| All Patents in class 173/144 |
Patents 1 -
6
of 6
      |
| Number | Date | Patentee | Title | Type |
| 91,117 | Jun. 08, 1869 | N.B. Hadley | Improvement in machines for threading screws | screw machines |
| 112,254 | Feb. 28, 1871 | S. Ingersoll | Improvement in rock-drills | mining apparatus |
| 120,279 | Oct. 24, 1871 | S. Ingersoll | Improvement in rock-drills | mining apparatus |
| 147,402 | Feb. 10, 1874 | S. Ingersoll | Improvement in rock-drills | mining apparatus |
| RE6,292 | Feb. 16, 1875 | S. Ingersoll | Improvement in machines for drilling rock | mining apparatus |
| 1,272,345 | Jul. 09, 1918 | J. Beaudry | Drilling Machine | |
