Abstract:
A bedding foundation having a nestably stackable spring assembly, including a border wire having a generally rectangular cross-section. The foundation&#39;s spring 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 border wire is generally rectangular in cross-section to reduce wire costs without compromising beam strength of the border wire.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 12/821,559 filed Jun. 23, 2010 entitled “Bedding Foundation Having Border Wire With Generally Rectangular Cross-Section”, which is fully incorporated herein. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to bedding and, more particularly, to a bedding foundation having a nestably stackable spring assembly. 
     Bedding foundations, or so-called box springs, generally include a base and an upper grid including a generally rectangular border wire 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. 
     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 components used in the box spring assemblies should be securely and firmly mounted in the assembly to avoid any wobble or shifting during use. 
     U.S. Pat. Nos. 5,052,064 and 7,237,282 disclose bedding foundations having nestably stackable spring assemblies which may reduce shipping costs. However, each of the foundations disclosed in these patents has an upper border wire having a round cross-sectional configuration. 
     The border wire of these and other known bedding foundations is often three-gauge having a diameter of 0.243 inches. To make a border wire having the same beam strength, but made from a smaller diameter wire, say four-gauge wire having a diameter of 0.224 inches, would save material and therefore reduce the end cost of the foundation. In order to achieve the same beam strength, the four-gauge border wire must be changed or shaped from a circular cross-section to a rectangular cross-section in accordance with the present invention. Thus, the present invention enables one to use a four-gauge wire rather than a three-gauge wire in the border wire of the bedding foundation and therefore, reduce wire cost without giving up any beam strength. 
     In order to achieve cost savings, it would be desirable to reduce the cross-sectional area of the border wire of a bedding foundation (by creating the border wire from a smaller diameter wire) while maintaining the same beam strength or increasing it. 
     Therefore, a bedding foundation having a nestable, stackable spring assembly, including a border wire with a rectangular cross-section that can be stacked for shipping without having to compress and tie the spring assembly, would be a significant improvement. 
     SUMMARY OF THE INVENTION 
     This invention provides the desirable cost savings in wire without compromising the integrity of known bedding foundations. In one embodiment, this invention is a bedding foundation having a nestably stackable spring assembly which may be shipped separately from the bases of the foundations. This bedding foundation comprises a rectangular base and a spring assembly fixedly attached atop the base. Padding overlies the spring assembly and a fabric covering surrounds the spring assembly, padding and base. 
     The nestable stackable spring assembly includes a rectangular border wire having two parallel sides and two parallel ends. The border wire has a generally rectangular cross-sectional configuration with the height being greater than the width of the cross-section. The spring assembly further comprises a plurality of spaced and longitudinally extending support wires parallel to the border wire sides and extending between the border wire ends and being welded thereto. Each support wire has ends welded to the border wire ends and is a continuous piece of wire. These support wires are generally corrugated along their lengths, having a plurality of flattened peaks and a plurality of flattened valleys. The flattened peaks are generally co-planar with the plane defined by the border wire, and the flattened valleys are displaced beneath and intermediate of the peaks. 
     The spring assembly further comprises longitudinally spaced, parallel and transversely extending upper connector wires parallel to the border wire ends and welded along their lengths to the peaks of the support wires. In addition, the spring assembly may comprise a plurality of longitudinal wires welded to the upper connector wires and having ends welded to the border wire ends and extending parallel the border wire sides. 
     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 spring assembly to be nestably stacked atop a second spring 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. 
     The border wire of the spring assembly of this invention has a unique cross-sectional configuration which enables the border wire to be made of a larger gauge, smaller diameter wire than heretofore known in the art without comprising the beam strength of the border wire when compared to prior art border wires having a round cross-sectional configuration. The smaller diameter wire, when re-shaped from a circular cross-section into a rectangular cross-section, has the same cross-sectional area as when it had a circular cross-section. One advantage of this invention is that it enables a bedding foundation having a wire core to be made using less steel or material, thereby reducing the ultimate cost of the foundation to the foundation&#39;s assembler. 
     In addition to reducing the quantity of wire necessary to manufacture a spring core for use in a bedding foundation, the unique shape of the border wire provides a secure connection between the ends of the support wires and the border wire. 
