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