| All Patents in class 408/157 |
Patents 1 -
9
of 9
      |
| Number | Date | Patentee | Title | Type |
| 10,872 | May 02, 1854 | A. Weeks | Expansion-bit | adjustable drill bits |
| 115,291 | May 30, 1871 | L.R. Faught | Improvement in die-stocks for cutting screws | taps and dies |
| 1,713,646 | May 21, 1929 | G.H. Deyo | Boring Head | boring heads |
| 1,769,230 | Jul. 01, 1930 | H.H. Manning | Rotary cutter | boring bars |
| 2,223,041 | Nov. 26, 1940 | T. Maxwell | Boring Head | boring heads |
| 2,605,655 | Aug. 05, 1952 | E.J. Kaiser | Boring Cutter | boring heads |
| 3,256,755 | Jun. 21, 1966 | W. Kraus | Adjustable Boring Head | boring heads |
| 4,162,867 | Jul. 31, 1979 | D.W. Barton, R.A. Rhinefrank, D.J. Calcaterra | Dual Cutter Boring Head | boring heads |
| 4,242,018 | Dec. 30, 1980 | H. Schürfeld | Boring Tool | |
