Improved Edge Support for a Mattress

Patentamt Europaisches ||| || 1 1| || || || || ||| || || || || 1 1| (19) J European Patent Office

Office europeen des brevets (11) EP 0 81 9 398 A2

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication:ation: (51) |nt. CI.6: A47C 27/06 21.01.1998 Bulletin 1998/04

(21) Application number: 97111924.3

(22) Date of filing: 14.07.1997

(84) Designated Contracting States: (72) Inventor: Sabalaskey, Robert J. AT BE CH DE DK ES Fl FR GB GR IE IT LI LU MC Carol Stream, Illinois 60188 (US) NL PT SE (74) Representative: (30) Priority: 19.07.1996 US 687798 Meddle, Alan Leonard FORRESTER & BOEHMERT (71 ) Applicant: Serta, Inc. Franz-Joseph-Strasse 38 Itasca, Illinois 60143 (US) 80801 Munchen (DE)

(54) Improved edge support for a mattress

(57) A mattress including an innerspring (12), stery foam layer (23) functions to provide a firmer mat- upholstery topper layers (1 4) including at least one foam tress edge without compromising the thickness of the layer, and quilt panel layers (16). At least one upholstery mattress or requiring additional materials or labor oper- foam layer (23) includes a firming edge (32) of foam ations during manufacturing. about its perimeter. The firming edge (32) of the uphol-

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Description filler material positioned over the foam, and finally a layer of ticking forming the cover. The number of layers Field of the Invention of foam and fiber in the quilt panel layer help to define the comfort level, quality, and expense of the mattress. The invention relates to mattresses, and in particu- 5 The entire layer is stitched together with thread to form lar, to the perimeter edge support of mattresses. a quilt pattern. The quilt pattern holds the components of the layer together and provides a composite structure Background of the Invention to the quilt panel layer. A common problem with such conventional mat- A conventional mattress generally consists of an 10 tresses has been a lack of support about the perimeter innerspring having at least one upholstery topper layer edge. The edge support provided by a conventional and at least one quilt layer about the top and bottom sur- mattress having a coil innerspring is usually inadequate faces of the innerspring. The level of support and com- due to the inherent physical characteristics of a coil. A fort provided by such a mattress, often referred to as coil is symmetric about its central axis and therefore "firmness," is a function of both the number and charac- 15 must be inset to avoid extending beyond the edge of the teristics of the upholstery topper and the quilting panel innerspring. Thus, the edge of the innerspring, and con- layers about the top and bottom of the innerspring and sequently the edge of the mattress, do not provide ade- of the performance characteristics of the innerspring. quate support. This lack of support is an inconvenience, The innerspring generally comprises border wires since the perimeter edge of a mattress commonly func- forming a rectangular structure and, within the structure, 20 tions to provide seating support for a sleeper. For exam- a plurality of interconnected coil springs. The coil ple, when a sleeper sits on the edge of a mattress to get springs are generally disposed in rows and columns up from bed, the edge, instead of providing a firm sup- over the entire area of the rectangular structure. When port surface for the sleeper, sags. As can be appreci- designing an innerspring, a number of variables which ated, this makes it more difficult for the