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The Whittmore and Petrenko Drawings


Whittemore and Petrenko submitted a patent for their
proving ring, number 1648375, to the United States Patent
Office on September 14, 1926. The patent was granted on
November 8, 1927. The drawings shown below were part of
the original submission.

patent for proving ring

patent for proving ring

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Tom Bartel

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301 975 6461 Telephone

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