Allen Cut-Off Valve, Patent Model

This model was submitted to the U.S. Patent Office with the application for the patent issued to Horatio Allen, of New York, New York, April 30, 1842, no. 2597.
This model represents a valve gear in which separate steam chests are employed for the head-end and crank-end main steam valves. The supply of steam to each of these steam chests is controlled by additional cut-off valves, the movement of which is adjustable. The inventor refers to this invention as an improvement in the valve gear patented by him August 21, 1841 (patent number 2227).
The model shows a portion of the cylinder of a horizontal engine with only the piston rod and cross head represented. A steam chest in which are located the ports leading to the inner or main steam chests is shown in section, revealing the cut-off valves on their seats. These cut-off valves are plain flat plates connected to opposite ends of a beam, which receives a vibratory motion from the cross head of the engine. The beam and its rock shaft are picoted in a lever by which the pivot can be moved and the time of cut-of varied. This the inventor calls “cut-off with movable rock shaft.” He suggests that a similar result can be obtained by constructing the cut-off ports in a movable plate which he calls “cut-off with single adjustable seat.”
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
Allen, Horatio
place made
United States: New York
associated place
United States: New York, New York
on green board-from catalog card: 21 in x 11 in; 53.34 cm x 27.94 cm
overall: 1 3/8 in x 20 7/8 in x 10 7/8 in; 3.4925 cm x 53.0225 cm x 27.6225 cm
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


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