US3421688A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid sealed mechanical vacuum pumps
Assignee: Edwards High Vacuum International Ltd
•
Filing: 1967-03-13
•
Granted: 1969-01-14
•
Expires: 1987-03-13
Abstract
No abstract record available.
Inventors
- 👤 Eric Spooner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 00:08
CPC Classifications
F; F04; F04C; F04C29/00; F04C29/12; F04C29/124; F04C29/126; F04C29/128; F04C27/00; F04C27/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2118356A
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US2929550A
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US2928588A
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US3053439A
Cited
US3042292A
Cited
US3151808A
Cited
US3130902A
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US3360193A
Cited
US3355095A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-01-14 | 1972-07-15 | 1973-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-01-14 | 1976-07-15 | 1977-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-01-14 | 1980-07-15 | 1981-01-14 | $7700.00 | Window Closed / Lapsed |