| All Patents in class 451/220 |
Patents 1 -
15
of 18
      |
| Number | Date | Patentee | Title | Type |
| 197,711 | Nov. 27, 1877 | E.J. Worcester | Improvement in machines for grinding lawn-motor cutter | grinders |
| 230,715 | Aug. 03, 1880 | I.L. Penney | Grinding Twist Drills | tool grinders |
| 324,669 | Aug. 18, 1885 | O.C. Donecker | Wood-fluting mechanism | routing machines |
| 407,577 | Jul. 23, 1889 | J.D. Cox, Jr. | Machine for back-clearing twist-drills | tool making machines |
| 418,977 | Jan. 07, 1890 | C.E. Forry | Machine for Grinding Lawn Mower Knives | sharpening machines |
| 626,436 | Jun. 06, 1899 | E. Mills | Grinding Machine | tool grinders |
| 636,540 | Nov. 07, 1899 | S.E. Louden | Device for Holding Lawn Mower Cutters for Sharpening | metal lathe accessories and attachments |
| 709,178 | Sep. 16, 1902 | S.C. Schofield | Tool Holder and Guide for Grindstones | grinding machines |
| 1,075,285 | Oct. 07, 1913 | A.L. De Leeuw | Cutter Setting Dial | tool grinders |
| 1,274,502 | Aug. 06, 1918 | O.S. Bickford | Machine for Flutiing Twist Drill Blanks | making drills and augers |
| 1,287,732 | Dec. 17, 1918 | F. Müller | Machine for Milling Knurls | embossing and knurling machines |
| 1,658,185 | Feb. 07, 1928 | R.L. Carter | Tool-grinding mechanism | woodworking machine sharpening mechanisms |
| 2,212,855 | Aug. 27, 1940 | W.N. Chittenden | Combination Tool Head and Grinding Mechanism | tool grinders |
| 2,768,478 | Oct. 30, 1956 | C.E. Waller | Pattern Controlled Cutter Grinder | tool grinders |
| 2,805,522 | Sep. 10, 1957 | T.S. Dayton | Apparatus for Sharpening Wood Bits | drill sharpening machines |
