The level lock is the mechanism arranged and designed taking into account package of plates (their complex and is called suvaldy) and figured cuts. When opening such device both the cuts, and plates are set in motion and pushed by small ledges grooves on key surface.
Level lock device
In the modern world there are several constructional features of similar devices, but the most widespread is such organization of the mechanism when the cut in suvalda has certain form at which in starting position it can move and move freely from top to down and in the opposite direction. How the key groove finds hitch with teeth on shaft of bolt, the suvalda holds certain position, and then the ledge on bolt shaft (it is also called the term "soldier") finds emphasis on the edge of cut in suvalda then the key crossbar cannot move ahead further.
Use in level lock design of several grooves is also frequent at once (usually two, the bigger quantity is very rare). And the similar key besides has received very interesting name – "butterfly". Such measure allows to increase many times degree of privacy of the lock at former quantity suvald: that is constructional simplicity is combined with its durability, good quality and reliability. The similar design allows also application of "the closed code window" at which suvalda start moving turn of key.
Degree of reliability of the level lock
Nevertheless, similar designs have also shortcomings. It is ordinary big size of the level lock and keyhole. The last provides quite easy passing to design of different types of the master keys and tools intended for so-called power breaking. Modern designers constantly improve similar types of mechanisms, seeking to remove this important shortcoming and adding so-called false grooves in moving suvalda. There is it by application of system for recognition of master keys and technological degrees of protection against power breaking. Still the inventor of one of the first level locks - Englishman Jeremy Chabb, in 1818 has built in protective suvalda which is capable to carry out blocking of the mechanism in attempt to open it with master key. After such blocking the castle owner needed to turn only key in the opposite direction, and then to open the level lock. This constructional decision not only complicated work of the burglar, but also allowed the owner to define easily happened breaking attempt. Very difficult level locks also allow use of special mechanisms of the reprogramming which is reading out profile of the inserted key which and will be applied further when opening.