why use a detent ball and stop pins?

Matt Shade

Matt Shade

Joined
Nov 24, 1999
Messages
4,981
I was looking at an old electricians knife of my dad's. At first I thought it was just a slip joint, then I opened the main blade and it wouldn't close. It has a liner lock to keep it open, and it uses the normal springs that a slip joint has to A- keep the blade closed, and B-work as a backstop for the blade. So why do we keep using detent balls when they sometimes fail or pop out. And why do we keep using stop pins, when they flatten out over time and cause blade play? Wouldn't the springs be better, or is that to much added work? I know they would make one handed opening a little harder, but with an adequate thumbstud or hole, it shouldn't be to much of a problem.
Just wondering.

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Fix it right the first time, use Baling Wire !
 
Using a stop pin and spacer combo keeps the spine open which allows the knife to be easily cleaned. I consider this important in an everyday carry or working knife. The method you are talking about would be pretty killer though in a gentleman's knife or fancy folder. Especially if it was file worked to some degree. I would think it would definitely have to be heat treated though. Great question, let's see who else comes to bat here.

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It's only a mistake if you fail to learn from it!
 
Matt,

this knife snap shut like a regular slip joint? if so what is the tang shape and the shape of the angled lock area on the tang?

i would be interested to see this.

tim
 
It sounds like a Klein Tool electricians knife, I also have a Schrade with the same setup, brass linerlock.

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Teach them everything they need to know, let them prove it themselves!
 
I don't remember the brand, but it is an electricians knife, and they are still sold today. I saw them at home depot about a week ago. I'll try and post a picture of the setup for those interested if I get a chance.
I know that a well made liner lock doesn't have many problems other than normal wear, if its made right. I was just thinking that this design eliminated alot of the places for error, and would hold up to normal wear better. The stop pins from the normal design are hardened but the shape of them allows them to flatten out over time, especially when a lot of force is used to open the blade.The spring would have to be hardened in order to work, and the face of it that works as a stop wouldn't flatten out because its already flat.


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Fix it right the first time, use Baling Wire !
 
Did you notice that there was an extreme amount of play on that blade. The lock on electricians knives is not a precision thing by any means. It's simply a safety. I'm not sure about the early ones but did you notice that it's the screwdriver blade that locks on modern ones not the main blade? Makes sense since any idiot can use a slipjoint knife properly without it closing but the pressure put on a screwdriver causes a lot of accidental closings. Also on many electricians knives the screwdriver blade has a portion that is sharpened. Without a lock it would be very dangerous to use but it's a sloppy lock.
 
My dad's knife is pretty solid, its also pretty old, so maybe they aren't made that well anymore. I'm not saying that all slip joints should be made with a locking liner, or that we should all start making liner locks with a backspring. I'm just saying I like the idea, and wondered what everyone else here thought. If you made it right it wouldn't have to be sloppy either. For one you would make the liner out of something other than brass, and you could put a little more precision into the tang and the liner.

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Fix it right the first time, use Baling Wire !
 
Hi Guys!

I have seen and worked with a custom folder made by Mike "Whiskers" Allen that has that very type of construction. He used a hardened spring as the stop which doubled as the detent. The tang was a marriage of a slip joint and a linerlock tang in shape. The knife works great, although it is more difficult to open.

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Barry
Jones Knives

Do you hear that?
That is the sound of inevitability.
 
i have always wanted a liner lock that snaps shut nicely instead of that weak little ball dropping the blade that last 1/4 inch.
sounds cool, can one of you post the tang shape here for me? thnx.

tim
 
I'll post a pic of it as soon as possible.

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Fix it right the first time, use Baling Wire !
 
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