Marquardt linear typewriter switch

[Halvar]

After Haata prodded me, I added a page for the Marquardt typewriter switch that I found on an Olympia typewriter keyboard a few months ago:

http://deskthority.net/wiki/Marquardt_T ... ter_switch

Not sure about the name, I first thought of "Marquardt two fingers typewriter switch" because the leaf has two "fingers" (contacts) like the already known "two fingers keyboard switch", so that's the lemma at the moment. Maybe somebody knows something better.

I took a lot of scary photos, but I'm not sure if I used the right terminology. Could one of you native speaker switch experts have a look at the article and edit away? Thanks!

Halvar

[Daniel Beardsmore]

Is it a dedicated typewriter switch?

[Halvar]

I don't know. We only found it on one typewriter keyboard so far.

[Daniel Beardsmore]

I originally encountered the Alps integrated dome switch on a page about the Roland TR-808, the same as how Omron B3G-S switches are mostly known for being used in arcade machines. Most people are more likely to know Alps clone switches for couple of Guitar Hero controllers …

Alps integrated dome is now on five variants and counting, and has its very own clone.

[Halvar]

You're right of course -- that's a problem with every descriptive name, isn't it? You call it "typewriter switch" -- turns out it's used in a computer keyboard nobody knew... You call it "two fingers" -- turns out there's another one with the same two fingers ...

I guess to be sure, you'd have to do it like particle physicists and invent names that aren't descriptive at all (top, bottom, charm, strange quarks). Or, the classic of engineer's namefinding -- use female first names or celebrity names.

I'll call it "Marquardt Snowden linear switch".

[HaaTa]

Interesting...Halvar, Beardsmore notice in this pic that there are spaces for two sets of pins



As well as the engineering symbols for physical switches connecting the two pins!
This leads me to believe that there is also a doubly actuated switch variant :D:D

Halvar, would you mind looking to see if any of the switches on the PCB have 4 soldered pins? Even if none do, my belief is that this switch was designed for repeat rate functionality using physical switches. And that one will likely be found.

[Halvar]

Yes, I thought so, too, and already looked for that, but there wasn't.

Also, while the bottom of the case is, the slider is not symmetrical, so the two-pole variant would either need a different slider variant, or be totally asymmetrical.

In contrast to other typewriters, the keyboard PBC of that one really only comprises the matrix, including the switches and a row of diodes, so no reason to have anything more than simple switches there...

[HaaTa]

If you look at the AP400 switch, it has a different slider for the double actuation mechanism. So, I would expect the switch would probably have some changes internally.

[HaaTa]

I don't have stuff ready to take pics yet, but some of the Marquardt Butterfly switches on the Olympia ES 101 are double click (white stem). Still trying to locate my other one...fortunately I think I know where it is (may have to wait until Thanksgiving though).