butters lock

[kwoswalt99-]

Hello,
I haven't seen any new ideas recently, so here's one. I am surprised that no one has done this yet.

I call this a reverse butter's system lock. It is based on what I call reverse sidebar locks, like the old GM car locks, or one of the Gold atom padlocks. I don't know what exactly to call them. It isn't totally original, because I didn't come up with the original idea, but then no lock is completely original. This is a rough drawing, so sorry for the poor drawing. The idea is that if tension is applied, it doesn't bind the levers. All locks have to be tensioned somehow though, and in this one the arm thingy tensions the levers by itself, but it isn't enough to hold a lever at the correct height. I designed it with a plug, kinda like a safe deposit box lock. So you couldn't make a pick kind of like a cross between a 2in1 or a tibbe centipede type pick. With a small and corrugated keyway, to make it difficult to design a tool to hold all of the levers at once. This would be very cheap to make, and could be made very small, and used in a safe deposit box lock. I have never seen a lock with this design, and if anyone knows of one please let me know. I think this actually has the potential to be manufactured. I would like to hear what you think.

[GWiens2001]

The idea has some merit, but there are a few issues you would need to deal with. Based on what I see:

1. The reverse "L" part pivots on a pin at the hole at the corner of the "L"
2. The "L" is spring loaded to push the nose against the lever.
3. There are several false gates in the lever, which the "L" is going to lean into at each false gate (Here is my first concern which will be addressed below).
4. When the true gate is reached, the "L" is able to tip further, raising a stump located at the left side of the "L" so it lines up with the cut in the bolt.
5. When all the levers are in place, the stump is raised and the lever can then move.

Assuming the above is correct, here are some questions:

1. Does each lever have a corresponding "L"?
2. What keeps the "L" parts from binding in the first false gate in the lever if it is spring loaded?
3. What allows it to move past the false gate? (Something has to counter the spring load)
4. Once the lock has been re-locked, what allows the "L" to move back to the top of the lever?

Not trying at all to shoot you down. Trying to make sure that I understand the drawing, and how the lock design is intended to operate. I like your idea, and want to see where this thread leads.

Gordon

[kwoswalt99-]

1. No, it is one piece.
2. It will go into the false gate, but will simply be pushed out of the way.
3. and 4. The spring on the L piece is very weak, and the force from the lever springs push it out of the way.
I hope that helps. Does anyone know what the L piece would be called?
I wish I could make an animation.

[Squelchtone]

I wish I could make an animation.

You might just be able to using Sketchup http://www.sketchup.com/

[kwoswalt99-]

I forgot to mention that another benefit of this design is that it is impression proof.

[Raymond]

If you use the triangle point to contact each lever, all will be properly bound except the one at the correct height. That V shape in the lever will be twice as wide and this will indicate the correct height. By repeating the measurement on each lever, looking for the 'wide' spot, the lock can probably be decoded.

If you could design a feature that keeps the fence on the L from contacting the levers until you can no longer move any lever it would be much more secure.

[kwoswalt99-]

I was thinking of making the false gates the same width as the real ones just not as deep. I am sure it's possible that it can be decoded, but it would be very difficult with such a small keyway. I don't know if it could be made to not contact the levers until they are in the correct position and not bind the levers when tensioned. If that could be done it would be unpickable. I don't think it's pick proof, but I think it's still a good idea that could easily be applied, and be effective.

[mh]

A concept that would block the levers would be the Western Electric lock: http://www.crypto.com/photos/misc/wecolock/

[kwoswalt99-]

A concept that would block the levers would be the Western Electric lock: http://www.crypto.com/photos/misc/wecolock/

In that lock, the levers bind when tensioned.

[peterwn]

Locks of this nature are almost of historical interest. The most significant remaining example would be the Chubb (now called Union) Castle. This has five levers and a nine cut symmetrical key. The bolt is operated via the keyhole curtain. There is a 'sidebar' which is also actuated by the curtain(once the key is turned far enough to lift the levers to the proper levels) which enters the lever slots and frees the bolt to move. It can be masterkeyed in the same way as a 'Butters' lock, but is generally sold as a high security lock without masterkeying. It is different from a conventional 'Butters' lock in that the bolt does not move until the sidebar is engaged whereas in a 'Butters' lock the initial movement of the bolt attempts to engage the sidebar.

It would be interesting to know if the Union arm of ASSA-Abloy still produces 'Butters' locks. It would seem that while lever locks were popular in the UK for commercial and institutional use especially for internal doors (and the 'Butters' system provided a decent and elegant way of masterkeying these locks), Euro or similar cylinders would be preferred now. Lever locks now seem to be limited to low security applications (eg 2-4 differs off levers and 6-10 differs off wards), detention purposes and safes.

It seems doubtful that a reverse 'Butters' scheme would be any improvement on the 'Castle' lock for high security applications, and there would seem to be minimal demand nowadays for low-medium security masterkeyed lever locks. A further problem with masterkeyed lever locks is if re-keying is required the lock furniture must be removed and the whole lock case removed from the door, so it seems doubtful that a compromised system would ever be replaced. Instead nightlatches would be added to any doors where more stringent key control is required.