Abstract:
A nestably stackable bedding foundation assembly replaces the traditional border wire and disposed coil spring foundation assembly in a so-called box spring. The foundation assembly may be nestably stacked with numerous other such assemblies for transportation, thereby avoiding the need to compress and tie the assembly for shipping. Each foundation assembly includes a number of corrugated support wires having alternating peaks and valleys. The valleys of selected support wires are twisted relative to their associated peaks to provide a more stable mounting to a base and offer a variety of firmness to specific zones of the assembly.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates generally to bedding, and more particularly to a nestably stackable bedding foundation.  
         [0002]     Bedding foundations or so-called box spring assemblies generally include spaced border wires between which coil or bent wire spring modules are located. As thus manufactured, these box spring assemblies are bulky and shipping them to the manufacturer for application of padding and covering thereto is costly because of space requirements. To reduce the space requirements, it is customary to compress the assemblies to reduce their individual thicknesses and to tie them in their compressed state. This involves using presses and ties which are expensive, and the extra operations of pressing and tying the assemblies also adds to their manufacturing cost. At the delivery end, the manufacturer must cut and discard the ties before applying the covering. These additional material and handling expenses increase the end cost of box spring assemblies.  
         [0003]     Box spring assemblies by their very nature are intended to provide a stable support foundation for mattresses or other bedding placed on top thereof. Toward that end, the spring modules used in the box spring assemblies should be securely and firmly mounted in the assembly to avoid any wobble or shifting during use.  
         [0004]     In some cases, bedding systems become unevenly depressed, often due to uneven loading. It is well recognized that the middle regions of a bedding system support a greater amount of the user&#39;s weight focused in the torso regions. Users commonly do not rotate or flip bedding systems as is often recommended to avoid uneven wear. Alternatively, bedding systems desirably provide differing support characteristics or firmness to different areas or regions of the bed to provide extended wear, durability and/or comfort to the user.  
         [0005]     Therefore, a bedding foundation assembly that can be stacked for shipping without having to compress and tie the assembly would be a significant improvement.  
         [0006]     Additionally, a bedding foundation assembly which is relatively simple to manufacture, and which may substitute for a traditional box spring assembly having coil spring modules is also desirable.  
         [0007]     Moreover, such a bedding foundation must provide a reliable and stable support surface for mattresses and other bedding products, preferably one which can be easily tailored with specific regions or zones of varying firmness.  
       SUMMARY OF THE INVENTION  
       [0008]     This invention provides a solution to these and other problems in the art. In one embodiment, this invention is a nestably stackable bedding foundation assembly for use in place of the traditional box spring assembly. This bedding foundation assembly includes a rectangular border wire and transversely-spaced, parallel, and longitudinally-extending support wires parallel to the border wire sides and with ends connected to the border wire ends. These support wires are generally corrugated along their lengths, having peaks and valleys with the peaks being generally coplanar with the plane defined by the border wire and the valleys being displaced beneath and intermediate of the peaks. Longitudinally-spaced, parallel and transversely-extending upper connector wires are parallel to the border wire ends and connected along their lengths to the peaks of the support wires. Longitudinally-spaced, parallel, and transversely-extending lower connector wires are parallel to the border wire ends and may be connected to the valleys of the support wires in certain embodiments of this invention.  
         [0009]     The longitudinal voids between the peaks of the support wires are of a greater dimension than the valleys of the support wires. This configuration enables one bedding foundation assembly of this invention to be nestedly stacked atop a second assembly since the support wire valleys of the first assembly fit into the voids between the peaks of the support wires of the second assembly. Such a nested and stacked arrangement results in a total height dimension which is less than the sum of the individual assembly height dimensions.  
         [0010]     The valleys of the support wires of this invention are uniquely configured to provide specific advantages to the bedding foundation. In one embodiment, selected valleys of the support wires are twisted or oriented relative to the remainder of the support wire. Selected support wire valleys are twisted, possibly 45° or 90° relative to the adjacent portions of the support wires to provide a more stable and substantial mounting and attachment of the support wire valley to a base frame. The twisted orientation of the spring wire valleys can be varied throughout the foundation unit to provide differing firmness and other characteristics to the associated regions or zones of the unit.  
