US3431746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulse tube refrigeration process
Assignee: BOC Group Ltd
•
Filing: 1967-02-14
•
Granted: 1969-03-11
•
Expires: 1987-02-14
Abstract
No abstract record available.
Inventors
- 👤 Thomas J Webster
- 👤 Michael E Garrett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:08
CPC Classifications
F; F25; F25B; F25B9/00; F25B9/14; F25B9/145; F25B2309/00; F25B2309/14; F25B2309/1407; F25B2309/1408; F25B2309/1418; F25B2309/1419; F25B2309/1424
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1321343A
Cited
US1459270A
Cited
US1275507A
Cited
US3302422A
Cited
US3237421A
Cited
US3314244A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-03-10 | 1972-09-09 | 1973-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-03-10 | 1976-09-09 | 1977-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-03-10 | 1980-09-09 | 1981-03-11 | $7700.00 | Window Closed / Lapsed |