Fri Mar 12, 2021 5:40 pm
Re: Friction-Fence Locks
A bit more information about the CNAB-6.
This one shows nicely the friction fence mechanism. I colored blue, what would be the drive cam in a real friction fence lock. It has moved away from the spindle and drives only the friction fence. The friction is happening at the red location driving the big part. This big part is then connected to the part which has the actual fence, which I have marked pink.
The part marked in red is basically the "software" of the lock. The cogs on this barrel control which wheel is moved. It is interfacing with the cogs on the primary gear stack (green). The program counter is incremented by the blue hook.
This figure shows the two gear stacks. The connection between them determines the combination. The missing cog (pink) on the secondary gears are the gates. The part marked in green is rewinding the program barrel to the start.
There is are also mechanisms to turn the primary gear stack back, to change the combination and to lock and unlock the back cover.
It is quite difficult to show the operation, because the primary gear stack is fixed to the T plate which covers a lot of the lock's mechanics. I made a few videos showing an opening with details hoping, that it helps understanding the lock. I think with the help of the above figures it is possible to understand what is shown in the videos.
https://vimeo.com/521935515
https://vimeo.com/521935609
https://vimeo.com/521935676
https://vimeo.com/521935750
This one shows nicely the friction fence mechanism. I colored blue, what would be the drive cam in a real friction fence lock. It has moved away from the spindle and drives only the friction fence. The friction is happening at the red location driving the big part. This big part is then connected to the part which has the actual fence, which I have marked pink.
The part marked in red is basically the "software" of the lock. The cogs on this barrel control which wheel is moved. It is interfacing with the cogs on the primary gear stack (green). The program counter is incremented by the blue hook.
This figure shows the two gear stacks. The connection between them determines the combination. The missing cog (pink) on the secondary gears are the gates. The part marked in green is rewinding the program barrel to the start.
There is are also mechanisms to turn the primary gear stack back, to change the combination and to lock and unlock the back cover.
It is quite difficult to show the operation, because the primary gear stack is fixed to the T plate which covers a lot of the lock's mechanics. I made a few videos showing an opening with details hoping, that it helps understanding the lock. I think with the help of the above figures it is possible to understand what is shown in the videos.
https://vimeo.com/521935515
https://vimeo.com/521935609
https://vimeo.com/521935676
https://vimeo.com/521935750
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In case you wonder ... Martin Hewitt is a fictional detective in stories by Arthur Morrison:
Martin Hewitt, Investigator Chronicles of Martin Hewitt
Martin Hewitt, Investigator Chronicles of Martin Hewitt
