Groove cutter for lens - has rotary diamond cutter with rotating lens holder holding lens at centre

摘要

The cutter for a peripheral groove on a lens (17) of spectacles comprises a rotary diamond cutter (41) and a lens holder and rotating section, gripping the lens at its centre by two opposed abutments (16,18). To accommodate axial and radial movements of the periphery, side guides (27) on arms (28,29) and a rocking plate (26) adjust the holding section. The rocking plate, by detecting angular changes, causes the lens rotating D.C. motor to vary speed for constant peripheral speed. Also included are a cutting pressure adjusting section and an operation responsive shutting-down section. One of the abutments is axially adjustable on a graduated rod to determine the position for mean curvature.