| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Germany | 7 | |
| #2 | United States | 5 | |
| #3 | United Kingdom | 4 | |
| #4 | France | 1 | |
| #5 | Ireland | 1 |
| # | Industry | |
|---|---|---|
| #1 | Mechanical elements | |
| #2 | Materials and metallurgy | |
| #3 | Machines | |
| #4 | Textiles and paper | |
| #5 | Medical technology | |
| #6 | Machine tools |
| # | Technology | |
|---|---|---|
| #1 | Unspecified technologies | |
| #2 | Pistons and sealings | |
| #3 | Alloys | |
| #4 | Shafts | |
| #5 | Typewriters | |
| #6 | Unspecified technologies | |
| #7 | Working metallic powder | |
| #8 | Venting or aerating devices | |
| #9 | Physical therapy devices | |
| #10 | Metal-working |
| # | Name | Total Patents |
|---|---|---|
| #1 | Koehler Max | 6 |
| #2 | Max Koehler | 2 |
| Publication | Filing date | Title |
|---|---|---|
| US3618960A | Piston ring | |
| IE31320L | Pressed and sintered piston ring | |
| GB1148558A | Piston ring and process for the production thereof | |
| GB1097618A | Heat treatment of sintered iron-base materials | |
| GB1088588A | Sintered iron-base materials | |
| GB807419A | Process for the production of piston rings | |
| US2910333A | Piston ring and method of making same | |
| US2759810A | Articles of sintered iron and method of making same |