| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Germany | 16 | |
| #2 | Switzerland | 4 | |
| #3 | France | 2 | |
| #4 | United Kingdom | 1 |
| # | Industry | |
|---|---|---|
| #1 | Electrical machinery and energy | |
| #2 | Control | |
| #3 | Telecommunications | |
| #4 | Machines | |
| #5 | Transport |
| # | Name | Total Patents |
|---|---|---|
| #1 | Rozumek Dipl-Ing Ernst | 5 |
| #2 | Birka Regulator G M B H | 4 |
| #3 | Rozumek Ernst | 2 |
| #4 | Ernst Rozumek | 2 |
| #5 | Doenges Walther | 1 |
| #6 | Ernst Rozumek Dipl Ing | 1 |
| #7 | Dipl Rozumek Ernst Ing | 1 |
| Publication | Filing date | Title |
|---|---|---|
| GB390151A | Method of cleaning the contact members and other metal parts in electric switches operating in evacuated containers |