A lifting jack and the force needed to raise a weight
Scissor-lift with screw and hook, gears and rack-and-pinion, and a statics problem
The left page is dominated by a lazy-tongs (scissor) lifting mechanism topped by a screw handle and terminating in a hook, mounted on a low wheeled base. Around it are a large toothed wheel meshing with a small pinion, a belt over a pulley, and a straight rack engaged by a pinion. The accompanying note poses a mechanics problem — to reckon what force at m is required to raise 4 pounds at n. Further untranscribed writing is present on the sheet.
On this page
Force at m to raise 4 pounds at n
The note asks for the reasoning of what force must be applied at m in order to lift a load of 4 pounds at n. It frames the lifting device as a statics problem of mechanical advantage between the two points.
Scissor-lift with screw and hook
A tall lazy-tongs mechanism of crossed links is capped by a screw with a crank handle and ends in a downward hook, rising from a shallow wheeled box. Turning the screw extends the crossed links to raise the hooked load.
Geared wheel, pulley belt and rack-and-pinion
At right are a large toothed wheel driven by a small pinion, a loop of belt over a pulley, and a straight toothed rack meshed by a pinion above a plain bar. These illustrate the transmission elements available for the lifting task.