Boye Dent: unintended release

K

Ken Cox

Moderator
Joined
Dec 11, 1998
Messages
15,923
In the big knife thread Karl "Safety Guy" and I got talking about unintentional releases with a lockback.
I thought I'd move it here and not compromise the big knife thread.

Over the years I have read three or four person's accounts of how they can release a lock back by squeezing with the whole hand.
I cannot do this, even intentionally, as hard as I might try.
Now, I haven't done any hard work with my hands for several years, and maybe if I had work-hardened hands and big calluses it might happen.

Karl says he has experienced the loosening of the lock (but not a complete release) in the hammer grip when practicing with his left hand.
So let's discuss this grip for a second.
Hammer grip, to me, means the same as a baseball bat grip except the thumb, instead of wrapping over the top of the index finger and maybe a little of the middle finger, lays next to the blade or handle, in front of the index finger.

Saber grip - thumb on top of blade or handle;
Hammer grip - thumb on side of blade or handle;
Baseball Bat grip - thumb wrapped over finger(s); and,
Paintbrush grip - like the Saber grip, except the knife rotated ninety degrees on the long axis so the thumb rests on the bolster or choil (with the Native, the thumb goes/stays in the hole).

Has anyone else had experience with a lockback loosening or releasing its lock from squeezing with the whole hand?
I don't think they invented the Boye Dent for nothing, but I just can't imagine it happening.
 
If I grip the knife "sideways," thumb on left bolster and spine along my palm, near the base of my fingers, I have experienced this (no bloodshed, yet . . .)with some lockbacks. Mid-locks seem the worst offenders in my hands. I've just become more cautious, now that I'm aware of the possibility.

In a "normal" grip, with the spine under the base of my thumb, I've never had this happen.
 
Actually Ken, maybe its the other way 'round.

I work at a desk all day long and not much hardcore work on the weekends - thus, I have pretty soft palms.

On most front-locks of medium to large size (Chinook excluded), I can fairly easily release the lock (part way) by firmly gripping the handle any number of ways. I can't imagine a full release, but a partial release is a reality.

I have NOT had this happen when using a front-lock, as I don't tend to grip that hard cutting boxes and whittling wood.
 
Ken, I've carried, used, and occasionally abused one lockback or another for well over twenty years, Bucks and Schrades till this year, now Spydercos. I've never had one give even a hint that I was lifting the lockbar by gripping the knife. I vaguely remember some writer years back saying that when you are doing something that places heavy downward pressure on the top of the blade, it is next to impossible to intentionally release the lock. Not a theory I'd want to try to prove or disprove, but it makes some degree of sense because of the pressure put on the lockbar by the blade in that situation.

As far a Boye dents go, I find them ok on larger knives like the Ayoob, and more of a pain in the butt than a help on the smaller ones like the Dragonfly. I have a hard time depressing the lockbar far enough when trying to closing the Dragonfly because of the dent. My CF D'fly, which lacks the dent, is much easier to close.
 
I have this little Kershaw with rubber over the handle, and about a a 2" blade. It's lock is at the but, and covered with rubber. If you hold this knife in a reverse grip, with the lock area at the base of your index finger, and stab down with a few ounces of pressure on the clip point, it will close every time. That is just one of many ways it can happen. Of course I use this knife to open boxes, and such, and have never had an accident with it, but it would be a sad thing to try to get agressive with. On this knife, if one looks at how far the back of the knife has to lift away from the blade to release it, it is about .7 MM (1/36")(I had a .7 mm lead pencil to hand) It's like a hair trigger. If it had a deeper engagement, it wouldn't be anywhere as nice to handle as a gents knife, but it would be tough for it to release by accident.

I feel with any lockback one should learn the right way to hold it. In fact, with any knife, there are ways you will hurt yourself if you don't hold them just so.
 
I have big hands and can do it on a puma general and a cold steel voyager. One's a midlock and opens when gripped low on the handle. The other's a bottom lock and opens in a tight regular grip. I always test every lockback before I buy to see if I can release it with a tight grip.
 
I do have hard hands and have never had one offer to unlock.I think it my just be the sahpe of the hand and the way it is held.
 
I usually use the traditional saber grip or a grip similar to a "weak" right-hand, golf grip (with the thumb rotated slightly toward the left side of the handle--somewhere in-between the saber and paintbrush grips). In normal use, I haven't had a lockback inadvertently release on me, yet.

Although I've heard the theory behind it, I still fail to see the mechanical advantages of the Boye detent over a normal release button. Further, imo, artistically, the Boye detent also detracts from the smooth profile lines of the handle design. Sort of a "rut" in the road, if you will.
 
Ken, the only time that I have ever had a backlock do that on me was a "cheapandnasty" that I should never have bought in the first damned place. It failed the "spine whack" test also. I have long since tossed it.

My wife was looking at a rip-off $6.99 version of the Dragonfly at the local Safeway and asked me about it. I went over with her and looked at it, tried the "spine whack", very gently, on the side of the cardboard display and had the blade collapse on it, so I never got to the point of trying a hard grip. I loaned Georgia my Cricket to try and she loved it, especially the tip, for the fine detail picky work that she wanted a little knife to do. I found a beautiful one that Vess, a BF member, was selling that he had done some file work upon and bought it for her as a gift. :) She has very much enjoyed it. Yes, I know that the Cricket is a liner lock, but the POS copy of the Dragonfly was a backlock.
 
On my Puma with the opening problem, I recently dremelled a Boye indent and it works. The knife will still open, but it takes a lot more pressure, you basically have to do it on purpose. It won't open by accident. So...the Boye detent works.
 
In my experience with my paired serrated/nonserrated Spyderco G-10 Police it is easier to find the lock with your thumb when it has the Boye dent.
As you start to press down on the lever, the dent helps hold the thumb on the lever.
Also i find the Boye dent spreads the contact area with the thumb, so you do not hurt it with a stiff lock or thin lock bar.
 
You must log in or register to reply here.
Back
Top