Patent ID: 8042421

Claim:
A multi-gear-speed transmission comprising: a plurality of drive gears fixed to a first gear shaft; and a plurality of driven gears fixed to a second gear shaft which is parallel to the first gear shaft, the drive gears and the driven gears normally being in a meshed state based on a gear speed, an engaging means provided between the plurality of drive gears and the plurality of driven gears so as to make engagement therebetween, and said engaging means being changed over by a gear shift driving means so as to make a gear shift, wherein said engaging means includes: an engaging projected part projectingly formed at an inner peripheral surface of each said driven gears at a required location in the circumferential direction in a state of having engaging surfaces in the circumferential direction; a cam rod which is put in sliding contact with an inner peripheral surface of an inner cavity of said second gear shaft so as to be movable in an axial direction, the cam rod having a sliding contact surface that is provided with a plurality of cam grooves at required locations in the axial direction; pin members which are inserted in pin holes bored in required portions of said second gear shaft in a radial direction, and which are capable of being advanced or retreated, while alternately making contact with said sliding contact surface of said cam rod moved in the axial direction and with said cam groove; and engaging claw members which are rotatably borne on pivot pins provided in said second gear shaft and which are capable of swinging by the advancing/retreating of said pin members so as to be engaged with or disengaged from said engaging projected parts, said swing claw members and said pivot pins are embedded in recessed parts formed in an outer periphery of said second gear shaft, annular bearing collar members externally fitted over said second gear shaft are so arranged as to press said pivot pins from an outer side, and wherein said driven gears are rotatably borne on said bearing collar members.