| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United States | 6 | |
| #2 | Germany | 4 | |
| #3 | United Kingdom | 4 | |
| #4 | Canada | 3 |
| # | Industry | |
|---|---|---|
| #1 | Engines, pumps and turbines | |
| #2 | Machines |
| # | Technology | |
|---|---|---|
| #1 | Rotary pistons | |
| #2 | Internal-combustion piston engines | |
| #3 | Unspecified technologies |
| # | Name | Total Patents |
|---|---|---|
| #1 | Hoffmann Ralph M | 10 |
| #2 | Hoffmann Benjamin | 3 |
| #3 | Hoffmann Ralph | 1 |
| Publication | Filing date | Title |
|---|---|---|
| US4728270A | Apparatus and method for replacing apex seals in a rotary device | |
| US4551083A | Dual rotor gear assembly for trochoidal rotary device | |
| US4395206A | Seal compensated geometry rotary motion device | |
| US4382755A | Driveshaft arrangement for trochoidal rotary device | |
| US4400145A | Driveshaft arrangement for a rotary expansible chamber device | |
| US4297090A | Rotary expansion power unit with valve disc connected to crankshaft |