A pivoting ball support is rotated and displaced as {HEAD ~ the ball} enters {TAIL ~ the device}, and is returned to a position whereby the ball is prevented from exiting the device 
enters
A pivoting ball support is rotated and displaced as { HEAD ~ the ball } enters { TAIL ~ the device } , and is returned to a position whereby the ball is prevented from exiting the device
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH