| Patents for Frank Douglas |
Patents 1 -
10
of 11
      |
| Picture | Number | Date | Patentee | Title |
 | 27,040 | Feb. 07, 1860 | F. Douglas | Improved steam-trap |
 | 27,704 | Apr. 03, 1860 | F. Douglas | Improved steam-trap |
 | 39,799 | Sep. 08, 1863 | F. Douglas | Improvement in governors for steam-engines |
 | 39,800 | Sep. 08, 1863 | F. Douglas | Improvement in skate-fastenings |
 | 77,013 | Apr. 21, 1868 | F. Douglas | Improvement in wood-planing machines |
 | 78,728 | Jun. 09, 1868 | F. Douglas | Spindle for shaper or molder |
 | 81,761 | Sep. 01, 1868 | F. Douglas | Improvement in machine for turning rods |
 | 95,782 | Oct. 12, 1869 | F. Douglas | Planing and molding machine |
 | 105,657 | Jul. 26, 1870 | F. Douglas | Improvement in planing and molding-machine |
 | 106,139 | Aug. 09, 1870 | F. Douglas | Improvement in planing-machines |
