Brake disk 2 rotates about fixed axis A and is rigidly attached to drum b about which flexible link c is wound in hoisting load d. Lever 1 turns about fixed axis B. Shoe 3 turns about axis D of lever 1. The load is hoisted by rotating the disk and drum counterclockwise. Reverse rotation of disk 2 and the drum (and dropping of the load) is prevented by the jamming of shoe 3 between disk 2 and lever 1 if angle γ is small enough. Flat spring 4 holds shoe 3 in contact with disk 2.
$3380$SmF,Br$