| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Netherlands | 4 | |
| #2 | Germany | 3 | |
| #3 | France | 3 | |
| #4 | United Kingdom | 3 | |
| #5 | Italy | 3 | |
| #6 | Canada | 2 | |
| #7 | Japan | 2 | |
| #8 | Spain | 1 | |
| #9 | United States | 1 |
| # | Industry | |
|---|---|---|
| #1 | Mechanical elements | |
| #2 | Machines |
| # | Technology | |
|---|---|---|
| #1 | Venting or aerating devices | |
| #2 | Unspecified technologies | |
| #3 | Pistons and sealings |
| # | Name | Total Patents |
|---|---|---|
| #1 | Weevers Henri H | 2 |
| #2 | Mokveld Nicolaas Jacobus | 2 |
| #3 | Mokveld Nicolaas J | 1 |
| #4 | Weevers Henri Herman | 1 |
| #5 | Nikoraasu Yakobusu Mookubuerut | 1 |
| #6 | Henri Heruman Ueebuaasu | 1 |
| #7 | Herman Weevers Henri | 1 |
| Publication | Filing date | Title |
|---|---|---|
| DE2929389A1 | CONTROL VALVE | |
| DE2821255A1 | NON-RETURN VALVE IN THE FORM OF A PISTON SLIDE | |
| GB1466017A | Non-return valve | |
| ES358850A1 | Fluid pressure control valve |