the surface, when used for lying down , consisting of one side of the seat frame and the back-rest frame

Full Title

Sofas; Couches; Beds > sofas, couches, settees, or the like, with movable parts ; Chair beds > changeable to beds by tilting or pivoting the back-rest > thereby uncovering one or more auxiliary parts previously hidden (A47C17/22 takes precedence) > the surface, when used for lying down , consisting of one side of the seat frame and the back-rest frame