| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Netherlands | 4 | |
| #2 | Germany | 3 | |
| #3 | United States | 2 | |
| #4 | EPO (European Patent Office) | 1 | |
| #5 | France | 1 |
| # | Industry | |
|---|---|---|
| #1 | Measurement | |
| #2 | Electrical machinery and energy | |
| #3 | Mechanical elements | |
| #4 | Control | |
| #5 | Machines | |
| #6 | Thermal processes |
| # | Name | Total Patents |
|---|---|---|
| #1 | Donkervoort Dorotheus | 6 |
| Publication | Filing date | Title |
|---|---|---|
| NL8003238A | Clamp ring. | |
| US4116380A | Control device for a central heating installation | |
| NL7601865A | Manometer with diaphragm separating liquid from pressure source - has elongated stopper with oval cross section and silicone rubber packing | |
| NL7501750A | Control device for adjusting the water temperature of a central heating boiler depending on the outdoor temperature. | |
| DE2361816A1 | PROTECTIVE AND DISPLAY METER FOR TEMPERATURE AND PRESSURE IN A HOT WATER BOILER | |
| DE1196919B | Valve with reversible pressure medium drive through a membrane and a return spring |