A Folded leaf springs is one of the mostly used flexure engineering fundamentals; it can be used for stiffness in one direction as an alternative for a rod. A major benefit is that the folded leaf spring does not comprise sag when displaced and the range of motion is often larger. A disadvantage in relation to the rod spring is the manufacturability.
No parasitic displacements
Force (grey arrow) and displacement (red arrow) are not Unidirectional. To obtain an identical direction an additional is necessary and thus ‘extra stiffness’ is introduced.