Hinge assembly

摘要

A cam portion 5 is composed of a first to fifth arcuate surfaces 51 to 55. The first arcuate surface 51 is arranged such that when a cover member C of a cellular telephone is located in a neutral position, a plate spring portion 22 contacts a crossing portion 56 where the first arcuate surface 51 crosses an orthogonal line Lp passing through a center of curvature of the first arcuate surface 51 and orthogonal to a rotation axis L. A second and a third arcuate surface 52, 53 are arranged on both sides of the first arcuate surface 51. Radii of curvature of the second and third arcuate surfaces are set to be larger than a radius of curvature of the fist arcuate surface 51.