     Although one type of wire core has been described, the present border wire may be used in any bedding foundation. For example, individual coil springs may be used rather than generally corrugated support wires, the individual coil springs being clipped to the unique border wire of this invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1  is a perspective view, partially broken away, of a bedding foundation according to one embodiment of this invention; 
         FIG. 2  is an enlarged perspective view illustrating a portion of the foundation of  FIG. 1 ; 
         FIG. 3A  is a cross-sectional view taken along the line  3 A- 3 A of  FIG. 2 ; 
         FIG. 3B  is a cross-sectional view taken along the line  3 B- 3 B of  FIG. 2 ; 
         FIG. 4  is a cross-sectional view illustrating prior art; 
         FIG. 5  is a cross-sectional view illustrating the border wire of the present invention; 
         FIG. 6  is a cross-sectional view taken along the line  6 - 6  of  FIG. 1  without padding or a fabric covering; 
         FIG. 7  is a side elevational view of two stacked spring assemblies of the foundation of  FIG. 1  without padding or a fabric covering; 
         FIG. 8  is a perspective view, partially broken away, of a bedding foundation according to another embodiment; 
         FIG. 9  is an enlarged perspective view illustrating a portion of the foundation of  FIG. 8 ; 
         FIG. 9A  is a cross-sectional view taken along the line  9 A- 9 A of  FIG. 9 ; 
         FIG. 9B  is a cross-sectional view taken along the line  9 B- 9 B of  FIG. 9 ; 
         FIG. 9C  is a cross-sectional view taken along the line  9 C- 9 C of  FIG. 9 ; 
         FIG. 10  is a cross-sectional view taken along the line  10 - 10  of  FIG. 8 ; and 
         FIG. 11  is a side elevational view of two stacked spring assemblies of the foundation of  FIG. 8  without padding or a fabric covering. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring first to  FIG. 1 , a bedding foundation  10 , according to one embodiment of this invention, is illustrated. As shown in  FIG. 1 , the foundation  10  has a longitudinal dimension or length L, a transverse dimension or width W and a height H. Although the length L is shown as being greater than the width W, they may be identical. 
     The foundation  10  has a base  12 , including a rectangular base frame  13  on which transverse wooden slats  14  are attached. A nestably stackable spring assembly or wire core  16  is fixed atop the base  12  and, more particularly, secured to the transverse slats  14  of base  12  with staples  15 , as shown in  FIG. 2 . Padding  18  overlies the nestably stackable spring assembly  16 , and a fabric covering  20  overlies the padding  18  and surrounds the nestably stackable spring assembly  16  and the base  12 . Although the base  12  is usually made of wood, it may be made of any other material, such as plastic, for example. 
     The nestably stackable spring 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  in the embodiment illustrated. 
     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 welded to and/or 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. See  FIG. 6 . The adjacent distal portions  36 ,  38  are joined together by linear connecting portions  39  of the support wire  28 . Alternatively, the support wires may be resilient with non-linear arms or connecting portions joining adjacent flattened peaks and flattened valleys. Examples of such support wires are disclosed in U.S. patent application Ser. No. 12/352,208, which is fully incorporated herein. 
     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 welded to and/or 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 intersections  44  to the flattened peaks  32  of the support wires  28 . 
     The support wires  28  have flattened distal peak portions  36  and flattened distal valley portions  38 , with the support wire ends  30  being welded to and/or crimped around the border wire  22 . In this embodiment, two upper connector wires  40  per flattened distal peak portion  36  are illustrated. However, any number of upper connector wires  40  may be secured, i.e., welded to each flattened distal peak portion  36  of each support wire  28 . 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  13 . 
     If desired, additional steel end wires (not shown) may be added either before or after the stackable spring 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 edgemost 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. 
     Referring again to  FIG. 1 , continuous longitudinal wires  46  may be included in the stackable spring assembly  16 . These longitudinal wires  46  have their ends  48  welded to and/or crimped around the border wire ends  26 ,  26 . These longitudinal wires  46  may be welded along their lengths to the upper connector wires  40  as desired. In the illustrated embodiment, two longitudinal wires  46  per foundation  10  are illustrated. However, any number of longitudinal wires  46  may be incorporated into the foundation. 
     The nestably stackable spring assembly  16  of bedding foundation  10  is generally manufactured by a supplier, who then ships it to an assembler. The assembler adds to the spring assembly  16  the wooden base  12 , incorporates padding  18 , and covers the components with upholstery  20  to make a completed product. 
     This invention facilitates shipment of the metal core or stackable assembly  16  by a supplier to the assembler. With reference to  FIG. 7 , 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 nest within the first assembly  16 , with the overall height of the nested assemblies  16 ,  16  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. 
