GB210533A - Improvements in or relating to apparatus for grinding and polishing lenses and the like - Google Patents

Abstract

210,533. Reid, R. C., and Stigmat, Ltd. Nov. 2, 1922. Lenses, grinding and polishing. - Spectacle and other lenses are roughed, ground, or polished by means of a wheel 2, which is rotated and reciprocated axially and the surface of which has a curvature, in an axial section, which is shaped, as required, to give either a toric lens or a spherical lens, the lenses being mounted in holders upon a table 5 so that they remain in contact with the grinding-surface. The wheel is carried by a vertical spindle 1 slidably mounted in a sleeve carried by ball bearings in a casing 3 attached to a frame 4. The lower end of the spindle is attached rotatably to a connecting-rod 6 adjustably connected, by means of a slot 8, to a lever 9, which is oscillated by means of a cam 11; the cam, which may be of grooved form, is shaped to vary, as required, the stroke of the wheel either in successive strokes, in alternate strokes, or in a sequence of strokes. The pivot of the lever 9 is eccentrically mounted to allow the grinding-wheel to be adjusted vertically. The cam is mounted on a driving-shaft 13 which drives the spindle 1 through a variable speed friction gear 14, 15 and cone pulleys 17, 18. The lenses are mounted on holders 26, Fig. 5, supported on centres 25, or knife-edges, on arms 23 pivoted to bases 20 clamped to the table 5. The arms 23 are pressed, by spring pressed centres 22, to keep the lenses in contact with the wheel; weights or pneumatic pressure may replace the springs. The arms 23 may be replaced by spring-pressed sliders. According to the Provisional Specification, the grinding-element may be fixed, the lenses being rotated and reciprocated.