Plastic and nonmetallic article shaping or treating: processes – Optical article shaping or treating – Composite or multiple layer
Patent
1998-06-23
2000-06-13
Vargot, Mathieu D.
Plastic and nonmetallic article shaping or treating: processes
Optical article shaping or treating
Composite or multiple layer
264 24, 264 27, 264 132, B29D 1100
Patent
active
060745797
ABSTRACT:
A method of manufacturing a prescription lens, for eyeglasses on site by compression molding, in a pair of upper and lower molds having a mold surfaces from a thermoplastic preformed lens blank having opposite surfaces and a periphery, comprising the steps of: preheating a preform blank at a first temperature and preheating the upper and lower molds to a second higher temperature; positioning the preheated preform between the upper and lower preheated molds such that the preform makes a single point or line contact with each of the mold surfaces; initially compressing the preformed at a first fixed rate of speed regardless of pressure exerted on the preform, with the preform being compressed to about 4 mm of a predetermined lens thickness desired for the prescription lens; finally compressing the preform to a substantially finished prescription lens at a second fixed rate of speed substantially higher than the first fixed rate of speed regardless of pressure exerted on the preform while substantially maintaining the predetermined temperature, and shutting off the heating to the molds, and stopping travel of the molds with respect to each other upon reaching the predetermined lens thickness; and cooling the molds to another, but lower predetermined temperature; and thereafter opening the molds so as to remove the finished prescription lens.
REFERENCES:
patent: 2298429 (1942-10-01), Smith
patent: 2304663 (1942-12-01), Smith et al.
patent: 2332674 (1943-10-01), Smith
patent: 2432668 (1947-12-01), Kingston
patent: 2479935 (1949-08-01), Johnson
patent: 2481809 (1949-09-01), Barnes
patent: 2640227 (1953-06-01), Johnson
patent: 3763290 (1973-10-01), Sheld
patent: 3833289 (1974-09-01), Schuler
patent: 5458820 (1995-10-01), Lefebvre
patent: 5718850 (1998-02-01), Takano et al.
patent: 5751481 (1998-05-01), Dalzell et al.
patent: 5851328 (1998-12-01), Kohan
Siegel Lackenbach
Vargot Mathieu D.
LandOfFree
Lens blanks and method of making a lens therefrom does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lens blanks and method of making a lens therefrom, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lens blanks and method of making a lens therefrom will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2065881