Abstract: Tool for machining a workpiece, comprising: a cutting insert; and a cutting insert holder comprising a first cutting insert receptacle extending along a first center axis and a second cutting insert receptacle extending along a second center axis, into which the cutting insert is selectively receivable; wherein the first and second center axes intersect at an imaginary crossing point located in a region that is covered by the cutting insert when the cutting insert is received in the first cutting insert receptacle as well as when the cutting insert is received in the second cutting insert receptacle.

Abstract: The present invention relates to a composition, in particular a blocking agent composition, in particular for fixing blanks for ophthalmic and/or optical lenses, preferably plastics material-based ophthalmic spectacle glass blanks. The composition comprises a mixture containing (a) at least one polyol (polyalcohol) and (b) at least one organic polyester. In addition, the present invention relates to a method for producing a composite structure, which comprises a carrier having a blank fixed thereon, and the composite structure as such. Furthermore, the present invention relates to a method for producing spectacle glass, in particular plastics material-based spectacle glass, and the spectacle lenses that can be obtained therefrom. Finally, the present invention relates to the use of the composition according to the invention in the production of ophthalmic and optical lenses, and for fixing the blank to a carrier.

Abstract: A polishing film for a polishing head for plastic spectacle lenses, for polishing zones on a front side or rear side of the spectacle lens, having a polishing surface which can be positioned against the spectacle lens and is bounded by a peripheral surface, wherein an edge is provided between the polishing surface and the peripheral surface, wherein the edge either has a radius r of at least 0.5 mm to 10 mm or has a chamfer f with an extent f1×f2, where the extent f1 or f2 is at least 0.5 mm to 10 mm, or the polishing film, when not in use, has a basic curvature G with a radius RG?75 mm and, in addition to this, a peripheral curvature G with a radius Rg?0.5 G, wherein the peripheral curvature g is limited to the peripheral zone, or the polishing film is formed without any basic curvature G and has a peripheral curvature g with a radius Rg?35 mm, wherein the peripheral curvature g is limited to the peripheral zone.

Abstract: A block piece for holding an optical lens to be worked in a machine tool, the block piece having a rotational axis 1.1, a holding surface that can be made to face the lens and a bearing surface that is directed radially outwards and can be brought to bear in a workpiece spindle, wherein the holding surface has at least one recess 1.2a or a number of recesses 2.1-2.6, which are distributed around the rotational axis 1.1, have a diameter DA and serve for receiving bonding compound for adhesive bonding to the lens.

Abstract: The present invention relates to a composition, in particular a blocking agent composition, in particular for fixing blanks for ophthalmic and/or optical lenses, preferably plastics material-based ophthalmic spectacle glass blanks. The composition comprises a mixture containing (a) at least one polyol (polyalcohol) and (b) at least one organic polyester. In addition, the present invention relates to a method for producing a composite structure, which comprises a carrier having a blank fixed thereon, and the composite structure as such. Furthermore, the present invention relates to a method for producing spectacle glass, in particular plastics material-based spectacle glass, and the spectacle lenses that can be obtained therefrom. Finally, the present invention relates to the use of the composition according to the invention in the production of ophthalmic and optical lenses, and for fixing the blank to a carrier.