Installation for controlling and monitoring the different coded locks of an assembly

Claim 1

In an installation for controlling and monitoring the differently coded locks of a system of such locks, said installation comprising: key issuing means for producing a plurality of coded keys having codes recorded thereon for controlling said locks and a reader means associated with each lock, for unlocking the associated lock in response to the simple presentation thereto of a correctly coded key, said key issuing means and reader means being adapted so that detection by said reader means of a code y recorded by said key issuing means on each new key of order p assigned to the lock associated with this reader means results in the invalidation of a code x recorded on the key of order p-1 previously assigned to this lock, each code y being derived from code x by an algorithm y=f(x) stored in at least the key issuing means, the improvement wherein said reader means is at all times during the intended operation thereof responsive simultaneously to a number m, greater than 2, of codes of an increasing succession of ranked codes x, f(x), f 2 (x) . . . f n (x) which have not been previously invalidated and provides, responsive to reading any one of these codes, for automatically invalidating all codes in the succession of ranked codes which are of a lower rank than the one code read thereby.