US2592729A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of etching ethylene diamine tartrate crystals
Assignee: AT&T Inc
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Filing: 1949-05-25
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Granted: 1952-04-15
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Expires: 1969-05-25
Abstract
No abstract record available.
Inventors
- 👤 Everett S Pennell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:23
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/01; H10N30/08; H10N30/082
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
59 words
THE METHOD OF ETCHING ETHYLENE DIAMINE TARTRATE CRYSTALS WHICH COMPRISES IMMERSING SAID CRYSTALS IN A MIXTURE OF WATER AND PROPYLENEGLYCOL IN CONTROLLED PROPORTIONS FOR A DESIRED TIME, LIFTING SAID CRYSTALS FROM SAID MIXTURE, AND INSTANTANEOUSLY DRYING THE SURFACE OF SAID CRYSTALS WHILE MAINTAINING SAID CRYSTAL, AND SAID WATER, AND PROPYLENE-GLYCOL MIXTURE AT A TEMPERATURE OF AT LEAST 41* C.
Claim 2
Independent Claim
59 words
THE METHOD OF ETCHING ETHYLENE DIAMINE TARTRATE CRYSTALS WHICH COMPRISES IMMERSING SAID CRYSTALS IN A MIXTURE OF WATER AND PROPYLENEGLYCOL IN CONTROLLED PROPORTIONS FOR A DESIRED TIME, LIFTING SAID CRYSTALS FROM SAID MIXTURE, AND INSTANTANEOUSLY DRYING THE SURFACE OF SAID CRYSTALS WHILE MAINTAINING SAID CRYSTAL, AND SAID WATER, AND PROPYLENE-GLYCOL MIXTURE AT A TEMPERATURE OF AT LEAST 41* C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-04-15 | 1955-10-15 | 1956-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-04-15 | 1959-10-15 | 1960-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-04-15 | 1963-10-15 | 1964-04-15 | $7700.00 | Window Closed / Lapsed |