GB115056A - Improvements in Grinding and Polishing Apparatus. - Google Patents

Abstract

115,056. Taylor, W. Jan. 31, 1917. Lenses and curved surfaces of mirrors &c., grinding and polishing.-A machine for grinding the spherical surfaces of lenses, reflectors, &c., of the kind in which the work and the tool are mounted on concave and convex members, one of which is moved relatively to the other to effect the rubbing, and in which these members are mounted on rotary spindles inclined to one another in the same plane, and with their axes intersecting at the centre of curvature of the co-acting surfaces, comprises a frame C carrying a series of vertical spindles A and a corresponding series of inclined spindles B, the axes of which intersect at a point z. The work is mounted on a convex member D having a spindle E of length appropriate to bring the centre of curvature of the member D to the point z. Fine adjustment is provided by supporting the spindle A in a footstep-bearing f in a frame F raised and lowered by a crank-handle g<2>. The spindle A carries a chuck e to support the spindle E, and the spindles are shaped at e<1> to engage and drive. The concave guiding &c. member J is supported by a ball at the end of a rod j<1> adjustable along a radius of the member J through the end of an arm K pivoted at k to a bracket L on a crank M on the shaft B. Adjustment of the rod j<1>, which can be clamped by a bolt j<2>, varies the eccentricity of the path of the ball j. Further, the bracket h is rotatable in the crank M about a pivot m both to vary the eccentricity and to facilitate removal of the co-acting members. A set-screw O bearing against a lug o on the arm K limits the angular position of this arm. The pressure between the tool and the work is furnished by a spring N enclosed in a tubular casing n pivoted at n<1> to the arm K and bearing against a curved surface l on the bracket L. The frame C may be divided into two parts pivoted along an horizontal axis passing through the point z. The spindles A may be driven by worms H<2> on a shaft H, and the spindles B by worms P<2> on a shaft P. The shaft H is driven by a belt from the shaft P, and the shaft P by a belt passing over a jockey pulley, which can be moved by a sliding handle to slacken the belt and stop the machine or to re-tighten the belt and start the machine again.