US3595725A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Toughening glass in sheet form
Assignee: Pilkington Group Ltd
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Filing: 1969-04-29
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Granted: 1971-07-27
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Expires: 1989-04-29
Abstract
Abstract A HEATED GLASS ARTICLE IS TOUGHENED BY A TWO-STAGE QUENCHING PROCESS IN THE FIRST STAGE OF WHICH GASEOUS CHILLING MEDIUM LOWES THE SURFACE TEMPERATURE OF THE GLASS AT A PREDETERMINED RATE AND IN THE SECOND STAGE OF WHICH A HIGHER RATE OF FLOW WHICH CONTINUES THE CHILLING IS SO CONTROLLED THAT THERE IS AN OVERALL SUBSTANTIALLY LINEAR RATE OF FALL OF THE SURFACE TEMPERATURE OF THE GLASS DURING THE WHOLE OF THE TOUGHENING PROCESS.
Inventors
- 👤 Ernesto Coen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:50
CPC Classifications
C; C03; C03B; C03B27/00; C03B27/04; C03B27/052; Y; Y10; Y10T; Y10T428/00; Y10T428/31; Y10T428/315
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) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |