Toric lens casting mold arbor.

摘要

The disclosure of this application is directed to injection molding methods and apparatus for the production of casting molds for toric lenses having prism ballast oriented properly with respect to the cylinder axis of the toric curves. The application discloses the use of a calibrated rotatable ring mechanism within the injection molding body, for producing a slot (16) or other alignment means on the lens casting mold at a point which is offset a predetermined number of degrees from the axis of the toric curve being formed in the casting mold. When the casting mold containing a newly cast lens is mounted on a precision lathe, the mating of the slot with a permanent ridge on the lathe spud ensures that the mold seats on the lathe at the same established place each time with respect to the position of the cutting tool. The offset between the toric axis and the position of the cutting tool has already been established, and therefore there is no need for the lathe operator to make any measurements or resetting of the cutting tool.