GB1164732A - Improvements in or relating to Apparatus for Mounting an Untrimmed Spectacle Lens for Trimming on a Trimming Machine - Google Patents

Abstract

1,164,732. Grinding. SOC. DES LUNETIERS. 1 March, 1967 [14 May, 1966], No. 9786/67. Heading B3D. A device for adjusting the position of an optical lens on a suction cup for transfer thereof to a grinding machine as a function of the pupillary distance of the wearer and the centre lines of the spectacle frame comprises a suction cup carrier, a transparent plate having engraved thereon the perpendicular centre lines AA, BB corresponding to the centre lines of the spectacle frame which are coincident with the centre lines of a template of the lens, a photograph of the spectacle frame having centre lines printed thereon corresponding to the centre lines AA, BB and the pupillary axes C<SP>1</SP>C<SP>1</SP>, D<SP>1</SP>D<SP>1</SP>, the optical lens having centre lines CC, DD, means for positioning the suction cup carrier coincident with the point of intersection of the centre lines AA, BB corresponding to those of the spectacle frame and means for positioning the centre lines CC, DD of the lens coincident with the pupillary axis C<SP>1</SP>C1, D1D<SP>1</SP>. With the lens 2, Fig. 1, mounted on the suction cup 1, the edge of the lens is trimmed by a grinding wheel 5 under the control of a template 4 and follower 6. The spectacle frame 12, Fig. 2, and template have axes AA, BB the suction cup has axes A<SP>1</SP>A<SP>1</SP>, B<SP>1</SP>B<SP>1</SP> and the lens 2 has axes CC, DD crossing at O which is to be coincident with the pupillary axis P at the intersection of axes C<SP>1</SP>C<SP>1</SP>, D<SP>1</SP>D<SP>1</SP>. A photograph, Fig. 3, is produced on which the axes AA, BB and C<SP>1</SP>C<SP>1</SP>, D<SP>1</SP>D1 are printed with the optical centre of the lens displaced a distance D from the mechanical centre of the spectacle frame. The photograph is placed under a transparent plate 13 which has engraved lines thereon corresponding to the axes AA, BB and is arranged so that these lines are coincident with the corresponding lines on the photograph. The lens is then positioned so that its axes CC, DD are coincident with the corresponding axes C<SP>1</SP>C<SP>1</SP>, D<SP>1</SP>D<SP>1</SP> on the photograph. The transparent plate is then placed with the centre of the axes AA, BB coincident with the centre line of a carrier 17, Fig. 5, for the suction cup 1 which is pressed on to the lens by a presser 16. In another embodiment, the suction cup is carried by a pivoted arm. In a further embodiment, the lens and the photograph and transparent plate are arranged side by side and moved according to the centre lines on a rule or rules, while in another embodiment, an optical system consisting of a prism and reflectors is used to determine the positions of the photograph, transparent plate, lens and suction cup.