Scientific Principles Explaining the Mechanism of the Typewriter

Any machine works according to a set of scientific principles and laws, they are grouped not by use but by Taking into account its principles, as an example we have the mechanism of the piano, which is a first cousin of the to write.
Mechanical machines work through moving parts such as: levers, gears, cams, belts, wheels, springs and cranks, they are also interconnected by complex links. Some large enough to move mountains, others tiny that almost disappear in a whirlwind of gears and still others, so slow that they seem to have no movement.
All machines are related to forces, either to produce motion or to impede it. Its mechanical parts move to change the applied force into a lesser or greater resultant, which will be the necessary to perform its function.
The mechanical typewriter has a system of levers that convert a slight movement of the fingertips on the keys, into a greater movement, enough to connect them with the type, they have at least five levers between the key and the rod at whose end is the kind. Depending on the height of the type holder, uppercase or lowercase letters are printed.

The type holders are rods that are arranged in a semicircular way, so that the types always strike in the center of the machine. The ink ribbon and paper shifts at each impact.