Abstract: A hinge mechanism for motor vehicle includes a base having two parallelly extended brackets; a supporting arm having a proximal end located between the two brackets and provided with a shaft hole having a diametrically extended stop rib; a pivot shaft extended through the two brackets with a longitudinally slotted end engaged with the stop rib on the supporting arm; a restoring spring located outside one of the two brackets to connect at two ends to the base and the pivot shaft to deform when the pivot shaft is rotated and thereby produces an elastic restoring force; and a damper located outside the other bracket to connect to the slotted end of the pivot shaft and form a resistance to the rotating pivot shaft, so that a saddle or a trunk lid connected to the supporting arm may be pivotally lifted and closed at a moderate speed.

Abstract: An automatic lifting mechanism for motorcycle saddle mainly includes a first and a second supporting arm respectively fixed to a saddle and a body of a motorcycle, at least one spiral spring having two sideward extended terminal ends separately pressed against the two supporting arms, and a damping device located in the at least one spiral spring to rotatably engage at two ends with the two supporting arms. While a spring force of each spiral spring quickly elastically stretches open the first and the second supporting arm when the saddle is unlocked, the damping device limits a rotating speed of the two supporting arms, so that the saddle could be automatically lifted or moved downward at a buffered speed without the risk of injuring a user.