| All Patents in class 175/394 |
Patents 1 -
9
of 9
      |
| Picture | Number | Date | Patentee | Title |
 | 91,387 | Jun. 15, 1869 | A. Vaughan | Improved post auger |
| | 629,539 | Jul. 25, 1899 | J. Bertram | Boring and excavating implement |
| | 880,140 | Feb. 25, 1908 | B. Hastings | Drilling Machine |
| | 2,349,033 | May 16, 1944 | N.R. Elliott | Boring Head |
 | 2,673,714 | Mar. 30, 1954 | J.M. Hargrave | Rock or masonry drill |
| | 2,863,640 | Dec. 09, 1958 | G.A. Petersen | Offset Boring Head for Auger |
| | 2,919,902 | Jan. 05, 1960 | M.J. Steffes | Masonry drill |
| | 2,969,122 | Jan. 24, 1961 | M.J. Steffes | Masonry drill |
 | 4,595,322 | Jun. 17, 1986 | B. Clement | Spade drill bit |
