I think I can answer your question, at least as it would apply to page 7. Look at the page again. Notice the block of metal with the threaded rod going through it. As the rod turns, the block of metal moves up and down it's length, like a nut on a bolt. Look at the picture one more time. Notice the two wire cables on the opposite side of the block of metal from where the the threaded rod enters. They are attached to adjustment bolts, which also run through the block of metal. The nuts on the cable adjustment bolts (look at the picture again) are turned, usually while the cable is not under load, until the cables are equally tensioned. Then, as the block of metal moves along the threaded rod, which is turned by a motor or crank, EQUAL pull is exerted on each cable. As with all things mechanical, keeping such a mechanism clean and lubricated ensures proper operation.
A common use for such an arrangement, in the realm of camping, would be to raise the top on a pop-up. The cables which transmit the lifting force to the four corners of the top must apply equal force to each corner simulantiously. Otherwise the lifting mechanism would bind. Gravity takes care of the return trip. Pulleys are also involved in this specific application, but that is another discussion.
Happy Camping! ///// Richard D.
2006 4x4 Ford 250 SD / 2007 Flagstaff 827 FLS
One very patient wife and one furry child who travels with us. Forty-two years of trailering and camping, and I still have a blast.