| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United Kingdom | 4 | |
| #2 | Germany | 3 | |
| #3 | United States | 2 | |
| #4 | Switzerland | 1 | |
| #5 | France | 1 |
| # | Industry | |
|---|---|---|
| #1 | Engines, pumps and turbines | |
| #2 | Machines | |
| #3 | Environmental technology |
| # | Name | Total Patents |
|---|---|---|
| #1 | Felix Gruebler | 3 |
| #2 | Gruebler Felix | 1 |
| Publication | Filing date | Title |
|---|---|---|
| GB388494A | Improvements in or relating to internal combustion engines | |
| US2018848A | Internal combustion engine | |
| GB294185A | Improvements in four-stroke internal combustion engines for use in high altitudes | |
| GB218160A | Improvements in or relating to two-stroke cycle internal combustion engines | |
| GB141349A | Improvements relating to the operation of internal combustion engines at various altitudes | |
| US1720414A | Method and means for working combustion engines at variable elevations |