IE20050182A1 - A mattress - Google Patents

Abstract

A mattress (1) comprising a spring base (2) sandwiched between upper (3), lower (4) and side upholstery layers (5). The spring base (2) has coil springs (10, 11) and a stiffening edge support structure (15) comprising a stiffening edge panel (16) of needled felt and a framework of upper and lower wires (17, 18) and inclined intermediate bands (19) al forming a tying framework for the stiffening edge support structure (15). <Figure 1>

Description

The present invention relates to a mattress and in particular to an inner sprung mattress.

Such inner sprung mattresses generally comprise an inner sprung structure having interconnected coil springs arranged in rows and columns to form a rectangular spring base assembly sandwiched between upper and lower upholstery layers. When individual coil springs or coils are used, they are held together by various means to form a unitary inner spring structure. Alternatively, a row of coils can be formed from a single continuous piece of wire wherein each of the single coils are connected in the row by interconnecting segments.

One of the major problems is the question of edge support in that due to people sitting on the edges of beds and indeed general use, the edges tend to bulge outwards giving a very unsightly appearance and also causing the upper and lower upholstery layers to come together. Generally, this continual pressure on the edges of the mattress causes the strengths of the sides of the mattress to be greatly reduced. Indeed, when people sit on the edge of mattresses, even new mattresses, the sides tend to bulge out which causes people to consider that the mattress is unsuitable for purchase. Further, in any case, the mattress should be firm around the edge giving more support so that it will not sag.

Indeed, there have been various attempts to firm the edges of a mattress such as described in US Patent No. 5704085. For example, in this and 9ther patents such as US Patent No. 6149143, a helical lacing structure, extended around the outside of the coils to couple the coils together and to provide firmer edges, has been described.

However, the problem is that as the amount of upholstery increases, it becomes more and more difficult to firm the edges because as the amount of upholstery, particularly on the top of the mattress, increases in depth, thickness and firmness, the load is more widely spread when a person sits on the edge of mattress thus causing sagging and unsightly outward bulging of the peripheral side of the mattress. While, ΙΕ ο 5 0 1 8 2 -2for structural reasons, it is preferable that this does not happen, one of the main objections to it is the general aesthetic appearance which causes people to believe that the mattress is in some way defective.

Yet another approach is to provide a biased wire support between the upper and lower outermost coils of the inner spring structure. Such a support is in the form of a framework comprising upper and lower peripheral wires interconnected by intermediate wires to tie the top and bottom of the outermost coil springs together. The problem with this arrangement is that while the intermediate wires and the top and bottom wires are all highly resistant to tensile forces, they are not particularly resistant to the forces that are applied to the edge of the mattress. Obviously, such a framework will combat tensile loads on the various parts of the framework but are generally unable to combat compressive forces, unless the framework is of a very rigid construction which obviously, if manufactured, for example, from steel, would be extremely expensive and heavy. A further proposal has been to use a stiffening edge panel such as described in US Patent Specification No. 6,568,014B1. This specification discloses an edge panel of relatively stiff material being extruded from a polymer material. Again, the strength of this support is based entirely on the resistance of the material to bulging outwards. Unfortunately, under repeated loading, such materials tend to crack and distort. This is particularly the case when the loading is not fully vertical. Attempts to use heavier material such as wood for a stiffening peripheral panel, have proved unsatisfactory as the wood is relatively heavy and also the continual bearing of upholstery materials onto the wood panel causes the materials to wear and thus for the mattress to become unsuitable. Further, sitting on a very stiff edge support panel is generally uncomfortable for the user.

Thus, to summarise, it is known to use stiffening edge panels to lend support to the edge of a mattress. However, such edge panels, if useful and efficient in use, have to be relatively stiff, being of wood or a flexible polymer. Such an edge panel must have sufficient load bearing capacity to avoid undue bulging. Further, over time, edge panels of flexible polymer tend to crack and distort leading to permanently unsightly bulges, as mentioned above.

At the same time, it is known as stated above to provide a biased wire support ΙΕ ο 5 0 1 β 2 -3between upper and lower border wires attached to the outermost rows and columns of springs. Even a relatively complex framework so formed does not work that satisfactorily as it does not combat direct vertical loads and the edge of the mattress tends to bulge. Such a framework will adequately handle loads which apply tensile forces to the framework.

The present invention is directed towards overcoming these problems.

