Ratchet wheel 1 rotates about fixed axis A. Lever 2 turns about fixed axis B and is connected by turning pairs C and D to pawls 3 and 4. When lever 2 is oscillated, pawls 3 and 4 alternately engage the teeth of ratchet wheel 1, turning the wheel intermittently clockwise. Pawls 3 and 4 also serve as locks preventing reverse rotation of wheel 1. In one complete oscillation of lever 2 (back and forth), ratchet wheel 1 turns through the angle α=360°/z, where z is the number of teeth on ratchet wheel 1.
$1796$LR,4L$