AXIS CONTROL IN TORIC CONTACT LENS PRODUCTION

Abstract

The invention provides methods of manufacturing toric lenses, apparatuses useful in the method of the invention, and lenses produced according to the method in which method the position of one mold half in relation to its complementary mold half is more precisely controlled so that tilting and rotation of the mold halves in relation to each other is substantially eliminated.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a top plan view of a front curve mold half useful in the apparatuses of the invention.

FIG. 1 b is a top plan view of a back curve mold half useful in the apparatuses of the invention FIG. 2 is a cross-section of a contact lens mold formed using the mold halves of FIGS. 1a and 1b.

FIG. 3 is a perspective view of one embodiment of a pallet of the invention.

FIG. 4 is a top plan view of a portion of the pallet of FIG. 3 showing front curve mold half within the pallet.

FIG. 4 a is a magnified view of a portion of the pallet of FIG. 4.

FIG. 5 is a perspective view of a second embodiment of a pallet of the invention.

Claims

1. A method for manufacturing toric contact lenses, comprising the step of holding each of a first and second mold half in a controlled alignment so that tilt and rotation of the mold halves with respect to each other is substantially eliminated.

2. An apparatus for controlling alignment of a first and second mold half in relation to each other, comprising: a.) a pallet having a base, a top surface and four sidewalls therebetween;b.) a plurality if front curve supports, each support comprising a curved wall and ledge extending radially therearound, wherein the curved wall is of a size and a shape suitable to receive a front curve mold half therein, the ledge is of a size and a shape suitable to support a flange of the mold half, and the support substantially prevents the rotation and tilting of the front curve mold half,c.) a plurality of risers arising upwardly from the pallet top surface, each riser comprising a top surface, sidewalls and a plurality of tab orientation channels sized and shaped for receiving a mold half so that tilting and rotation of the mold half is substantially eliminated.

3. The apparatus of claim 2, wherein the front curve pocket is of a size and shape suitable to receive a triangular tab.

4. The apparatus of claim 2, wherein each of the plurality of risers comprises four tab orientation channels.

5. The apparatus of claim 3, wherein each of the plurality of risers comprises four tab orientation channels.

6. The apparatus of claim 4, wherein the four tab orientation channels are located at about 45°, 135°, 225° and 315° relative to a horizontal axis of the pallet top surface.

7. The apparatus of claim 5, wherein the four tab orientation channels are located at about 45°, 135°, 225° and 315° relative to a horizontal axis of the pallet top surface.

8. A mold assembly, comprising: a.) a first and second mold half, andb.) an apparatus for controlling alignment of first and second mold halves in relation to each other, the apparatus comprising: (i.) a pallet having a base, a top surface and four sidewalls therebetween;(ii.) a plurality if front curve supports, each support comprising a curved wall and ledge extending radially therearound, wherein the curved wall is of a size and a shape suitable to receive a front curve mold half therein, the ledge is of a size and a shape suitable to support a flange of the mold half, and the support substantially prevents the rotation and tilting of the front curve mold half;(iii.) a plurality of risers arising upwardly from the pallet top surface, each riser comprising a top surface, sidewalls and a plurality of tab orientation channels sized and shaped for receiving a mold half so that tilting and rotation of the mold half is substantially eliminated.

9. The mold assembly of claim 8, wherein the front curve pocket is of a size and shape suitable to receive a triangular tab.

10. The mold assembly of claim 8, wherein each of the plurality of risers comprises four tab orientation channels.

11. The mold assembly of claim 9, wherein each of the plurality of risers comprises four tab orientation channels.

12. The apparatus of claim 8, wherein the four tab orientation channels are located at about 45°, 135°, 225° and 315° relative to a horizontal axis of the pallet top surface.

13. The apparatus of claim 9, wherein the four tab orientation channels are located at about 45°, 135°, 225° and 315° relative to a horizontal axis of the pallet top surface.