Niels Christensen

Niels Christensen ( * 1865 in Tørring, Denmark, † 1952) was the inventor of the O- ring.

Life

Niels Christensen learned machinist in Vejle, Denmark. He attended the Technical Institute in Copenhagen and immigrated at the age of 26 years in the United States, where he worked as a draftsman in Chicago. His specialty was the development of vehicle brakes.

In 1933 he invented the age of 68 years, the O-ring for private experiments, for which he filed a U.S. patent in 1937 and 1939 received. After the entry of the United States into the Second World War, the military declared the patent for the war effort and expropriated Christensen, as well as other civil licensor of high technology, for the duration of the " national emergency " for a flat severance payment of $ 75,000 by the government, took control of licensing and freed in particular the defense industry for the production and further development of the O- ring of any license fee. This "national emergency" should last until the peace treaty with Japan on 28 April 1952. Christensen processed since the expropriation of the rest of his life unsuccessful, however, and only his heirs received the patent back with a remaining term of only four years. Since the defense and high technology producers were exempt for the use of patents for eleven years by a license fee payment, they refused with reference to the continuance of the non- validity limited to the duration of the emergency government contracts all payments to the patent heirs. The patent had been caused by misuse by the longtime owner, the United States, de facto worthless because the protection for Christensen's intellectual property on the market was not enforceable. The case against the government for this misappropriation ended only in 1971 with a final compensation of only $ 100,000.