| Year | Patent Download | Comment | Title | Engine type |
|---|---|---|---|---|
| 1865 | Baldwin patent #46,320 | Improvement in Hot Air Engines | ||
| 1865 | Baldwin patent #48,639 | Improvement in Hot Air Engines | ||
| 1884 | Baldwin patent #292,400 | Hot Air Engine | ||
| 1887 | Baldwin patent #355,633 | Hot Air Engine | ||
| 1887 | Baldwin patent #404,818 | Air Engine |