         [0011]     One advantage of this invention is that it enables relatively inexpensive bedding foundation wire cores to be tightly nested, compacted and shipped in a minimum of space to an assembly destination, thereby reducing the ultimate cost of the unit to the assembler.  
         [0012]     Another advantage of this invention is that bedding foundation assemblies may be rapidly loaded by a manufacturer for transportation to the destination of assembly without the need for compressing and tying the assemblies together.  
         [0013]     Yet another advantage of this invention is avoiding the need for costly presses and ties necessary to compress a conventional box spring assembly for transportation.  
         [0014]     A further advantage of this invention is that bedding foundation assemblies may be rapidly unloaded without the time consuming and labor intensive tasks of clipping and discarding the tie wires used to hold conventional box spring assemblies in a compressed state.  
         [0015]     A still further advantage is to provide such a foundation assembly that is both stable and secure when in use to support a mattress or the like and provide different firmness regions or zones to the assembly. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     The objectives and features of the invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawings in which:  
         [0017]      FIG. 1  is a perspective view, partially broken away, of a bedding foundation assembly according to one embodiment of this invention;  
         [0018]      FIG. 2  is a side elevational view illustrating portions of two unmounted foundations stacked and nested one within the other for shipment; and  
         [0019]      FIGS. 3-10  are each a top plan view of an alternative embodiment of a bedding foundation assembly without a fabric covering according to this invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     Referring first to  FIG. 1 , a bedding foundation assembly  10  according to one embodiment of this invention is illustrated. The foundation  10  has a rectangular wooden base frame  12  on which transverse wooden slats  14  are attached. A nestably stackable spring assembly or wire core  16  is atop these transverse slats  14 . A foam pad  18  overlies the nestably stackable spring assembly  16 , and a fabric covering  20  overlies the foam pad  18  and surrounds the nestably stackable assembly  16  and the base frame  12 .  
         [0021]     The nestably stackable assembly  16  includes a rectangular steel border wire  22  having two parallel sides  24 ,  24  and two parallel ends  26 ,  26 . The parallel sides  24 ,  24  are longer than the parallel ends  26 ,  26 . Transversely-spaced, parallel, and longitudinally-extending steel support wires  28  are parallel to the border wire sides  24 ,  24  and have ends  30  which are crimped around the ends  26 ,  26  of the border wire  22 . These support wires  28  are formed so as to be generally corrugatedly-shaped along their lengths, having peaks  32  and valleys  34 . These peaks  32  and valleys  34  are flattened at their respective distal portions  36  and  38 , respectively. The adjacent distal portions  36 ,  38  are joined together by connecting portions  39  of the support wire  28 . According to various embodiments of this invention, these valleys  38  are twisted relative to the plane defined by the peaks  36  being vertically spaced beneath and intermediate of the flattened peaks  36 .  
         [0022]     Longitudinally-spaced, parallel, and transversely-extending steel upper connector wires  40  extend parallel to the border wire ends  26 ,  26  and have ends  42  which are crimped around the border wire sides  24 ,  24 . These upper connector wires  40  are welded intermediate of their ends  42 ,  42  along their lengths at  44  to the flattened peaks  36  of the support wires  28 .  
         [0023]     Longitudinally-spaced, parallel, and transversely-extending steel lower connector wires  46  extend along the selected slats  14  and parallel to the border wire ends  26 ,  26  in some embodiments (see  FIGS. 6-10 ) and are welded at their ends  48  and along their lengths at  50  to the flattened valleys  38  of the support wires  28 .  
         [0024]     The support wires  28  have flattened distal peak portions  36  and flattened distal valley portions  38 , with the support wire ends  30  being crimped around the border wire  22 . In this embodiment, three upper connector wires  40  per flattened distal peak portion  36  are illustrated. The distal valley portions  38  of the support wires  28  may be stapled or otherwise attached to the transverse slats  14  which are in turn affixed to the base frame  12 .  
         [0025]     If desired, additional steel end wires (not shown) may be added either before or after the stackable assembly  16  has reached its final assembly destination. These end wires have spaced ends which are crimped around the border wire  22  and the endmost upper connector wire  40 , respectively. These end wires provide additional stiffness to the stackable assembly  16  in an edge most location of the ends of the assembly  16  so as to prevent the end border wires from deflecting and being permanently distorted when a person sits on the end of a bed of which the foundation forms a part. Such steel end wires are shown in U.S. Pat. No. 5,361,434 which is hereby incorporated by reference in its entirety.  
         [0026]     Referring again to  FIG. 1 , continuous longitudinal wires  52  are included. These longitudinal wires  52  have their ends crimped around the border wire ends  26 ,  26 . These longitudinal wires  52  may be welded along their lengths to the upper connector wires  40  as desired.  
         [0027]     The spring assembly  16  of a bedding foundation  10  is generally manufactured by a supplier, who then ships it to an assembler. The assembler adds to the assembly the wooden base  12 , slats  14 , padding  18 , and upholstery  20  to make a completed product.  
         [0028]     This invention facilitates shipment of the metal core or stackable assembly  16  by a supplier to the assembler. With reference to  FIG. 2 , a first stackable spring assembly  16  may be placed upon a surface with the flattened distal valley portions  38  of the support wires  28  oriented downwardly and the flattened distal peak portions  36  of the support wires  28  oriented upwardly. Next, a second like assembly  16  is placed atop the first assembly  16 , with its flattened distal valley portions  38  and flattened distal peak portions  36  likewise oriented downwardly and upwardly, respectively. The flattened distal valley portions  38  of the second assembly  16  are thereby allowed to enter into the voids between the flattened distal peak portions  36  of the first assembly  16 . The second assembly  16  nestles downwardly within the first assembly  16  until the outside dimension of the connecting portions  39  of the valleys  34  of the second assembly  16  is equal to the inside dimension of the connecting portions  39  of the valleys  34  of the first assembly  16 . At this point, the second assembly  16  comes to rest within the first assembly  16 , with the overall height of the nested assemblies  16 ,  16  is substantially less than the sum of the individual heights of the assemblies  16 ,  16 . Of course, any number of assemblies  16  may be nested and stacked together for storage or shipment.  
         [0029]     One advantage of the spring assembly  16  and associated bedding foundation  10  according to this invention is that the distal valley portions  38  of the support wires  28  are uniquely configured to provide added stability to the bedding foundation  10 . In the embodiment of the bedding foundation  10  and associated spring assembly  16  shown in  FIG. 1 , the distal valley portions  38  of the support wires  28  are twisted or oriented approximately 90° relative to the distal peak portions  36  of the support wire  28 . As a result, the flattened distal valley portions  38  of the support wire  28  is more securely mounted to the slats  14  and wooden base frame  12  to provide additional support when the foundation unit  10  is loaded and in use. Nevertheless, the non-parallel, twisted or obliquely oriented distal valley portions  38  of the support wires  28  relative to the distal peak portions  36  does not diminish the ability to nest the spring assemblies  16  with one another as shown in  FIG. 2  thereby maintaining this advantage of the invention. In past known spring assemblies for bedding foundations of the type shown in  FIG. 1 , the support wires were generally planar as shown in U.S. Pat. No. 5,361,434. While such assemblies could be nested, lateral support is enhanced by the orientation of the distal valley portions  38  relative to the distal peak portions  36  of the spring support wires  28  of this invention.  
         [0030]     Moreover, a variety of different support wire shapes and configurations can be utilized with this invention. The support wires  28  shown in the foundation unit  10  of  FIG. 3  are all generally parallel and similarly configured and oriented with the connecting portion  39  of the support wire  28  between the distal peak and valleys portions all having the same angular inclination. The distal valley portions  38  are oriented about 90° relative to the distal peak portions  36  in  FIG. 3 .  
