Preferably, the selector shaft 2 is driven by a brushless motor 5 by means of a double planetary stage 6 and {HEAD ~ a toothed segment} 7 which engages {TAIL ~ a toothed wheel} 16 that is preferably positioned in a housing element 17 
Preferably , the selector shaft 2 is driven by a brushless motor 5 by means of a double planetary stage 6 and { HEAD ~ a toothed segment } 7 which engages { TAIL ~ a toothed wheel } 16 that is preferably positioned in a housing element 17
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 HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH