULTANEOUS AXIAL RECIPROCATION AND ROTATIONAL OSCILLATION OF THE SHAFT, WHEREBY SAID CURVED PLATE IS CONTINUOUSLY OSCILLATED ON A CYLINDER OF REVOLUTION IN THE ETCHING SPRAY EMANATING FROM SAID PERFORATE SHELL.