5.4.1 Manually Operated Machines

In manually operated machines (Figure 5.4.1-1 ) a hand operated lever activates a mechanism to provide a direct pull on an integral rope which is attached to the load. The pull is applied by means of two pairs of self-energising jaws, which exert a grip on the rope, the distance of travel being limited only by the length of the rope. The initial pressure which causes the jaw to grip the rope and give the self-energising action is provided by powerful springs.