Kerberos 309-lever lock with "curtain"

[kerti]

That is 8 levers Russian lock. Kerberos 309. It is modified Kerberos 308


Inside lock. You can see modified lever with no code gates. Also that lever has T-shape slot.Top of that lever is bent.





That modified lever works like curtain in the English style lever lock. It blocks key way from hook lockpicks when key engages with levers.

[ARF-GEF]

I am still amazed by these Russian lever locks.

Tell me Keri is it installed on the inner surface of the door or inside the door itself?

At the 3rd picture, the 1st "lever" have only 2 gates instead of 4 like the other ones. Why is that?

[kerti]

Tell me Keri is it installed on the inner surface of the door or inside the door itself?

This is special version of lock for armored door. It has no side plate.

[kerti]

At the 3rd picture, the 1st "lever" have only 2 gates instead of 4 like the other ones. Why is that?

It is a part of "master system" for lever lock. For that version of lock are two keys.
First-installer key. For armored door manufacturer, for example.
Second-for home owner.

First key can make only two turns. Second key can make all four turns.

So, you can give the installer key to anybody for installing and verifing the door work. And if somebody copied that key, he can not open the door in future. Because you will close the lock with four turns of key.

[ARF-GEF]

Clever, clever!
I think the theory is called "construction keying" in English, though I've never seen it in a lever lock before.

[GWiens2001]

Construction keying is different in that once the final homeowner key is used, the construction key will not work. The final homeowner key displaces tiny bearings, so the pin heights are changed. Think of the bearings as a lock with a master wafer that is removed when the proper key is used. The other keys which require that master wafer (bearings) will no longer work.

There are several lever locks which allow a key to move two 'turns', and a master key that will move the lock four 'turns'. Have one in my collection. Have heard the 2-step key referred to as a 'servant's key' as well. The housekeepers can enter and do their work during the day, but once the master key is used to fully lock the lock, the housekeeper's key will not open the lock until the master key turns the lock back to the 2-step or unlocked position.

Gordon

[kerti]

"construction keying" in English

Thank you!

[ARF-GEF]

you are welcome, thanks for the awesome post Kerti!
But it seems I was wrong! It is not called construction keying... That is a bit different thing.
Read Gordon's post above this Kerti

[kerti]

:D you are welcome, thanks for the awesome post Kerti!
But it seems I was wrong! It is not called construction keying... That is a bit different thing.
Read Gordon's post above this Kerti

Yes, read it.Сonfusion of terms
But now I know that the 2 and 4 turns lever lock is not invention of Russian lock makers.
Thank you Gordon!

[GWiens2001]

No problem, Kerti.

Also, just because the lock was or was not designed by Russian lock makers does not mean that the lock is not interesting, because it is!

Gordon