Patent ID: 8196262

Claim:
A hinge comprising: a fixing member; a shaft non-rotatably fixed to the fixing member, the shaft comprising a shaft post; a rotating member rotatably sleeved on the shaft post; an interfering assembly comprising a male element and a female element rotatable relative to the male element, the male element non-rotatably fixed to the shaft post, a first raised portion and a second raised portion protruding from the male element, the female element being non-rotatably fixed to said rotating member and defining a through hole in a center of the female element; wherein the shaft post is rotatably extended through the through hole of the female element, a circular slot is defined in the female element, a center of the slot is apart from a center of the through hole, an inner ring adjacent to the through hole and an outer ring adjacent to a circumference of the female element are formed beside the slot, the inner ring defines a first depressed portion, and a width of the inner ring is gradually varied along an edge bounding the through hole, the outer ring defines a second depressed portion, and a width of the outer ring is gradually varied along the circumference of the female element, the first and second depressed portions are correspondingly engaged with the first and second raised portions; an elastic assembly rotatably sleeved on the shaft post, to provide elasticity along an axis of the shaft post to tighten the interfering assembly and the rotating member; and a fastener fixed to a distal end of the shaft post; wherein when the rotating member is rotated relative to the fixing member, the first and second raised portions are slid out from the first and second depressed portions, respectively, in frictional engagement with the inner and outer rings, together with partial portions of the first and second raised portions covering the circular slot, thereafter, the region of friction between each of the first and second raised portions, and a corresponding one of the inner and outer rings is varied.