US3420648A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microscope cover glass and method
Assignee: Chance Brothers Ltd
•
Filing: 1965-09-01
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Granted: 1969-01-07
•
Expires: 1985-09-01
Abstract
No abstract record available.
Inventors
- 👤 Richard Charles Andrews
- 👤 Arthur Hugh Bedford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:22
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/089; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/903
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
95 words
A METHOD OF PRODUCING MICROSCOPE COVER GLASSES COMPRISING THE STEPS OF FORMING MOLTEN GLASS CONSISTING ESSENTIALLY OF BY WEIGHT FROM 63% TO 68% SILICA (SIO2), 6 TO 10% SODIUM OXIDE (NA2O), 3 TO 7% POTASSIUM OXIDE (K2O), 1.8 TO 5% ALUMINA (AL2O3), 4 TO 9% BORON OXIDE (B2O3), 1 TO 4% BARIUM OXIDE (BAO), 1.5 TO 6% ZINC OXIDE (ZNO), 1.5 TO 4% TITANIUM DIOXIDE (TIO2), 0.4 TO 1% ANTIMONY OXIDE (SB2O3) AND 1 TO 2% ZIRCONIA (ZRO2), AND DRAWING A RIBBON OF GLASS HAVING A THICKNESS LESS THAN 0.350 MM. FROM THIS MOLTEN GLASS.
References Cited (Backward Citations)
USRE23049E
Cited
BE551390A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-01-07 | 1972-07-08 | 1973-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-01-07 | 1976-07-08 | 1977-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-01-07 | 1980-07-08 | 1981-01-07 | $7700.00 | Window Closed / Lapsed |