Abstract: A folding bed, such as a sofa bed, with an assembly configured to counteract the gravitational forces acting on both a rotation of the main panel in relation to the frame and a rotation of the foot panel in relation to the main panel. A transmission may be used in the assembly to connect the first pivotal connection, where the main panel pivots with respect to the frame, to the second pivotal connection, where the foot panel pivots with respect to the main panel. The transmission transmits torque from the first pivotal connection to the second pivotal connection, so as to counteract gravitational forces acting on the foot edge of the foot panel.

Abstract: A linkage assembly includes a first link connected at a first point to a translation mechanism attached to a support structure. The translation mechanism is arranged to allow the first point of the first link to translate along a substantially straight axis. A second link is pivotally connected at a first point to the support structure, and at a second point to the first link. A second point of the first link travels on or near an arc of substantially constant finite radius when the first link pivots with respect to the second link.