by GWiens2001 » 10 Jul 2016 11:26
It may also be that the old lever locks and warded locks had the bitting on the bottom of the key. The keys, with the flag of bitting on them, would naturally rest in the hand with that bitting down. There was less trouble with dirt on keys or in locks since gravity pulled the dirt down, while the actual locking components were up. So dirt fell away from anywhere it could cause trouble.
When the old-world locksmiths started using pin tumbler locks, they simply retained the old-world key orientation of the keys. But, as has been mentioned, the dirt now falls down into the locking mechanism, which is a problem.
When the modern variant of pin tumbler locks were being developed/implemented on this side of the pond, our locksmiths probably early on realized the problem with dirt in the lock causing failure, and started mounting the locks with the mechanism (in this case the pins and springs) at the top so that like lever locks, when the dirt fell down, it did not affect the mechanism nearly as much.
Just my own thinking, but to me it makes some sense.
Gordon
Just when you finally think you have learned it all, that is when you learn that you don't know anything yet.