The support arms are pivotally attached through {HEAD ~ rotary shafts}, which are individually mounted at opposite ends of each of {TAIL ~ the support arms} 
The support arms are pivotally attached through { HEAD ~ rotary shafts } , which are individually mounted at opposite ends of each of { TAIL ~ the support arms }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL