EXCESS SPEED DETECTOR WITH MULTIPLE LIGHT BARRIER

摘要

This equipment serves for the production of a shaft information for a lift plant. A cage (2) guided in a lift shaft (1) is driven by way of cables (5) from a drive motor (3) with a drive pulley (4). A redundant measuring strip (6) is mounted at one side of the lift shaft (1). A multichannel forked light barrier (7) is arranged at the cage (2). The measuring strip (6) consists of a markings track in the shape of a flag track (8) and a check track (9), which are each scanned by a light barrier. At those places, where a flag (10) stands at the flag track (8), a window (13) is arranged at the check track (9). The speed of the lift is measured by means of the flags (10) and the lift is stopped in the case of possible excess speed. By reason of the arrangement of the flag track (8) and the check track (9), possible faults can be detected at the measuring strip (6), since one light barrier must always be interrupted by reason of the flags (10) and windows (13).