Patent ID: 7481087

Claim:
A safety interlock system for securing an industrial appliance operative in a safety mode or an operational mode, comprising: a lock including a lock housing and an operating component arranged rotatably in the lock housing, wherein the operating element is adapted to cooperate with the appliance so as to bring the appliance as a result of rotation of the operating component from the operational mode to the safety mode and wherein the operating component is provided with one or more lock code elements which can be positioned in different positions to be selected, wherein the selected positions of the lock code elements correspond to a specific lock code; a key for unlocking the lock, wherein the key comprises one or more key code elements which can be positioned in different positions to be selected and the selected position of the key code elements corresponds with a specific key code, the key further including a housing, at least one of the one or more key code elements include at least one pin having an element to hold the rotational position of the pin with respect to the housing, wherein the rotational position of the pin defines one of a plurality of different key codes for the pin at a same depth, wherein the lock is adapted so as to lock the operating component with respect to the lock housing except when the key code is identical to the lock code when the key is inserted; and wherein the length of the pin defines another of a plurality of different key codes for the pin at a same rotational position; and wherein the key codes inclued a plurality of key codes defined by an equation N=(Q*R) P , where Q is the number of axial rotation positions of each of the key pins, R is the number of different depth positions of each key pin, and P the number of key pins.