Patent ID: 8141451

Claim:
A shift drive device comprising: a drum shifter turning around the same axis as an axis of a shift drum to turnably drive the shift drum; a pin projecting from the drum shifter and located offset from the turning axis; a shift arm includes one end secured to a shift spindle turnably secured by a transmission case, said shift arm includes a guide hole formed as an elongate hole lengthwise and extending in a radial direction of the shift spindle and adapted to receive the pin inserted therethrough and engaged therewith, and with a turn-restriction hole adapted to receive a restriction pin inserted therethrough provided in the transmission case; and the pin is movable in the guide hole in response to the turn of the shift arm along with the shift spindle to turn the drum shifter and, to bring the restriction pin into abutment against a lateral edge of the turn-restriction hole, thereby restricting a turning range of the shift spindle and of the shift arm; wherein the turn-restriction hole is provided in the shift arm so as to be disposed on a straight line connecting an axial line of the shift spindle with the center of the guide hole.