Method and apparatus for separating contact lens mold sections

• US 6,033,603 A
• Filed: 11/04/1997
• Issued: 03/07/2000
• Est. Priority Date: 11/06/1996
• Status: Expired due to Term

• Current Assignee: Bausch & Lomb Incorporated (Bausch Health Cos., Inc.)
• Original Assignee: Bausch & Lomb Incorporated (Bausch Health Cos., Inc.)
• Inventors: Bentley, Christopher, Beebe, Kevin D., Lesczynski, Michael A., Wu, Mingway B.
• Primary Examiner(s): Vargot, Mathieu D.
• Application Number:
  US08/964,169
• Time in Patent Office: 854 Days
• Field of Search: 264/1.1, 264/2.2, 264/2.3, 264/334, 264/1.36, 264/1.37, 425/440, 425/808, 425/436 R
• US Class Current: 264/1.1
• CPC Class Codes: B29C 2043/3652 Elastic moulds or mould parts, e.g. cores or inserts
• CPC Class Codes: B29C 33/44 with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles
• CPC Class Codes: B29C 33/48 with means for collapsing or disassembling
• CPC Class Codes: B29C 33/50 elastic or flexible for isostatic pressing B29C43/3642
• CPC Class Codes: B29C 37/0007 using means operable from outside the mould for moving between mould parts, e.g. robots
• CPC Class Codes: B29C 43/36 Moulds for making articles of definite length, i.e. discrete articles
• CPC Class Codes: B29D 11/00 Producing optical elements, e.g. lenses or prisms grinding or polishing of optical elements B24B; constructional form of optical elements G02B; optical parts of spectacles G02C7/00
• CPC Class Codes: B29D 11/00057 characterised by the shape or surface condition of the edge, e.g. flashless, burrless, smooth
• CPC Class Codes: B29D 11/00125 Auxiliary operations, e.g. removing oxygen from the mould, conveying moulds from a storage to the production line in an inert atmosphere
• CPC Class Codes: B29D 11/00192 Demoulding, e.g. separating lenses from mould halves
• CPC Class Codes: B29D 11/00221 using prying means
• CPC Class Codes: Y10S 425/808 Lens mold

Abstract

A method for separating one mold section from another mold section and a contact lens molded in the two mold sections provides improved reliability that the lens is not damaged during this operation and that the lens is retained selectively on the desired. Various embodiments of apparatus for carrying out the method are disclosed.

Claims

1. A method of separating a first mold section from a second mold section and a contact lens molded therein, where molding surfaces of the mold sections are in contact with surfaces of the contact lens, said method comprising:

applying a force to and around a peripheral region of the first mold section whereby the first mold section molding surface is first separated from the contact lens surface at the periphery thereof and then inwardly towards a central region thereof; and

separating the first mold section from the second mold section with the contact lens being retained in the second mold section, wherein the first and second mold sections include respective engaging cylindrical walls.

2. The method of claim 1, including stabilizing the second mold section against forces exerted on the first mold section.

3. The method of claim 1, wherein when the first and second mold sections are separated, a ring of excess cured lens material is removed with the first mold section.

4. The method of claim 1, further comprising moving the second mold section to a desired position and then releasing the contact lens therefrom.

5. The method of claim 1, wherein the first mold section is a posterior mold for molding a posterior lens surface and the second mold section is an anterior mold for molding an anterior lens surface.

6. The method of claim 1, wherein the force applied to and around the peripheral region is applied by inserting a wedge between the respective engaging cylindrical walls of the first and second mold sections and in a first direction axially aligned with a central axis of the first mold section.

7. The method of claim 6, further comprising applying a force to a central region of the first mold section while applying the force to and around the peripheral region thereof, the force applied to the central region being along a second direction axially aligned with the central axis of the first mold section and opposite to the first direction.

8. The method of claim 6, wherein the wedge includes a first surface for contacting a periphery of the first mold section at its cylindrical wall and a second surface for contacting a periphery of the second mold section at its cylindrical wall, the second wedge surface substantially corresponding to a surface of the second mold section cylindrical wall which it contacts, and the first wedge surface being tapered such that the first and second wedge surfaces meet to form a tapered wedge-shaped tip.

