Elijah McCoy was granted U.S. Patent 179,585 for an “Improvement in Steam-Cylinder Lubricators” on July 4, 1876. This patent was a direct improvement on his previous lubricator design (Patent No. 173,032). It addressed a specific problem: the inability to inject cold oil into an engine when using steam packing, which was often needed to prevent the packing from becoming “gummed up.”
The key innovation was a hollow double valve with a vertical oil passage running through it. This passage allowed cold oil to flow directly from the top of the lubricator, through the valve, and down into the steam cylinder. The valve’s design, with a small opening at the bottom, ensured that the oil would be delivered even while the engine was running. This provided a crucial new function that his earlier patents could not perform.
Societal Impact and Legacy
This patent is a clear example of McCoy’s genius and his relentless pursuit of perfecting his inventions. He didn’t just invent a product; he continually refined it to meet the practical needs of engineers and machinists.
- Enhanced Functionality: The ability to inject cold oil to “un-gum” steam packing was a major improvement for locomotive and factory maintenance. It offered a practical solution to a common operational problem, further cementing his lubricator’s reputation for superior performance.
- The “Real McCoy”: This patent is a testament to the quality and reliability of McCoy’s inventions. The superior design and functionality of his lubricators, which were far more effective than the numerous imitations, are widely believed to have given rise to the phrase “The Real McCoy.”
- The Inventor’s Legacy: Elijah McCoy was a brilliant African American inventor who, despite immense racial discrimination, became a foundational figure in American industrial technology. His numerous patents were critical to the development of the railroad system and factory machinery of the late 19th century.
