Title:
Educational device
Document Type and Number:
United States Patent 2476580


Inventors:
Jack, Bergman
      Plaque It!

Sponsored by:
Flash of Genius
Publication Date:
07/19/1949
View Patent Images:
Images are available in PDF form when logged in. To view PDFs, Login  or  Create Account (Free!)
Export Citation:
Click for automatic bibliography generation
Assignee:
Jack, Bergman
Primary Class:
434/206
Other Classes:
273/143R
International Classes:
G09B19/02
US Patent References:
0069482
0198934
0209416
0238122
0296900
0412489
0845276
0924406
1052460
1159133
1256224
1536119Demonstrating index device
1581390Educational device
2152777Indicator mechanism for educational purposes
2342325Counter unit mechanism
Foreign References:
GB246174A
DE420775C
DE450877C
FR502263A