looking for design info on bolster & button release, for dbl. action auto's. Thanx much.

I've had my 1st D/A linerlock prototype on the bench for a WHILE... Don't know that I've ever seen anything in writing ANYWHERE. You'll just have to find someone with one and figure it out.
Basically a linerlock, just add the button to hold the kicker. Button release can be a pain to tune though.

A bolster release auto will most likely be just like a scale release auto, using a coil spring in a pocket. Bolster release will just anchor to the release in a different spot.

Boy, I look back and this is very vague... Sorry, but the info on autos is not just floating around out there to point you right to it. My suggestion is to get to the next big show you can and figure out who there is doing what you like. Visit and you'll find most makers are more than willing to guide and share.

I can help you somewhat if you are specifically interested in the Linerlock/kicker ideas. Email me if you need anything.

Another alternative is to go and buy a cheap D/A clone and take it apart to understand the mechanism. For instance, the LCC clone has a unique bolster release design and you could probably take one apart and copy it, although I am not sure if it is a patented design. You might want to check on that if you do decide to copy it.

I've been down this road before, and when you start talking about duel action bolster release or duel action scale release knives you are opening up a big can of worms.

As I understand it, a traditional bolster release knife works in much the same way as a scale release knife. The locking system is based on a lock-back design where a tooth on the lock bar drops into a notch on the blade holding it opened and closed.

The first problem with this design when it comes to duel action is that with the lockbar tooth in the blade, you can not manually open the blade without raising the lockbar.

Also, because most bolster release and scale release autos work with coil springs, there is not an easy way to just lock the spring in place like you can do when using a knife driven by a leaf spring.

That brings us to an answer to the first problem. Rather than using the coil spring, you can use a leaf spring just as Jason had mentioned. The rocker-bar method is a good method because you can use the front tooth of the rocker to hold the leaf spring in place. I'm not sure if you could make the knife duel action with a push-button because most push-button knives work off coil springs.

The biggest problem you are going to find when trying to make a DA bolster release is this: The bolster is going to pivot on the blade's pivot pin. Therefore its movement will be side to side. Now, the leaf spring is being held down by some kind of tooth that will need to be lifted in order to release the spring. The bolsters action is side to side, and the tooths action is up and down. The problem is linking the two. Finding a way in which moving the bolster side to side raises the tooth releasing the spring.

I got one of the DA Bolster release knock off knives and took it apart to see how it worked. It was quite complex inside and making one in that manner would require a good bit of milling and tooling.

It's a very interesting and unique design, but I believe it limits your knives to being large and bulky.

Just a few of my ideas.

-chris

Thanks much , this info has been quite helpfull, and shed some light into the deep recesses of my cranium