| All Patents in class 91/459 |
Patents 1 -
9
of 9
      |
| Picture | Number | Date | Patentee | Title |
 | 255,236 | Mar. 21, 1882 | C.E. Ball | Electric drill |
| | 558,749 | Apr. 21, 1896 | G.L. Thomas | Electrically Controlled Gas Engine or Motor |
| | 1,927,583 | Sep. 19, 1933 | W. Ernst | Hydraulic Motor Control Means |
 | 2,148,348 | Feb. 21, 1939 | W.F. Groene, H.J. Siekmann | Turret lathe |
| | 2,605,751 | Aug. 05, 1952 | R.D. Baumgardner, R.D. Perry | Fluid Pressure Tool Slide Control Assembly |
 | 2,778,342 | Jan. 22, 1957 | H.W. Ringman | Poppet type valve distributing system for a servo-motor |
| | 2,840,956 | Jul. 01, 1958 | C.M. Grinage | Grinding Machine |
| | 2,951,342 | Sep. 06, 1960 | H.E. Boyer, N.V. Gusching, W.H. Ulman, D.E. Lundeen | Electro-hydraulic servo system |
| | 4,790,233 | Dec. 13, 1988 | L.W. Durham, B.S. Backe | Method and Apparatus for Controlling Hydraulic Systems |
