Sheaves 6 and 7, of equal diameter, rotate about axes D and B of platform 3 which is being hoisted. Flexible link 4, shown by dot-and-dash lines, is secured to the fixed member at point F and runs over sheaves 6, 7 and 9. Sheave 9 rotates about fixed axis E. Flexible links 10 and 11 are connected to platform 3 at points N and K, and run over sheaves 5 and 8, of equal diameter, which rotate about fixed axes A and C. Equal weights 1 and 2, serving as counterweights, are secured to the other ends of flexible links 10 and 11. To hoist platform 3, a force P is applied to flexible link 4. The platform has straight translational motion along a vertical axis.
$3186$CmL,ML$