| 摘要 |
Described is a device for monitoring a lock element (1) to determine whether it is closed or open. Even when manufacturing and installation tolerances are large, operation of the device is very simple, secure and reliable by virtue of the fact that a light-transmission path (7) passes through the lock element, the light path being unobstructed when the lock element (1) is in the closed position. The light path (7) has at least two optically discrete light-transmission zones (7a, 7b, 7c) disposed adjacent to each other with respect to the direction of motion of the element (1). |
