| All Patents in class 451/117 |
Patents 46 -
60
of 64
      |
| Number | Date | Patentee | Title | Type |
| 1,425,684 | Aug. 15, 1922 | T.A. Parmenter | Valve Grinding Tool and the Like | valve grinding tools |
| 1,441,032 | Jan. 02, 1923 | J.W. Schab | Valve Grinder | valve grinding tools |
| 1,450,788 | Apr. 03, 1923 | W.S. Bellows | Valve Grinding Tool | valve grinding tools |
| 1,468,055 | Sep. 18, 1923 | W.I. Tuttle | Valve-Grinding Apparatus | valve grinding tools |
| 1,471,769 | Oct. 23, 1923 | C.H. Beach | Valve Grinder | valve reseating machines |
| 1,475,153 | Nov. 20, 1923 | H. Athenas | Portable electric combination drill | handheld power drills |
| 1,503,206 | Jul. 29, 1924 | A.W. Ojerholm | Combination valve grinder and drill | valve and seat maintenance |
| 1,518,579 | Dec. 09, 1924 | O.D. Hapgood | Valve-grinding tool | |
| 1,553,871 | Sep. 15, 1925 | D.W. Means | Valve Grinding Tool | valve grinding tools |
| 1,564,017 | Dec. 01, 1925 | J.C. Pewther | Valve Grinder | valve grinding tools |
| 1,591,400 | Jul. 06, 1926 | J. Orawiec | Valve Grinding Tool | valve grinding tools |
| 1,707,572 | Apr. 02, 1929 | L.G. Roller | Valve Grinder | valve grinding tools |
| 1,709,428 | Apr. 16, 1929 | J.H. Carpenter | Valve grinder | handheld power tools |
| 1,749,300 | Mar. 04, 1930 | E.H. Peterson, W.H. Odlum | Valve grinder | |
| 1,808,856 | Jun. 09, 1931 | F.W. Miller | Valve Grinder | valve grinding tools |