9. A method of separating a first mold section from a second mold section and a contact lens molded therein, where molding surfaces of the mold sections are in contact with surfaces of the contact lens, said method comprising:

applying a force to and around a peripheral region of the first mold section whereby the first mold section molding surface is first separated from the contact lens surface at the periphery thereof and then inwardly towards a central region thereof, wherein the force applied to and around the peripheral region is applied by a hollow cylindrical member against a bottom periphery of the first mold section and in a first direction axially aligned with a central axis of the first mold section; and

separating the first mold section from the second mold section with the contact lens being retained in the second mold section.

10. The method of claim 9, wherein the first and second mold section include respective engaging cylindrical walls, the hollow cylindrical member having an annular upper surface that contacts the bottom periphery of the first mold section cylindrical wall.

11. A method of separating a first mold section from a second mold section and a contact lens molded therein, where molding surfaces of the mold sections are in contact with surfaces of the contact lens, said method comprising:

applying radial forces to and around a peripheral region of the first mold section whereby the first mold section molding surface is first separated from the contact lens surface at the periphery thereof and then inwardly towards a central region thereof; and

separating the first mold section from the second mold section with the contact lens being retained in the second mold section, wherein the first and second mold sections include respective engaging cylindrical walls.

12. The method of claim 11, wherein when the first and second mold sections are separated, a ring of excess cured lens material is removed with the first mold section.

13. The method of claim 11, further comprising moving the second mold section to a desired position and then releasing the contact lens therefrom.

14. The method of claim 11, wherein the first mold section is a posterior mold for molding a posterior lens surface and the second mold section is an anterior mold for molding an anterior lens surface.

15. An apparatus for separating a first mold section from a second mold section and a contact lens molded therein, where molding surfaces of the mold sections are in contact with surfaces of the contact lens, said apparatus comprising:

means for supporting a mold assembly comprised of said first and second mold sections and said contact lens; and

clamps that clamp a peripheral region of the first mold section and apply radial forces to and around the first mold section, in a manner that the first mold section molding surface is first separated from the contact lens surface at the periphery thereof and then inwardly towards a central region thereof, wherein the first and second mold sections include respective engaging cylindrical walls.

16. An apparatus for separating a first mold section from a second mold section and a contact lens molded therein, where molding surfaces of the mold sections are in contact with surfaces of the contact lens, said apparatus comprising:

means for supporting a mold assembly comprised of said first and second mold sections and said contact lens; and

means for applying a force to and around a peripheral region of the first mold section in a manner that the first mold section molding surface is first separated from the contact lens surface at the periphery thereof and then inwardly towards a central region thereof, wherein the first and second mold sections include respective engaging cylindrical walls.

17. The apparatus of claim 16, wherein the first mold section is a posterior mold for molding a posterior lens surface and the second mold section is an anterior mold for molding an anterior lens surface.

18. The apparatus of claim 16, wherein the means for applying a force comprises a wedge that is inserted between the respective engaging cylindrical walls of the first and second mold sections.

19. The apparatus of claim 18, wherein the wedge includes a first surface for contacting the first mold section cylindrical wall and a second surface for contacting the second mold section cylindrical wall, the second wedge surface substantially corresponding to a surface of the second mold section cylindrical wall which it contacts, and the first wedge surface being tapered such that the first and second wedge surfaces meet to form a tapered wedge-shaped tip.

20. An apparatus for separating a first mold section from a second mold section and a contact lens molded therein, where molding surfaces of the mold sections are in contact with surfaces of the contact lens, said apparatus comprising:

means for supporting a mold assembly comprised of said first and second mold sections and said contact lens; and

a hollow cylindrical member that contacts a bottom peripheral region of the first mold section and applies a force to and around a peripheral region of the first mold section, in a manner that the first mold section molding surface is first separated from the contact lens surface at the periphery thereof and then inwardly towards a central region thereof.

21. The apparatus of claim 20, wherein the first and second mold section include respective engaging cylindrical walls, the hollow cylindrical member having an annular upper surface that contacts the bottom periphery of the first mold section cylindrical wall.