What three things did Elijah mccoy event?

Elijah McCoy was an African American inventor best known for inventing a lubricating device for steam engines, which allowed trains to run more efficiently without frequent stops for maintenance. He also developed a type of automatic lubricator for machinery, which contributed to the industrial revolution. Additionally, McCoy patented improvements in the design of railroad car bearings. His innovations significantly enhanced the reliability and performance of locomotives and other machinery.