| All Patents in class 91/33 |
Patents 1 -
6
of 6
      |
| Number | Date | Patentee | Title | Type |
| 336,604 | Feb. 23, 1886 | R.H. Tweddell, J. Fielding | Hydraulic Forging Press | forging presses |
| 1,456,014 | May 22, 1923 | F.E. Stevenson | Means for Operating Presses | hydraulic presses |
| 1,672,561 | Jun. 05, 1928 | W. Ernst | High Speed Hydraulic Press | hydraulic presses |
| 1,693,109 | Nov. 27, 1928 | W. Ernst | Semiautomatic Valve | hydraulic valves |
| 1,851,622 | Mar. 29, 1932 | W. Ernst | Valve Mechanism for Hydraulic Presses | hydraulic presses |
| 2,811,141 | Oct. 29, 1957 | A.C. Nolte, R.T. Van Coney | Control Mechanism | metal lathe mechanisms |
