What Leonardo da Vinci device was intended to produce continuous motion from a falling weight?

The Leonardo da Vinci device intended to produce continuous motion from a falling weight was a perpetual motion machine.

Leonardo investigated perpetual-motion proposals involving wheels, weights, and mechanical arrangements. Such machines were designed to keep moving without a continuing energy supply, often by having weights fall on one side of a wheel and rise on the other. Leonardo eventually recognized that these arrangements could not provide unlimited useful motion.

His studies are historically valuable because they show a transition from speculative machine ideas toward more careful mechanical analysis. A wheel can move for a while after being started, but friction, air resistance, and the energy needed to lift the weights eventually stop it.

The term does not describe a successful Leonardo invention. It describes a class of proposed machines that violate established physical principles when claimed to run indefinitely and produce usable work. Leonardo’s notebooks include investigations of such designs, but no working perpetual-motion machine was built by him.