Method of manufacture of a tool serving to the drawing of the cloths formaires of a round shape which is used for carrying out of the watermarks, and a device for implementing the process.

摘要

1. Method for the production of a steel tool serving for the stamping of a forming wire of a mould used in the fiduciary paper industry for producing watermarks, said tool being obtained by electro-erosion from an electrode, comprising the following successive stages : a) the values of a black and white image are digitized (2) in pixels with several shades of grey, b) an electrode is engraved automatically by machining (6), plane by plane, directly from the preceding data, with an engraving depth increasing uniformly with respect to the initial surface of said electrode, the engraving depth being in biunivocal correspondence with the shades of grey, c) the electrode thus engraved is disposed (7) in a bench for machining by electro-erosion until a tool (8) having the desired surface state is obtained.