Patent US5411940A successfully refreshed from Google Patents.
US2579709A
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Glass composition
Assignee: PPG Industries Inc
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Filing: 1948-09-22
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Granted: 1951-12-25
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Expires: 1968-09-22
Abstract
No abstract record available.
Inventors
- 👤 John J Smith
- 👤 Duncan James Earle
- 👤 Harry A Truby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:09
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/102; C03C3/105; C03C3/11; C03C3/112
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
102 words
A CLEAR LEAD GLASS HAVING A THERMAL COEFFICIENT OF LINEAR EXPANSION OF 8.9$0.2X10-6 PER DEGREE CENTIGRADE BETWEEN 25* C. AND 300* C. AND A MAXIMUM SOFTENING POINT OF 645* C. COMPRISING BY WEIGHT FROM 66 TO 70 PERCENT OF SILICON DIOXIDE, FROM 14.5 TO 16 PERCENT OF ALKALI METAL OXIDE, FROM 10 TO 15 PERCENT OF LEAD OXIDE, FROM 2 TO 3 PERCENT OF ALUMINUM OXIDE, APPROXIMATELY 1 PERCENT OF FLUORINE AND FROM ABOUT 0.5 TO 1.5 PERCENT OF A MODIFYING METAL OXIDE SELECTED FROM THE GROUP CONSISTING OF ANTIMONY OXIDE, CERIUM OXIDE, ARSENIC OXIDE, TITANIUM OXIDE, ZINC OXIDE AND ZIRCONIUM OXIDES.
Claim 2
Dependent Claim
102 words
A CLEAR LEAD GLASS HAVING A THERMAL COEFFICIENT OF LINEAR EXPANSION OF 8.9$0.2X10-6 PER DEGREE CENTIGRADE BETWEEN 25* C. AND 300* C. AND A MAXIMUM SOFTENING POINT OF 645* C. COMPRISING BY WEIGHT FROM 66 TO 70 PERCENT OF SILICON DIOXIDE, FROM 14.5 TO 16 PERCENT OF ALKALI METAL OXIDE, FROM 10 TO 15 PERCENT OF LEAD OXIDE, FROM 2 TO 3 PERCENT OF ALUMINUM OXIDE, APPROXIMATELY 1 PERCENT OF FLUORINE AND FROM ABOUT 0.5 TO 1.5 PERCENT OF A MODIFYING METAL OXIDE SELECTED FROM THE GROUP CONSISTING OF ANTIMONY OXIDE, CERIUM OXIDE, ARSENIC OXIDE, TITANIUM OXIDE, ZINC OXIDE AND ZIRCONIUM OXIDES.
References Cited (Backward Citations)
US1721979A
Cited
US2230199A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-12-24 | 1955-06-25 | 1955-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-12-24 | 1959-06-25 | 1959-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-12-24 | 1963-06-25 | 1963-12-25 | $7700.00 | Window Closed / Lapsed |