NIST logo

The Second Whittemore and Petrenko's Patent


On August 24, 1929 Whittemore and Petrenko filed for a second proving ring patent with the United States Patent Office. The drawings contained with the patent are shown below. They include improvements in the design of the proving ring.

Second patent for proving ring

Second patent for proving ring

*
Bookmark and Share

Contact

Tom Bartel

General Information:
301 975 6461 Telephone

100 Bureau Drive, M/S 8222
Gaithersburg, MD 20899-8222