wherein operation of the pushbutton causes {HEAD ~ the link} and cam to move, the link moving in a direction about perpendicular to {TAIL ~ the cams direction} of motion 
wherein operation of the pushbutton causes { HEAD ~ the link } and cam to move , the link moving in a direction about perpendicular to { TAIL ~ the cams direction } of motion
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH