Semi-pick proof lock

[xBMW M3 GTR]

Heres my idea for a lock that is meant to lock the plug in place if picked, yet the way my idea works out there is a possibility of being picked successfully. Have your normal 5 pin plug, but surrounding the plug would be a tube like fitting called the "outer plug" which would be about half as thick as a driver pin, and will also have holes drilled in the outer plug for pins to fit through. Several serrated pins in the lock might catch this "outer plug" if picked which means the outer plug would rotate along with the inner plug when rotated after picking. This inner plug will have dimples drilled half way through it. When the outer plug is turned, the dimples will align with trap pin chambers 45 degrees from the locks original locking positions. The trap pins drop in the dimples, locking up the plug. Since the trap pins fall in the dimples and not in the chambers in the inner plug, it cannot be re-picked and is instead locked up for good. This system would most likely be able to be reset my disassembling the lock from the inside of the door and disassembling the trap pin assembly and return the plugs to their original positions.

Now it would be possible for it to be picked correctly if all of the serrated pins are picked above the proper shear line. All of the pins would be serrated in order to maximize the chance of the outer plug being gripped onto and rotated.

As for the correct key being inserted, the pins would only be raised to the top of the inner shell, so the driver pins will block the shear line between the locks shell and outer plug, so the outer plug will not rotate and engage the trap pins. With the correct key in, the inner plug would rotate and unlock the lock as normal.

Added notes:
I was thinking of having the trap pins have more powerful springs in it to defeat a plug spinner by-passing the trap pins, but I figured the drag given from the heavy springs behind the trap pins against the outer plug, would take more tension to urn with the tension wrench. This would make the picker aware that the outer plug is being rotated and will allow them to turn back and reset the lock before its too late. I figured it would be better to have the inner plug spring loaded when turned both directions. Not so much that the key would be hard to turn but just enough so that a plug spinner would not be able to easily spin the plug. The spring loaded plug would also make constant tension harder to achieve.

So, give me your feedback guys. I have plans drawn out, but I do not have a working scanner at the moment. I may take pictures of the design via webcam or possibly draw them on MS paint.

[vov35]

I have no clue what you're saying without a diagram.

[CastleBravo]

I think I know what your saying. I found a patent for a similar trap pin design a while ago; I'll see if I can find it. I'm not sure I completely understand what your saying, but I'll give it a go. I think biggest problem is that after the pins set to the false shear line, the key pins will fall down and cause the inner plug to rotate instead of the outer plug. This will probably cause the lock to be even easier to open than normal locks. Lets say that half the drivers are set to the false line and the other half catch the real line. Either way, all drivers (as long as all are on one of the shear lines) will be above the real line, allowing the key pins to fall back down, allowing the lock to open at the real shear line.

I don't know if I'm understanding the lock properly, so please don't complain too much if my interpretation is incorrect. Below I included a quick diagram made in MS Paint. It isn't very well done, it is just a simple sketch of what I believe the lock to be. Don't believe this is necessarily the actual design; I could easily be wrong.





Uploaded with ImageShack.us

[mh]

after the pins set to the false shear line, the key pins will fall down and cause the inner plug to rotate instead of the outer plug.

I also think that this might happen (maybe a typo: I think the driver pins will fall down again).

There a two-shearline locks on the market - the BEST SFIC system, see http://www.crypto.com/photos/misc/sfic/ - from trying to pick these, one could estimate how such system would behave.

Cheers
mh

[xBMW M3 GTR]

In response to the person stating that the inner plug would still rotate after the outer plug is locked up..
..I( did not see that flaw, thank you for pointing that out.

The design could be changed a little. Looking at the angle of the trap pins setting, I guess it wouldnt hurt to have a hole drilled into the outer plug and partially into the inner plug and just have a longer trap pin to jam the shear lines between both plugs and the shell. The trap pins on one side would not slide into the normal pin chambers on the inner and outer plug, thus jamming both plugs instead of just the one. For some reason, I thought the serrated pin would keep both plugs together in my original idea.

