Pulley systems are simple machines that make lifting heavy objects easier. They consist of a rope or cable that passes over one or more wheels (pulleys). A single pulley changes the direction of force ...

We still use belay lines when raising or lowering our personnel distances of 12 feet or more. There are many ways to accomplish this task, but when multiple rescuers must enter a space in which ...

A gear close gearA gear is a mechanical part with teeth that interlock with another gear or belt to transfer motion and power while changing speed, or direction in a mechanical system. is a special ...

Generally speaking, the gear mechanism of automobiles and bicycles is usually to increase or decrease the rotation speed in one direction, but by using a special mechanism it is possible not only to ...