Patent Application
20050235417
Bed foundations, or “box springs” as they are often called, typically include a wooden frame to which a plurality of metal supports are attached and arranged to form a substantially planar upper surface. A sheet of cardboard is placed over the metal supports to create a continuous upper surface. The underside of the frame is then covered with a thin unwoven polyester material to hide the unimpressive construction from the consumer.
One problem with this traditional foundation design pertains to the weak areas between the metal supports. If too much pressure is placed between the metal supports, the cardboard gives way and a puncture results.
Another problem with this design is its inherent lack of rigidity. The foundation design was aimed at producing an economic platform for placement on a metal bed frame, capable of supporting a mattress. Longevity was not a primary consideration. The lack of rigidity considerably reduces the life of the foundation, and possibly the mattress, and also results in undesirable noises, such as squeaking and creaking, when a user's weight is shifted on the mattress supported thereby.
Yet another problem with this design is that it is not conducive to either disassembly, or final assembly by a retailer or an end user. Thus, the foundation must be assembled at the factory and shipped in an assembled state. Doing so adds significantly to the shipping costs due to the dimensions of the assembled foundation.
There is a need for an economic foundation that includes with a strong, continuous upper surface free of weak areas that could be compromised through normal use, or even predictable misuse.
There is also a need for a bed foundation designed to prevent annoying noises arising from a loss of rigidity. Preferably this design is capable of providing a stable platform for a mattress over an extended lifetime.
There is also a need for a bed foundation that is capable of being assembled by an end user or a retailer such that the foundation may be shipped in an unassembled state. Preferably, this foundation is capable of being shipped in a single, relatively small, container when unassembled such that a lower shipping charge applies.
The present invention is directed toward a bed foundation that addresses the above-identified needs. The bed foundation utilizes longitudinal and transverse members having I-beam construction, and a plurality of cross members placed across the longitudinal members to provide a rigid frame. The cross members are topped with a layer of plywood, further adding to the rigidity of the frame. The pieces are held together with traditional fasteners, such as screws, thereby simplifying final assembly.
The I-beam construction of the longitudinal and transverse members has many advantages over the prior art. First, a support member having I-beam construction is approximately three times stronger than a solid support member having the same weight. Second, I-beam construction minimizes beam “racking” or twisting of the support member. Additionally, increasing strength and eliminating racking minimizes noise. The increased strength of this foundation also increases its versatility. For example, the hospitality industry uses approximately six different metal bed frames. The bed foundation of the present invention is strong enough to be used will all of these different frames. Indeed, the foundation is so strong that it may be supported only at the ends of the foundation, whereas standard foundations must be supported along their longitudinal sides.
One aspect of the present invention provides a bed foundation comprising a plurality of longitudinal members each having an upper surface defining a plurality of grooves. A pair of transverse end members are operably attached to opposite ends of the longitudinal members. A plurality of cross members are operably disposed in the grooves of the longitudinal members. There is at least one top panel operably disposed on upper surfaces of the longitudinal members. The foundation is constructed and arranged such that the upper surfaces of the cross members are substantially flush with the upper surfaces of the longitudinal members, thereby creating a substantially planar support grid onto which the top panel is operably disposed.
Another aspect of the present invention provides a bed foundation comprising a plurality of parallel longitudinal members. Each of the longitudinal members includes an upper portion, a middle portion, and a lower portion. The upper and lower portions are thicker than the middle portion, thereby forming an I-beam construction. The foundation includes a pair of parallel transverse end members, operably connected to opposite ends of the longitudinal members. Each of the transverse members also has an upper portion, a middle portion, and a lower portion configured such that the upper and lower portions are thicker than the middle portion, thereby forming an I-beam construction. The foundation further includes a plurality of cross members transversely spanning, and operably attached to the longitudinal members. Additionally, there is at least one top panel operably disposed on top of the cross members.
Referring now to the drawings, and first to
Preferably, the longitudinal members 12 are configured to have an I-beam construction, with an upper portion 20, a lower portion 22 and a middle portion 24, the upper and lower portions 20, 22 being thicker than the middle portion 24. Additionally, the longitudinal members 12 preferably include end portions 26 that are thicker than the middle portion 24, thereby framing the middle portion 24 in a panel-like fashion. The I-beam construction of a longitudinal member 12 is shown in
The upper portions 20 of the longitudinal members 12 also include upper surfaces 28 that define a plurality of notches or grooves 30. The grooves 30 are arranged and sized to accommodate the cross members 16. The arrangement of the grooves 30 is such that the grooves 30 of adjacent longitudinal members 12 align with each other to receive a cross member 16 that is perpendicular to the length of the longitudinal member 12. The grooves 30 are sized such that when the cross members 16 are placed in the grooves 30, top surfaces 32 of the cross members 16 are substantially flush with the upper surfaces 28 of the longitudinal members 12 receiving the cross members 16. This configuration is best shown in
Though any rigid materials, including plastic, may be used, the longitudinal members 12 are preferably made of wood. More preferably, the upper portions 20, lower portions 22, and end portions 26, are made of a relatively inexpensive material such as pine. The middle portions 24, are preferably made of MDF, particle board, or plywood.
Similar to the construction of the longitudinal members 12, the transverse members 14, seen in
Like the longitudinal members 12, any rigid materials, including plastic, may be used to construct the transverse members 14. However, the transverse members 14 are preferably made of wood. More preferably, the upper portions 20, lower portions 22, and end portions 26, are made of a relatively inexpensive material such as pine. The middle portions 24, are preferably made of MDF, particle board, or plywood.
The construction of the transverse members 14 may be identical to the construction of the longitudinal members 12.
The cross members 16 are substantially straight pieces sized to rest within the grooves 30 such that the top surfaces 32 of the cross members 16 are substantially flush with the upper surfaces 28 of the longitudinal members. Though a variety of cross member widths, and inter-cross-member spacing, may be used to accomplish the present invention, consideration should be given to the structural integrity of the resulting foundation 10. Thus, narrow cross members should be accompanied by relatively small spacing between cross members, thereby resulting in the use of more cross members. Conversely, wider cross members might accommodate larger inter-cross-member spacing. These considerations are important to ensure a sufficiently rigid surface, thereby preventing unwanted noises, and to reduce the chances of a puncture in one of the top panels 18. Any rigid material may be used to form the cross members 16. Preferably, the cross members 16 are wood. More preferably, the cross members 16 are a cost effective wood such as pine.
The top panels 18 are planar pieces that rest on the upper surfaces 28 of the longitudinal members 12, the top surfaces 32 of the cross members 16, and on upper surfaces 42 of the transverse members 14. The top panels 18 are flat, rigid pieces that are preferably resistant to warping, such as extruded plastic or more preferably, plywood or particle board. The thickness and strength of the top panels 18 should also be considered when determining the optimal spacing between the cross members. Thicker top panels 18 can be used in conjunction with fewer cross members. Though cardboard has been discussed as undesirable, given the appropriate number of cross members, closely spaced, cardboard could function adequately to be considered within the scope of the invention.
In an assembled state, as is shown in
The queen-sized embodiment of the foundation 10 shown in
Not unlike many convention box springs, the king-sized foundation 10 of
Like the queen-sized embodiment, the king-sized foundation 10 of
The invention has herein been described in its preferred embodiments to provide those skilled in the art with the information needed to apply the novel principles and to construct and use the embodiments of the examples as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself, which is set out in the following claims:
