Machine for machining optical workpieces, especially plastic spectacle lenses

摘要

#CMT# #/CMT# A machine has a workpiece spindle (24) that rotatably drives the plastic spectacle lens about a rotation axis. A fast-tool assembly (36) moves a turning cutter (48) to and away from the lens. The spindle and assembly are movable relative to each other in a transverse to the rotation axis. A second fast-tool assembly (38) is adjacent to the first assembly and has a graver (50) with a punctiform end that faces the lens. The graver is carried by and movable by the second assembly to and away from the lens. A marking is produced through needling engagement of the graver with the lens. #CMT#USE : #/CMT# For machining optical workpiece particularly plastic spectacle lens. #CMT#ADVANTAGE : #/CMT# The workpiece is provided in the operating space of the same machining unit directly following the actual turning operation with a permanent engraving. This done without the workpiece having to be re-clamped on a separate engraving machine for a rapid and precise machining process. The graver end is essentially punctiform so that the produced geometry of the marking is not limited by the geometry of the turning cutter. Very fine detailed engravings can be produced by needling engagement of the pointed graver with the workpiece, i.e. an engraving operation during which the graver strikes the workpiece in quick succession. The engraving of the workpiece does not cause any wear on the turning cutter and the turning operation on the workpiece does not cause any wear on the graver to increase the tool life. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a perspective oblique view from behind/above of the machine. 24 : Workpiece spindle 36 : First fast tool assembly 38 : Second fast-tool assembly 48 : Turning cutter 50 : Graver #CMT#INDUSTRIAL STANDARDS : #/CMT# The prescription surface is a progressive surface with the permanent engraving required by DIN EN International Organization for Standardization (ISO) 8980-2, which contains for alignment two e.g. circular markings 34 mm apart on the lens horizontals running through the lens center point.