When {TAIL ~ the amount} of {HEAD ~ the wound web} 7 reaches a predetermined value, the detector 32 outputs electrical signals by detecting the position of the surface of the outermost convolution of the wound web 7 
When { TAIL ~ the amount } of { HEAD ~ the wound web } 7 reaches a predetermined value , the detector 32 outputs electrical signals by detecting the position of the surface of the outermost convolution of the wound web 7
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH