| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Germany | 5 | |
| #2 | United Kingdom | 5 | |
| #3 | Belgium | 4 | |
| #4 | France | 4 | |
| #5 | Netherlands | 4 | |
| #6 | United States | 3 | |
| #7 | Australia | 2 | |
| #8 | Canada | 2 | |
| #9 | Denmark | 1 | |
| #10 | Spain | 1 | |
| #11 | Italy | 1 | |
| #12 | Japan | 1 |
| # | Industry | |
|---|---|---|
| #1 | Thermal processes | |
| #2 | Electrical machinery and energy |
| # | Technology | |
|---|---|---|
| #1 | Fluid heaters | |
| #2 | Casings for combustion chambers | |
| #3 | Controlling combustion | |
| #4 | Burners | |
| #5 | Heat-exchange device details | |
| #6 | Steam generation | |
| #7 | Electric discharge tubes |
| # | Name | Total Patents |
|---|---|---|
| #1 | Widdershoven Louis Hubertus | 6 |
| #2 | Widdershoven Louis H | 4 |
| #3 | Widdershoven L H | 2 |
| #4 | Ruisu Fuubaatousu Uiderushiyoo | 1 |
| #5 | Hubertus Widdershoven Louis | 1 |
| Publication | Filing date | Title |
|---|---|---|
| JPS5595022A | Gas combustion boiler | |
| GB2005392A | Gas-fired boiler installation with draft inerrupter | |
| CA1062100A | Gas-fired boiler | |
| GB1564939A | Gas-fired boilers | |
| NL165839C | Heat exchanger. | |
| GB1350964A | Steam generating apparatus |