This Bicycle Shift System Didn't Catch On

The National Archives (of the U.S. of A.) has published a "coloring book" as a PDF, making use of digitized oddball patent drawings from their collections. One of them is a fairly strange looking bicycle related patent application from 1899, from a Mr. John J. Hentz of Baltimore.


Full patent is online in Google's patent database

From the patent application text:

The object of my invention is to furnish a device by which to connect or disconnect the sprocket-wheels with the shaft on which they are placed, so that the motion of the shaft may be communicated to the one or the other of the sprocket-wheels, as desired, for the purpose of increasing or decreasing the speed of the bicycle while propelling it on a level or up an incline.

and later, "The operation of the device is obvious."

While operation of this gear shift device may be obvious, it was also not a very good design, with two entirely separate chains. Like most bicycle improvement patents of the 1890s, it didn't catch on.