Around 1920, a French patent was published in the name of Leon Hatot, which described the principle of a clock powered by the pendulum using electromagnetism. The so called ATO principle. There should have been two names in the patent application, Leon Hatot and Marius Lavet. Lavet worked very closely with Leon Hatot. Incidentally, the first “automatic watch” came from this extremely fruitful collaboration between the two gentlemen, i.e. a watch that was only wound up by the movement while wearing it.
Around 1924 Hatot granted a license to the Haller & Benzing company to build and sell the ATO clocks. H&B was the first company in the Germany to manufacture clocks under this license. However, Hatot’s clockwork had to be obtained from Hatot’s factory in France, only the rest was added in Germany. This type of clock also received other options and they were further developed. Clock systems were created that could operate up to 160 slave clocks. After H&B went bankrupt in May 1929, the license for Hatot’s ATO clocks was transferred to HAU (Hamburg-American Watch Factory). However, just for a very short time. Around 1930 the depression hit hard in Germany and created extreme financial problems. The HAU factory was converted into an limited company and joined forces with a few other manufacturers in order to survive. Eventually with a hostile take-over Junghans took ownership of HAU, by simply buying the outstanding shares of HAU, and presented the owner with a fait accompli. The take-over didn’t include the license of Hatot, nonetheless Junghans continued to manufacture Hatot clocks without the appropriate license. Hatot sued Junghans and won this patent dispute, but only after WWII, in 1953. Junghans was ordered to pay the license fees retrospectively. Leon Hatot didn’t get much out of it, as he died shortly after the 1953 verdict. Hatot transferred the license for ATO watches to KUNDO. Kundo manufactured ATO principal clocks with great success well into the 1970s.