Homage to The Fichet 787s (Image Heavy)

[MrAnybody]

The French Fichet 787s has a beautiful mechanism with over 80 components and is regarded as an extremely secure lock. I’ve read that John Falle once designed a tool to pick it, and I'd simple love to see it.

Now I’ve had the chance to do some pics of a tear-down, I’ve been really looking forward to sharing them with you guys. There are a couple of examples of Fichet 787 threads out there, but I’ve yet to find one that explains how the mechanism works. So from that point of view, I thought it worth a post.

My apologies to anyone who has problems with such an image heavy post.

Pro tip Press 'CTRL' and click on an image for a larger view of it in a new tab.

1.JPG

First off, the non-reversible key has a total of 8 cuts on each side, but only an alternate 4 are used on each side of the key. With 10 possible depths on each cut, the number of possible combinations runs into 100 million:

2-edit.JPG

Notice the difference in the key when comparing a Fichet 787, 787s and 787z. The 787 (left), 787s (middle) and 787z (right) all contain 2 packs of 4 levers. Fichet first developed a 787z with 10 levers, but withdrew it quickly from the R&D stage or testing as it either had some issue in production or durability. It never really got to market. As a result, the differences between the 's' and the 'z' were more about key security rather than anything else:

Fichet 787 Keys_edit.jpg

There are front and rear cylinders to lock, and the one shown in detail here is the front section:

4.JPG

To remove the cylinder from the housing rotate the locking ring and the cylinder and tail piece slides straight out:

5.JPG

6.JPG

8.JPG

9.JPG

The key enters 2 closed spring-loaded gates at the front of the cylinder. Ingeniously, if the spring loaded gates are open more than required for the key to enter, rotation of the cylinder will be blocked (I haven’t found out how ….. yet!) :

10.JPG

The mechanism of the 787s includes 8 levers in 2 packs of 4. This pic shows the one pack of 4 at rest:

11.JPG

These engage (along with another pack of 4 levers on the other side of the mechanism) with a set of 8 rear cogs. Here are the rear cogs at rest:

12.JPG

The 2 sets of 4 levers are mounted on axles at the front of the cylinder (see left), and the 8 rear cogs are mounted on a separate axle at the back (see right):

13.JPG

As the non-reversible key engages with each pack of 4 levers, the bitting on each side causes each of the levers to ride up, as that happens the rear end of the lever (with is toothed) rotates 1 cog either counter-clockwise or clockwise depending on which of the 2 stacks it belongs to.

Here’s the position of the levers once the key is inserted. The levers that were previously visible at rest are pushed down, while the pack of 4 on the other side of the cylinder is pushed up (giving the clockwise and counter-clockwise rotation):

14.JPG

Only the correct cut on the key for each lever will allow that lever to raise the correct amount, which in turn rotates each cog to the right degree. The tail-piece (not shown) can now engage with the slot in the cogs (see below pic) as pressure of the key being inserted drives the cylinder through the housing.
And Voilà as they say

Only the correct key will align all 8 rear cogs into the correct position. If the correct rotation of the cogs is achieved the cylinder can move through the housing through pressure of the key on insertion). As a result, the tail-piece can engage with the cam:

15.JPG

Another sweet feature is the blocking bar that drops into the cylinder once the correct rotation of the cogs is achieved. It is only once the blocking bar drops into the cylinder that the cylinder can move through the housing in order to engage with the tail piece and cam:

16.JPG

I’d just love to break this puppy down further, but I really can’t see how it’s done without specialist tools. If anyone has got some help on this for me, I’m all ears.

Any comments, additions or corrections are very welcome.

I’d really recommend buying ‘High-Security Mechanical Locks: An Encyclopedic Reference’ by Graham W. Pulford for a much more detailed understanding of this lock. He devotes nearly 5 pages to it (page 409 onwards).

Patent drawing can also be found here

A great breakdown diagram can be found here

Enjoy, enjoy ……

[MBI]

I know that must have taken a decent amount of time to take all those excellent pictures and do the writeup, thank you.

