Luttgens’ Patent Model of a Steam Engine Governor – ca 1851
Object Details
- Description
- 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.
- 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.
- 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.
- 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.
- Data Source
- National Museum of American History
- date made
- 1851
- patent date
- 1851-10-21
- ID Number
- MC.251288
- catalog number
- 251288
- accession number
- 48865
- patent number
- 8,447
- inventor
- Luttgens, H. A.
- Object Name
- governor, steam engine, model
- patent model, governor, steam engine
- Measurements
- overall: 14 1/2 in x 9 in x 6 3/4 in; 36.83 cm x 22.86 cm x 17.145 cm
- place made
- United States: New York
- associated place
- United States: New York, New York City
- Related Publication
- Frank A. Taylor. Catalog of the Mechanical Collections of the Division of Engineering United States National Museum, Bulletin 173
- See more items in
- Work and Industry: Mechanical and Civil Engineering
- Engineering, Building, and Architecture
- Patent Models
- Exhibition
- Power Machinery
- Exhibition Location
- National Museum of American History
- Subject
- Patent Models
- Steam Engines
- Record ID
- nmah_846305
