Editing Wilhelm Maybach (section)

==Daimler and Otto's four-stroke engine (1869 to 1880)==
In 1869, Maybach followed Daimler to [[Maschinenbau-Gesellschaft Karlsruhe AG]] in [[Karlsruhe]], a manufacturer of heavy locomotives. Daimler was on the Executive Committee and they spent long nights discussing new designs for engines, pumps, lumber machinery, and metalworking.

In 1872, Daimler moved to [[Deutz AG|Deutz-AG-Gasmotorenfabrik]] in [[Cologne]], then the world's largest manufacturer of stationary gas engines. [[Nicolaus Otto]], part owner of the company, focused on engine development with Daimler. Maybach joined them as Chief Designer.

In 1876, Nicolaus Otto patented the [[Otto cycle]] engine. It was a [[four-stroke cycle]] gas internal combustion engine with intake, compression, power, and exhaust strokes. One of Otto's more than 25 patents on this engine was later challenged and overturned, allowing Daimler and Maybach to produce their high-speed engine.{{clarify|reason=Whose patent was overturned? Otto held it as company co-owner, or as actual developer of the item? I.e., was it the work of Otto, Otto and Maybach, a team,...?|date=May 2021}}

Also in 1876, Maybach was sent to show Deutz's engines at the [[World Fair|Philadelphia World's Fair (USA)]]. On returning to Cologne in 1877, he concentrated on improving the four-stroke design to prepare it for its impending commercial launch.

In 1878, Maybach married Bertha Wilhelmine Habermaas, a friend of Daimler's wife, Emma Kunz. Her family members were landowners who ran the post office in [[Maulbronn]]. On 6 July 1879 Karl Maybach was born, the first of their three children.

In 1880, Daimler and Otto had serious disagreements, resulting in Daimler's leaving Deutz-AG. Daimler received 112,000 [[German gold mark|goldmarks]] in Deutz-AG shares as compensation for patents granted to him and Maybach. Maybach also left shortly afterwards, and followed his friend to found a new company in [[Cannstatt]].