| All Patents in class 91/420 |
Patents 1 -
9
of 9
      |
| Number | Date | Patentee | Title | Type |
| 1,285,475 | Nov. 19, 1918 | W. Turnwald | Automatic exhaust-valve | steam engine valves |
| 1,892,568 | Dec. 27, 1932 | W. Ernst | Surge Valve for Hydraulic Presses or the Like | hydraulic presses |
| 2,077,894 | Apr. 20, 1937 | I. Patrick | Surge control valve for hydraulic presses | hydraulic metalworking presses |
| 2,286,880 | Jun. 16, 1942 | W.A. Traut | Hydraulic Control System | |
| 2,444,474 | Jul. 06, 1948 | B.R. Purvin | Fluid pressure device | |
| 2,501,387 | Mar. 21, 1950 | G. Haumann | Veneer lathe | veneer machines |
| 2,730,074 | Jan. 10, 1956 | W. Ernst | Servo-motor valve | hydraulic apparatus |
| 2,951,342 | Sep. 06, 1960 | H.E. Boyer, N.V. Gusching, W.H. Ulman, D.E. Lundeen | Electro-hydraulic servo system | |
| 6,988,363 | Jan. 24, 2006 | M. Bitter | Hydraulic Active Boom Suspension for a Telehandler | telehandlers and lifts |
