Higginson’s Patent Model of a Radial Steam Engine - 1877

Description:

This model was filed with the application to the U.S. Patent Office for Patent Number 196,451 issued to Andrew Higginson of Liverpool, England on October 23, 1877. The patent was for an improved design for reciprocating steam engines. His patent application described three designs. One was for a single rectangular piston, non-reversing engine. The second was for a three piston version that was non-reversing. The third design, and the one represented by this model, was for a three piston engine that could be reversed. The control lever seen at the right of the image of the model was for controlling the direction of rotation.

Higginson provided two ports in the walls of each of the steam “cylinders.” As a piston oscillated up and down, a port in the skirt of the piston alternately exposed each of the ports in the wall. The control lever determined which port received steam and which acted as the exhaust and, thus, the direction of rotation. He claimed that the use of rectangular “cylinders” made the engine easier to construct and to obtain tight seals with the pistons.

The patent model is constructed of brass and illustrates of the important elements of Higginson’s design. Although not visible in the image, the rear of the model has cut-away sections to reveal parts of the pistons and valve ports. A full description of the operation of the engine 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.