PURPOSE: To prevent malfunction and to make an instrument light weight, by impressing modulated light to a drive section having a photo detecting section via an optical fiber, demodulating the signal and driving/stopping an electric machine corresponding to each switch.
CONSTITUTION: An optical fiber cable 3 is taken as a pendent member to a crane 1, a switch box 2 is made pendent, and modulated light transmitted from the box 2 is impressed to a receiving drive section in a crane running body 5 with the optical fiber cable 4. The modulated light obtained from the operation of a push button switch group 10 of the box 2 is demodulated at a demodulating means 16 of the drive section 6 and applied to an electric instrument 20 such as a motor as a control signal via a malfunction preventing means 17 and a device control means 18. Further, the driving/stopping of the electric instrument 20∼n corresponding to each switch group 10 is performed, the malfunction is prevented, the weight of the entire system is made light and ease of maintenance and inspection is attaind.
HIRAKAWA YUUZOU
NAGATA ITSUO
OSAKA PREFECTURE
| JP57115754B |