I hope you'll consider uploading those pictures directly to our server for this thread. I'd hate for them to all end up as broken links at some point down the road as happens so often with older posts on various forums, as different image hosting sites fall into disuse over time.

[MrAnybody]

I know that must have taken a decent amount of time to take all those excellent pictures and do the writeup, thank you.

I hope you'll consider uploading those pictures directly to our server for this thread. I'd hate for them to all end up as broken links at some point down the road as happens so often with older posts on various forums, as different image hosting sites fall into disuse over time.

That's a great option. I didn't know I could. How do I upload to the KP server?

[GWiens2001]

I know that must have taken a decent amount of time to take all those excellent pictures and do the writeup, thank you.

I hope you'll consider uploading those pictures directly to our server for this thread. I'd hate for them to all end up as broken links at some point down the road as happens so often with older posts on various forums, as different image hosting sites fall into disuse over time.

That's a great option. I didn't know I could. How do I upload to the KP server?

+1 on the great writeup. But Andy, you are a bas###d!!! Now I gotta try harder to find one of these babies, and I've been looking for a while!

Also, would not mind uploading pictures for some of my writeups to the KP server, too.

Gordon

[MrAnybody]

I know that must have taken a decent amount of time to take all those excellent pictures and do the writeup, thank you.

I hope you'll consider uploading those pictures directly to our server for this thread. I'd hate for them to all end up as broken links at some point down the road as happens so often with older posts on various forums, as different image hosting sites fall into disuse over time.

That's a great option. I didn't know I could. How do I upload to the KP server?

But Andy, you are a bas###d!!! Now I gotta try harder to find one of these babies, and I've been looking for a while!

[MBI]

When you're making a new thread or posting a reply, scroll down near the bottom of the window and you'll see a tab labelled "upload attachment". That will let you upload multiple images, then once they're uploaded you just place your cursor in your text where you want an image, then click the "place inline" button next to the image in question.

Here is a tutorial Aedalas wrote that has screencaps and better descriptions than I've written here.
viewtopic.php?f=58&t=6755

[TheNatural]

That is probably the coolest lock and key design I have ever seen. Thanks much for the great post! Awesome photography!

[huxleypig]

Whoa, nice lock Mr A. Your French collection is coming along a treat.

Regarding picking these locks, do you know if you can get any meaningful feedback when you apply tension and push down the teeth (?). The bits that the key pushes down to engage the dials? If you could get some sort of feedback (but the return springs push the teeth back up when you release pressure) then you could devise a tool where you can lock the tynes into place once you feel them at their correct height. Or does the key interact directly with those dials?

About the spring loaded mouth to the lock stopping rotation should they be opened too much, it looks like the tabs just stick out a little too much if you do this, no? I've seen other 787's that have a 'toothed' sprung entryway, is that what you're demonstrating with the different keys at the beginning of your post?

Send it me dude, I'll try it! If Mr Falle can do it...And if you want to preserve the keys I promise not to destroy any of them in the making of the pick!

[MrAnybody]

Regarding picking these locks, do you know if you can get any meaningful feedback when you apply tension and push down the teeth (?). The bits that the key pushes down to engage the dials? If you could get some sort of feedback (but the return springs push the teeth back up when you release pressure) then you could devise a tool where you can lock the tynes into place once you feel them at their correct height. Or does the key interact directly with those dials?

The cogged teeth are unreachable from the front of the lock. the contact you have to the part of the mechanism is through the pivoted levers that engage with the key. The degree that those pivot dictates the degree with which the toothed cogs turn. The key doesn't interact directly with the toothed cogs.

I think the art for a pick tool would be to keep each lever static and then move to the next, but (and it's a huge 'but'), there is no feedback to know when the cog is set correctly. It's only when all cogs are set correctly that any forward movement occurs. I'm just itching to find out how John Falle got around this issue. With that in mind, it CAN be done.

About the spring loaded mouth to the lock stopping rotation should they be opened too much, it looks like the tabs just stick out a little too much if you do this, no? I've seen other 787's that have a 'toothed' sprung entryway, is that what you're demonstrating with the different keys at the beginning of your post?

