| All Patents in class 74/421A |
Patents 1 -
10
of 23
      |
| Picture | Number | Date | Patentee | Title |
 | 14,327 | Feb. 26, 1856 | J. Temple | Boring-machine |
| | 595,731 | Dec. 21, 1897 | M.B. Pengnet | Electric motor |
 | 693,837 | Feb. 25, 1902 | W.E. Canedy | Motor-gearing |
| | 805,499 | Nov. 28, 1905 | S.D. Stoycheff | Electric drill |
 | 1,104,736 | Jul. 21, 1914 | F. Schneider | Gearing |
 | 1,109,325 | Sep. 01, 1914 | W.O. Duntley | Electric drill |
| | 1,142,357 | Jun. 08, 1915 | R.A. Norling | Transmission gearing |
 | 1,356,297 | Oct. 19, 1920 | A.T. Lochner | Power-hammer |
| | 1,497,513 | Jun. 10, 1924 | G.L. Kelley | Machine for operating on floors or other surfaces |
 | 1,679,884 | Aug. 07, 1928 | H.T. Thomas | Attachment for drills |
