{HEAD ~ The side members} are gripped by gripping {TAIL ~ means} to maintain the side members along respective straight transverse axes 
{ HEAD ~ The side members } are gripped by gripping { TAIL ~ means } to maintain the side members along respective straight transverse axes
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH