Leonardo da Vinci’s vehicle design powered by wound springs is commonly called the self-propelled cart.
Leonardo drew the cart around 1478–1480, making it one of his earliest recorded mechanical designs. Two large leaf springs, wound by hand, supplied the energy. Gear trains transferred that energy to the wheels, allowing the vehicle to move without an animal or person pushing it.
The cart was probably intended for theatrical or ceremonial use rather than transportation. A steering mechanism could make it travel along a preset route, and reconstructions have demonstrated that the design can work. The drawing does not provide every construction detail, so modern builders have had to interpret some parts.
It is often described as an early robot or automobile, but those labels are modern comparisons. Leonardo did not build a gasoline engine or a modern motorcar; his design was a spring-driven stage machine.