Hi
I have never had a clear understanding of how these Escort cuffs were keyed.
From what I do know, all the cuffs sold and used in a particular city were keyed alike.
I would like to know if there are at least 2 cities that share the same key paterns and how many different key changes were made for these cuffs.
I realize that there were 2 different keyways as they upgraded the lock on the later models.
Any help on this topic is appreciated.
mark
"Kuffs"
O--O
OK I agree with most of what has been said. The Chubb Escort handcuffs have 4 different models:
MK 1 Aluminium Lock Case 10 discs very restricted key blank (very thin key-way)
MK 2 Black lock Case 10 discs very restricted key as above.
MK 3 Black Lock Case 9 Discs CHUBB engraved on bottom of lock case where the key enters, restricted key but thicker than MK 1 & 2)
MK 4 Black Lock Case 9 Discs CHUBB name cast into lockcase where the shackle fits. Same key way as MK 3
The Chubb AVA mechanism consists of springless discs that are free to move within the cylinder. There is simply 1 compression spring that effectively pushes the discs down, There are 3 different discs which can be put in the barrel. Discs 1 and 2 can be turned around 180 degrees to form disc 4 and 5. So we have 5 different cuts possible on the key.
So with 9 discs the theoretical number of keys is;
5x5x5x5x5x5x5x5x5 = 1953125
10 discs theoretical keys = 9765625
However there will always be 3 different discs within the lock. Chubb are happy to have keys with a 1 cut (virtually no cut) to a 5 cut (very deep cut)next to each other and this does cause a weak key but the problem of broken keys seems to occur more with the AVA locks that Ford fitted to their Cars in the late 1980's.
So we really end up with:
9 discs 5x5x5x5x5x5x5x4x3 = 937,500
10 discs =4,687,500
I mentionned about the Ford Car keys that used this AVA lock, did they use it in the USA? Basically the key looked identical to the 10 disc padlock / door key but it only has 5 working discs in it. The reason being is that the key could be inserted in 2 ways.
The codes issued with the car would be e.g. C21345
This would actually represent a key cut as:
4,2,5,1,3,3,2,4,1,5 side A
2,4,1,5,3,3,4,2,5,1 side B
You will notice that each pair has to add up to 6.
With this combination there were only 3125 different keys and probably 1500 actual combinations used. Just goes to show how exponentially the key differs go up with each disc added.
So without doubt the Chubb Escort has the greatest number of key differs. When I was a partner with Fetters and we supplied the Escorts they were all supplied to us with the same key marked CC6. Generally speaking Chubb supply batches of 10 keyed alike handcuffs to the Prison authorities. To put the key differs in perspective I think the Hiatt HSS range are next as a manufacturered handcuff (rather than an add on such as the Medico/Assa Peerless cuffs). The Lowe & Fletcher locks used on the Hiatt cuffs have just 2000 differs.
Hope this all makes sense.
Chris
