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