sleeper to get affect innerspring performance must be taken into con- 25 out of bed. sideration. Some of these variables include the coil In order to address this problem, various attempts count, the coil density, the coil shape, the number of have been made to provide additional support to the turns of the coil, the gauge of the wire, the heat treat- innerspring of the mattress in hopes of providing a ment of the wire, the technique used to assemble the firmer edge for the mattress. One approach involves innerspring, and the edge treatment. 30 providing foam supports around individual springs In addition to the innerspring, a conventional mat- located about the perimeter of the innerspring. Each tress is provided with upholstery topper layers adjacent support consists of a foam piece which is wrapped to the top and bottom surfaces of the innerspring. Each about the circumference of a spring located along the upholstery topper layer commonly includes an insulat- perimeter of the innerspring. Another approach involves ing layer of material in direct contact with the inner- 35 providing a foam rail along each side of the mattress spring to mask or insulate from the sleeper the noise vertically in the innerspring between the first row of produced by the interaction between the components of springs located along the perimeter and the second row the innerspring and also to prevent softer upholstery of springs from the perimeter. materials from falling or pocketing into the innerspring. Yet another approach for solving this problem This insulating layer of material can be constructed of, 40 involves providing a biased wire support between the for example, wire mesh, plastic mesh, woven fabric, or upper and lower border wires of the innerspring. The non-woven fabric. Each upholstery topper layer further biased wire support structurally can take various forms. includes a layer of padding material which affects the However, all such supports are positioned between the firmness of the mattress. This layer of padding material upper and lower border wires along the perimeter of the is located directly adjacent to the insulating layer and 45 innerspring. Under the load of a sleeper sitting on the can be constructed of natural fibers such as, for exam- edge of a mattress, the supports act against the upper ple, cotton, synthetic fibers, foam, or a fiber/foam com- and lower border wires to keep them separated and pro- bination. It should be understood that additional layers vide a firming effect. of padding can be provided for each upholstery topper All these approaches, however, have the same dis- layer, the number of padding layers depending upon the 50 advantage. After providing some form of additional sup- comfort level and quality of the mattress. port to the perimeter of the innerspring, upholstery A quilt panel layer is provided adjacent to each topper layers and quilt panel layers are necessarily upholstery layer. The quilt panel layers of the mattress added to the innerspring to complete the manufacturing provide the direct contact with the sleeper and thus the process of the mattress. Once these additional layers immediate perception of softness or "feel." Each quilt 55 are added, any innerspring perimeter firming effect panel layer commonly includes a layer of mesh or cloth achieved is masked by the additional layers of uphol- bottom or backing material, a layer of foam material stery and quilting. Consequently, any strength gained at positioned over the backing material, a layer of fiber or the innerspring level of the mattress does not result in a

