Wheelock Valve and Valve Seat Model

This is a nicely made model of the valve and valve seat patented by Jerome Wheelock, of Worcester, Massachusetts, September 22, 1885, no. 326820.
The model represents a wide gridiron slide valve assembled on a skeletonized taper plug, which serves as the valve seat and supports the rock shaft connected to the slide by links or “toggles.” The whole assembly is designed to fit into a taper hole bored into the cylinder block and connected by suitable ports to the cylinder. The advantage of this arrangement over ordinary plug valves is that it does not require that a valve seat be formed within the large cylinder casting, and it permits the delicate fitting of the valve to the valve seat to be performed at a work bench or upon a machine away from the engine.
The complete Wheelock valve gear (U.S. patent number 326819) consists of one steam valve and one exhaust valve at each end of a cylinder with the rock arms of the exhaust valves permanently connected to the eccentric, so that the valve is at rest during part of the travel of the eccentric, while the steam valves are connected through a detachable latch so that they may be detached and closed quickly at any point during the stroke of the piston.
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
place made
United States: Massachusetts
overall: 1 1/2 in x 6 1/4 in x 1 1/2 in; 3.81 cm x 15.875 cm x 3.81 cm
ID Number
catalog number
accession number
Credit Line
Gift of Franklin Machine Company, Providence, R. I.
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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