Box spring, box spring frame and making same

The box spring and box spring structure include a versatile frame made at appreciably lesser expense than presently known frames of equal rigidity and light weight. End rails of rectangular cross section carry no springs and are arranged completely underneath and overlap the side rails at the frame corners. All the rails have upper surfaces planar throughout their widths, those of the end rails being in secured engagement with the lower wide faces of the side rails at the frame corners to dispense with braces. The cross slats are parallel to each other and spaced any desired distances apart, equal or unequal. The end slats which carry the end rows of springs are arranged in close proximity to the respective end rails and are spaced above the end rails while extending inwardly enough in width to locate said spring rows in the proper position for upholstering. However, each end slat is securely connected to the end rail adjacent thereto by a longitudinal brace inserted between said end rail and said end slat and constituting the end part of the box spring frame. The brace, end rail and slat cooperate to form a self- reinforcing and self supporting structural unit, the members of which mutually transfer stresses between them. The brace so connected is intended to change the nature of the stresses to which the end parts of box springs have heretofore been subjected. The end portion of the box spring consequently is made capable of supporting unusually heavy loads concentrated on relatively small areas of said end portion. The frame is assembled upside down without rehandling and then righted if the springs have previously been attached to the slats to form the box spring structure or for the attachment of springs if needed and final upholstering.