What type of vehicle did Leonardo da Vinci sketch with a conical gear system for self-propulsion?

Leonardo da Vinci sketched a self-propelled cart driven by a conical gear system.

The cart appears in drawings from around 1478–1480 and is often described as an early ancestor of the automobile. Springs stored inside the vehicle supplied energy, while a system of gears transferred that energy to the wheels. Steering and movement could be preset through the mechanism, allowing the cart to follow a planned route.

Leonardo may have intended the device for theatrical performances or court spectacles rather than transportation. The surviving drawings do not provide every construction detail, and scholars have debated exactly how the mechanism worked. In 2006, engineers at the Museo Galileo in Florence built a working interpretation based on the sketches.

It is commonly called Leonardo’s self-propelled cart. Although it used no engine in the modern sense, it demonstrated mechanical motion from stored spring energy and anticipated later ideas in automated vehicles.