     One advantage of the spring assembly  16  and associated bedding foundation  10 , according to this invention, is that the border wire  22  is uniquely configured to enable the border wire  22  to be made of a lesser gauge, smaller diameter wire than existing border wires without giving up any strength. In the embodiment of the bedding foundation  10  and associated spring assembly  16  shown in the drawings, the border wire  22  has a rectangular cross-sectional configuration with the height H 2  of border wire  22  being greater than the width W 2  of the border wire  22 . See  FIG. 5 . 
       FIG. 4  illustrates a cross-section of a prior art border wire  50  made of three-gauge wire. The cross-section is round and has a diameter of H 2  (0.243 inches in the case of three-gauge wire). 
       FIG. 5  illustrates a rectangular cross-section of the border wire  22  of foundation  10 . The border wire  22  is re-shaped into a rectangular cross-section from a four-gauge wire having a round cross-section (shown in dashed lines in  FIG. 5 ) having a diameter of H 1 , which is less than the diameter H 2  of the three-gauge wire shown in  FIG. 4 . In the example, H 1  is 0.224 inches and H 2  is 0.243 inches. The cross-section of border wire  22  shown in  FIG. 5  is rectangular and has a height of H 2  (0.243 inches, same as the diameter of the three-gauge wire shown in  FIG. 4 ) and a width of 0.153 inches. Thus, in switching from a three-gauge wire having a round cross-section to a four-gauge wire having a rectangular cross-section, no height is lost. In changing the shape of the border wire  22  from a round cross-section to a rectangular cross-section, the cross-sectional area remains approximately identical. The generally rectangular cross-section of border wire has rounded corners  52  as shown in  FIG. 5 . 
       FIG. 3A  shows one of the upper connector wires  40  passing underneath one of the sides  24  of border wire  22  and having its end  42  wrapped over and around the border wire  22 .  FIG. 3B  shows one of the longitudinal wires  46  passing over one of the ends  26  of border wire  22  and having its end  48  wrapped under and around border wire  22 . 
       FIGS. 8-11  illustrate an alternative embodiment of bedding foundation  10   a . As shown in  FIG. 8 , the foundation  10   a  has a longitudinal dimension or length La, a transverse dimension or width Wa and a height Ha. Although the length La is shown as being greater than the width Wa, they may be identical. 
     The foundation  10   a  has a base  12   a , including a rectangular base frame  13   a  on which transverse wooden slats  14   a  are attached. A nestably stackable spring assembly or wire core  16   a  is fixed atop the base  12   a  and, more particularly, secured to the transverse slats  14   a  of base  12   a  with staples  15   a , as shown in  FIG. 9 . Padding  18   a  overlies the nestably stackable spring assembly  16   a , and a fabric covering  20   a  overlies the padding  18   a  and surrounds the nestably stackable spring assembly  16   a  and the base  12   a . Although the base  12   a  is usually made of wood, it may be made of any other material, such as plastic, for example. 
     The nestably stackable spring assembly  16   a  includes a rectangular steel border wire  22   a  having two parallel sides  24   a ,  24   a  and two parallel ends  26   a ,  26   a . The parallel sides  24   a ,  24   a  are longer than the parallel ends  26   a ,  26   a  in the embodiment illustrated. 
     Transversely spaced, parallel, and longitudinally extending steel support wires  28   a  are parallel to the border wire sides  24   a ,  24   a  and have end portions  30   a  which are welded to the ends  26   a ,  26   a  of the border wire  22   a . These support wires  28   a  are formed so as to be generally corrugatedly-shaped along their lengths, having flattened peaks  32   a  and flattened valleys  34   a . These peaks  32   a  and valleys  34   a  have different lengths  36   a  and  38   a , respectively. See  FIG. 10 . The lengths  36   a ,  38   a  are joined together by linear connecting portions  39   a  of the support wire  28   a . Alternatively, the support wires may be resilient with non-linear arms or connecting portions joining adjacent flattened peaks and flattened valleys. Examples of such support wires are disclosed in U.S. Pat. Nos. 7,805,780 and 7,930,777, each of which is fully incorporated herein. 
     As best shown in  FIG. 9 , an end portion of each of the support wires  28   a  is welded to a lower surface  50  of the border wire  22   a  and, more specifically, to the lower surface  50  of one of the ends  26   a ,  26   a  of the border wire  22   a.    
     Longitudinally spaced, parallel and transversely extending steel upper connector wires  40   a  extend parallel to the border wire ends  26   a ,  26   a  and have ends  42   a  which are welded to the border wire sides  24   a ,  24   a . These upper connector wires  40   a  are welded intermediate of their ends  42   a ,  42   a  along their lengths at intersections  44   a  to the flattened peaks  32   a  of the support wires  28   a.    
