[mejbtjry] Two linked locks

Take two door locks and connect them by a linkage, perhaps simple gears.  Both keys need to be turned simultaneously to unlock.

Motivation is to make it more difficult to pick: one lock already requires two hands by conventional lock picks, two simultaneous locks will require more sophisticated, bulkier tools, or an accomplice.

Inspired by the "two keys" lockout of nuclear launch triggers, but these two locks may be operated simultaneously by one person with two hands.

On further thought, this will probably not work.  Pick the first lock and turn the cylinder a tiny bit as possible within the tolerances of the linkage, enough to keep the pins from dropping.  Then pick the second lock.  Maybe if the tolerances of the pins should be greater than the tolerances of the linkage.