Frederick E. Sickels, a pioneer of early steam engine development, is known for his cut-off valve. This type of valve gear provides a means of rapidly cutting off the admission of steam to the cylinder of the engine at any point in the stroke of the piston. It was widely used on the engines of the side wheel steamboats up to the beginning of the 20th century and was the forerunner of the many subsequent designs of drop cut off valve gears.
This model is a copy of the model that was filed with his application for patent. The Sickels valve gear is generally considered to be the first successful and practical drop cut off valve. The original patent model is also in the collections and can be found using its Catalog Number MC.308650.