US2972971A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of drawing door knobs
Assignee: HILLGREN Manufacturing CO
•
Filing: 1955-07-18
•
Granted: 1961-02-28
•
Expires: 1975-07-18
Abstract
No abstract record available.
Inventors
- 👤 Carl C Hillgren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:13
CPC Classifications
B; B21; B21D; B21D26/00; B21D26/02; B21D26/033; B21D26/045; B21D26/047
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
GB190009889A
Cited
US795020A
Cited
US1766098A
Cited
US2210437A
Cited
US2592867A
Cited
US2407855A
Cited
US2493053A
Cited
US2688297A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-02-28 | 1964-08-29 | 1965-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-02-28 | 1968-08-29 | 1969-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-02-28 | 1972-08-29 | 1973-02-28 | $7700.00 | Window Closed / Lapsed |