What machine did Leonardo da Vinci design to produce mechanical motion from a spring wound by hand?

Leonardo da Vinci designed a spring-powered cart to produce mechanical motion from wound springs.

The machine is commonly known as Leonardo’s self-propelled cart. Inside the cart, coiled springs stored energy when wound. Gears transferred that energy to the wheels, while a programmable steering mechanism could guide the vehicle along a predetermined path. This makes the design an important early example of a mechanical automaton rather than a vehicle powered by an engine or animal.

The cart is sometimes described as a robot, but that modern term should be used cautiously. It did not sense its environment or make independent decisions. Reconstructions have shown that the mechanism can move when built from the drawing, although questions remain about the exact historical details and whether Leonardo built a working full-size version.