Corliss Vacuum Dash Pot, Patent Model
date: label: date made
content: 1876
label: patent date
content: 1876-06-06
name: label: inventor
content: Corliss, George H.
notes: label: Description
content: The model was filed on October 27, 1875, to the U.S. Patent Office with the application for the patent issued to George H. Corliss, June 6, 1876, no. 178275.
label: Description
content: The model is a brass miniature of a vacuum dash pot designed to combine the functions of supplying the force to close the steam valve and to arrest the motion without shock after the valve is closed. The vacuum dash pot has some advantages over heavy weights and springs for closing valves.
label: Description
content: The dash pot consists of a casting in which is bored a cylinder having a lower section of small diameter and an upper section of larger diameter. A plunger, having corresponding sections of large and small diameters, fits the cylinder. When the steam valve to which the plunger is attached is opened the plunger rises in the cylinder forming a vacuum in the part of smaller diameter. At the same time small leather valves in the larger part of the plunger open and allow air to enter the cylinder under this part of the plunger. When the valve is released the vacuum draws down the plunger and closed the valve. The air under the upper part escapes through a port in the cylinder until the plunger covers the port. The air trapped in the cylinder at this point acts a s a cushion and brings the valve quickly but gently to rest.
label: Description
content: Reference:
label: Description
content: 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.
label: Location
content: Currently not on view
place: label: place made
content: United States: Rhode Island
label: associated place
content: United States: Rhode Island, Providence
setName: label: See more items in
content: Work and Industry: Mechanical and Civil Engineering
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content: Bulletin 173
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content: Engineering, Building, and Architecture
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content: Work
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content: Industry & Manufacturing
publisher: label: Related Publication
content: Frank A. Taylor. Catalog of the Mechanical Collections of the Division of Engineering United States National Museum, Bulletin 173
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: ER.308692
label: accession number
content: 89797
label: catalog number
content: 308692
label: patent number
content: 178,275
objectType: label: Object Name
content: dash pot, model
label: Object Name
content: patent model, dash pot for steam engine
label: Object Type
content: Patent Model
physicalDescription: label: Physical Description
content: brass (overall material)
label: Measurements
content: overall: 6 1/2 in x 2 3/4 in; 16.51 cm x 6.985 cm
label: Measurements
content: brass cylinder - from catalog card: 6 in; 15.24 cm