Here the two spring bars 5 and 6 are shown in the form of arms pivotably attached to the portions 2 and 4, and {HEAD ~ the known principle} of {TAIL ~ parallelogram guidance} is apparent 
of
Here the two spring bars 5 and 6 are shown in the form of arms pivotably attached to the portions 2 and 4 , and { HEAD ~ the known principle } of { TAIL ~ parallelogram guidance } is apparent
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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH