Patent US3725023A successfully refreshed from Google Patents.
US3725023A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure molding of glass articles
Assignee: PPG Industries Inc
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Filing: 1970-10-21
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Granted: 1973-04-03
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Expires: 1990-10-21
Abstract
Abstract PRESSURE FORMING GLASS SHEETS, IN PARTICULAR SOLID HEMISPHERES, BY CASTING MOLTEN GLASS UPWARD UNDER SUPERATMOSPHERE PRESSURE BETWEEN GRAPHITE MOLDS WHILE THE MOLDS ARE MAINTAINED WITHIN A DESIRED TEMPERATURE RANGE BELOW A TEMPERATURE AT WHICH MOLTEN GLASS ADHERES TO GRAPHITE ANDAOVE A TEMPERATURE AT WHICH THE MOLDS CAUSE CHILL CRACKIN AND OPTICAL DEFECTS IN THE SURFACES OF THE CAST GLASS.
Inventors
- 👤 J Parris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:54
CPC Classifications
C; C03; C03B; C03B19/00; C03B19/02; C03B19/025
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |