Gilles Gas Engine, Patent Model

This model was submitted to the U.S. Patent Office with the application for the patent issued to Friedrich W. Gilles, of Kalk, Germany, July 11, 1876, no. 179782.
The engine represented by the model is a 1-cylinder vertical gas engine employing two pistons, a working piston (the lower one) and a loose piston (the upper one). The loose piston was intended to fly to the top of the cylinder where it would be caught and held, producing within the cylinder a reduced pressure, which would cause the work piston to return under the pressure of the atmosphere and thereby perform work on the return stroke as well as the explosion stroke. Provision was made to cushion the free piston at the top of its stroke for the purpose of quiet running. The combustion mixture was drawn in and ignited on the explosion stroke without compression.
This description comes from the 1939 Catalog of the Mechanical Collections of the Division of Engineering United States Museum Bulletin 173 by Frank A. Taylor.
Currently not on view
Object Name
engine, steam, model
patent model, engine, gas
date made
patent date
Gilles, Friedrich W.
Physical Description
metal (overall material)
wood (base material)
overall: 12 3/4 in x 4 5/8 in x 4 1/4 in; 32.385 cm x 11.7475 cm x 10.795 cm
place made
associated place
Deutschland: North Rhine-Westphalia, Köln, Kalk
ID Number
catalog number
accession number
patent number
See more items in
Work and Industry: Mechanical and Civil Engineering
Industry & Manufacturing
Bulletin 173
Engineering, Building, and Architecture
Data Source
National Museum of American History, Kenneth E. Behring Center


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