MacGyver101 wrote:Raymond wrote:Did the patent info state specifically that it was for bump prevention?
I'm viewing it with the same degree of skepticism as everyone else, but that is their claim:In a conventional lock, relatively quick movement of the inner pins could be caused by bumping the inner pins with an improper or inappropriate key (not shown) in an attempt to pick the lock. In [this] lock cylinder, the [side pins] limit or resist movement of the inner pins [vertically] when the inner pins are bumped. [...] As a result, relatively quick movement of the inner pin is inhibited, [and] the outer pin remains partially disposed in the inner pin chamber, and the plug cannot be rotated to the unlocked position.
I agree with the point about the pool balls, but I think what they're trying to do is to limit the amount of force the bump-key can apply to the drivers, by making the bottom pins harder to raise. I'm in need of a coffee at the moment -- so I may not be quite thinking of this correctly -- but I think the "pool ball" analogy works better with a pick-gun than with a bump-key. A bump-key works by sliding its tiny "teeth" underneath the bottom pins, in order to quickly raise and drop them. If you can't quickly raise the bottom pins, then (I think?) the bump-key's teeth are going to "catch" on the bottom pins, and far more of the bump hammer's energy will be directed back (i.e., in the direction that the key's moving), rather than upwards and into the drivers? (This differs from a pick-gun, which isn't trying to translate the "horizontal" motion into a "vertical" one.)
Either way, I like mcm757207's suggestion of a Michaud-like attack, if the grooves actually run right down to the bottom of the pin (which they do in the patent diagrams). Nice idea!
The twisting motion of the bottom pins necessitated by the perpendicular guide pins and groove slots would use up some of that kinetic energy potential transmitted by the bumping process into mechanical work -- also the guide pins would provide quite a bit of friction/drag especially if they are employed in all six pin chambers of a Schlage commercial lock cylinder...
Whether or not that design would be able to successfully foil bumping attempts in real life conditions is a good question, all the pins pictured in the patent art are identical in size -- seems logical to assume that any protection afforded would be reduced in chambers with the shorter bottom pins and would be increased in chambers with the longer bottom pins... Who knows how this twisting pin design would be effected by the presence of master pins in all chambers...
At the very least it looks as if ideal deployment of this technology would impact the design and capacity of the keying system used in such cylinders... I would offer my opinion that such cylinders would best be used with a Rotating Constant masterkeying system to reduce the number of required master pins used in the locks...
~~ Evan