Ratchet wheel 1 turns about fixed axis A. Pawls 3 and 4 turn about axis B which is mounted on slider 2. When slider 2 reciprocates vertically, pawls 3 and 4 alternately engage the teeth of ratchet wheel 1, thereby turning it intermittently counterclockwise. Pawls 3 and 4 also serve as locks preventing reverse rotation of wheel 1. In one complete stroke (up and down) of slider 2, wheel 1 turns through the angle α=720°/z, where z is the number of teeth on wheel 1.
$1792$LR,4L$