Patent Explorer
Browse, filter, and analyze 2 patents across global jurisdictions.
| Patent Number | Title | Assignee | Status | Filing Date | Grant Date | Expires | Remaining | Claims | Actions |
|---|---|---|---|---|---|---|---|---|---|
| US3484950A | Teaching machine | Educational Testing Service | Expired / Lapsed | 1968-06-12 | 1969-12-23 | 1988-06-12 | 0.0 yrs | 0 | |
| US3382588A | Response expression apparatus for teaching machines | Educational Testing Service | Expired / Lapsed | 1965-01-11 | 1968-05-14 | 1985-01-11 | 0.0 yrs | 1 |