Switch identification on an old calculator

[stoddartc1]

Hey all, I found an old calculator and I was just wondering if anybody could identify the switches it uses?

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It's an Olympia CD401A (not the Nixie tube model unfortunately).

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The return force is driven by an external coil spring, and there appears to be an o-ring to dampen the sound. The switches are extremely smooth which I why I was curious as to what it uses, as an entire keyboard decked out with them would be awesome!

Any help is appreciated

Picture of internals:

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Source for that picture:
http://www.vintagecalculators.com/html/ ... brary.html
Other helpful sources:
http://www.calcuseum.com/SCRAPBOOK/BONUS/16606/1.htm

[Anakey]

hmm the keycap mount along using the external coil spring would suggest to me that it is some form of foam and foil switch however without seeing the back of the keyboard pcb there is no way to be sure

[kelvinhall05]

hmm the keycap mount along using the external coil spring would suggest to me that it is some form of foam and foil switch however without seeing the back of the keyboard pcb there is no way to be sure

I bet it's foam and foil. I think you're right.

[soyuz]

necro - this is alps spring bridge