Patent ID: 6981296

Claim:
A hinge apparatus for connecting a fold and a main body of a mobile phone to each other, comprising: a fixed hinge part provided at said main body; and a rotary hinge part provided at said fold and hinged to said fixed hinge part so to be rotated relative to the fixed hinge part, said rotary hinge part comprising: a power generating unit generating a rotating drive force; a rotary cam and a fixed cam selectively performing power transmission of the rotating drive force of the power generating unit; a camshaft assembled with the fixed cam such that the camshaft and the fixed cam are axially movable relative to each other, said camshaft being connected at an end thereof to the fixed hinge part such that an idle rotation of the camshaft relative to the fixed hinge part is prevented; and an elastic biasing member provided in said camshaft to elastically bias the fixed cam and the camshaft in opposite directions; wherein the camshaft includes: a boss assembled with the fixed cam such that the boss and the fixed cam are axially movable relative to each other; and a boss shaft integrated with the boss into a single structure, said boss shaft being received in a boss shaft receiving slot of the fixed hinge part, so that an idle rotation of the boss shaft relative to the fixed hinge part is prevented; and wherein a key guide groove is formed on an internal surface of the boss, and a key is formed on an external surface of the fixed cam, said key movably engaging with the key guide groove, so that the boss and the fixed cam are axially movable relative to each other.