         [0031]     In another alternative embodiment of the foundation unit  10  of this invention as shown in  FIG. 4 , the connecting portions  39  of the support wires  28  joining the distal valley portions  38  to the distal peak portions  36  are oppositely oriented relative to the adjacent connecting portion  39  of each support wire on the opposite side of each distal peak portion  36 . Once again, the support wires  28  are generally parallel in the foundation unit of  FIG. 4  and the distal valley portions  38  oriented approximately 90° relative to the adjacent distal peak portions  36 .  
         [0032]     A still further alternative embodiment of the foundation unit  10  is shown in  FIG. 5  in which the connecting portions  39  are alternately oriented for each support wire. However, in a variation from the configuration shown in  FIGS. 3-4 , the support wires  28  are not generally parallel with each another and are grouped in adjacent pairs  54  of oppositely oriented, mirror image support wires  28  in the foundation unit  10 .  
         [0033]     In a still further alternative embodiment shown in  FIG. 6 , the distal valley portions  38  of the support wires  28  are oriented approximately 45° relative to the distal peak portions  36 . With the 45° orientation of the distal valley portions  38 , the longitudinally-spaced, parallel and transversely-extending steel lower connecting wires  46  are connected thereto and extend along selected slats  14  and parallel to the border wire ends  26 ,  26 . The lower connecting wires  46  may be welded at  50  to the distal valley portions  38  of the support wires  28 . The support wires  28  shown in  FIG. 6  are all generally parallel and similarly oriented with respect to each other.  
         [0034]     A further alternative embodiment of the foundation unit  10  is shown in  FIG. 7  utilizing distal valley portions  38  oriented 45° relative to the distal peak portions  36 ; however, unlike the orientation shown in  FIG. 6 , the support wires  28  are not generally parallel with each other but are grouped in adjacent pairs  54  of support wires  28  which are oriented in a mirror image of each other similar to the support wire  28  orientation shown in  FIG. 5  in that regard.  
         [0035]     Another alternative embodiment of the foundation unit  10  according to the invention is shown in  FIG. 8  and is similar to that shown in  FIG. 7  except with respect to the connecting portions  39  adjacent to each distal peak portion  36  of the support wire  28  being generally parallel with each other. The connecting portions  39  adjacent each distal peak portion  36  of the support wires  28  in  FIG. 7  are oppositely oriented relative to each other, but in  FIG. 8  these portions  39  are similarly oriented  
         [0036]     A further alternative embodiment of the foundation unit  10  according to this invention is shown in  FIG. 9  in which the support wires  28  are generally parallel with each other throughout the foundation unit  10 . However, the distal valley portions  38  at the longitudinal ends of the unit  10  are oriented 90° relative to the distal peak portions  36  and the distal valley portions  38  of the adjacent slats  14  are oriented 45° relative to the distal peak portions  36 . Moreover, the distal valley portions  38  in the longitudinal central zone of the foundation unit  10  are co-linear with the distal peak portions  36 .  
         [0037]     A still further alternative embodiment of the foundation unit  10  according to this invention is shown in  FIG. 10  in which the support wires  28  are generally parallel with one another and the distal valley portions  38  in the longitudinal central zone are oriented 45° relative to the distal peak portions  36 . The distal valley portions  38  of the adjacent zones are oriented 90° relative to the distal peak portions  36 . The distal valley portions  38  adjacent to the ends  26 ,  26  of the border wire  22  are generally co-linear with the distal peak portions  36  of the foundation unit  10  in  FIG. 10 .  
         [0038]     One advantage of the variety of embodiments possible with the foundation unit  10  according to this invention is the ability to customize the support characteristics of the foundation unit  10 . Moreover, the foundation unit  10  may include zones of differing degrees of support and firmness due to the differing orientations of the distal valley portions  38  as is readily apparent from the embodiment shown in  FIGS. 9-10 .  
         [0039]     One of ordinary skill in the art will readily recognize that the alternative embodiments of the foundation unit  10  shown herein are exemplary only of a wide variety of alternative configurations that are readily possible within the scope of this invention.  
         [0040]     From the above disclosure of the general principles of the present invention and the preceding detailed description of at least one preferred embodiment, those skilled in the art will readily comprehend the various modifications to which this invention is susceptible. Therefore, we desire to be limited only by the scope of the following claims and equivalents thereof.