Automatic punch for holes in printing plates - has roller feed through punches with plates supported on air film

摘要

The punching of holes in printing plates used in offset printing is totally automatic. The punching system consists of two rows of punches (4,4a) each of which has a mechanism that consists of a shaft turned by a crank (5) with either a pneumatic or rotary actuator. The printing plate is fed to the start point and is detected by a non contact sensing element (6) operating on the leading edge. The base of the punching unit has a number of valve outlets (13) that supply compressed air to the underside of the plates. On the top side the plate locates against rollers (11).