A pair of {HEAD ~ rollers} 4 constituting one part of a wave generator 3 and functioning as {TAIL ~ a cam} are disposed to be rotatable within the flexible gear 2 
functioning as
A pair of { HEAD ~ rollers } 4 constituting one part of a wave generator 3 and functioning as { TAIL ~ a cam } are disposed to be rotatable within the flexible gear 2
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH