electric drive means for driving, when said first switch of said controlling device is turned ON, said second body in one direction relative to said first body, and driving, when said second switch of said controlling device is turned ON, said second body in {HEAD ~ another direction} relative to said {TAIL ~ first body} 
electric drive means for driving , when said first switch of said controlling device is turned ON , said second body in one direction relative to said first body , and driving , when said second switch of said controlling device is turned ON , said second body in { HEAD ~ another direction } relative to said { TAIL ~ first body }
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 OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH TAIL TAIL TAIL TAIL TAIL TAIL