A method for the production of the grinding grinding pressure and the relative movement between the objects, whose surface by means of grinding is to be machined (glass, lens, etc.), and of the grinding surface of the circumferential grinding tool

摘要

218,863. Optische Anstalt C.P. Goerz Akt.-Ges., Goerz, P., and Jacobi, E. Aug. 9, 1923. Lenses, grinding and polishing; rotating tool apparatus.-In a machine for grinding or polishing lenses &c. the lens and grinding &c. surface are pressed together by centrifugal force. As shown in Fig. 1, the abrasive tool 7 has an inner annular operative surface and is carried by a pin 6 mounted in a rotating support 2 and rotated through gear-wheels 3, 5 by a stationary gearwheel 4 mounted coaxially with the support 2. The speed of rotation is adjusted so that the lens 8, which is pressed by centrifugal force against the tool, remains stationary, or in the case of a spherical lens, rolls about its main axis with its edge in contact with a flange 9 on the tool. The outer annular surface of the tool may be employed as the abrasive surface, as shown in Fig. 3, the lenses 16, 19 being mounted on arms 12, 13 pivoted on the support 2, the arms being pressed radially of the tool by the centrifugal force of a weight 17 and of the arm 13 respectively. In a modification, the tool is driven by means of a friction disc and a flanged carrier in place of the gear wheels. The tool may have several concentric operative surfaces of different curvature, or mav have a flat horizontal surface and a verticalannular surface. Spherical lenses may be ground on an internal cylindrical surface, the blanks having an initial curvature greater than that of the cylindrical surface.