     As best shown in  FIG. 9A , an end portion  42   a  of each of the upper connector wires  40   a  is welded to a top surface  52  of the border wire  22   a  and, more specifically, to the top or upper surface  52  of one of the sides  24   a ,  24   a  of border wire  22   a.    
     The support wires  28   a  have flattened peaks  36   a  and flattened valleys  38   a , with the support wire end portions  30   a  being welded to the border wire  22   a . As best shown in  FIG. 9C , an end portion  30   a  of each of the support wires  28   a  is welded to lower surface  50  of the border wire  22   a  and, more specifically, to the bottom or lower surface  50  of one of the ends  26   a ,  26   a  of border wire  22   a.    
     In this embodiment, two upper connector wires  40   a  per flattened peak  36   a  are illustrated. However, any number of upper connector wires  40   a  may be secured, i.e., welded to each flattened peak  36   a  of each support wire  28   a . The flattened valleys  38   a  of the support wires  28   a  may be stapled using staples  15   a  or otherwise attached to the transverse slats  14   a  which are, in turn, affixed to the base frame  13   a.    
     If desired, additional steel end wires (not shown) may be added either before or after the stackable spring assembly  16   a  has reached its final assembly destination. These end wires have spaced ends which are secured to the border wire  22   a  and the endmost upper connector wire  40   a , respectively. These end wires provide additional stiffness to the stackable assembly  16   a  in an edgemost location of the ends of the assembly  16   a  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. 
     Referring again to  FIG. 8 , continuous longitudinal wires  46   a  may be included in the stackable spring assembly  16   a . These longitudinal wires  46   a  have their ends  48   a  welded to the border wire ends  26   a ,  26   a . These longitudinal wires  46   a  may be welded along their lengths to the upper connector wires  40   a  as desired. In the illustrated embodiment, two longitudinal wires  46   a  per foundation  10   a  are illustrated. However, any number of longitudinal wires  46   a  may be incorporated into the foundation. 
     As best shown in  FIG. 9B , an end portion of each of the continuous longitudinal wires  46   a  is welded to lower surface  50  of the border wire  22   a  and, more specifically, to the bottom or lower surface  50  of one of the ends  26   a ,  26   a  of border wire  22   a.    
     The nestably stackable spring assembly  16   a  of bedding foundation  10   a  is generally manufactured by a supplier, who then ships it to an assembler. The assembler adds to the spring assembly  16   a  the wooden base  12   a , incorporates padding  18   a , and covers the components with upholstery  20   a  to make a completed product. 
     This invention facilitates shipment of the metal core or stackable assembly  16   a  by a supplier to the assembler. With reference to  FIG. 11 , a first stackable spring assembly  16   a  may be placed upon a surface with the flattened valleys  38   a  of the support wires  28   a  oriented downwardly and the flattened peaks  36   a  of the support wires  28   a  oriented upwardly. Next, a second like assembly  16   a  is placed atop the first assembly  16   a , with its flattened valleys  38   a  and flattened peaks  36   a  likewise oriented downwardly and upwardly, respectively. The flattened valleys  38   a  of the second assembly  16   a  are thereby allowed to enter into the voids between the flattened peaks  36   a  of the first assembly  16   a . The second assembly  16   a  nestles downwardly within the first assembly  16   a  until the outside dimension of the connecting portions  39   a  of the valleys  34   a  of the second assembly  16   a  is equal to the inside dimension of the connecting portions  39   a  of the valleys  34   a  of the first assembly  16   a . At this point, the second assembly  16   a  comes to nest within the first assembly  16   a , with the overall height of the nested assemblies  16   a ,  16   a  substantially less than the sum of the individual heights of the assemblies  16   a ,  16   a . Of course, any number of assemblies  16   a  may be nested and stacked together for storage or shipment. 
     One advantage of the spring assembly  16   a  and associated bedding foundation  10   a , according to this invention, is that the border wire  22   a  is uniquely configured to enable the border wire  22   a  to be made of a lesser gauge, smaller diameter wire than existing border wires without giving up any strength. In the embodiment of the bedding foundation  10   a  and associated spring assembly  16   a  shown in the drawings, the border wire  22   a , like border wire  22 , has a rectangular cross-sectional configuration with the height H 2  of border wire  22   a  being greater than the width W 2  of the border wire  22   a . Border wire  22   a  of the embodiment shown in  FIGS. 8-11  is identical to border wire  22  and has the same characteristics and advantages described herein. 
     One of ordinary skill in the art will readily recognize that the alternative embodiments of the foundations shown herein are exemplary only of a wide variety of alternative configurations that are readily possible within the scope of this invention. 
     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.