Luttgens’ Patent Model of a Steam Engine Governor – ca 1851
date: label: date made
content: 1851
label: patent date
content: 1851-10-21
name: label: inventor
content: Luttgens, H. A.
notes: label: Description
content: This model was filed with the application to the U.S. Patent Office for Patent Number 8,447 issued to H.A. Luttgens of New York, New York on October 21, 1851. The patent was for an improvement in controlling the speed of a steam engine by varying its cut-off valve timing. Luttgens claimed that his concept better controlled the speed of the engine under varying loads and steam pressures.
label: Description
content: The patent uses a common fly-ball governor to sense speed variations of the engine, and in the image of the model it can be seen at the top of the mechanism. The Luttgens design does not use the position of the fly-balls directly for control of the cut-off valve. Instead, the position of the balls controls a feedback mechanism that progressively changes the eccentric until the desired, steady-state speed is achieved. The feedback mechanism is powered by the engine shaft itself. It uses a very complex system of gears, pulleys, belts and friction brakes to measure the difference between actual speed and desired speed. It then moves the eccentric in progressively smaller adjustments until the engine returns to proper speed.
label: Description
content: This control method allowed the governor to make continuous, small adjustments to bring the engine back to proper speed whereas the more common approach made a one-time adjustment based on a change in speed. The result was the Luttgens unit had much better steady state accuracy. However, it was much less able to respond rapidly to large and sudden engine speed variances.
label: Description
content: The patent model is constructed of brass, steel and wood. All the key elements of the patent are illustrated by the model. It includes a small hand crank to permit demonstration of actual operation. A full description of the operation of the governor along with complete diagrams of the patent can be found in the patent document online at the United States Patent and Trademark Office website, www.uspto.gov.
place: label: place made
content: United States: New York
label: associated place
content: United States: New York, New York City
topic: label: Subject
content: Patent Models
label: Subject
content: Steam Engines
setName: label: See more items in
content: Work and Industry: Mechanical and Civil Engineering
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content: Engineering, Building, and Architecture
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content: Patent Models
label: Exhibition
content: Power Machinery
label: Exhibition Location
content: National Museum of American History
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: MC.251288
label: catalog number
content: 251288
label: accession number
content: 48865
label: patent number
content: 8,447
objectType: label: Object Name
content: governor, steam engine, model
label: Object Name
content: patent model, governor, steam engine
physicalDescription: label: Measurements
content: overall: 14 1/2 in x 9 in x 6 3/4 in; 36.83 cm x 22.86 cm x 17.145 cm