Patent ID: 7401381

Claim:
A folding mechanism for folding a first housing with respect to a second housing, the folding mechanism comprising: a stationary body with a stationary shaft projecting at a center of a side of the stationary body, the stationary body coupled to one of the first housing or the second housing; a movable body arranged rotatably as against the stationary body; a spring for biasing the movable body in an open direction as against the stationary body; a rotor substantially tube-like, arranged between the stationary body and the movable body; and a movable case substantially tube-like, that contains the stationary body, the movable body, the spring, and the rotor, the movable case coupled to the other of the first housing or the second housing, wherein the rotor includes first and second rotor cams at opposite ends of the rotor, the stationary body includes a stationary cam, the movable body includes a movable cam and gaps are arranged (a) between the first rotor cam and the stationary cam and (b) between the second rotor cam and the movable cam; wherein the stationary shaft is rotatably coupled to the movable case; and wherein a first lubricating layer is formed between an outer circumference of the stationary shaft and an inner circumference of the rotor.