from the Alloy Artifacts link JAFE posted earlier
Park Metalware Company
Park Metalware was a small tool maker operating in Orchard Park, New York. During the 1920s the company developed and patented a line of interchangeable open-end wrenches, and produced other tools including the adjustable drain-plug wrench shown below.
Park sold its tools under the XCEL brand, and later used the brand name Xcelite for a line of screwdrivers and nut drivers. The Xcelite brand continues today as part of the Cooper Tools conglomerate.
Park Metalware Adjustable Drain-Plug Wrench
Fig. 100 shows a Park adjustable socket wrench for drain-plug service, marked "Park Metalware Co." and "Orchard Park, N.Y. U.S.A." on the rotating handle, though the markings are very faint due to wear and rust.
The overall length (when retracted) is 7.8 inches, and the finish is plain steel.
Although not marked on this example, this wrench design is covered by patent #1,639,831, issued to J. Zilliox in 1927.
Readers familiar with our Blackhawk article will undoubtedly recognize the similarities between this tool and the Blackhawk 151 "Adjusto" Wrench shown in that article. The Park tool preceded the Blackhawk model by some number of years, and clearly must have influenced the Blackhawk design.