GB1492985A - Lens edgers - Google Patents

Abstract

1492985 Grinding edges of lenses RAPHAEL'S Ltd 22 May 1975 [7 June 1974] 25441/74 Heading B3D [Also in Division G3] A multiwheel lens edging machine comprises a lens carriage 10 movable locate a lens against one of a plurality of grinding wheels, and a variable speed drive for rotating the lens. The carriage is mounted for pivotal movement on a shaft 35 and is moved by a servo motor to engage the edge of a lens 12 clamped between pads 20, 21 on the carriage with a selected one of grinding wheels 14, 15, 16. The carriage is also movable laterally to align the lens with any one of the grinding wheels. The pads 20, 21 are mounted on coaxial shafts 23, 24, shaft 24 being freely rotatable and axially movable by a high speed motor 27 and reduction gearing to provide torque for gripping the lens between the pad, stalling of the motor upon gripping of the lens operating an electronic cut-out. The shaft 23 has a wheel 30 engaged by a worm 31 driven from an electromagnetic clutch 42 and electronically controlled stepping motor 40 40 which is also engageable through a second electromagnetic clutch 44 with rack and spur gearing 60 for laterally moving the carriage. The variation of speed of the motor 40 for both the rotation of the lens and the lateral movement of the carriage is controlled from a store 50 having programmed logic circuits selected by the operator, such as a plug-in switch plate, punched tape or key, which control the various electric motors and clutches in a desired sequence and the final size of the lens. Further mechanism may be controlled from mechanism 52. In another embodiment, a constant speed electric motor is connected by an electromagnetic clutch to a gearbox having various ratios which can be selected to determine the speed of lens rotation. The motor and clutches may be arranged in a removable drive module to permit easy replacement during servicing or to provide different performance.