Ball transfer units are omni-directional load-bearing spherical balls mounted inside a restraining fixture. They are identical in principle to a ball computer mouse upside-down, or a trackball, except there is an array of them side-by-side. Typically the design involves a single large ball supported by smaller ball bearings.
They are commonly used in an inverted ball up position where objects are quickly moved across an array of units, known as a ball transfer table, a type of conveyor system. This permits manual transfer to and from machines and between different sections of another conveyor system. They are used in airports for luggage delivery, or in industry as part of manufacturing systems.
