The second ends of the elongated flexible elements are connected respectively to the first and second surfaces at one end of the surface, wherein the fexible elements are operable to be wound or unwound on the respective surfaces as {HEAD ~ the member} rotates about {TAIL ~ the axis} 
rotates about
The second ends of the elongated flexible elements are connected respectively to the first and second surfaces at one end of the surface , wherein the fexible elements are operable to be wound or unwound on the respective surfaces as { HEAD ~ the member } rotates about { TAIL ~ the axis }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL