Apparatus for grinding optical lenses

Claim 1

Apparatus for producing convex and/or concave spherical surfaces in workpieces such as optical lenses, comprising a frame, a workpiece spindle selectively mounted relative to the frame and having an end face to which is securable a workpiece to be machined to provide a spherical surface of selective radius and having a corresponding apex, a tool spindle selectively mounted on the frame and carrying a machining tool of correspondingly selective effective diameter relative to the selective radius of the spherical surface of the workpiece for machining the workpiece, the two spindles being disposed for corresponding rotation at a pre-selective angle to one another, and angular positioning means including two mutually adjustable members for retaining the tool spindle in its corresponding angular position relative to the workpiece spindle in conformity with such pre-selective angle between the two spindles, the first of said members being mounted for pivoting about a primary pivotal axis which is tangential to the apex of the spherical surface to be produced, and having a selective effective longitudinal dimension extending from the primary axis, such first member being adjustably locatable at a pre-selected angle of inclination initially generally corresponding to such pre-selective angle between the two spindles in dependence upon the selective radius of the spherical surface to be machined, the second of said members having the tool spindle directly mounted for rotation thereon and being mounted for pivoting about a secondary pivotal axis on the first member, the pivotal axes of mounting of the two members extending substantially parallel to one another and being spaced apart by a distance corresponding substantially to the effective longitudinal dimension of the first member, the second member which is pivotable about the secondary axis being locatable at an angular position with respect to a line joining the two axes, which angular position is selected in dependence upon the effective diameter of the machining tool for final accurate angular alignment thereof with respect to the apex of the spherical surface to be produced, and the first member being in the form of a swivel arm having a pivot mounting end at which such primary axis is located and a free end in opposed relation thereto, and the second member being mounted on the first member and being in the form of a rocker arm, and a spindle sleeve being provided in the rocker arm which receives the tool spindle and which is selectively axially displaceably mounted in the rocker arm for extending therebeyond for adjusting the location of the machining tool relative to the primary axis and apex of the spherical surface to be produced.