Levers 2 and 3, turning about fixed axes B and A, are connected by turning pairs E and D to links 4 and 5. Lever 1 turns about fixed axis C and is connected by turning pairs F and G to links 4 and 5. When force P is applied to lever 1, shoes a and b, mounted on levers 2 and 3, are pressed by means of links 4 and 5 against the rim of rotating pulley 6, thereby braking the pulley.
$873$LW,Br$