Statements of Invention According to the invention, there is provided a mattress comprising: an inner sprung structure having interconnected wire coil springs arranged in rows and columns to form a rectangular spring base assembly sandwiched between upper and lower upholstery layers; and a continuous stiffening edge support structure connected around the periphery of the spring base to the outermost rows and columns of the coil springs comprising spaced-apart upper and lower stiff wire bands interconnected by inclined intermediate bands to form a wire framework and a stiffening edge panel secured to the framework, said edge panel comprising a pad of dense pliable material.

The innovation and advantage of the present invention is to combine the two edge stiffening panels, already referred to, which surprisingly combine together most satisfactorily. The tying of the stiffening edge panel to the wire framework transfers any outward force, i.e. a lateral force exerted by the panel as it tries to bulge outwards on application of a vertical load, directly to the framework. This application of the load directly to the framework causes it to apply a tensile force to the bands forming the framework. At the same time, there will be some “give” in the edge of the mattress and it will thus not exhibit excessive hardness to somebody sitting on the edge of the mattress. Further, the use of a pad of pliable dense material for the edge panel overcomes problems of permanent deformation over time, while the framework, due to its combination with the stiffening edge panel, is being loaded in an -4ΙΕ ο 5 0 1 8 2 efficient manner.

To summarise, therefore, the advantage of such a pad is that while, in itself, it may not be that strong, it’s strength, when under a vertical edge load pressing directly down on it, is quite high, particularly in combination with the stiffening framework.

Further, in accordance with the invention, the stiffening edge panel may be of channel-shape in cross-section to lie above and below the outermost rows and columns of the coil springs. This particular channel-shape construction adds further rigidity to the edge of the panel, particularly when it is tied to the coil springs, as there is now further resistance to outward bulging of the edge panel.

In one embodiment, the inclined intermediate bands comprise one band alternately inclined in one direction from the lower wire band to the upper wire band and then inclined downwards away from the other band to the lower band. A modification of the latter embodiment is to provide two sets of inclined bands crossing intermediate the upper and lower wire bands.

In one embodiment of the invention, the diameter of the wire is of the order of between 1.3 to 1.5 times that of the wire forming the outermost coil springs.

In another embodiment of the invention, the diameter of the wire forming the outer coil springs is of the order of 1.1 to 1.3 times that of the other inner coils.

Ideally, the diameter of the wire of some of the inner coil springs adjacent each corner of the spring base assembly is of the same diameter as that of the outer coil springs.

In one embodiment of the invention, additional reinforcing panels are provided on the top and bottom of the coil springs forming the corners of the spring base assembly.

One of the great advantages of the present invention is that by having a stiffening edge panel, the side periphery of the mattress is further tightened up. Thus, the side edge of the panel does not bulge outwards when somebody sits on it, nor eventually ΙΕ ο 5 0 1 8 2 -5does it permanently deform in use after wear.

This particular channel-shaped construction adds further rigidity to the edge of the bed.

Detailed Description of the Invention The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:Fig. 1 is a perspective partially cut-away view of one construction of mattress according to the invention; Fig. 2 is a plan view of portion of a spring base assembly; Fig. 3 is a plan view of the fully assembled spring base assembly; Fig. 4 is a detailed side view of a stiffening edge panel according to the invention, Fig. 5 is a plan view of an alternative construction of spring base assembly; Fig. 6 is a sectional view along the lines VI-VI of Fig. 5; and Fig. 7 (a) to (c) illustrates alternative arrangements of stiffening edge support structures.

Referring to the drawings and initially to Figs. 1 to 4 thereof, there is provided a mattress, indicated generally by the reference numeral 1, comprising a spring base assembly, indicated generally by the reference numeral 2, sandwiched between an upper upholstery layer 3 and a lower upholstery layer 4 and side upholstery layers 5. The upper, lower and side upholstery layers 3, 4 and 5 are of conventional construction and require no further description. They will generally comprise ΙΕ ο 5 0 1 8 2 -6combinations of various materials such as cloth, felt and foamed plastics, needled felt and other upholstery materials.

The spring base assembly 2 comprises rows and columns of coil springs and is illustrated in Fig. 2. It further comprises two rows and columns of outermost coil springs 10 and inner coil springs 11. The outermost coil springs 10 are of a heavier gauge wire than the inner coil springs 11. Also adjacent each corner, further coil springs 13 are provided which are generally of heavier construction as the outermost coil springs 10.

Referring now to Fig. 3, there is provided a continuous stiffening edge support structure 15 surrounding the spring base assembly 2 and connected to the outermost coil springs 10. The stiffening edge support structure 15, illustrated in more detail in Fig. 4, comprises a stiffening edge panel 16 formed by a dense material connected to a framework comprising spaced-apart upper and lower wires 17 and 18 interconnected by intermediate bands 19, again of wire. The wires 17, 18, 19 thus form a reinforcing and tying framework for the stiffening edge support structure 15.

