This model was submitted to the U.S. Patent Office with the application for the patent issued to George H. Corliss, August 8, 1882, no. 262209.
The model represents a flyball governor in which the motion of the slide, owing to a change in the speed of the engine to which the governor is attached, not only changes the position of the cut-off or throttle devices to regulate the speed of the engine but also changes the gear ratio between the engine and the governor to change the speed of the governor relative to the speed of the engine.
When the governor speed is increased by an increase in the speed of the engine, the balls rise and communicate motion to a slide, which, in turn, affects the throttle or cut-off to return the engine to its lower speed. At the same time the motion of the slide shifts a friction roller on its driving disk so that the governor speed is increased relative to the engine causing an additional motion of the slide in the same direction. As a result, the governor slide is given a greater motion for a given change in speed than would otherwise result.
Reference:
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.