Porter’s Patent Model of a Steam Engine Governor – ca 1858


This model was filed with the application to the U.S. Patent Office for Patent Number 20,894 issued to Charles T. Porter of New York, New York on July 13, 1858. The patent was for an improvement in controlling the speed of a steam engine by use of a fly ball governor. This design was one of the earliest weighted fly ball governors. It differed from the common fly ball governor in that the balls were of very light weight, and the governor was intended to be operated at much higher speeds of rotation. The governor included gearing that rotated the fly balls at approximately ten times the speed of the engine's rotation. The design did not suffer from the increased friction of heavy fly balls which would reduce responsiveness. The inventor claimed the advantages of his design were more sensitive and rapid responses to small changes in engine speed. The Porter governor design was used in the Porter-Allen engine introduced about 1867, and the weighted fly ball principle was widely used from then on.

The patent model is constructed of cast iron and steel. All of the key elements of the patent are illustrated by the model. It includes a hand crank to permit demonstration of actual operation. A full description of the workings of the governor and diagrams showing the complete design of the patent can be found in the patent document online at the United States Patent and Trademark Office website, www.uspto.gov.

Date Made: 1858Patent Date: 1858-07-13

Inventor: Porter, Charles T.

Place Made: United States: New YorkAssociated Place: United States: New York, New York City

Subject: Patent ModelsSteam Engines


See more items in: Work and Industry: Mechanical and Civil Engineering, Engineering, Building, and Architecture, Work, Industry & Manufacturing, Patent Models

Exhibition: Power Machinery

Exhibition Location: National Museum of American History

Related Publication: Frank A. Taylor. Catalog of the Mechanical Collections of the Division of Engineering United States National Museum, Bulletin 173

Data Source: National Museum of American History

Id Number: MC.251289Catalog Number: 251289Accession Number: 48865Patent Number: 20,894

Object Name: governor, steam engine, loaded type, modelpatent model, governor, steam engine

Physical Description: brass (overall material)steel (overall material)Measurements: overall: 12 in x 12 in x 11 in; 30.48 cm x 30.48 cm x 27.94 cm

Guid: http://n2t.net/ark:/65665/ng49ca746a6-692d-704b-e053-15f76fa0b4fa

Record Id: nmah_846143

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