Patent US3536391A successfully refreshed from Google Patents.
US3536391A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flare control shield for an overhead projector
Assignee: 3M Co
•
Filing: 1968-03-04
•
Granted: 1970-10-27
•
Expires: 1988-03-04
Abstract
No abstract record available.
Inventors
- 👤 Raymond H Anderson
- 👤 Roger H Appeldorn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:30
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/132; Y; Y10; Y10S; Y10S353/00; Y10S353/06
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US3126786A
Cited
US703858A
Cited
US1333033A
Cited
US1662693A
Cited
US1708776A
Cited
US2034441A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-10-26 | 1974-04-27 | 1974-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-10-26 | 1978-04-27 | 1978-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-10-26 | 1982-04-27 | 1982-10-27 | $7700.00 | Window Closed / Lapsed |