Leonardo da Vinci designed a screw jack to make heavy loads easier to lift.
A screw jack uses the mechanical advantage of a threaded screw: turning the screw moves a load through a smaller distance while multiplying the applied force. Leonardo’s notebooks contain designs for lifting mechanisms that combine screws with frames and supports, reflecting his interest in construction and machine mechanics.
The screw principle was already known in antiquity, so Leonardo did not create the basic idea of the screw jack from nothing. His contribution was to study, draw, and adapt mechanical arrangements with unusual detail. A screw jack differs from a pulley block, which uses rope and wheels, and from a water turbine, which converts flowing water into rotary motion.