A hinge assembly for an apparatus, wherein the hinge assembly comprises: a first hinge part configured to be fixed to a first frame member and a second hinge part configured to be fixed to a second frame member, the first and second hinge parts being arranged to pivot about a first eccentrically mounted pivot pin which is sufficiently off-set above an axis (L1, L2) of the first and second frame members to allow the first and second frame members to pivot between an unfolded condition in which the first and second frame members are generally aligned and located on opposite sides of the hinge assembly and a folded condition in which the first and second members are generally parallel and located on the same side of the hinge assembly; and a third hinge part configured to be fixed to a third frame member and arranged to pivot about a second pivot pin which is sufficiently off-set from the first pivot pin to allow pivotal movement of the third frame member relative to the first and second frame members (16, 18) between an unfolded condition in which the third frame member is angled relative to the first and second frame members and a folded condition in which the third frame member is generally parallel with the first and second frame members and located on the same side of the hinge assembly as the first and second frame members, characterised in that the first hinge part has an asymmetric profile relative to the first pivot pin and pivotal movement of the first and second hinge parts (28, 30) between the unfolded and the folded conditions varies the spacing between the asymmetric profile and the second pivot pin. a first hinge part configured to be fixed to a first frame member and a second hinge part configured to be fixed to a second frame member, the first and second hinge parts being arranged to pivot about a first eccentrically mounted pivot pin which is sufficiently off-set above an axis (L1, L2) of the first and second frame members to allow the first and second frame members to pivot between an unfolded condition in which the first and second frame members are generally aligned and located on opposite sides of the hinge assembly and a folded condition in which the first and second members are generally parallel and located on the same side of the hinge assembly; and a third hinge part configured to be fixed to a third frame member and arranged to pivot about a second pivot pin which is sufficiently off-set from the first pivot pin to allow pivotal movement of the third frame member relative to the first and second frame members (16, 18) between an unfolded condition in which the third frame member is angled relative to the first and second frame members and a folded condition in which the third frame member is generally parallel with the first and second frame members and located on the same side of the hinge assembly as the first and second frame members, characterised in that the first hinge part has an asymmetric profile relative to the first pivot pin and pivotal movement of the first and second hinge parts (28, 30) between the unfolded and the folded conditions varies the spacing between the asymmetric profile and the second pivot pin.