| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Austria | 11 | |
| #2 | Switzerland | 8 | |
| #3 | Canada | 4 | |
| #4 | Denmark | 3 |
| # | Industry | |
|---|---|---|
| #1 | Transport |
| # | Technology | |
|---|---|---|
| #1 | Vehicle brake control systems |
| # | Name | Total Patents |
|---|---|---|
| #1 | Drolshammer Ivar | 20 |
| #2 | Ivar Drolshammer | 6 |
| Publication | Filing date | Title |
|---|---|---|
| CA260107A | Railway brake | |
| CA241537A | Pneumatic brake | |
| CA271486A | Valve mechanism for compressed air brakes | |
| CA249473A | Valve mechanism for railway brakes |