| All Patents in class 137/536 |
Patents 1 -
6
of 6
      |
| Number | Date | Patentee | Title | Type |
| 123,546 | Feb. 13, 1872 | H.G. Ashton | Improvement in Lock Safety-Valves for Steam-Boilers | steam safety valves |
| 301,079 | Jul. 01, 1884 | H.G. Ashton | Safety-Valve | steam safety valves |
| 631,370 | Aug. 22, 1899 | J. Hughes | Safety Valve and Muffler | steam safety valves |
| 794,034 | Jul. 04, 1905 | F.A. Hannah, J.H. Millett | Steam Safety Valve | steam safety valves |
| 1,020,921 | Mar. 19, 1912 | E.F. Miller | Safety Valve | steam safety valves |
| 1,949,930 | Mar. 06, 1934 | K.S. Davidson | Steam Valve | steam safety valves |
