Claims
- 1. A method of molding to form a glass lens which method comprises:
- forming a glass preform of desired configuration,
- providing a mold assembly having a mold cavity therein,
- preheating said preform and said mold assembly,
- placing the preform within the cavity of said mold assembly
- initially pressing said preform within the cavity of the said mold assembly by providing a force on the mold assembly, said initial pressing being carried out at temperatures wherein the glass of said preform is at a viscosity of about 10.sup.8 -10.sup.10 poises,
- maintaining a force on the mold assembly while it is cooled to a temperature where the glass is at a viscosity of about 10.sup.11 -10.sup.12 poises,
- holding the pressed lens within said mold assembly for a time sufficient to provide an isothermal condition for the mold and the lens
- and removing the pressed lens from said mold assembly.
- 2. A method of molding a glass lens as defined in claim 1 where the step of forming said glass preform includes casting a glass pellet from a melt and shaping said glass pellet.
- 3. A method of molding a glass lens as defined in claim 1 including the step of providing the mold assembly with a mold cavity of predetermined fixed volume therein.
- 4. A method of molding a glass lens as defined in claim 3 including the step of pressing said preform within said cavity to a stop abutment means for fixing the volume of said mold assembly cavity.
- 5. A method of molding a glass lens as defined in claim 1 including the step of including a ring means as part of said mold assembly for determining the thickness of said molded glass lens.
Parent Case Info
This is a division of application Ser. No. 850,180, filed Apr. 10, 1986 which application is a division of Ser. No. 643,412, filed Aug. 22, 1984, which application is a continuation of application Ser. No. 515,662, filed July 20, 1983, now U.S. Pat. No. 4,481,023, which application is a continuation of Ser. No. 316,861, filed Oct. 31, 1981, now abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (4)
Number |
Date |
Country |
501283 |
Jun 1930 |
DE2 |
56-00378 |
Jan 1981 |
JPX |
617391 |
Jul 1978 |
SUX |
814906 |
Mar 1981 |
SUX |
Non-Patent Literature Citations (1)
Entry |
Derwent Publications Week 42--1985, pp. 3 and 6. |
Divisions (2)
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Number |
Date |
Country |
Parent |
850180 |
Apr 1986 |
|
Parent |
643412 |
Aug 1984 |
|
Continuations (2)
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Number |
Date |
Country |
Parent |
515662 |
Jul 1983 |
|
Parent |
316861 |
Oct 1981 |
|