NOTE: Looking at the way the plugs would turn, yes one set of trap pins would fall into the normal chambers of the plug, but on one side, while the trap pins falling on the other side would not be accessible to picking

I will post a diagram when I get the chance. Says the attachment quota had been reached

[xBMW M3 GTR]

to keep things simple, the image CastleBravo posted almost hits the nail on the head, but with the flaw in the design posted before, i would want the dimple (would be considered more of a chamber at this point) to extend through the outer plug and into the inner plug, at an angle that it would not cross the chambers the normal pins set into. Also have longer trap pins to block the shear lines between both plugs and the lock shell, leaving the inner plug immobile

[CastleBravo]

I found the patent I was referring to earlier, except the patent sets the trap with multiple pins in each chamber instead of two shear lines. It might be helpful for improving your design.http://www.google.com/patents?id=SCQuAAAAEBAJ&zoom=4&pg=PA1#v=onepage&q&f=false

[xBMW M3 GTR]

Now let's say this idea were already painted ( didn't look into that before designing the lock) how different would my design have to be from the patent incase I wanted this lock sold to the public (not likely to ever happen. I'd like to build this lock and keep it as my own for several reasons)

[Raymond]

Any idea presented to the public, as in this forum, is presumed to be freely given to the public. It can no longer be patented as presented. You would have to make significant changes to be patentable. You would have to search the patent database to eliminate similar designs. Best to see a patent attorney or researcher and be prepared to invest some money.

[CastleBravo]

It shouldn't be much of a problem changing the design to patent it if you do decide to try to sell it, because the problems we discovered need to be worked out. Google has conveniently made a version of their search engine for searching the patent database (http://www.google.com/patents?hl=en). I did a quick search, and didn't find anything that could conflict with your idea; but you'll want to do much more research before filing a patent. A few years ago I also had some ideas for improvements to locks. I had an idea to make Medeco locks bump-proof, a way to retrofit masterlock locker combination locks (or most other padlocks) to prevent the use of a shim, and a few other things, but because it costs a lot to file a patent ($2,000-$3,000), I decided my ideas would probably never be used and the patent wouldn't me worth it; so really think about your idea before applying for a patent. If you do invent a better design, I have a bunch of documents somewhere about filing patents from when I was planning on filing several, and I can help you with it. Good luck with your invention!

[FarmerFreak]

Any idea presented to the public, as in this forum, is presumed to be freely given to the public. It can no longer be patented as presented. You would have to make significant changes to be patentable.

That is also my understanding.

I'd like to build this lock

Do it!! I find it much more rewarding to actually have built the lock. And once it's made you can test it all out. Sometimes they work better than planned and other times you can find an exploit you may not have thought of without having the real thing in your hands .

[vov35]

Build it as a wafer lock instead of a pin tumbler. you'd end up with a fairly large area that would turn the outer plug when a picking attempt occurs. Plus you'd probably end up with 2 false sets and 1 true as a result. It's going to be easier to jam, but hey, shouldn't be picking it in the first place.

[xBMW M3 GTR]

I am in the process of making a slightly larger scaled wooden model simply using different sized dowels. Writing out some plans on where to make the cut aways and such. I don't really have the resources to have a metal version made. Not even sure if there is a place that could do it for me without costing me too much. (though I believe with some time and effort, I could fabricate the outer plug out of an old lock shell and just use a regular lock plug and drill the trap chambers into it.)

As far as this idea no longer being able to be patented due to it being publicized, Its fine by me. I just enjoy knowing I came up with a good idea in my opinion. Thats all I need to be satisfied.

In the next few weeks, keep a look out for pics or video link of the new lock in action.

[vov35]

I can't imagine wood working smoothly.
Also I'm wondering how hard it would be to bump this... (another reason I like the idea of using wafers)

[xBMW M3 GTR]

wood would just be used to show inner workings and such. Its just easier to build this lock out of for now. Id just be using differently cut and sized dowels as the plugs and pins. As for it being bump proof, if this lock were ever commercially available, chances are I would stray away from the common KW1 key way and make some custom shaped key way to restrict the availability of key blanks to make a bump key (although it could obviously be made out of a working key...maybe might scrap that whole idea) As for it being bump proof, due to the 2 shear lines, I believe the chances of it bumping without engaging the rotation of the outer plug would be quite slim.