Leonardo da Vinci designed a screw jack for raising heavy loads.
A screw jack converts rotary motion into controlled vertical movement. When a handle turns the screw, the threaded mechanism advances slowly and lifts the load. Leonardo’s engineering notebooks contain detailed studies of screws, gears, and lifting devices, including mechanisms that apply this principle to heavy objects.
The screw jack suited Renaissance construction and engineering because it offered mechanical advantage and precise movement. A person could raise a substantial load gradually with less force than would be required to lift it directly. The same basic principle later became useful in presses, machinery, vehicle repair equipment, and adjustable supports.
Leonardo did not invent the screw itself; ancient Greek engineers had already used screws and related mechanisms. His contribution was the detailed mechanical development and application of such devices. The term “screw jack” is therefore a modern name for the lifting mechanism represented in his studies.