Means for sensing {HEAD ~ an abnormal condition} of {TAIL ~ the machine tool} is provided in the vicinity of an essential portion of the machine tool 
of
Means for sensing { HEAD ~ an abnormal condition } of { TAIL ~ the machine tool } is provided in the vicinity of an essential portion of the machine tool
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH