by Peaky » 16 May 2005 5:31
The curtain is the part that the key goes into, some locks the curtain throws the bolt and on others the key does the work,
It is the curtain which dedicates the gauge of the lock as well,
The idea is that once the curtain is turned nothing else can get into the keyway,
They are generally a round disc of metal with the keyhole in the centre, this is on the inside of the lock,
I am sorry but i still havent replaced my stolen camera so am a little stuck to give you a picture, sorry.
5 lever BS locks have these and in most cases you will not find them on non BS 5 lever, 2 lever and 3 lever locks but there are allways exceptions.
Hope this is of some help until pinky or such a person comes on explains better and gives you a picture.