Control device for fastening strap unit

Abstract

A fastening strap unit includes a frame with a mandrel and a strap connected thereto. The strap is wrapped to the mandrel, and the first end of the strap is fixed to the mandrel and a hook is connected to the second end of the strap. A shaft extends from the frame and a motor drives the shaft which drives the mandrel. A first sensing chip is connected to the second end of the strap and a second sensing chip is connected to the first end of the strap. A sensor is connected to the frame so as to detect the first sensing chip or the second sensing chip when the strap is retracted or released to its final position, and the motor is stopped.

What is claimed is: 
     
         1 . A fastening strap unit comprising:
 a frame having a mandrel and a strap connected thereto, the strap wrapped to the mandrel, the strap has a first end fixed to the mandrel and a hook connected to a second end of the strap, a shaft extending from the frame and a motor driving the shaft which drives the mandrel, a first sensing chip connected to the second end of the strap and a second sensing chip connected to the first end of the strap, and   a sensor connected to the frame and detecting the first sensing chip or the second sensing chip to stop the motor.   
     
     
         2 . The unit as claimed in  claim 1 , wherein each of the first and second sensing chips is a metal chip.