| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Netherlands | 5 | |
| #2 | Australia | 2 | |
| #3 | EPO (European Patent Office) | 2 | |
| #4 | WIPO (World Intellectual Property Organization) | 2 | |
| #5 | United States | 1 |
| # | Industry | |
|---|---|---|
| #1 | Civil engineering | |
| #2 | Mechanical elements |
| # | Technology | |
|---|---|---|
| #1 | Sewers | |
| #2 | Pipes | |
| #3 | Hydraulic engineering |
| # | Name | Total Patents |
|---|---|---|
| #1 | Roggekamp Aloysius Gerardus Ma | 5 |
| #2 | Tol Johannes Van Den | 3 |
| #3 | Van Den Tol Johannes | 2 |
| #4 | Van Den Tol Johan | 1 |
| #5 | Roggekamp Aloysius Adrianus Ma | 1 |
| Publication | Filing date | Title |
|---|---|---|
| NL1021681C1 | Concrete pipe for drains or sewers, has inside wall with lower region having relatively small radius of curvature | |
| NL1013571C1 | Sewer pipe with liquid permeable mantle, especially for removing rain water, has mantle made from liquid impermeable material and containing holes | |
| NL1005336C2 | Tube. | |
| NL1004853C2 | Method for the manufacture of a ready-to-use sewer pit, as well as such a sewer pit. | |
| NL1000840C2 | Collection pit for sewers |