| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Germany | 4 | |
| #2 | United States | 3 | |
| #3 | Netherlands | 2 | |
| #4 | South Africa | 2 | |
| #5 | Australia | 1 | |
| #6 | France | 1 | |
| #7 | United Kingdom | 1 |
| # | Industry | |
|---|---|---|
| #1 | Mechanical elements | |
| #2 | Machines | |
| #3 | Materials and metallurgy | |
| #4 | Packaging and shipping | |
| #5 | Machine tools | |
| #6 | Civil engineering |
| # | Technology | |
|---|---|---|
| #1 | Pipes | |
| #2 | Unspecified technologies | |
| #3 | Metal tempering | |
| #4 | Transport or storage devices | |
| #5 | Soldering, welding and flame cutting | |
| #6 | Safety devices |
| # | Name | Total Patents |
|---|---|---|
| #1 | Esser Alexander | 9 |
| #2 | Siller Vinzenz | 1 |
| #3 | Esser Hans Prof Dr-Ing Dr | 1 |
| #4 | Schulenburg G | 1 |
| #5 | Kuehme E | 1 |
| Publication | Filing date | Title |
|---|---|---|
| DE3148498A1 | "DOUBLE-WALLED TUBE FOR SOLID TRANSPORT AND METHOD FOR PRODUCING SUCH A TUBE" | |
| DE3140936A1 | Process and device for hardening the inside of a two-ply steel pipe | |
| DE3034800A1 | Pneumatic or hydraulic transport pipe - with accurately aligned welded flange and flanged spigot on middle part | |
| US4030711A | Method and apparatus for the surface hardening of the inner surface of tube bends |