Referring again to Fig. 3, additional reinforcing panels 20 are provided on the top and bottom of the coil springs 10 forming the comers of the spring base assembly, although only the reinforcing panel at the top of the coil springs is illustrated in Fig. 3. Again, the reinforcing panels 20 are made in substantially the same way as the stiffening edge panel 16.

It will be appreciated that the reinforced stiffening edge support 15 will ensure that the sides of the mattress will not bulge outwards when somebody sits on it and that the sides of the mattress will be tied closely together to the outer coil springs. Further, the outer coil springs, which are generally of a heavier gauge of wire than the inner coil springs, will further maintain the rigidity of the side of the mattress. Needless to say, the reinforcing panels 20 will ensure that the corners of the mattress will have added rigidity as corners are where considerable loading often occurs.

Referring now to Figs. 5 and 6, there is illustrated an alternative construction of spring base assembly, indicated generally by the reference numeral 25, in which parts IE 050 1 8 2 -Ί similar to those described with reference to the previous drawings are identified by the same reference numerals. In this embodiment, the only difference between the construction of this spring base assembly 25 and the spring base assembly 2 is that additional reinforcing panels 26 are provided on the top and bottom of the outer coil springs 10 to form the stiffening edge panel 16 to provide a reinforced inwardly directed load bearing channel which will further stiffen the edges of the mattress. Ideally, these additional reinforcing panels are manufacturing in substantially the same way as the stiffening edge panel, as can be seen from Fig. 6.

Fig 7(a) to (c) show various stiffening edge support structures. Figs. 7(b) and 7(c) show how the various intermediate bands 19 may be arranged to provide additional stiffening.

In use, it has been found that an ideal construction of the various reinforcing panels is to use a padded dense material connected to a framework. Ideally, needled felt is used and the wire band has a diameter of the order of between 1.3 and 1.5 times that of the wire forming the outermost coil springs and thus is of heavier gauge than the rest of the wire used. Similarly, the diameter of the wire forming the outer coil springs is of the order of 1 to 1.3 times that of the other inner coils and thus again is of a heavier wire gauge.

In practical embodiments of the invention, a stronger 12 gauge wire is used to form the outer springs, together with a lighter 13 gauge wire for the remainder of the inner springs with relative diameters of 2.68 mm and 1.25 mm.

Generally, a 9 gauge wire band is used to strengthen the reinforcing side panels which has a diameter of the order of 3.65 mm.

In the specification the terms “comprise, comprises, comprised and comprising” or any variation thereof and the terms “include, includes, included and including” or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation and vice versa.

The invention is not limited to the embodiment hereinbefore described, but may be IE Ο 5 Ο 1 8 2 -8varied in both construction and detail within the scope of the appended claims. -9IE 0 5 0 1 8 2

Claims (9)

1. A mattress comprising: an inner sprung structure having interconnected wire coil springs arranged in rows and columns to form a rectangular spring base assembly sandwiched between upper and lower upholstery layers: and a continuous stiffening edge support structure connected around the periphery of the spring base to the outermost rows and columns of the coil springs comprising spaced-apart upper and lower stiff wire bands interconnected by inclined intermediate bands to form a wire framework and a stiffening edge panel secured to the framework, said edge panel comprising a pad of dense pliable material.

2. A mattress as claimed in claim 1, in which the stiffening edge panel is of channel-shape in cross-section to lie above and below the outermost rows and columns of the coil springs.

3. A mattress as claimed in claims 1 and 2, in which the inclined intermediate bands comprise one band alternately inclined in one direction from the lower wire band to the upper wire band and then inclined downwards away from the other band to the lower band.

4. A mattress as claimed in claim 3, in which the intermediate bands comprise two sets of inclined bands crossing intermediate the upper and lower wire bands.

5. A mattress as claimed in any preceding claim, in which the pad is of a needled felt and the wire band has a diameter of the order of between 1.3 to 1.5 times that of the wire forming the outermost coil springs.

6. A mattress as claimed in any preceding claim, in which the diameter of the IE Ο 5 Ο 1 8 2 -10wire forming the outer coil springs is of the order of 1.1 to 1.3 times that of the other inner coils.

7. A mattress as claimed in any preceding claim, in which the diameter of the 5 wire of some of the inner coil springs adjacent each comer of the spring base assembly is of the same diameter as that of the outer coil springs.

8. A mattress as claimed in any preceding claim, in which additional reinforcing panels are provided on the top and bottom of the coil springs forming the 10 corners of the spring base assembly.

9. A mattress substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.