Patent ID: 8365357

Claim:
A hinge mechanism, comprising: a pivot shaft defining a through hole in a radial direction of the pivot shaft; a resilient member coiling around the pivot shaft; a first cam rotatably sleeved on the pivot shaft and defining at least one recess at one end of the first cam; a second cam sleeved on the pivot shaft and defining a groove at one end of the second cam facing the first cam; and a rolling assembly comprising a pin and at least one rolling bearing sleeved on the pin, wherein the pin penetrates the through hole of the pivot shaft and is received in the groove of the second cam, and the at least one rolling bearing is partially received in the groove of the second cam; wherein a depth of the groove of the second cam recessing from a surface facing the first cam exceeds the radius of the at least one rolling bearing, and a width of the groove in the surface of the second cam facing the first cam is less than the diameter of the at least one rolling bearing.