Editing Olivetti dome with slider

{{TODO photo|more=true|reason=full disassembly, showing the helical spring and intermediate peg}}

{{infobox dswitch
| image name          = Olivetti dome with slider.jpg
| manufacturer        = [[Olivetti]]
| product code        = 
| switch type         = Tactile
| actuation force     = 
| introduced          = 
| discontinued        = 
| switch mount        = [[Plate mount]]
| keycap mount        = Proprietary
| sense method        = Conductive dome over PCB
| patents             = [http://www.google.com/patents/EP0104956B1 EP0104956B1] (1983)
}}

'''Olivetti dome with slider''' is a provisional name for a series of [[spring over dome]] switches from [[Olivetti]] using conductive domes over a PCB. It is a cost-reduced development of the similar-looking [[Olivetti snap action]] switch.

==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.

==Keyboards==
*AT&T PC6300 keyboard (KBD 302) (red sliders)<ref name="olivetti_ds9"/>
*Logabax Persona 1600 Keyboard (appears to be a re-brand of ANK 2462) (red sliders)<ref name="olivetti_ds6"/>
*[[Olivetti Keyboard 1]] (red sliders)
*[[Olivetti Keyboard 2]] (red sliders)<ref name="olivetti_ds4"/>
*Olivetti Keyboard 2 (ANK 2462) (white sliders)<ref name="olivetti_ds3"/>
*Olivetti M20HD keyboard (white sliders)<ref name="olivetti_ds5"/>
*Olivetti M21 keyboard (red)<ref name="NFB-M21" />
*Xerox 6060 Keyboard (appears to be a re-brand of the ANK 2463) (white sliders)<ref name="olivetti_ds7"/>

==Gallery==
The following images are of an Olivetti Keyboard 2.

<gallery widths=250 heights=187>
File:Olivetti ANK 2462 - Switch Housing and Spring.JPG   | Switch with rubber dome still in place
File:Olivetti ANK 2462 - Switch Housing Bottom View.JPG  | Bottom view of rubber dome showing carbon contact pad
File:Olivetti ANK 2462 - Switch Housing Dome Removed.JPG | Switch as viewed from below, with rubber dome removed
File:Olivetti ANK 2462 - PCB Trace.JPG                   | Switch mounting plate with switch removed and PCB visible below
</gallery>

==References==
<references>
<ref name="olivetti_ds3">Deskthority — [http://deskthority.net/photos-videos-f8/olivetti-keyboard-2-rubberdome-t4783.html Olivetti Keyboard 2 Rubberdome]</ref>
<ref name="olivetti_ds4">Geekhack — [https://geekhack.org/index.php?topic=44486.0 Olivetti Personal Computer Keyboard 2] Posted 2013-06-07. Retrieved 2015-07-31.</ref>
<ref name="olivetti_ds5">z80ne.com — [http://www.z80ne.com/m20/index.php?argument=sections/photos/antonio_hd/antonio_hd.inc Antonio Busi's M20 BC and ST] Retrieved 2015-07-31.</ref>
<ref name="olivetti_ds6">System.cfg — [http://forum.system-cfg.com/viewtopic.php?p=35090&sid=3cd36a642e10f451b438fec50eafd199#p35090 Logabax Restauration Persona 1600] Dated 2010-07-25. Retrieved 2015-07-31.</ref>
<ref name="olivetti_ds7">reddit — [http://www.reddit.com/r/MechanicalKeyboards/comments/1tz41j/an_old_xerox_keyboard_with_a_switch_i_dont/ An old Xerox keyboard with a switch I don't recognize...] Dated 2013-12-30. Retrieved 2015-07-31.</ref>
<ref name="olivetti_ds9">Imgur — [http://imgur.com/a/3Frye AT&T PC6300 KBD 302] Dated 2013-12-31. Retrieved 2015-07-31.</ref>
<ref name="NFB-M21">Nightfall Blog — [http://www.nightfallcrew.com/23/02/2014/repairing-a-defective-olivetti-m21/?nggpage=4 Repairing a defective Olivetti M21] (page 4) Dated 2014-02-23. Retrieved 2015-07-31.</ref>
</references>

[[Category:Olivetti switches]]
[[Category:Spring over dome switches]]
[[Category:Tactile switches]]
[[Category:List of all keyboard switches]]