Drum 2 rotates about fixed axis A and carries pivoted pawl 5 turning about axis C. Flexible link 1 runs over drum 2 and is attached to the drum at point B. Ratchet wheel 3 rotates freely about axis A. Slotted slide 4 reciprocates in fixed guides E-E and has slot a along which pin b of ratchet wheel 3 slides. When the free end of link 1 travels downward, drum 2 turns counterclockwise and pawl 5 turns ratchet wheel 3 one half revolution. At this, pin b moves slide 4 horizontally. When link 1 is released from its load, drum 2 is returned by a spiral spring (not shown) to its initial position. During this motion, ratchet wheel 3 is held stationary by spring pawl 6.
$3536$CFL,ML$