If this embodiment is equipped with a drive 14, {HEAD ~ the force} of the drive 14 can reinforce {TAIL ~ the spring} 23 
reinforce
If this embodiment is equipped with a drive 14 , { HEAD ~ the force } of the drive 14 can reinforce { TAIL ~ the spring } 23
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH