Patent US3672921A successfully refreshed from Google Patents.
US3672921A
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US
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Glass for ultrasonic delay line
Assignee: Hoya Glass Works Ltd
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Filing: 1970-05-19
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Granted: 1972-06-27
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Expires: 1990-05-19
Abstract
Abstract AN ULTRASONIC DELAY LINE GLASS HAVING IMPROVED TEMPERATURE-COEFFICIENT AND TIME DEPENDENCIES OF DELAY TIME AND STABILITY DURING MELTING CAN BE OBTAINED BY INCORPORATING B2O3 INTO A GLASS COMPOSITION OF THE SIO2-K2O-PHO SYSTEM AND REDUCING A CONTENT OF K2O.
Inventors
- 👤 Yoshiyuki Asahara
- 👤 Tetsuro Izumitani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:31
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/0057; C03C3/00; C03C3/04; C03C3/076; C03C3/102; C03C3/108
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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |