The most important patent of Nicolaus August Otto is the "Deutsches Reichspatent N° 532". It was initially filed in the at the time German state Alsace-Lorraine. With the creation of the Imperial Patent Office (Kaiserliches Patentamt) on 1 July 1877 in Berlin the patent application was converted into a German Imperial patent.


The claims as filed read:



  1. Introducing into an enclosed space combustible, with air mixed gases and air of a different kind prior to their combustion in such manner that at a point of an initiated combustion it [the combustion] slows down while [the combustion is] continuing from gas particle to gas particle, whereby the combustion products and the kind of air that envelopes them expand by the produced heat and thus release operational power.

  2. Generating the under 1 pronounced effects with gases which until combustion have atmospheric pressure.

  3. Generating the under 1 pronounced effects with gases which have before combustion more than atmospheric pressure.

  4. Set up the mode of operation of a gas engine with crank motion such that for two rotations of the crankshaft of one side of the piston the following effects are generated:

    1. Sucking in the gas types into the cylinder;

    2. Compression of those;

    3. Combustion and generating work of those;

    4. Exiting of those of the cylinder.

  5. The construction of a machine, as described.


Please note that the art of patent drafting is not very developed at this time in Germany, as before the start of the Imperial Patent Office on 1 July 1877, if one wanted to cover the area of the Germany, patent applications had to be filed in the various small states. Not all of these small states granted patent rights and no common rules had been established before. I deliberately did not correct what today would be perceived as grammatical errors such as not using the same term for same features or the wrong use of the direct article. In order to improve clarity for the reader I added the terms that are embraced by square brackets.