Patent Explorer
Browse, filter, and analyze 2 patents across global jurisdictions.
| Patent Number | Title | Assignee | Status | Filing Date | Grant Date | Expires | Remaining | Claims | Actions |
|---|---|---|---|---|---|---|---|---|---|
| US2321812A | Tape driving system for magnetic sound recording machines and the like | Heller | Expired / Lapsed | 1940-11-19 | 1943-06-15 | 1960-11-19 | 0.0 yrs | 0 | |
| US2213631A | Method of and apparatus for magnetically recording sound | Heller | Expired / Lapsed | 1937-10-25 | 1940-09-03 | 1957-10-25 | 0.0 yrs | 0 |