The swinging end slides on a surface of the interlocking member as {TAIL ~ the swinging} of {HEAD ~ the interlocking member} 
The swinging end slides on a surface of the interlocking member as { TAIL ~ the swinging } of { HEAD ~ the interlocking member }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD