Patent ID: 8555465

Claim:
A hinge assembly for rotationally attaching a first member to a second member to allow rotational movement of the first member relative to the second member, the hinge assembly comprising: (a) a shaft having at least a first portion and a second portion; (b) an adaptor attached to said first portion of said shaft such that said adaptor is constrained to rotate with said shaft as a unit, said adaptor being adapted for attachment to the first member so as to move with the first member as a unit; (c) a hinge base adapted for attachment to the second member so as to move with the second member as a unit, said hinge base rotationally supporting said shaft such that, when said adaptor is attached to the first member and said hinge base is attached to the second member, the first member is rotationally attached to the second member such that the first member can move pivotally relative to the second member; and (d) a detent mechanism for holding said adaptor in at least one detent position relative to said hinge base as long as a torque applied between said adaptor and said hinge base is lower than a threshold torque value, said detent mechanism comprising at least one cylindrical roller having a first end portion, a second end portion, and a cylindrical surface extending between said first end portion of said roller and said second end portion of said roller, at least one groove provided in one of said second portion of said shaft and said hinge base, and biasing means for biasing said roller into engagement with said groove such that said roller engages said groove when said adaptor is in said detent position relative to said hinge base, wherein said biasing means comprises: at least one journal bearing surface matching at least a portion of said cylindrical surface of said roller for rotationally supporting said roller such that said journal bearing surface has the shape of a sector of a cylindrical surface; at least one resilient arm having at least one free end portion, said journal bearing surface being provided in said free end portion of said resilient arm; and means for preventing relative rotation between said biasing means and one of said shaft and said hinge base.