PURPOSE: To detect optically the number of a temporary car truck and its passage at low cost and with simple constitution, by providing the temporary car truck with through-holes for light and by closing a hole at a different position for each temporary car truck.
CONSTITUTION: On the ground, a projector 1 and a photodetector 3 are installed, and a temporary car truck is provided with a light transmitter 2. The light transmitter 2 consists of five light-transmittable holes 21W25 and a light-transmittable- hole arrangement blind part, and provides a different combination of the light- transmittable holes for the number of each temporary car truck. When one temporary car truck moves in a moving direction 31 and reaches a line connecting the projector 1 and photodetector 3, light 11 passes through one light-transmittable hole 21 of the light transmitter 2 arranged specially for each car track to reach a photodetection hole 21A as light 12. Thus, the number and passage of the temporary car truck are detected.
KUROSAWA HARUHIRO
KATOU KATSUTOSHI
