US2561520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuumtight seal for electrical apparatus and method of forming such seals
Assignee: Hartford National Bank and Trust Co
•
Filing: 1947-07-03
•
Granted: 1951-07-24
•
Expires: 1967-07-03
Abstract
No abstract record available.
Inventors
- 👤 Lemmens Hendricus Johannes
- 👤 Dorgelo Eduard Gerardus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:31
CPC Classifications
C; C03; C03C; C03C27/00; C03C27/02; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US789515A
Cited
US1768869A
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US2138660A
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GB463889A
Cited
US2248644A
Cited
US2156988A
Cited
US2313025A
Cited
US2197562A
Cited
GB520635A
Cited
US2301940A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-07-23 | 1955-01-22 | 1955-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-07-23 | 1959-01-22 | 1959-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-07-23 | 1963-01-22 | 1963-07-24 | $7700.00 | Window Closed / Lapsed |