Split plug

[dls]

What about splitting the plug in three pieces with two pins each or two pieces with three pins each, the pieces would be conected with a loose dovetail joint so that they move together with a key inserted and seperatly when tensioned from the front just enough to block the back pins in a simmilar way to a curtain in a lever lock. The keyway would have to be designed so that a long tension wrench cant be passed to the back of the lock

[Squelchtone]

What about splitting the plug in three pieces with two pins each or two pieces with three pins each, the pieces would be conected with a loose dovetail joint so that they move together with a key inserted and seperatly when tensioned from the front just enough to block the back pins in a simmilar way to a curtain in a lever lock. The keyway would have to be designed so that a long tension wrench cant be passed to the back of the lock

Look around at Schuyler's early posts here, I think he modified a lock to have a split plug. Or maybe it was FarmerFreak, check out this plug split the *long* way viewtopic.php?f=25&t=47049

Squelchtone

[dls]

split verticaly not horizontaly in effect putting one 3 pin plug in front of another but connected via a dovetail which alows the two to turn together with a key or when being picked alows the outer to turn about 5 degrees blocking the inner keyway.

[Squelchtone]

split verticaly not horizontaly in effect putting one 3 pin plug in front of another but connected via a dovetail which alows the two to turn together with a key or when being picked alows the outer to turn about 5 degrees blocking the inner keyway.

yeah, I understood what you meant, that's why I said FarmerFreaks was split "the *long* way"

I do believe Schuyler made a cylinder just like what you are describing. At least I think it was him. The point was so you could not tension all the pins with front of keyway tensioning.

Squelchtone

[FarmerFreak]

viewtopic.php?f=9&t=44569

I believe that is more of what you are thinking. Except with three pieces instead of two.

Not sure how to prevent a long tension wrench from overcoming this little trick.

[dls]

Thats along the lines im thinking about.
As for preventing the lock from being tensioned with a long wrench one idea i have is to have a step in the key simmilar to a best sfic tip stop but half the length of the key, the plug would have a simple brass filler in the bottom of the keyway.
The bitting on the front plug would be such that at least two nasty spools on deep cuts or long pins are used in the outer plug these would force the picker to pick the rear first as picking the outer first would close the door on the inner due to the long pins.
By picking the rear first tension would have to be released in order to get the tension wrench out of the way of the longer front pins, one rear pin with a cone shaped top pin would almost certainly reset the rear plug once tension is released.
So what if you made a tension wrench with a step in it and made it small enough to get a pick under the front pins? a simple side bar which has pins which must enter the keyway in the only possible area for the wrench would go a long way here.

[FarmerFreak]

If you implemented all of those things, the end result is going to be an extremely weak key with a high probability of breaking. Deep cuts in the first half of the key plus some side cuts for a sidebar mechanism?! Followed by cutting off the bottom of the tip of the key, the part that ultimately operates the lock.

Simply put, if you want to make the key stronger then there will be more room for tension. If you don't mind a weaker key then this is less of an issue.

[dls]

Yes i did think of that the shoulder of the key at the bow could be beefed up and a recess could be made in the front of the plug, the shoulder would then turn the plug and not the blade this is a common feature on many locks which have deep cuts.
The area in the center of the key where the two plugs meet would have to be left un cut for maximum strength and the warding on the key could be designed to optomise its strength.

[deolslyfox]

I have seen a video of at least one "challenge lock" that was cut in half between pins 3 and 4. I don't remember who made it. Might have been locksmitharmy or kokomolock.

Anyhow, the key works because it "joins" the two halves of the core when inserted. However, when you tension the lock and pick it, you are only tensioning the front half, and eventually it will turn, but naturally the lock won't open because the back half of the plug is still locked.

The solution is run a thin shim thru the lock before you start picking so that you are tensioning the entire core at the same time ....

[GWiens2001]

It may have been FarmerFreak. He has done it, too.

Gordon

[Jacob Morgan]

Was looking thorough some old posts, and the concept in this thread reminded me of a a patent I had seen. Looking for that patent found another one. The first patent was not that great, and the inventor apparently never sold it and stopped paying the patent office to keep it in force and the patent lapsed. If I recall correctly the inventor had put it on eBay but it did not sell. For a split plug design a person could mill down the bottom portion of a key to use it for a tension wrench, as one would use to pick a Schlage wafer lock.

The second patent is an older one and is a more clever design, it also uses a split core and would prevent one from using the above sort of tension wrench.

I don't think there is much to the idea, but in case someone finds the original post via a search in the future the links may be of interest to them.

http://pdfpiw.uspto.gov/.piw?Docid=06170307&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect2%3DPTO1%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%2Fnetahtml%2FPTO%2Fsearch-bool.html%2526r%3D1%2526f%3DG%2526l%3D50%2526d%3DPALL%2526S1%3D6170307.PN.%2526OS%3DPN%2F6170307%2526RS%3DPN%2F6170307&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page

http://pdfpiw.uspto.gov/.piw?docid=03863476&SectionNum=1&IDKey=456167D51C59&HomeUrl=http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1%2526Sect2=HITOFF%2526p=1%2526u=/netahtml/PTO/search-bool.html%2526r=1%2526f=G%2526l=50%2526d=PALL%2526S1=3863476.PN.%2526OS=PN/3863476%2526RS=PN/3863476

[Squelchtone]

Was looking thorough some old posts, and the concept in this thread reminded me of a a patent I had seen. Looking for that patent found another one. The first patent was not that great, and the inventor apparently never sold it and stopped paying the patent office to keep it in force and the patent lapsed. If I recall correctly the inventor had put it on eBay but it did not sell. For a split plug design a person could mill down the bottom portion of a key to use it for a tension wrench, as one would use to pick a Schlage wafer lock.

The second patent is an older one and is a more clever design, it also uses a split core and would prevent one from using the above sort of tension wrench.

I don't think there is much to the idea, but in case someone finds the original post via a search in the future the links may be of interest to them.

http://pdfpiw.uspto.gov/.piw?Docid=06170307&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect2%3DPTO1%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%2Fnetahtml%2FPTO%2Fsearch-bool.html%2526r%3D1%2526f%3DG%2526l%3D50%2526d%3DPALL%2526S1%3D6170307.PN.%2526OS%3DPN%2F6170307%2526RS%3DPN%2F6170307&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page

http://pdfpiw.uspto.gov/.piw?docid=03863476&SectionNum=1&IDKey=456167D51C59&HomeUrl=http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1%2526Sect2=HITOFF%2526p=1%2526u=/netahtml/PTO/search-bool.html%2526r=1%2526f=G%2526l=50%2526d=PALL%2526S1=3863476.PN.%2526OS=PN/3863476%2526RS=PN/3863476

That's an interesting design. Check out Google Patents, I find their interface and prior art PDF's to be easier to navigate: Here's the 2nd patent: https://patents.google.com/patent/US3863476A/en

Squelchtone

[kwoswalt99-]

The second patent is an older one and is a more clever design, it also uses a split core and would prevent one from using the above sort of tension wrench.

I don't think there is much to the idea, but in case someone finds the original post via a search in the future the links may be of interest to them.

Some people get thread notifications, but he likely didn't set them. I agree, I don't think the ideas have much merit.