Patent ID: 7168136

Claim:
A hinge assembly for interconnecting a main body and a cover of a portable electronic device, comprising: a hinge housing adapted to be rotatably attached to the main body, and defining a first engaging hole and a second engaging hole perpendicular to the first engaging hole; a first hinge apparatus contained in the first engaging hole for enabling the cover to open relative to the main body; and a second hinge apparatus contained in the second engaging hole, for enabling the cover to rotate about an axis perpendicular to the hinge housing after the cover is opened relative to the main body; wherein the first hinge apparatus comprises a sleeve fixed in the first engaging hole, a cam follower fixed in the sleeve, a cam rotatably attached to the hinge housing and adapted to be fixed to the main body, and two roller bearings between the cam and the cam follower; and the second hinge apparatus comprises a boom adapted to be fixed to the cover, a support rotatably attached to the boom and fixed to the hinge housing, a boom cover fixed on an end of the boom, and two ball bearings between the boom and the boom cover.