Mechanical linkages are two or more levers put together. They are usually designed to take an input and produce a different output, altering the motion, velocity, acceleration, and applying mechanical advantage.
Reverse motion
As the top rod moves to the left the bottom rod moves to the right. The bars move in opposite directions. Another way of describing this linkage is the the direction of movement in one rod is reversed in the other rod. The fixed pivot is the centre of rotation
Parallel motion
As the large rod at the top of the diagram moves to the left the two small rods at the bottom move to the right. All the rods are parallel to each other
Crank and slider linkage
The rods move forwards and backwards in slider. The fixed pivot anchor the linkages to one place
Bell crank linkage
This linkage allows horizontal movement to be converted to vertical movement. It also works the opposite way round. A practical example of this is the brake mechanism on a bicycle. |