by raimundo » 19 Nov 2005 11:58
I believe that I know the type you are looking at, does it have dark areas on the outside that appear sand cast with raised bands that are ground to a smooth finish? dust the dark sand cast area with some flour and see if you can find a code number just beneath the top smooth band, two letters, and on the other side of the yale and town circle two numbers. I havent got the code book, but if you go to somewhere where this lock is displayed, some old lock shop with a collection, if they have the key, you will find that when it opens, a spring throws the shackle open, by pushing a piston up under the opening end of the of the shackle. the other end of the shackle is hinged.
This is definately not just a warded lock, although there are plenty of wards. there is some sort of locking dog that enters the shackle in a way that is not the warded lock type. I do not have much information on the mechanism, but I once got one open by first doing a smudge impression on a strip of steel, then putting in a strip of brass that was cut with a jewlers saw so that it had comb teeth, bend this a little bit and remove it while you still can, (if you bend it too far, it will not come out of the lock, but just cut the kurfs of the comb to fit the besidethe impression on the steel blank, into the softer thinner brass blank,) you cannot find suitable blanks but just strips of metal will do. when the brass blank comes out with some of the comb teeth bent back slightly, you have located the wards and you can cut them on the steel blank, put this in again and try it. this method eventually worked for me once. on another occasion it failed, but find the code number and see if any antique lock dealer has a code book. this could help. there are antique lock sites on google.