| All Patents in class 451/252 |
Patents 1 -
10
of 11
      |
| Picture | Number | Date | Patentee | Title |
 | 1,445,875 | Feb. 20, 1923 | R.W. Ellingham, C.E. Van Norman | Grinding machine |
| | 1,659,220 | Feb. 14, 1928 | C. Booth, C.O. Smith | Centerless Grinding |
| | 1,816,171 | Jul. 28, 1931 | C. Booth | Valve Grinder |
| | 1,938,764 | Dec. 12, 1933 | H. Fritschi, F.S. Haas | Grinding Machine |
| | 1,949,345 | Feb. 27, 1934 | H.H. Asbridge | Grinding or abrading machine |
| | 2,120,198 | Jun. 07, 1938 | R.G. Anderson, J.Y. Blazek | Valve grinder |
 | 2,136,188 | Nov. 08, 1938 | L. Spraker, G.R. Gagne | Valve Refacing Device |
 | 2,746,758 | May 22, 1956 | A.M. Stoner, G.S. Haviland | Chucks |
| | 3,378,960 | Apr. 23, 1968 | W.B. Seidel | Machine Tool Workpiece Driving Mechanism |
 | 4,987,701 | Jan. 29, 1991 | M.H. Humbert | Endless belt valve grinder |
