Abstract: A method of lathing a lens, especially a contact lens, involves attaching the cylindrical blank of lens material to a first block of machineable plastic material, lathe cutting a desired first lens surface in the cylindrical blank, attaching the machined first lens surface of the blank to a second block, lathe cutting to remove the block of machineable plastic material, and lathe cutting a desired second lens surface in the blank. Both the first and second blocks may be adhered to the lens blank with an adhesive curable by ultraviolet radiation, and a two-piece block, composed of a head section and a body section, is disclosed.

Abstract: A method of lathing a lens, especially a contact lens, involves attaching the cylindrical blank of lens material to a first block of machineable plastic material, lathe cutting a desired first lens surface in the cylindrical blank, attaching the machined first lens surface of the blank to a second block, lathe cutting to remove the block of machineable plastic material, and lathe cutting a desired second lens surface in the blank. Both the first and second blocks may be adhered to the lens blank with an adhesive curable by ultraviolet radiation, and a two-piece block, composed of a head section and a body section, is disclosed.

Abstract: A method of lathing a lens, especially a contact lens, involves attaching the cylindrical blank of lens material to a first block of machineable plastic material, lathe cutting a desired first lens surface in the cylindrical blank, attaching the machined first lens surface of the blank to a second block, lathe cutting to remove the block of machineable plastic material, and lathe cutting a desired second lens surface in the blank. Both the first and second blocks may be adhered to the lens blank with an adhesive curable by ultraviolet radiation, and a two-piece block, composed of a head section and a body section, is disclosed.

Abstract: A reciprocating tool post assembly is disclosed that may provide substantially linear excursions of a cutting tool mounted therein. The apparatus includes a voice coil assembly having a longitudinal axis that provides for the reciprocating movement of the assembly and to which a pair of coil arms is attached. The assembly also includes a pair of lever arms, each being pivotally attached between a respective coil arm and a draw bar, with a pair of fulcrum members attached to a base of the assembly that engage each respective lever arm to provide a fulcrum about which each respective lever arm may pivot. One end of the draw bar is attached to a tool support that is guided in a substantially axial movement by a guide member, such that, when a cutting tool is attached to the tool support and the movement of the voice coil causes the cutting tool to reciprocate substantially axially with respect to the base.

Abstract: A lathe and a method of using the lathe are disclosed for forming an aspheric surface on a workpiece, in which the workpiece is mounted to a holder that is rotatably carried by the spindle, headstock and bed of a lathe, with that spindle and workpiece being rotated about the axis of the spindle with the workpiece being engaged by a forming tool which forming tool is moved through an arcuate path about an axis that is generally transverse to the spindle axis. The method and apparatus provide further for determining the time-varying angular position of the forming tool along the arcuate path, for determining the time-varying angular position of a point on the workpiece about the spindle axis and for reciprocating the workpiece holder and the workpiece held thereby relative to the lathe headstock and to the forming tool in synchronization with the movement of the forming tool and with the rotation of the workpiece about the spindle axis to form the desired contoured surface.

Abstract: A lathe and a method of using the lathe are disclosed for forming an aspheric surface on a workpiece, in which the workpiece is mounted to a holder that is rotatably carried by the spindle, headstock and bed of a lathe, with that spindle and workpiece being rotated about the axis of the spindle with the workpiece being engaged by a forming tool which forming tool is moved through an arcuate path about an axis that is generally transverse to the spindle axis. The method and apparatus provide further for determining the time-varying angular position of the forming tool along the arcuate path, for determining the time-varying angular position of a point on the workpiece about the spindle axis and for reciprocating the workpiece holder and the workpiece held thereby relative to the lathe headstock and to the forming tool in synchronization with the movement of the forming tool and with the rotation of the workpiece about the spindle axis to form the desired contoured surface.

Abstract: A unique lens (10) having a peripheral carrier surface (13), a central optical zone (18) providing the toricity required to achieve a given spherical and cyclinder correction that is oriented to a selected axis angle (.psi.) and an intermediate, annular, transitional surface (15) between the optical and carrier surfaces (16 and 13). The method and apparatus for providing such a toric lens (10) employs a generator (50) that produces a sinusoidal signal in response to rotaton of the lathe spindle (26), and a signal that is selectively phased at a predetermined angularity with respect to the circumference of the rotatable spindle (26). The aforesaid signal is applied to a tool post oscillator (90) in order to oscillate the tool (36) in synchronization with rotation of the spindle (26) thereby cutting both curves of the toric surface (16) in one pass.

Abstract: A device for controlling the thickness of a contact lens produced on an automatic and computerized numerically controlled (CNC) lathe is disclosed. A sensor control device is incorporated on a lens lathing machine for engaging the front surface of a lens button upon which the convex surface of the contact lens is to be machine lathed. Immediately upon contact between the sensor and the front surface, the sensor provides for breaking an electrical circuit in the lathe controller providing for automatic position registration of the lens button front surface relative to the cutting tool and its pivot point, and a lens of desired center thickness and power curve radius is subsequently generated. Close tolerances and high repeatability are domonstrated in contact lenses lathed generated by these principles.