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...http://www.google.es/patents/US5640690?utm_source=gb-gplus-sharePatente US5640690 - Hinge assembly having cam follower
