Patent US2840482A successfully refreshed from Google Patents.
US2840482A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Potassium-fluorine glasses
Assignee: Pennwalt Corp
•
Filing: 1952-02-27
•
Granted: 1958-06-24
•
Expires: 1972-02-27
Abstract
No abstract record available.
Inventors
- 👤 William J Knapp
- 👤 Mockrin Isadore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:00
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/11; C03C3/112; C03C3/062; C03C3/064; C03C3/115; C03C3/118; C03C8/00; C03C8/02; C03C8/06; C03C2207/00; C03C2207/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
66 words
A GLASS COMPOSITION CONTAINING ON A CALCULATED BASIS 45 TO 55% BY WEIGHT K2SIF6 AND AT LEAST TWO MATERIALS OF THE GROUP CONSISTING OF AL2O3, SIO2 AND B2O3 IN AMOUNTS NOT SUBSTANTIALLY IN EXCESS OF 36% BY WEIGHT AL2O3, 47% BY WEIGHT SIO2 AND 2% TO 50% BY WEIGHT B2O3, SAID K2SIF6, AL2O3, SIO2, AND B2O3 MAKING UP AT LEAST 90% OF THE TOTAL GLASS COMPOSITION.
Claim 2
Dependent Claim
66 words
A GLASS COMPOSITION CONTAINING ON A CALCULATED BASIS 45 TO 55% BY WEIGHT K2SIF6 AND AT LEAST TWO MATERIALS OF THE GROUP CONSISTING OF AL2O3, SIO2 AND B2O3 IN AMOUNTS NOT SUBSTANTIALLY IN EXCESS OF 36% BY WEIGHT AL2O3, 47% BY WEIGHT SIO2 AND 2% TO 50% BY WEIGHT B2O3, SAID K2SIF6, AL2O3, SIO2, AND B2O3 MAKING UP AT LEAST 90% OF THE TOTAL GLASS COMPOSITION.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-23 | 1961-12-23 | 1962-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-23 | 1965-12-23 | 1966-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-23 | 1969-12-23 | 1970-06-24 | $7700.00 | Window Closed / Lapsed |