Method and device for edge-machining of a plastic optical lens and a combination tool therefor

Method for the edge-machining of an optical lens (L), namely a plastic spectacle lens rotatable with a controlled angle of rotation (φB) about a rotational axis of a workpiece (B) with the following steps:

• preliminary machining of the edge (R) of the lens (L) by means of at least one combination tool (10) adjustable at least radially relative to the rotational axis of the workpiece (B) and rotatable about a rotational axis of a tool (C) whereby, seen in plan view, the lens (L) is given a circumferential contour (U) that corresponds to a circumferential contour of a holder for the lens (L) apart from a slight degree of oversizing if necessary and
• finish-machining of the edge (R) of the lens (L) by means of the combination tool (10) whereby the edge (R) of the lens (L) is provided, when viewed in cross section, with a prespecified edge geometry corresponding to its intended means of fastening to the holder, optionally with a protective chamfer (F1, F2) at the transition to one or both optically effective surfaces (O1, O2) and optionally polished;
• characterised in that the preliminary machining of the edge (R) and the finish-machining of the edge (R) is performed by means of a combination tool (10) comprising both milling cutters (26, 28, 66, 68, 70, 72, 74) and at least one lathe tool (36) with said combination tool being rotated at a controlled rotational speed (nc) about the rotational axis of the tool (C) during a milling machining of the edge (R), and being swivelled with a controlled angle of rotation (φC) about the rotational axis of the tool (C) before and optionally also during the lathe machining of the edge (R).