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