May 30, 2021
Improved Nut Tapping Machine, patented 5/30/1871.
It’s used for cutting internal threads into hexagonal nuts.
Series: Utility Patent Drawings, 1837 - 1911
Record Group 241: Records of the Patent and Trademark Office, 1836 - 1978
Image description: Line drawing of a very confusing-looking machine. As far as I can tell, there is a drill or tap that points upward, and cuts threads into hex nuts, which collect on the shaft of the tap. There are a lot of other moving parts, gears, supports, etc whose function is less clear.
