Carpenter Compound Hydraulic Engine, Patent Model

The model was submitted to the U.S. Patent Office with the application for the patent issued to Oramill C. Carpenter, of Brooklyn, New York, December 17, 1878, no. 210915.
The engine is essentially a hydraulic transmission, which takes motion from eccentric cams on a central shaft turned by a steam or other engine and transmits the motion to shafts on either side of and parallel to the central shaft. The inventor designed the engine to be applied to a streetcar, and the model is mounted in a miniature nickel-plated car truck.
It is a 4-cylinder engine with opposed cylinders in groups of two. Single-acting plungers work in and out of the cylinders as the central shaft is turned. The head of each cylinder leads directly to another cylinder of reduced diameter in each of which a driven piston works through a longer stroke in time with the short stork of the driving piston. Valves for the relief of an excess pressure of liquid and spring-cushioned piston heads are described for smoother running.
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
date made
patent date
Carpenter, Oramill C.
place made
United States: New York
associated place
United States: New York, Brooklyn
Physical Description
nickel (overall material)
overall - from catalog card: 7 in x 12 in; x 17.78 cm x 30.48 cm
overall: 2 3/8 in x 7 1/8 in x 12 1/2 in; 6.0325 cm x 18.0975 cm x 31.75 cm
ID Number
catalog number
accession number
patent number
Patent Models
See more items in
Work and Industry: Mechanical and Civil Engineering
Industry & Manufacturing
Bulletin 173
Patent Models
Engineering, Building, and Architecture
Data Source
National Museum of American History


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