Patent US3852207A successfully refreshed from Google Patents.
Patent US3634836A successfully refreshed from Google Patents.
Patent US3580868A successfully refreshed from Google Patents.
Patent US1382149A successfully refreshed from Google Patents.
Patent US1766355A successfully refreshed from Google Patents.
← Back to Patent Explorer
US1766355A Expired / Lapsed US ⏱️ 0.0 years remaining

Educational apparatus

Assignee: Central Scientific Co
•
Filing: 1928-05-31
•
Granted: 1930-06-24
•
Expires: 1948-05-31
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

No abstract record available.

Inventors

  • 👤 Sterling L Redman

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 14:08
CPC Classifications
G; G09; G09B; G09B23/00; G09B23/06; G09B23/08; G09B23/10

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) 1933-06-23 1933-12-23 1934-06-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1937-06-23 1937-12-23 1938-06-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1941-06-23 1941-12-23 1942-06-24 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag