when said {TAIL ~ support frame} is at the closed position, the upper ends and {HEAD ~ the lower ends} of said oblong holes of said side support frame are so positioned as to maintain a predetermined gap relative to said coupling shaft; and 
when said { TAIL ~ support frame } is at the closed position , the upper ends and { HEAD ~ the lower ends } of said oblong holes of said side support frame are so positioned as to maintain a predetermined gap relative to said coupling shaft ; and
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD 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