Alternatively, the shaft could be provided with a plurality of keys or keyslots, and {HEAD ~ the disc} 51 provided with {TAIL ~ a single keyslot} or slot engaging member 
provided with
Alternatively , the shaft could be provided with a plurality of keys or keyslots , and { HEAD ~ the disc } 51 provided with { TAIL ~ a single keyslot } or slot engaging member
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH