forming {HEAD ~ at least part} of the periphery of the motor member with an exterior diameter greater than that of the bore of {TAIL ~ the jacket member} 
forming { HEAD ~ at least part } of the periphery of the motor member with an exterior diameter greater than that of the bore of { TAIL ~ the jacket member }
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 TAIL TAIL TAIL TAIL TAIL TAIL TAIL