Patent ID: 7509710

Claim:
A damper apparatus adapted to be connected coaxially with a hinge used in a foldable electronic device, comprising: a stationary housing defining a cavity with an opened end and a wall opposite the opened end; a damper body rotatably installed in the cavity of the stationary housing, the damper body having a head, a cylindrical guiding portion axially protruding from the head, and a pushing portion radially protruding from a portion of an outer periphery of the guiding portion, the pushing portion having two side ends apart from each other; and a plurality of rotatable sheets and a plurality of stationary sheets respectively received in the cavity of the stationary housing and alternately disposed on the guiding portion and the pushing portion, the stationary sheets being fixed to the stationary housing, each of the rotatable sheets protruding inwardly to form a retaining portion, the two side ends of the pushing portion alternately engaging the retaining portions when the elastic force of the hinge being released to drive the damper body rotating to open or close the foldable electronic device, at least two of the retaining portions being different in width so as to make the side end of the pushing portion asynchronously contact the retaining portions, damper resin being filled between the adjacent stationary sheets and rotatable sheets for restraining the pushing portion rotating.