Editing Marquardt Butterfly (section)

==Variants==
{| class="wikitable variants-table"
! !! Switch !! Description
|-
| [[File:Marquardt butterfly -- black, variants table.jpg|175px]] || The black one || Standard switch
|-
| [[File:Marquardt butterfly -- grey, variants table.jpg|175px]]  || The grey one  || Multi-switch operation
|-
| [[File:Marquardt butterfly -- grey, variants table.jpg|175px]]  || The grey one  || Alternate action
|-
| [[File:Marquardt butterfly -- white, variants table.jpg|175px]] || The white one || Double action
|-
| [[File:Marquardt butterfly -- multi-switch module.jpg|175px]] || Olympia multi-switch module || Multi-switch operation
|}

Head-to-head press tests indicate that black actuates first, then white, then grey, yet all three types have the same spring.

===Black===
The black switch is the standard momentary single pole switch.

The depicted switch is NOS from STRONIC in France.

<gallery widths=250 heights=187>
File:Marquardt butterfly -- black, opened.jpg         | Opened
File:Marquardt butterfly -- black, spring removed.jpg | Spring removed
File:Marquardt butterfly -- black, terminals.jpg      | Terminals, inside
</gallery>

===Grey===
The discrete grey switch facilitates multi-switch operation. The switch contains a small control bar that is extended when the switch is pressed. This bar rotates a metal rod that runs the width of the alphanumeric area, and is likely part of a shift lock mechanism where shift lock is released by pressing either shift key. The control bar is not self-closing: a spring in the multi-switch module will be return the control rod to its rest state, and this will push the control bar home. In the illustrations below, the switch is held vertically to allow gravity to retract the control bar. A cam on the slider is used to push the bar sideways as it is depressed.

The depicted switch is NOS from STRONIC in France.

<gallery widths=250 heights=187>
File:Marquardt butterfly -- grey, open.jpg                       | Switch opened, with control bar retracted
File:Marquardt butterfly -- grey, closed.jpg                     | Switch closed, with control bar extended
File:Marquardt butterfly -- grey, control bar placement.jpg      | Control bar placement, seen from inside
File:Marquardt butterfly -- grey, disassembled, bottom views.jpg | Disassembled, bottom views of components
</gallery>

===Grey Alternate action===
Alternate action version.
<gallery widths=250 heights=187>
File:Marquardt butterfly -- grey, alternate action.jpg       | View from the top
File:Marquardt butterfly -- grey, alternate action, disassembled.jpg | Disassembled
</gallery>

===White===
The white switch is double action. It has a second pair of terminals, arranged perpendicularly to the normally-open terminals. These provide stage two of the double action mechanism. Just as with stage one, stage two provides click feedback and hysteresis.

Both internally and externally, the second pair of terminals are surrounded by a powdery clear foam that rubs off readily. The stage two mechanism lives inside a sub-assembly partially hidden inside the foam-covered enclosure moulded into the switch. These mechanism is partially exposed, allowing it to be engaged by the slider.

The depicted switch is NOS from STRONIC in France.

<gallery widths=250 heights=187>
File:Marquardt butterfly -- white, bottom.jpg               | Bottom of the white switch showing the dry foam surrounding the second pair of terminals
File:Marquardt butterfly -- white, terminals, primary.jpg   | Primary terminals, interior portion
File:Marquardt butterfly -- white, terminals, secondary.jpg | Secondary terminals, interior portion
</gallery>

===Olympia multi-switch module===
Olympia typewriters with Butterfly switches use a three-way multi-switch module on the left side of the alphanumeric area. The front and centre switches are grey and the rear switch is black. The likely explanation is that the two grey switches form a latching shift lock with remote release (by pressing either shift key). Existing photos of the insides of this module don't quite clarify the functionality of this module.

The module is completely indivisible: it is not three switches semi-permanently attached, but rather a single moulding divided into three switch units.