Mark, one way of typing is to look to the application, padlock, safelock, passage door and the untold other specialized types. Another basic distinction is between combination and non-combination or fixed key types. Not all combination locks use wheel tumblers although most do. This catagory has to include any type of trick lock and those that require certain manipulations to be done. A card key with magnetic coding would fall into the fixed key type wheras a push button electric is a combination lock. And then speaking of electrics, that type and pure mechanicals gives us yet another distinct division. Then of course we have the warded type versus the tumbler type. Or combinations of the two as we see in pin and lever tumbler locks that use warding grooves (different keyways). During the 1800’s permutation locks became popular. Although the term was often confused with combination locks, its use is best left to describe a lock that changeable or more correctly easily changeable. My own area of concern is obviously safe locks of the 1800’s and it continues to amaze me at the number of different examples of key and combination locks that were patented then.
