In business by 1910, Joseph Weidenhoff, Inc. was a manufacture of electrical test equipment, particularly equipment for use in repairing and maintaining motor vehicles. During their heyday from the 1930s until the mid-1950s they were the largest maker of automotive electrical test equipment in the United States. They also made, or put their name on, lathes that were likely intended for use in an automotive repair shop.

Automotive test equipment is not of interest to this Vintage Machinery website, but Joseph Weidenhoff, Inc., also manufactured electric motors, which are of interest to us.

Joseph Weidenhoff, Inc., was reportedly acquired by Snap-On, Inc. in 1956.

Information Sources

• More information can be found on the lathes.co.uk page on Weidenhoff lathes.
• A 1938 decision of the Federal Trade Commision, In the matter of Joseph Weidenhoff, Inc., involves patent 1,323,531 for the use of a vacuum gauge on an engine's intake manifold. Joseph Weidenhoff Inc., provided such a patent vacuum gauge as a relatively minor component in several motor analyzer products they sold. They then entered into "agreements and understandings between itself and other manufacturers or distributors of such devices to fix and maintain prices to be extracted from purchasers thereof...through threatened infringement suits based on said patented vacuum gauge...Each of said license agreements...did not confine itself either to the use of the said vacuum gauge...but included the complete testing devices with all of their separate and unrelated parts and items in now way covered by respondent's said patent.". The FTC found that the Weidenhoff company had engaged in anti-competitive practices and issued a cease-and-desist order. The decision provides some useful information on the company. "Respondent manufactures and sells approximately $450,000 of these testing devices annually, being considerably the largest manufacturer and distributor of testing devices of that and similar character in the United States." The report identifies six competitors in this market, including Allen Electric & Equipment Co., Electric Heat Control Co. of Cleveland, Sun Manufacturing Co. of Chicago, and Stromberg Motor Corp. of Chicago.
• A history of Joseph Weidenhoff, Inc., plus several ads, are available via a Garage Journal discussion.