{HEAD ~ the carriage} of {TAIL ~ each push button} having its own tongue element projecting rearwardly therefrom in the predetermined direction of depressing movement thereof, 
of
{ HEAD ~ the carriage } of { TAIL ~ each push button } having its own tongue element projecting rearwardly therefrom in the predetermined direction of depressing movement thereof ,
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