{TAIL ~ A control cam} is formed on {HEAD ~ a first transmission linkage} and a feeler roller is rotatably mounted on a second transmission linkage 
{ TAIL ~ A control cam } is formed on { HEAD ~ a first transmission linkage } and a feeler roller is rotatably mounted on a second transmission linkage
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH