US3540530A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gradated heat exchange fins
Assignee: Peerless of America Inc
•
Filing: 1968-06-12
•
Granted: 1970-11-17
•
Expires: 1988-06-12
Abstract
No abstract record available.
Inventors
- 👤 Richard W Kritzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:07
CPC Classifications
F; F28; F28F; F28F1/00; F28F1/10; F28F1/12; F28F1/122; F28F1/14; F28F1/16; F28F1/24; F28F1/26; Y; Y10; Y10S; Y10S165/00; Y10S165/908; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49377; Y10T29/49378
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-11-16 | 1974-05-18 | 1974-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-16 | 1978-05-18 | 1978-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-16 | 1982-05-18 | 1982-11-17 | $7700.00 | Window Closed / Lapsed |