suggestion on a better lockback

[dialex]

First thing, let's try to post the picture.



<br /><a href="/forums/attachmentarchive/4872-7-Lockback.gif" target="_new">View Attachment...</a><br />

[dialex]

One for the money...

[dialex]

Two for the show...

[dialex]

Three for the Spyderco

[dialex]

Here I go again

[dialex]

on my own

[dialex]

Walking on the only road

[dialex]

I've ever known...

[dialex]

Does anyone have a picture of the webmaster? Post it here with the subject &quot;Find Him and Kill Him&quot;

[dialex]

And you may add &quot;Good Reward&quot;. I'll gladly send my humble contribution.

[dialex]

And I'll try to make it generous...

[dialex]

And even more generous...

[dialex]

And if this still won't work...

Edited by - dialex on 5/26/2002 12:18:36 AM

[dialex]

No, wait, I'll post the topic myself. Kill the webmaster!

[dialex]

Now that the image is finally here, let's do the talk. There are complaints regarding a not so smoothly opening at lockbacks. I have now a Delica, and though I'm quite pleased of the way it works, I'm a perfectionist myself, so I came with several ideeas that might help, at least theoretically <img src="smile.gif" width=15 height=15 align=middle border=0>
1. A new shape at the cam at the end of the blade. The regular cam provides a constant angular motion around the pivot pin. So I modified it over an excentrical logarithmic spiral, as seen in the picture, that would make - theoretically - the lock to glide easier and easier as the blade opens, just the way a box will slide on an agled plane.
The blade has actually two cams, the first to guide the blade open, and the second smaller one to guide it closed. Once an impulse is given, the blade should open or close according to the direction of the momentum.
2. A small ball on the lock, just where it meets the blade, so the friction is minimal.
As usually I value your input an I'm expecting you oppinions. Thank you in advance!
Just for the record, I actually tried a prototype (without the ball), at one of my knives (The Mako - see topic &quot;Shark and Dolphin...&quot<img src="wink.gif" width=15 height=15 align=middle border=0>, which quite works. I can open the knife with just a shake of the wrist. <img src="smile.gif" width=15 height=15 align=middle border=0>

Edited by - dialex on 5/26/2002 2:33:38 AM

[difkat]

Dialex, You're amazing!

My opinion: This calls for high precision manufacturing. If the ball bearing doesn't properly sit in the detent, it could cause the lock to only partly closed.

Kn.i.Fe - Knowledge is Forever.

[Tightwad]

Very good work mate, Very good work.

Your design over looks a basic problem with
lockbacks that doesn't crop up to often ,but
when it does you've got a handful of trouble.
Dirt / debris in the blade notch.

Linerlocks aren't bothered by dirt or debris in the same
way as lockbacks can be. Fill that notch even part way
and the lock simply will not be able to engage properly.
Add to that some (NO spyderco's ) makers will use a
weak lock spring which makes it even worse. Now if you
add the precision design notch AND a ball the sensitivity
to dirt increases all out of perportion to any gain in lock
strength. lets also not forget the increase in operations to
manufacture this notch nor the tolerance increase that all
adds greatly to the overall cost.

All in all a great idea that is well presented that more than
likely won't sell. Don't give up with work like this you'll
hit an idea that will work. However, don't publish here until
you sell it as these forums are public domain.

[sal]

Hi Dialex. Intersting concepts. Good to see you are thinking. Always a good activity for humans.

We generally put a small dome on the tang cam of the blade. This works in a similar manner to the ball bearing idea, but without the problems associated with ball bearing hardness.

Most of our lockbacks employ a variation in the cam to assist in the opening as you mention. A small amount of variation in the cam makes a big difference.

sal

[AllenETreat]

Hey DiALEX :

GOOD SHOW! I L-I-K-E that ball bearing idea!
BTW : Have you checked out the &quot;Techkno-junkies&quot; forum? <img src="wink.gif" width=15 height=15 align=middle border=0>

ATE <img src="wink.gif" width=15 height=15 align=middle border=0>

[AllenETreat]

<img src="wink.gif" width=15 height=15 align=middle border=0>

ATE <img src="wink.gif" width=15 height=15 align=middle border=0>

[AllenETreat]

That also looks like a more solid &quot;lock up&quot;
too! You'll have a job at <img src="spyder.gif" width=15 height=15 align=middle border=0> one of these
days! <img src="smile.gif" width=15 height=15 align=middle border=0>

ATE <img src="wink.gif" width=15 height=15 align=middle border=0>

[dialex]

Oh, you mean the double dent? Forgoted about it, it was already present at the Raptor design.

[Sword and Shield]

Dialex, you scare me, you know that? <img src="smile.gif" width=15 height=15 align=middle border=0> Here I am, simply using elbow grease and Zoom-Lube to loosen up a tight <img src="spyder.gif" width=15 height=15 align=middle border=0> and you come up with an entirely new way of thinking!

Unbelievable!

Keepin' it real...real sharp, that is.

[AllenETreat]

Just thought this thread was meritorious
of another &quot;rise&quot; to the top <img src="smile.gif" width=15 height=15 align=middle border=0>

ATE <img src="wink.gif" width=15 height=15 align=middle border=0>