| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Germany | 11 | |
| #2 | United Kingdom | 4 | |
| #3 | United States | 2 | |
| #4 | France | 1 |
| # | Industry | |
|---|---|---|
| #1 | Textiles and paper | |
| #2 | Civil engineering | |
| #3 | Chemical engineering | |
| #4 | Environmental technology | |
| #5 | Basic materials chemistry | |
| #6 | Materials and metallurgy | |
| #7 | Mechanical elements |
| # | Technology | |
|---|---|---|
| #1 | Mechanical leather treatments | |
| #2 | Footwear manufacturing machines | |
| #3 | Separating solids using liquids | |
| #4 | Gas-flow silencers for machines | |
| #5 | Fuels | |
| #6 | Foundry moulding | |
| #7 | Mining | |
| #8 | Pipes | |
| #9 | Shafts | |
| #10 | Fire-fighting |
| # | Name | Total Patents |
|---|---|---|
| #1 | Karl Lehmann | 2 |
| #2 | Lehmann Ernst | 1 |
| #3 | Lehmann Karl | 1 |
| Publication | Filing date | Title |
|---|---|---|
| GB873248A | Ring linings for mine galleries | |
| US2275912A | System of working bedlike deposits, particularly thick beds of lignite and mineral coal | |
| GB375779A | Improvements in or relating to the manufacture of briquettes from fine coal | |
| GB348968A | Mixing and centrifuging machine for moulding substances | |
| US1854659A | Process of dressing coal | |
| GB363618A | Improved process of dressing or grading coal |