| All Patents in class 408/194 |
Patents 1 -
15
of 32
      |
| Number | Date | Patentee | Title | Type |
| 9,398 | Nov. 16, 1852 | C.L. Barnes | Expanding bit | adjustable drill bits |
| 10,872 | May 02, 1854 | A. Weeks | Expansion-bit | adjustable drill bits |
| 17,038 | Apr. 14, 1857 | A. Hall | Expansive bit | adjustable drill bits |
| 20,192 | May 11, 1858 | W.A. Clark | Method of seating the movable cutter in expansive bits | adjustable drill bits |
| 21,597 | Sep. 28, 1858 | W.A. Clark | Expansive bit | adjustable drill bits |
| 22,195 | Nov. 30, 1858 | M. Norris | Auger for wood | adjustable drill bits |
| RE3,516 | Jun. 22, 1869 | W.A. Clark | Improvement in expansive bits | adjustable drill bits |
| RE3,733 | Nov. 16, 1869 | W.A. Clark | Improvement in expansive bits | adjustable drill bits |
| RE4,668 | Dec. 12, 1871 | W.A. Clark | Improvement in expansive bits | adjustable drill bits |
| 131,946 | Oct. 08, 1872 | E. Ford | Improvement in expansive bits | adjustable drill bits |
| 269,406 | Dec. 19, 1882 | P.A. Gladwin | Auger | adjustable drill bits |
| 313,735 | Mar. 10, 1885 | G.H. Hill | Expansible bit | adjustable drill bits |
| 360,990 | Apr. 12, 1887 | C.E. Billings | Expansive bit | adjustable drill bits |
| 415,988 | Nov. 26, 1889 | W.S. Whiting | Extension-bit | adjustable drill bits |
| 458,091 | Aug. 18, 1891 | C. Beauchene | Expansion-Bit | adjustable drill bits |
