Patent US3439450A successfully refreshed from Google Patents.
US3439450A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous block for conserving soil moisture
Assignee: University of California Berkeley
•
Filing: 1965-04-08
•
Granted: 1969-04-22
•
Expires: 1985-04-08
Abstract
No abstract record available.
Inventors
- 👤 Sterling J Richards
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:52
CPC Classifications
A; A01; A01G; A01G13/00; A01G13/30; A01G13/31; A01G13/32; Y; Y02; Y02A; Y02A40/00; Y02A40/10; Y02A40/28; Y10; Y10T; Y10T428/00; Y10T428/26
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-04-21 | 1972-10-21 | 1973-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-04-21 | 1976-10-21 | 1977-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-04-21 | 1980-10-21 | 1981-04-22 | $7700.00 | Window Closed / Lapsed |