Robert Huber was "Mr. Free Piston" for 37 years (1924-1962) and beyond. Under his supervision, over 25 different sizes and types of free piston engines were designed. 18 types (incl. GM XP-500) were built and tested, thousands were sold.

Robert Huber was a native of Switzerland and graduated from the Federal Institute of Technology ETH in Zurich, as a favorite pupil of the renowned Professor Stodola, who had great influence on the ETH in Zurich.

Robert Huber was was far ahead of his time. His extensive technical heritage, and also his biography - which he wrote after he retired - was an invaluable help for this homepage's author in understanding the free piston engine.

This historic photograph shows the first experimental engine AC-2 from Pescara, on the test bench near Paris in Meudon-Val-Fleury. The research and development performed by Robert Huber correspond to the work of Rudolf Diesel,Nicolaus Otto and Felix Wankel. 

This engine, however, bears the name of its inventor, Pescara, whereas it was designed and built by Swiss engineer Robert Huber.

1924-25
Robert Huber at the Swiss Federal Institute of Technology, Zurich: July-March assistance at Professor Aurel Stodola. Professor Stodola was Huber's main teaching degree in thermal machines. Stodola was a consultant engineer for Pescara. Huber constructed the first opposite free-piston engine AC-2 running on petrol. The plans were sent to Paris to build the engine.

1925-26
July - February: Robert Huber at Imperial College of Science and Technology, London, UK

1926
From Summer: SLM Winterthur, Switzerland
From Autumn: Societé Industrielle Pescara in Meudon-Val-Fleury, France (Paris office). 
The prototype AC-2 is completed by the end of year. Tests starting from December

1927 Birth of the Free Piston Engine
Moving to Maison Breguet, rue Didot, Paris (aircraft manufacturer). Construction of the "AC-3 Maison Breguet" (same construction as AC-2, but running on Diesel instead of petrol). Engine runs from late March 

1928
Pescara founded "Fabrica National de Automobiles" in Barcelona, Spain, construction of "Nacional Pescara"

1929
Moving to Barcelona to "Fabrica National de Automobiles". Construction of "AC-4 Maison Breguet", test runs until 1931

1930
Entrance of Huber's brother Oscar R. Ulrich in the society 

1931-32
Escape from Barcelona to France (Upcoming elections, fear of takeover by the communists). Quartered at factory Automobiles Voisin, Issy les Moulineaux (Pescara was main shareholder)

1932
Moving to Maison Breguet, rue Didot, Paris
R. Huber reads a book by Prof. Lomonosov about diesel locomotives. There was a proposal by Petro Shelest to drive turbines via compressed air > initial impetus for free-piston gas turbines

1948
"Electricité de France" EdF first SIGMA order: 1400 KW power plant

1949
SEP assigns sublicense to "Chantiers et Ateliers Augustin-Normand", Le Havre for marine applications
SEP assigns sublicense to "Regie Nationale des Usines Renault", Billancourt, Seine (in collaboration with "Forges de la Loire") for locomotive applications

1950
Moving to Malmaison, France
S.E.P. assigns sublicense to "Ateliers et Chantiers de la Seine Maritime", Paris for marine applications

1953
Alan Muntz assigns sublicense to Charles D. Holmes and Co. Ltd, Hull, Yorks. for marine and industrial applications
Alan Muntz assigns sublicense to "Smith's Dock Co. Ltd", Middlesbrough, Yorks. for marine and industrial applications ​

1955
Construction of the "Hyprex Engine" G-10 "SEME-GMCo" for the XP 500 Firebird
S.E.P. assigns sublicense to "Forges et Chantiers de la Mediterannee", Paris for marine applications
Alan Muntz assigns sublicense to "Mackay Industrial Equipment, Ltd", Feltham, Middx. exclusively for compressor applications
​