| Patents for Hartford Machine Screw Co. |
Patents 1 -
5
of 5
      |
| Number | Date | Patentee | Title | Type |
| 275,431 | Apr. 10, 1883 | C.M. Spencer | Metal Screw Machine | screw machines |
| 409,441 | Aug. 20, 1889 | G.E. Witherell | Machine for Dressing the Ends of Screw Blanks | nut or bolt making machines |
| 511,829 | Jan. 02, 1894 | G.E. Witherell | Turret Tool Machine | metal lathe accessories and attachments |
| 578,802 | Mar. 16, 1897 | G.E. Witherell | Thread Cutter | tap and die holders |
| 925,041 | Jun. 15, 1909 | E.R. Seward | Stop Motion for Metalworking Machines | metalworking power transmission |
