Yale Bicentric padlock

bbcci · 2012-05-06T14:49:52+00:00

I wanted to reply/add to your point of information post Pete. "Point of Information- The Yale Bicentric cylinder was an early answer to avoiding the problem of key interchange for masterkeyed locks. Most pin tumbler masterkeyed locks use a “split-pin” system and as a result many unintended keys may operate the lock. As an example, a 6-pin cylinder with a single master key disc in all six chambers could be operated by 64 different keys! The Bicentric cylinder has two plugs, neither of which is masterkeyed. One, normally the upper plug, is controlled by the master key while the other plug, usually the lower one, is controlled by the change key. The lock can be operated by the use of either key in its own plug. Thus it is not dual custody in the sense that both keys would be needed to open the lock like a safety deposit box." While the majority of these locks I see are opened by either key, they did make a dual custody configuration with ‘guard’ and ‘change’ cylinders. I’ve included a couple pictures of one I have. The guard key must first be turned before the change key will open, neither will open the lock by itself.

gizmo9326

Donnie wrote
Thanks to ALL who responded to my question about a this type of lock.
Since I already have a "master/change key…. YALE padlock………
My search is for a “dual custody” lock showing at the plug’s = GUARD & CHANGE, yes?
Looks like a difficult lock to find, from the various answer’s that I received
thank you again, Donnie

link:

http://www.ebay.ca/itm/Very-Rare-Yale-Duplex-Dual-Custody-Antique-Padlock-make-an-offer-/141114169513?pt=Architectural_Garden&hash=item20db0f58a9&_uhb=1

[unknown]

cowboyup

gizmo9326 wrote
Here are a few pics of the rare dual custody padlock by Yale.
Requires both keys to open this padlock.
One key is turned first then the other to open.
I picked this up on EBay a number of years ago, I paid through the nose for it and have not seen another one for sale since.
i just HAD to have it.
mike

Hi Mike,
Here’s pics of a bicentric Yale I owned that could be opened by either key.
Interesting that they look identical yet operate differently.

[unknown]

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