| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Canada | 2 | |
| #2 | United States | 2 | |
| #3 | Austria | 1 | |
| #4 | Australia | 1 | |
| #5 | Brazil | 1 | |
| #6 | China | 1 | |
| #7 | Denmark | 1 | |
| #8 | EPO (European Patent Office) | 1 | |
| #9 | United Kingdom | 1 | |
| #10 | Hungary | 1 | |
| #11 | India | 1 | |
| #12 | Republic of Korea | 1 | |
| #13 | Netherlands | 1 | |
| #14 | Norway | 1 | |
| #15 | Singapore | 1 | |
| #16 | WIPO (World Intellectual Property Organization) | 1 |
| # | Industry | |
|---|---|---|
| #1 | Civil engineering |
| # | Technology | |
|---|---|---|
| #1 | Earth drilling |
| # | Name | Total Patents |
|---|---|---|
| #1 | Dudman Roy L | 14 |
| #2 | Dudman Roy Leiand | 1 |
| Publication | Filing date | Title |
|---|---|---|
| US5154243A | Bent sub | |
| US4760889A | High bending strength ratio drill string components |