A laser engraving machine for preparing rotary screen printing screens.

摘要

A laser engraving machine for engraving rotary printing screens includes a shaft (1) having one end connected to a rotary drive (3) for rotating the shaft (1), two end ring assemblies (7, 8) at least one (8) of which is movable along the shaft (1) and which are arranged to locate concentrically and fix opposite ends of a rotary printing screen (2) to the shaft (1). The machine also includes a laser engraving device including a head (4) movable backwards and forwards parallel to the axis of rotation of the shaft (1) to engrave a printing screen (2) and a support (9, 13). The support (9, 13) is movable along the screen (2) with the laser engraving head (4) to provide local support for the screen (2) so that the part being engraved is supported at a constant predetermined position with respect to the head (4) of the laser engraving device. Preferably the support includes a ring (9, 13) having a cylindrical supporting surface and the ring (9, 13) has a radius of curvature slightly greater than that of the screen (2) and has its axis slightly offset radially inwards from the axis of rotation of the shaft (1).