| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Switzerland | 5 | |
| #2 | France | 4 | |
| #3 | Germany | 3 | |
| #4 | Canada | 2 | |
| #5 | United Kingdom | 2 |
| # | Industry | |
|---|---|---|
| #1 | Audio-visual technology | |
| #2 | Electrical machinery and energy | |
| #3 | Control |
| # | Technology | |
|---|---|---|
| #1 | Special information storage | |
| #2 | Electrically-conductive connections | |
| #3 | Electric motor controls | |
| #4 | Coin-freed |
| # | Name | Total Patents |
|---|---|---|
| #1 | Etablissements Igra | 5 |
| #2 | Rebikoff Wassily | 2 |
| Publication | Filing date | Title |
|---|---|---|
| GB334825A | Improved control device for the electrical driving mechanism of phonographs | |
| GB308589A | Sparkless commutator chiefly for phonograph motors | |
| CA301670A | Device for keeping constant the speed of electrically driven phonographs | |
| CA295969A | Sparkless commutator |