2 3 EP 0 819 398 A2 4 firmer edge after the various upholstery layers are invention, the edge firming means comprises an edge applied. For example, in the approach involving the made of a material provided about the perimeter of the biased wire supports positioned between the border foam layer which is firm relative to the foam layer of the wires, the use of these supports brings about an upholstery layer. In the preferred embodiment, the edge increase in firmness of the innerspring perimeter itself 5 is made of a foam which is approximately 4 to 6 times of approximately 30%. However, after the upholstery firmer than the foam of the foam layer. This firming edge topper layers and quilt panel layers are put in place, the about the perimeter of the foam layer functions to pro- increase in firmness of the mattress perimeter edge is vide a firm edge for the entire mattress. only 8-9%. Thus, despite these attempted solutions to The present invention addresses the problem of firm up the perimeter of the innerspring, the perimeter 10 inadequate perimeter edge support of mattresses while side edges of the mattress remain soft. avoiding reducing the padding in the mattress. Unlike One attempt to minimize the resulting disadvantage the solutions of the past, there is no need in the present of these solutions is to provide thinner upholstery topper invention to reduce the number or thickness of uphol- layers and quilt panel layers in order to allow a sleeper stery topper layers and quilt panel layers in order for the to feel the additional innerspring support. However, 15 sleeper to feel the additional support provided to the reducing the thickness of the upholstery and quilt layers innerspring. Since the edge firming means is provided results in a thinner mattress. Since consumers usually on the foam layer of the upholstery topper layer, which equate thinner mattresses with a cheaper, lower quality is a common component of a conventional mattress, the product, this approach would likely result in lost sales thickness of the mattress is not adversely affected. and revenues and thus, would not be desirable. 20 In addition, the present invention does not increase The above enhancements to the innerspring also the number of components used during the manufac- bring about other disadvantages as well. Since the ture of a conventional mattress. Thus, as there is no enhancements involve use of additional elements, such need to stock additional materials to be used during the as foam supports or wire supports, this adds signifi- manufacturing process, a substantial increase in mate- cantly to the cost of the mattress. Additionally, since the 25 rial costs is prevented. Further, since it involves no mattresses include additional elements, the assembly increase in the number of components used during of the mattresses requires more time which, in turn, manufacture, the present invention does not result in brings about an increase in the cost of labor. Thus, increased labor costs due to the manufacturing proc- these enhancements not only fail to adequately solve ess. the problem, but also bring about a substantial increase 30 in the costs associated with manufacturing a mattress. Brief Description of the Drawings Thus, there is a need for a new and improved mattress which provides a firm edge about the perimeter of Figure 1 is a top perspective view of a foam layer the mattress. The firm edge should be provided without made in accordance with the principles of the present compromising the thickness of the mattress. Further, 35 invention. providing such a firm edge should not require additional Figure 2 is a perspective, cut-away view of a portion materials or labor operations during the manufacture of of a mattress made in accordance with the principles of the mattress, thereby avoiding a significant increase in the present invention. material and labor costs. Figure 3 is a cross section of the foam layer of Fig- 40 ure 1 taken along line-3-3. Summary of Invention Detailed Description of the Invention The present invention provides a new and improved mattress with a firm edge about the perimeter of the A mattress 10 made in accordance with the princi- mattress. In providing a firm edge, the present invention 45 pies of the present invention is seen in Figures 1 -3 and does not compromise the thickness of the mattress and includes an innerspring 12, upholstery topper layers 14, thus does not lead to negative consumer perceptions. and quilt panel layers 16. Although the upholstery top- Further, the present invention does not require addi- per layer 14 and the quilt layer 16 are shown in Figure 2 tional materials or labor operations during manufactur- only about the top surface of the mattress 10, it should ing and thereby avoids a significant increase in material so be understood that the mattress 10 is generally pro- and labor costs. vided with such upholstery topper and quilt layers about The present invention achieves these advantages its bottom surface. by providing a mattress having a means for providing a The innerspring 12 of the mattress 10 generally firm edge. The mattress includes an innerspring, uphol- comprises border wires (not shown) forming a rectangu- stery topper layers, and quilt panel layers. Each uphol- 55 lar structure and, within the structure, a plurality of inter- stery topper layer includes a foam layer, with at least connected coil springs 19. The coil springs 19 are one of the foam layers of the upholstery layers being generally disposed in rows and columns over the entire provided with the edge firming means. In the present area of the rectangular structure. The number of coils,

