US2913345A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ophthalmic glass
Assignee: PPG Industries Inc
•
Filing: 1954-12-20
•
Granted: 1959-11-17
•
Expires: 1974-12-20
Abstract
No abstract record available.
Inventors
- 👤 Duncan James Earle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:33
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/078; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/903
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
65 words
A CLEAR, COLORLESS GLASS CONSISTING ESSENTIALLY OF 53 TO 73 PERCENT BY WEIGHT OF SIO2, 8 TO 20 PERCENT BY WEIGHT ALKALI METAL OXIDE, 5 TO 18 PERCENT BY WEIGHT ZNO AND 1 TO 8 PERCENT BY WEIGHT TIO2, THE ABOVE LISTED ESSENTIAL INGREDIENTS PLUS SMALL AMOUNTS OF IMPURITIES WHICH DO NOT IMPART COLOR TO THE GLASS CONSTITUTING 100 PERCENT BY WEIGHT OF THE GLASS.
Claim 2
Dependent Claim
65 words
A CLEAR, COLORLESS GLASS CONSISTING ESSENTIALLY OF 53 TO 73 PERCENT BY WEIGHT OF SIO2, 8 TO 20 PERCENT BY WEIGHT ALKALI METAL OXIDE, 5 TO 18 PERCENT BY WEIGHT ZNO AND 1 TO 8 PERCENT BY WEIGHT TIO2, THE ABOVE LISTED ESSENTIAL INGREDIENTS PLUS SMALL AMOUNTS OF IMPURITIES WHICH DO NOT IMPART COLOR TO THE GLASS CONSTITUTING 100 PERCENT BY WEIGHT OF THE GLASS.
References Cited (Backward Citations)
US1957116A
Cited
US1957117A
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US2435995A
Cited
US2523362A
Cited
US2523264A
Cited
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-11-16 | 1963-05-18 | 1963-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-11-16 | 1967-05-18 | 1967-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-11-16 | 1971-05-18 | 1971-11-17 | $7700.00 | Window Closed / Lapsed |