| 摘要 |
A hinge assembly for hingedly connecting a cover and a housing theretogether, such as a keypad cover and a housing of a portable radiotelephone. A generally tubular hinge arm is formed at an end portion of the cover, and two hinge pins, each having identical cam surfaces formed upon edge surfaces thereof are inserted into the hinge arm and positioned such that the cam surfaces of the respective hinge pins extend beyond opposing sides of the hinge arm such that the hinge pins are caused to rotate in unison with rotation of the cover. A spring member is tandemly-positioned between the two hinge pins to exert spring forces thereupon. Two cam followers are affixed to the housing in a manner such that the cam surfaces of the hinge pins abut against the cam followers. The cover may be rotated between an opened and a closed position and forces exerted upon the cam surfaces of the hinge pin by their abutting engagement with the cam followers urge the cover into or out of the open and closed positions during rotation of the cover, and urge the cover to remain in the open or the closed position in the absence of rotational moments exerted thereupon by the spring forces exerted upon the hinge pin by the spring member. |
