Wiegand’s Patent Model of a Gas Engine – ca 1864
date: label: date made
content: 1864
label: patent date
content: 1864-10-04
name: label: inventor
content: Weigand, S. Lloyd
label: maker
content: Wiegand, S. Lloyd
notes: label: Description
content: This model was filed with the application to the U.S. Patent Office for Patent Number 44,572 issued to S. Lloyd Wiegand of Philadelphia, Pennsylvania on October 4, 1864. Mr. Wiegand’s patent was for improvements in gas engines. Claimed improvements included: protection against the buildup of carbon deposits on the piston and cylinder; more accurate and fuel-efficient speed control; and a lower cost and higher durability construction.
label: Description
content: Mr. Wiegand’s engine was designed to use “illuminating gas” which was a coal based product used for gas lighting. Due to inefficiency in combining the gas and air, carbon deposits were left on the surfaces of the combustion chambers. This damaged the seals between the cylinders and pistons resulting in leakage and reduced power. The patent called for a fluid to be injected into the cylinders via channels near the seals. The fluid would loosen and eject the carbon through the exhaust.
label: Description
content: To improve the speed regulation and fuel-efficiency of the engine, Mr. Wiegand varied the timing of the intake valves. A shaft governor was included in one of the engine’s two flywheels, and this was coupled to a mechanism that adjusted the angle of the cam which opened and closed the valve. If the engine exceeded its desired speed, the cam adjustment would shorten the time the intake valve was open. The reduction in the amount of fuel entering the engine soon slowed it.
label: Description
content: A search of available literature did not reveal any practical use of the patent. Shortly after Mr. Wiegand’s patent, N. A. Otto and others patented advances in gas engine such as compressing the fuel-air mixture prior to combustion and the introduction of the four stroke engine design.
label: Description
content: The model as shown in the image illustrates all of the key elements of the patent except for the internal details of the valves and cylinders. It is constructed of metal. Diagrams showing the complete design can be found in the patent document online (www.USPTO.gov).
label: Location
content: Currently not on view
place: label: place made
content: United States: Pennsylvania, Philadelphia
label: associated place
content: United States: Pennsylvania, Philadelphia
topic: label: Subject
content: Patent Models
label: Subject
content: Internal Combustion
label: Subject
content: 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
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: ER.325619
label: accession number
content: 249602
label: catalog number
content: 325619
label: patent number
content: 44,572
objectType: label: Object Name
content: gas engine, model
label: Object Name
content: patent model, engine, gas
physicalDescription: label: Physical Description
content: iron, brass (overall material)
label: Measurements
content: overall - from catalog card: 72 in x 7 1/2 in x 10 in; 182.88 cm x 19.05 cm x 25.4 cm
label: Measurements
content: flywheels - from catalog card: 7 1/2 in; x 19.05 cm
label: Measurements
content: overall: 11 7/8 in x 11 in x 7 3/8 in; 30.1625 cm x 27.94 cm x 18.7325 cm
label: Measurements
content: overall: 12 in x 7 1/4 in x 10 in; 30.48 cm x 18.415 cm x 25.4 cm