US3500635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas pressure producing apparatus
Assignee: JOHN H ROPER
•
Filing: 1968-04-11
•
Granted: 1970-03-17
•
Expires: 1988-04-11
Abstract
No abstract record available.
Inventors
- 👤 John H Roper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:14
CPC Classifications
F; F04; F04B; F04B41/00; F04B41/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US355594A
Cited
US1111556A
Cited
US1143395A
Cited
US1327769A
Cited
US1414993A
Cited
US1516857A
Cited
US3216181A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-03-16 | 1973-09-15 | 1974-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-03-16 | 1977-09-15 | 1978-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-03-16 | 1981-09-15 | 1982-03-17 | $7700.00 | Window Closed / Lapsed |