sentences:  The air caster (originally called the air bearing) was invented by Harry A Mackie in December 1961 as the “pendant air bearing load supporting device” for General Motors Corporation as an alternative to the overhead crane, which ran opposed to a rail, creating friction free movement.In November 1963, Mackie, on behalf of General Motors Corporation, filed a patent for an “air bearing support with automatic air flow regulation”.This was the first air caster designed to be used on the ground.