183 - Nicolas-August OTTO (1832 - 1891) [1] [2] [3]

In 1876 OTTO invented an internal combustion engine which became known as the 4 stroke engine. His company was called Deutz AG.

On 22 July 1876 OTTO applied for a brevet d’importation for 15 years in Luxembourg under the title of:

Verbesserter Gasmotor

‍ In his corresponding US patent OTTO explained: [4]

In gas-motor engines as at present con­structed, an explosive mixture of combustible gas and air is introduced into the engine-cyl­inder, where it is ignited, resulting in a sudden development of heat and expansion of the gases, a great portion of the useful effect being lost by absorption of heat, unless special provisions are made for allowing the gases to expand very rapidly. 

According to my present invention an in­timate mixture of combustible gas or vapour and air is introduced into the cylinder, to­gether with a separate charge of air or other gas, that may or may not support combustion, in such a manner and in such proportions that the particles of the combustible gaseous mix­ture are more or less dispersed in an isolated condition in the air or other gas, so that on ignition, instead of an explosion ensuing, the flame will be communicated gradually from one combustible particle to another, thereby effecting a gradual development of heat and a corresponding gradual expansion of the gases, which will enable the motive power so pro­duced to be utilised in the most effective man­ner. 

On 14 January 1878 experts Eugène MULLER and A. WEISS issued a lengthy report on the invention and concluded: [5]

Die Beschreibung und Zeichnungen des verbesserten Motors sind so ausführlich, dass wir es für überflüssig halten auf einen nähere Erklärung einzugehen. Wir schlagen deshalb die Ertheilung eines Patentes auf die Dauer von fünf Jahren vor.

The Chambre de commerce forwarded the report to the Government with the following cover letter:

La Chambre de commerce partageant les conclusions des experts WEISS et MÜLLER dans leur rapport ci-joint, a été d'avis, … , d'accorder le brevet sollicité, sauf à en limiter la durée à cinq ans.

The patent was granted on 23 April 1878, but only for a duration of 5 years and not for the requested 15 years.

Corresponding patents worldwide

DE 532, GB 2081, FR 113251, US 194047, SE 2310, ES 5479

see also « Do patents enable disclosure? Strategic innovation management of the four-stroke engine » by  Patricio Sáiz, and Rubén Amengual.


[1] Wikipedia

[2] FamilySearch database

[3] see « Distinguished inventors, Otto »

[4] US patent n° 194,047

[5] drafted in old German handwriting and not yet transcribed