For example, a slot could be provided on {HEAD ~ the shaft}, and slot engaging members could be provided on {TAIL ~ the disc} 
For example , a slot could be provided on { HEAD ~ the shaft } , and slot engaging members could be provided on { TAIL ~ the disc }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL