Buffer Spring or Volute Spring
Buffer Springs or Volute Springs are also known by the following descriptions:
Strip Spring, Conic strip spring, Dumper Spring, Buffer Spring, or originally named as Puffer Federn.
A buffer spring or volute spring is made from a thin strip of iron, rolled in a spiral over the same stripped side, in the way that the turns make a cone one inside the other with a flat base. Since the strips do not superimpose, the closed height of the spring is equal to the width of the strips from which it is conformed.
One of the characteristics of this type of spring is that it has a variable force constant, because as it increases the deflexion the quantity of active strips decreases, for which the elastic constant will be variable.
Another characteristic to highlight of the buffer spring or volute spring is that if the strips are enrolled within themselves in such a way that they have contact, so that they rub against each other, the generated friction can be used to absorb vibrations or other unwanted perturbations.
Due to this friction these springs are not recommended for continuous dynamic Works. Nevertheless, we can manufacture springs with free space between the strips in order to have a friction-free spring if necessary for dynamic work.
d: Internal Diameter
D: External Diameter
h: Width of Strip
b: Thickness of Strip
Lo: Height without load