Here are some pictures of the Stackpole key switches. I tried to stump Daniel Beardsmore with this one but he got the damn thing right on the first guess from the patent picture. He already had a Wiki page for it with no example here:
wiki/Stackpole_discrete_switch I added these pics below.
You will note that these switches are oblong. As such, there is a short side and a long side so I took pics of both. Sorry, no internal pics or I'd have to destroy a switch because they are sealed. You'll have to check out the wiki page for the patent to see the internals here:
http://www.google.com/patents/US3767878

Long side with key cap and spring removed

Short side with key cap and spring removed

Overhead angled view

External parts (mainly the spring and key cap to hold the spring on

Long side assembled

Short side assembled

Bottom with Stackpole markings (or I would never have known what it was)