A force modifying {HEAD ~ member rotatable} about {TAIL ~ a fixed axis} is provided and includes first and second outwardly facing surfaces of predetermined lengths which curve about the axis 
A force modifying { HEAD ~ member rotatable } about { TAIL ~ a fixed axis } is provided and includes first and second outwardly facing surfaces of predetermined lengths which curve about the axis
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH