Patent US2938808A successfully refreshed from Google Patents.
US2938808A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Glass composition
Assignee: PPG Industries Inc
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Filing: 1957-02-25
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Granted: 1960-05-31
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Expires: 1977-02-25
Abstract
No abstract record available.
Inventors
- 👤 James E Duncan
- 👤 George L Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:14
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/02; C03C14/00; C03C14/006
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
110 words
A NEUTRAL GRAY COLORED, HEAT ABSORB GLASS HAVING SUBSTANTIALLY UNIFORM TRANSMITTANCE OF LIGHT IN THE PORTION OF THE SPECTRUM LYING BETWEEN 440 AND 660 MILLIMICRONS AND AN EXCITATION PURITY BELOW 7 PERCENT CONSISTING ESSENTIALLY OF THE FOLLOWING INGREDIENTS IN PERCENT BY WEIGHT: 60 TO 75 PERCENT SIO2, 11 TO 20 PERCENT NA2O, 0 TO 10 PERCENT K2O, THE SUM OF NA2O AND K2O BEING 11 TO 21 PERCENT, 6 TO 16 PERCENT CAO, 0 TO 10 PERCENT MGO, THE SUM OF CAO AND MGO BEING 6 TO 18 PERCENT, 0.2 TO 1 PERCENT FE2O3, 0.003 TO 0.05 PERCENT NIO, 0.0003 TO 0.02 PERCENT COO AND 0.008 TO 0.2 PERCENT SE.
References Cited (Backward Citations)
US2524719A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-05-31 | 1963-11-30 | 1964-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-31 | 1967-11-30 | 1968-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-31 | 1971-11-30 | 1972-05-31 | $7700.00 | Window Closed / Lapsed |