I've always wondered exactly how a forward clicky switch (momentary on) worked. I have taken apart a reverse clicky (see here) and it works similar to the inside of a ball point pen, much as I suspected. I have never had the opportunity to dissect a forward clicky, that is, until tonight.
The photos below are from the switch in my NiteCore Defender Infinity, my EDC since the day I got it and my favorite light up to this point. A couple of weeks ago, my switch started intermittently sticking in the on position, so EdgeTac sent me a replacement switch- gotta love their customer service- it's top-notch. I got the replacement switch today and decided to take apart the defective one, partly to see what was the cause of the sticking and also to see how a forward clicky works (I'm the type of person that just has to know how everything works).
The defective switch in all its glory.
Bottom of the switch with the legs folded under for soldering onto the circuit board. I wasn't crazy about this method, so I cut the legs off before soldering my new switch back onto the board.
Top of the switch removed with insides placed exactly how they are with cover on. The clicky parts look a lot like a ball point pen inside as well.
Closeup of the inside of the bottom piece. These are the contacts that get closed by the spring supported metal disk providing momentary on until the switch is clicked into the on position.
Individual parts arranged in the correct order of an assembled switch.
I couldn't find out what was causing the sticking, but my light works perfectly again with the new switch installed. And a bonus of the little glitch with my light- I get to see how a forward clicky works.
A couple more photos added 1-29-08:
Closeup of the metal disc as it makes contact with switch contacts (spring under disc removed). The disc overlaps the contacts about 1 - 1.5 mm on each side.
Straight on closeup for a better angle.