14 March 1909: The prechamber principal is patented

14 March 1909: The prechamber principal is patented
March 2009
  • Prosper L’Orange’s key discovery for the diesel-powered car
  • The engineer was employed at Benz & Cie. from 1908 to 1922
  • The first agricultural vehicle with diesel engine was the Benz tractor presented in 1922
The German engineer and inventor Prosper L'Orange was awarded a patent for his prechamber principal (DRP 230 517) on 14 March 1909. The prechamber principal made possible the development of the diesel engine from being a stationary source of power to one with mobile applications. Nowadays, given current environmental regulations and the importance of fuel economy, it is hard to conceive of life without the diesel engine for passenger cars and trucks. And right across its various brands, Daimler AG continues to make significant pioneering developments in the field of the diesel engine.
Prosper L’Orange (born 1 February 1876in Beirut , Ottoman Empire, died 30 July 1939in Stuttgart ) worked at Benz & Cie. in Mannheim from 1908 to 1922. The prechamber principal played a key role in the evolution of the diesel engine into a compact, high-speed vehicle drive system. A semispherical chamber was introduced between the injection nozzle and the cylindrical combustion chamber to facilitate rapid combustion at high temperatures. With the prechamber diesel unit it was possible to achieve much higher engine speeds and thus high outputs than with older versions of the compression-ignition engine. Other groundbreaking inventions by L’Orange include the funnel prechamber (1919), the pintle-type injection nozzle (1919) and the variable injection pump (1921) – all of them landmarks along the route taken by the compression-ignition engine towards its application in the automobile and providing at the same time a basis for the first vehicle diesel engines.
L’Orange’s work led to the first agricultural vehicle equipped with the diesel engine, the . A Benz truck followed in 1923 and that same year the Daimler-Motoren-Gesellschaft also unveiled a diesel-powered truck. Since then there has been a continuous stream of diesel innovations from all the Daimler AG brands. ()


Diesel pioneer: Prosper L’Orange (1876 - 1939)