New Banham cylinder breakdown (images)

[mhole]

Here's a look at the new* Banham patent cylinder, in this case for a mortice cylinder, as used on the new M2002 B.S. hookbolt. It works just like a euro cyliner, and has a solid brass shroud to protect each end from brute force attacks (you know what I mean). The external shroud is fixed on with 2 concealed alan screws, and the internal shroud screws onto the threaded portion of the cylinder, and is then secured in place by screwing on the escutcheons (not shown).



Here it is with the outer shroud removed. You can see the hardened anti drill insert in front of the cylinder. this insert sits in the brass shroud, and is held in place by a small lip at the end of the shroud. It has a punched tab which engages in a notch in the cylinder so it can't spin independantly of the plug.



Here's the cylinder with both shrouds removed.



The plug is held in by a small clip at the front of the cylinder. Here the clip is slipped out, and the plug removed.



And here's the money shot There are another 6 pins on the other side of the cylinder, which are operated by the other side of the key.



And a closeup.



I've not seen a system exactly like this before. Rather than a bottom pin and a spring in the body of the lock, the pin acts against a spring which is held in place by a doughut shaped cap, with both the pin, spring, and cap contained in the plug.




*Yeah, I know - not that new, but as distinct from the 'old' Banham euro profile cylinders.

[mh]

Thanks for the pictures!

If you look at this at first glance, one would think that the springs push the pins into the plug, and therefore the plug would be free spinning without a key inserted, that would be a not-so-secure lock design...

The key to understanding it would be if the pins were be balanced, and a left plus a right pin always added up the same length. In that case they would push out of the plug on one side by default in most locations (unless they require are centered position to open),
and they would be moved by the correct key to a centered position.

Quite bump-proof

Cheers,
mh

[Squelchtone]

For all interested, here is the patent for said lock. Scroll all the way down for the patent drawings.

http://nynex.s5.com/lp101/EP0892130B1.pdf

Squelchtone

[toomush2drink]

When the key is in the lock the pins actually touch each other through small holes in the key. i would go as far as to say its almost pick proof because if you tension it and set a pin on one side it means the opposite pin is now over set.
There are loads of these locks where i operate in london,nasty locks to encounter but luckily most people don't use them properly so entry can be gained.

I spent quite a bit of time projecting these trying lots of different methods to overcome it with little success.

[dougfarre]

Im still confused

[greyman]

Thanks to the original poster for these nice images. It's a nice little design. I think the key is the different springs (light/heavy) on either side of the key - the key finds the right "break points" between the pin pairs, but this would be very hard to do by manipulation. A similar idea pops up in the DUO lock where their are pairs of wafers with a strong internal spring.

[mh]

Thanks to the original poster for these nice images. It's a nice little design. I think the key is the different springs (light/heavy) on either side of the key - the key finds the right "break points" between the pin pairs, but this would be very hard to do by manipulation.

Are you sure the springs are different? And why? Wouldn't it work as well with identical springs?

Cheers,
mh

[Olson Burry]

Hello. This lock had me somewhat confused for a while. Having read through the rather long-winded patent language and studied the diagrams I think I get it:

First and foremost, yes the spring are of different strengths as this except shows:


I suppose the bias is to make sure the shorter and longer pins meet in the middle of the keyway, as we will see in a second:

I was confused until I realised that out of the two pins that meet, only one of the pair stop the plug from rotating.

The issue here is, that if you attempt to pick it under torque as normal, the pins already past the shear will bind there, meaning they would have to be pulled, not pushed past the shear.



So an over-lift on one side would result in binding, as would an under-lift on the other side.

This amusing piece of language wasn't wasted on me though:

I was thinking about the more eccentric people I've met in my life and didn't realise eccentric could also mean off center (I always thought it was a ascentric or something). Learn something everyday.

Hope that helps, I spent some time writing more words than this a minute ago and then firefox crashed, upon recovery I'd lost it all so I hope this will do.

Cheers

[lunchb0x]

looks like a very interesting lock, couldn't work out how it would lock at first, so thanks Olson Burry for clearing it up.

[mhole]

For reference, with the outer caul removed, the lock can be easily 'picked' by accessing the outer faces of the pins, but this isn't possible with the caul and escutcheon in place, and they can't be removed from the outside of the door.

Still useful to know if you need to remove one or open one from inside a property without access to the key.

[Olson Burry]

So, to pick this lock then, one idea might be:

1) Apply tension to the plug and seek out the binding pin. This will be the one trapped in the shear line.

2) Release tension and push the pin opposite to the binding pin towards its own side, allowing the release of the binding pin. then reapply tension.

3) repeat.

Not knowing which side the binding pins are on is the main problem I think.

This would be an interesting lock to get hold of
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