Pulley 1 rotates about fixed axis A. Pulley 2, rigidly attached to ratched wheel 4, rotates about axis B of link 5 which turns freely about axis A. Link 5 carries pivoted pawl 6 which engages the teeth of ratchet wheel 4. Flexible link (rope) 7 runs over pulleys 1 and 2, and over freely suspended rollers 8 and 9 which carry loads 10 and 11. Load 11 is hoisted by turning pulley 1 counterclockwise. The ratchet device prevents clockwise rotation of pulley 2 while load 11 is being hoisted. Load 10 serves to tension flexible link 7.
$3521$SFL,MH$