Patent:US2910786
Patent: | US 2910786 |
Titel: | Calculating device for teaching arithmetic |
Datum: | 03.11.1959 |
Ort: | |
Land: | USA |
Person: | Howard Healey, Cohn Irwin |
Firma: | Great American Plastics Co |
Links im Rechnerlexikon: | |
Schlagworte: | |
Link zum Patentamt: (ohne Garantie) | US2910786 (espacenet), US2910786 (uspto) |
- DATUM: 03.11.1959
- TITEL: Calculating device for teaching arithmetic
- PERSON: GREAT AMERICAN PLASTICS CO