The automatic coupler was invented by Eli Janney in 1873 and eventually became a standard among railroads in North America.
Since the railroads first appeared in North America, railroads had relied upon the link and pin coupler to hold trains together. But the old couplers were dangerous because they required a railwayman’s personal touch; countless fingers and hands had been accidentally caught in the old couplers, and crushed. Alfred Cosens lost his lower arm in a coupling accident while working for the Canada Southern Railway (CSR.) Also, many train wrecks were blamed on old couplers that broke after long use and much stress.
Eli H. Janney, a clerk at a dry goods store and former officer in the Confederate Army, was an amateur inventor who used his lunch hour to design new, safer couplers. He created prototypes by whittling miniature models from wood. One of his prototypes – a knuckle-style coupler with an automatic locking system – eliminated the need for an operator. Janney received a patent for his innovative automatic coupler on April 29, 1873.
In 1893, when the U.S. Congress was searching for an automatic coupler that would become the standard for the commercial railroad industry, they sifted through numerous designs before choosing the Janney coupler.
The Janney coupler, also known as the Buckeye or Knuckle Coupler, is still used today by railroads around the world.