The lengths of the links comply with the conditions: A͞B=A͞D and B͞C=D͞C. Slider-crank linkages ABC and ADC, with common slider 1, are connected by turning pairs B and D to pawls 2 and 4 which engage ratchet wheel 3. Ratchet wheel 3 rotates about fixed axis A. When slider 1 travels to the right, pawl 2 turns ratchet wheel 3 clockwise; when slider 1 travels to the left, pawl 4 turns wheel 3 in the same direction. In one complete stroke of slider 1 (back and forth), ratchet wheel 3 is turned through the angle α=720°/z, where z is the number of teeth on wheel 3.
$1825$LR,ML$