a lever having {HEAD ~ one end} fixedly connected with {TAIL ~ said support shaft} and the other end pivotally connected with said shutter means, and 
fixedly connected with
a lever having { HEAD ~ one end } fixedly connected with { TAIL ~ said support shaft } and the other end pivotally connected with said shutter means , and
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH