Editing Olivetti dome with slider (section)

==Description==
The switch appears in a patent application by 'Ing. C. Olivetti & C., S.p.A.', filed in September 1983. The patent references the 1974 patent related to the [[Alps plate spring]] switch.

The rubber domes are discrete, and are held in place under the main switch housing by four pegs that insert into the corners of the dome. Each switch module is also discrete and removable: the ability to easily pull out a switch module from the top of the keyboard for replacement is cited as a design goal in the patent.

The design is similar to that of [[Fujitsu Peerless]] in that there is a [[helical spring]] between the slider and the dome. Instead of a plastic tube to keep the spring captive, a peg is placed inside the spring instead.<ref name="olivetti_ds4"/> The patent describes in detail the interaction between the helical spring and rubber dome, illustrated with [[force graph]]s; while not specified explicitly, it is clear from the explanation and diagrams that this design allows for both [[overtravel]] and [[hysteresis]]. When the dome collapses, the spring extends to fill the gap, leading to an overtravel period where the only force is from the spring. When releasing the key, the dome does not spring back until the force from the helical spring has been sufficiently reduced.

Red and white sliders are known to exist. The significance of the slider colour is not yet understood.