Elijah McCoy’s patent for a “Lubricator”, No. 383,746, describes a self-contained, multi-functional lubricator. Patented on May 29, 1888, this invention was a complete apparatus that combined a visible-feed lubricator and a “blind-feed” lubricator into a single unit. It was an improvement on his previous “Lubricator Attachment” (Patent No. 361,435).
The primary innovations of this patent included:
- All-in-One Design: Unlike his previous attachment, which required a separate oil reservoir, this lubricator had its own integrated oil and condensing chambers. It was a complete device.
- Slush-Cup with Hollow Stem: The device included a slush-cup with a hollow stem that was designed to sit on a valve seat. When the sight-feed glass was intact, the stem was lifted, and oil flowed from the sight-feed glass. However, if the glass broke or a clog occurred, the stem could be seated. This action would seal the oil chamber, and a valve on the slush-cup could be opened to manually deliver a controlled stream of oil through the hollow stem.
- Dual Functionality: This design meant that the lubricator could function as a visible-feed device for normal use and instantly convert to a blind-feed device for emergencies. This eliminated the need for railroad companies to purchase and carry two separate units, saving them significant money and hassle.
Societal Impact and Legacy
This patent is a powerful testament to McCoy’s dedication to creating practical and reliable industrial tools.
- Economic and Practical Efficiency: The all-in-one design was a major economic advantage for businesses. It reduced the cost of equipment and simplified maintenance. By providing an immediate backup system, it ensured that vital machinery could continue to operate, preventing costly downtime and potential accidents.
- Industrial Reliability: The ability to convert from a visible-feed to a blind-feed system with a single action provided engineers with a reliable, built-in solution to a common problem. This design further solidified his reputation for creating products that were superior in both function and durability.
- The “Real McCoy”: As with his other patents, this lubricator was a superior product. Its thoughtful design and functionality, which were far more effective than the numerous imitations, are widely believed to be the origin of 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.
