Lever-and-screw mechanism with reversing motion
A lever driving a screw up and down through a cord wound on its nut
The central drawing shows a mechanism in which a hand lever governs a screw through a cord wound about the screw's nut. As the lever n m o is moved right or left, the cord a b c d turns around the mother (nut) of the screw e f, driving the screw up or down so that it releases one lever face and engages another. Reversing the lever's motion reverses the screw's travel.
On this page
Lever, cord and screw with reversible travel
When the lever n m o is moved to the right or left, the cord a b c d wraps around the nut of the screw e f and drives the screw down, releasing the front of lever g and catching beneath lever b. Moving the lever the opposite way reverses the screw's motion.