Silent tactile switches

[mf68]

@Deadeye To quote myself from a different thread about springs:

@mf68

From a purely mechanical engineering perspective, you would assume only Hooke’s law would come at play. Hence, only the spring length and its stiffness constant k would be important, where the latter is determined by the spring material and its wire thickness. For that reason, I cannot recall any other typical mechanical application where “multi-stage” springs are being used.

However, this is not counting with the buckling effect, so nicely described by @flashquark above. The upper part of a two-stage spring may experience some support from the stem and buckle differently than the lower part that is perhaps more free to buckle. This gives rise to interesting effects not seen in run-of-the-mill mechanical engineering applications. In this context, two-stage springs make sense, but three-stage probably not.