{HEAD ~ A spring} 23, for example, a gas spring, acts on {TAIL ~ the axis} 22 of the guide roller 20 
{ HEAD ~ A spring } 23 , for example , a gas spring , acts on { TAIL ~ the axis } 22 of the guide roller 20
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH