Also known as: sheave, block Description: A pulley is a simple machine that consists of a wheel that is looped over
by a rope, cable, or belt. The pulley may have a groove between two flanges
around its circumference for the rope, cable, or belt to ride in.
Type 1 pulleys have a fixed axle and are used to change the direction of
an applied force without increasing mechanical advantage.
Type 2 pulleys have a free axle and are used to increase mechanical
advantage.
A compound pulley is a system consisting of a combination of pulleys
with both fixed and free axles.
Mechanical advantage is realized when a pulley system lessens the force
required to move a load by requiring a longer pulling distance. |
