Clicker

A metal dome, a spring consisting of a strip of spring steel. The steel is thus characterized in that it has a stable and a metastable state. He is bent until it passes through bumps suddenly the metastable state by force.

The sudden jumping of at this point produces the loud eponymous popping noise. Does the power back, done jumping back, in which again a loud crack is generated. Knack figures operated at the ear, there can produce a sound pressure levels up to 135 dB, which can lead to noise damage.

Applications

The most obvious use is the clicker as children's toys, while the spring steel is most often combined with a small iron grip, to easily build the pressure between thumb and forefinger can. The handle is occasionally printed with a frog motif. In so-called Knatterbooten a clicker produces the characteristic noise in the training of animals, it is used in the Clicker and heat cushion he solves by acoustic shock waves from the crystallization process, which releases the latent heat. During World War II British infantry used the clicker as a badge at night raiding party companies.

Mechanisms based on similar principles, are also used in industrial applications. However, closing and retention mechanisms are usually bistable, ie, running stably in both states. An example of this are terminals for closure of tea bags.

Another application has the effect of some twist-off screw caps that indicate the fact that the glass is unopened and the vacuum in the glass is intact. By the negative pressure of the embossed as clicker middle part is held in the unstable state, the air flows into a glass, the cover is in the stable state.

Snap disc

An analogous application are key switches, for example, in the control part of many electronic devices such as computer mice, which should have a noticeable pressure point. Here, the effect will be perceived primarily tactile. The click spring is also usually the contact-making component and is called the snap disc.