| All Patents in class 318/257 | 
| Patents 1 - 
					9
					of 9 
       | 
| Number | Date | Patentee | Title | Type | 
| 295,454 | Mar. 18, 1884 | F.J. Sprague | Electro Dynamic Motor | electric motors | 
| 320,630 | Jun. 23, 1885 | L. Daft | Electric Switch | electric switches | 
| 321,147 | Jun. 30, 1885 | F.J. Sprague | Electro Dynamic Motor | electric motors | 
| 700,310 | May 20, 1902 | R. Eickemeyer | Alternating-current electric motor and controlling means therefor |  | 
| 1,043,325 | Nov. 05, 1912 | J.C. Lincoln | Variable Speed Electric Motor | DC motors | 
| 1,053,940 | Feb. 18, 1913 | J. Burke | Universal motor | universal motors | 
| 1,144,935 | Jun. 29, 1915 | A.L. De Leeuw | Machine Tool Control | machine tool controls | 
| 2,845,589 | Jul. 29, 1958 | J.H. Osgood | Electronic Table Motor Drive Unit for Optical Comparators and the Like | comparators | 
| 3,586,949 | Jun. 22, 1971 | K.D. Spear, C.F. Raber | Three-Phase Motor Control System | motor controls |