@bep said:
"So, at this point the spring has tension and the red part has made contact with the pin, and further movement of the handle will begin to slide the blade out of its contact. Right?"
[highlight=#ff4040:2cbrobxo]Yes![/highlight:2cbrobxo]
"But, just to keep my reputation as a royal pain-in-the-butt alive, I do have a question -- To keep the spring from just raising the blade with the arm, there would have to be tension, or pressure, that holds the blade in place until the arm raises the blade far enuf that it can break free and snap up, right?"
[highlight=#ff4040:2cbrobxo]Yes!, the pressure should ensure for enough friction wen the spring gets loaded to prevent the blade from sliding out of the contact fingers
Whit this design the "red part" slides the blade out off the contact fingers.
Then at some point the blade snaps away from the contact fingers[/highlight:2cbrobxo]
But, while every blade switch that I have found uses a contact that is formed into a sort of spring shape to ensure good contact with the blade this beast seems to have relatively thick "arms" that stick straight up, and I don't see how they can provide the spring action to ensure good contact, let alone provide enuf pressure against the blade to prevent it from just moving up with arm.
[highlight=#ff4040:2cbrobxo]They somehow can get enough contact pressure wih this design, without enough contact pressure the contact resistance would be to high, and the switch could burn/melt at that place.[/highlight:2cbrobxo]
"Also can't figure out why they would go to the trouble of cutting the contact down the middle like that. Does that have something to do with it?"
[highlight=#ff4040:2cbrobxo]Yes, this is done to ensure a big enough good contact area, to keep the contact resistance as low as possible
Wider fingers would be more difficult to get them plane to the switch blade[/highlight:2cbrobxo]
About your drawing.
A part of the blade and the top of the fingers should be slightly rounded, to let the blade slide in easier.
Some things to read up on the switch topic:
https://phasetophase.nl/kalenders/kalender_2009.html (translate with google)
https://ecprops.com/products/knife_switches/knife_switches.html
http://0330de8.netsolhost.com/test/html/products/knife-switch.php
Together we have 4 active brain cells
Hopefully the move to your new home goes very well.
Hey Bep,
Really appreciate all the time and effort you have put into setting me straight on this. But for now everything has taken a back seat to other higher-priority things in my life.
Again, many thanks.
Steve