Yep, I think that's it. This would prevent any forward movement in the cylinder. Thereby preventing it engaging with the tailpiece and cam. i didn't think about that earlier.

Send it me dude, I'll try it! If Mr Falle can do it...And if you want to preserve the keys I promise not to destroy any of them in the making of the pick!

Man, youre gonna have to catch me on a good day for that to happen, my friend

[MrAnybody]

When you're making a new thread or posting a reply, scroll down near the bottom of the window and you'll see a tab labelled "upload attachment". That will let you upload multiple images, then once they're uploaded you just place your cursor in your text where you want an image, then click the "place inline" button next to the image in question.

Here is a tutorial Aedalas wrote that has screencaps and better descriptions than I've written here.
viewtopic.php?f=58&t=6755

All done. Works out nice too. Many thanks, MBI.

[ARF-GEF]

+1 on the great writeup. But Andy, you are a bas###d!!! Now I gotta try harder to find one of these babies, and I've been looking for a while!

My thoughts exactly!
Such an amazing lock!! Wow, just wow! You must give it to them, the French know how to make delicious locks... The heart at the name is really well deserved.

[huxleypig]

I love the way the key translates vertical movement into horizontal movement. Well, sort of. I mean as in the how the cuts on the key interact with the levers, not the gearing mechanism.

So if you were to pick the lock you could push each lever downwards to the right position but much easier would be to push them into the sides of the lock. At first I thought the cuts on the key were vertical, sorta like tubular lock cuts. But they're not, they're more like a lever lock and how much eaten into the key dictates the cut. I also love the way the centre of each cut is staggered and forms a 'V' shape on the key tip too. I guess it mirrors the 'V' shape of the mouth on the key for the sprung gates.

I too would love to see the Falle tool for this. Whether he uses downward or sideward movement to move the levers. The more I look at this lock the cooler it becomes!

[huxleypig]

Hey Mr A, in the 10th image down, the close up of the pack of 4 levers at rest - what is that 5th spring at the top biasing (the set copper arm type springs)? I see the 4 are pushing back the 4 levers on the other side but not sure why the 5th one is there? In fact, I keep counting 9 cuts on the key too, any idea what that is about?

[fgarci03]

MrA, you know I'd kill for a lock like this!
Thank you for the breakdown, it's a beautifull and interesting lock!

I particularly like the part that if the 2 spring loaded gates are opened, it blocks rotation. Very ingenious!


Are there any reports of this lock being successfuly picked?

[MrAnybody]

Hey Mr A, in the 10th image down, the close up of the pack of 4 levers at rest - what is that 5th spring at the top biasing (the set copper arm type springs)? I see the 4 are pushing back the 4 levers on the other side but not sure why the 5th one is there? In fact, I keep counting 9 cuts on the key too, any idea what that is about?

I'm thinking you mean this, hux:

11 - for KP followup.JPG

The 5th is redundant, and is the same on the other side of the cylinder with the other pack of 4 levers.

This is better seen in the pic that shows the position of the levers once the key is inserted. The 2 packs of levers are positioned alternately, so producing this copper arm mechanism with 5 arms means that it's unnecessary (and cost saving) to produce and fit 2 opposite arm mechanisms that mirror each other (one space left then 4 arms, the other space right and then 4 arms). Simple and elegant.

I see the 4 are pushing back the 4 levers on the other side but not sure why the 5th one is there? In fact, I keep counting 9 cuts on the key too, any idea what that is about?

Only 4 cuts are needed on each side of the key to engage with the 4 levers on each side of the mechanism (see below in red). And each side is a completely different bitting (non-reversible). The 2 longest cuts are to marry the key and lock mechanism (see below in yellow). These are all positioned 1 cut to the right of the other side of the key since the 2 packs of 4 levers are positioned alternately to each other. The last cut (not arrowed) is redundant to allow for the opposite cuts on the other side of the key.

2-edit - for KP followup.JPG