Patent ID: 6619450
Filing Date: 2003-09-16
Classification: B60W,F16H,Y10T

Abstract:
A transmission for changing a ratio of a rotational frequency of a power source and a rotational frequency of an output shaft by switching a gear train provided between the power source and the output shaft by moving a shift fork, said transmission comprising:a shift drum for moving the shift fork; a clutch provided between the power source and the gear train; a shift spindle for urging the shift drum and the clutch; intermittent driving means provided between the shift spindle and the shift drum for starting to operate from a first operation angle of the shift spindle and pivoting the shift drum by a predetermined angle; and urging means provided between the shift spindle and the shift drum for starting to urge the shift drum in a pivoting direction at a third operation angle smaller than a second operation angle of the shift spindle at which disengagement of the clutch is finished, wherein the intermittent driving means includes: a clutch arm and a sub arm fixed to the shift spindle; a master arm pivotably supported in a circumferential direction on the shift spindle; and a preload spring and a return spring, each of the springs being wrapped around the shift spindle.