resilient means defining opposite limit positions along the travel of the reciprocable means and operative to be impacted by the reciprocable means to reverse the direction thereof at {HEAD ~ each} of {TAIL ~ the opposite limit positions} and to cause the reciprocable means to rebound from the resilient means 
resilient means defining opposite limit positions along the travel of the reciprocable means and operative to be impacted by the reciprocable means to reverse the direction thereof at { HEAD ~ each } of { TAIL ~ the opposite limit positions } and to cause the reciprocable means to rebound from the resilient means
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH