Also known as a heim joint in the United States or a rose joint in the United Kingdom, a rod end bearing is a mechanical joint that features a rounded ball-like swiveling tip. They were invented in Germany during the 1930s to 40s for use in aircraft control systems. This promoted a company called H.G. Heim Company to patent and produce its own rod end bearings in North America, which is why the mechanical joint now has the moniker “heim joint.”http://www.remotioner.com/bearing/rod-end-bearing/