A hinge assembly (1) used for a foldable cellular telephone, wherein a
pair
of abutment members (5, 6) are forcibly rotated by the biasing force of
a bias means (7) to a neutral position where the center parts of the projection
(54) and the recess (64) of the abutment members are generally aligned
with each other in circumferential direction, the projection is brought into contact
with the recess at both side parts of the abutment members in circumferential direction
when the pair of abutment members are rotated to the neutral position, and the
outer surface of the projection and both side surfaces of the recess in circumferential
direction should desirably be formed in an arcuate surface and an outwardly projecting
arcuate surface, respectively.
