Patent · US Expired

Combined keyboard and electronic learning aid

USD318491S · kind S · design

0Cited by
9References
1Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 15, 1988
Grant dateJul 23, 1991
Priority date
Expiry dateJul 23, 2005

Classification

  • Technology area (CPC —)General

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.