Patent US3986528A successfully refreshed from Google Patents.
Patent US2721704A successfully refreshed from Google Patents.
US2721704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blower discharge volume control
Assignee: PERFECTION IND Inc
•
Filing: 1951-10-18
•
Granted: 1955-10-25
•
Expires: 1971-10-18
Abstract
No abstract record available.
Inventors
- 👤 Malcom W Patrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:30
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/40; F04D29/42; F04D29/44; F04D29/46; F04D29/462; F04D29/464; F04D29/4206; F04D29/4226
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US449743A
Cited
US783267A
Cited
US1965444A
Cited
US1834958A
Cited
US1956829A
Cited
US2075587A
Cited
US2156405A
Cited
US2255917A
Cited
US2308655A
Cited
US2292082A
Cited
US2385096A
Cited
US2491380A
Cited
US2478457A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-10-24 | 1959-04-25 | 1959-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-10-24 | 1963-04-25 | 1963-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-10-24 | 1967-04-25 | 1967-10-25 | $7700.00 | Window Closed / Lapsed |