3 5 EP 0 819 398 A2 6 their structure, and their arrangement depend upon the tional support so as to provide a firm mattress edge for type of support to be provided and the size of the mat- the sleeper. tress. It should be mentioned that the edge 32 functions to The upholstery topper layers 14 are provided along increase the height and strength characteristics of the the top and bottom surfaces of the innerspring 12. The 5 innerspring 12 of the mattress 10 without reducing the quilt panels 16 are, in turn, provided along the top and mattress thickness or overall softness of the mattress in bottom surfaces of the upholstery topper layers 14. its center. When the load of a sleeper is applied to the Each upholstery topper layer 14 is constructed of a periphery of the mattress, the foam edge collapses only number of layers, including an insulator layer 21 con- slightly as compared to the remainder of the upholstery structed of, for example, wire mesh, plastic mesh, 10 layer. Thus, the load of the sleeper is transmitted to and woven fabric, or non-woven fabric and at least one pad- carried directly by the innerspring. However, when the ding material layer 23 comprised of, for example, foam. sleeper is lying in the center of the mattress, the comfort Each of the quilt layers 1 6 is constructed of foam and/or level of the mattress is not adversely effected. fiber layers 25 with a covering of ticking 27. As can be While the invention has been described in connec- seen in Figure 2, the components of the quilt layer 16 15 tion with certain embodiments, it should be understood are stitched together with thread 30 to form a quilt pat- that it is not intended to limit the invention to these par- tern. ticular embodiments. To the contrary, it is intended to In order to provide a firmer edge about the perime- cover all alternatives, modifications and equivalents fall- ter of the mattress 10, the present invention provides at ing within the spirit and scope of the invention as least one foam layer 23 of an upholstery topper layer 1 4 20 defined by the appended claims. with edge firming means for providing a firm edge about the perimeter of the mattress 10. The edge firming Claims means comprises an edge 32 provided about the perimeter of the foam layer 23. The edge 32 is of a firmer 1. A mattress (10) having a perimeter, comprising: an material than the foam layer 23 and is to be constructed 25 innerspring (12); at least one upholstery topper of a material that will provide a firming effect. Examples layer (14) provided about the innerspring; and at of such materials are polyurethane foam, rebond foam, least one quilt panel layer (16) provided about an fiber pad, and polystyrene foam. The foam used for the upholstery topper layer (14) characterised by; edge 32 is in the range of approximately 130 to 170 means (32) provided in an upholstery topper layer indentation force deflection (IFD), preferably approxi- 30 (14) for providing an edge about the perimeter of mately 150 IFD; in comparison, the foam used in the mattress (1 0) which is firmer than the remainder remainder of the upholstery foam layer 23 varies from of the upholstery topper layer (14). approximately 20-40 IFD, preferably approximately 30 IFD. Thus, the foam of the edge 32 is in the range of 2. The mattress of Claim 1 wherein the edge firming approximately 4 to 6 times firmer and preferably approx- 35 means (32) is approximately from 4 to 6 times imately 5 times firmer than the foam used in the foam firmer than the remainder of the upholstery topper layer 23. Although the figures depict the edge firming layer (14). means to be provided to a foam layer made of flat foam, it is within the scope of this invention that such edge 3. The mattress of Claim 2 wherein the edge firming firming means can be provided to a foam layer con- 40 means (32) is approximately 5 times firmer than the structed of convoluted foam. remainder of the upholstery topper layer (14). As can be seen in Figure 1 , the firming edge 32, in a sense, frames the perimeter of the foam layer 23. The 4. The mattress of any one of Claims 1 to 3 wherein firming edge 32 can be attached to the perimeter of the the edge firming means comprises an edge of foam layer by any suitable means, such as glue 34, as 45 material (32) attached about the perimeter of the seen in Figure 3. Other attaching means include heat upholstery topper layer. bonding or adhesive solvents. In the preferred embodiment, the edge 32 is approximately 4 inches in width. Its 5. The mattress of Claim 4 wherein the edge (32) is length varies with the size of the mattress 10. Its thick- attached to the perimeter of the upholstery topper ness is preferably constant with the thickness of the so layer (14) with glue. foam layer. In the preferred embodiment, the thickness of the edge is approximately 5/8 inch. 6. The mattress of Claim 4 or 5 wherein the edge (32) When a sleeper sits on the edge of a mattress 1 0 is constructed of foam. made according to the principles of the present invention, the weight of the individual is supported by the quilt 55 7. The mattress of Claim 6 wherein the edge (32) is layers 16, the upholstery layers 14 with at least one firm- constructed of polyurethane foam. ing edge 32, and the innerspring 12. The firming edge 32 functions to provide the mattress edge with addi- 8. The mattress of Claim 6 or 7 wherein the foam of

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the edge (32) is in the range of approximately 130 to 170 IFD.

9. The mattress of Claim 8 wherein the foam of the edge (32) is approximately 150 IFD. s

10. The mattress of any one of Claims 4 to 9 wherein the material of the edge (32) has the same thickness as the material of the upholstery topper layer (14). 10

11. The mattress of any preceding claim wherein the upholstery topper layer (1 4) includes a foam layer (23). 15 12. The mattress of Claim 1 1 wherein the foam of the foam layer (23) is in the range of approximately 20 to 40 IFD.

13. The mattress of Claim 12 wherein the foam of the 20 foam layer (23) is approximately 30 IFD.

14. The mattress of any one of Claims 1 1 to 13 wherein the foam layer (23) is provided with the edge firming means (32) about its perimeter. 25

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