AU715385B2 - Spring assembly for mattress - Google Patents

Description

Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

.1.

Name of Applicant: SLEEP HAVEN BEDDING CO PTY LTD Actual Inventor: GRAHAM F MORITZ Address for Service: MADDERNS, 1st Floor, 64 Hindmarsh Square, Adelaide, South Australia, Australia Invention title: "SPRING ASSEMBLY FOR MATTRESS Details of Associated Provisional Application No: PO 1325 dated 30th July 1996 The following statement is a full description of this invention, including the best method of performing it known to us.

method of performing it known to us.

This invention relates to mattress construction and in particular to spring assemblies and edge support arrangements for a mattress.

A typical bedding mattress has an inner spring assembly comprising a single layer of elongate springs which are fixed in side to side relation to each other by a variety of known means and surrounded at their upper and lower peripheries by edge support means (typically a single strand of wire) to form a rectangular shape to suit a bedding mattress application.

The upper and lower rectangular areas of the inner spring assembly are then covered with a variety of materials (typically referred to as a comfort layer) to provide varying degrees of support for the user of the mattress. The mattress is covered in the S same manner on each of its upper and lower surfaces because it is typical for the mattress to be turned over during its lifetime to even out its wear.

°.Different levels of comfort are provided by varying the density and placement of different comfort materials over the upper and lower rectangular areas of the mattress. For example, a less firm zone of support can be provided midway between the base and top of the upper and lower rectangular areas so as to comfortably 20 support the hips of the user. It is also known to provide an array of inner springs in chosen zones which have different characteristics to the springs used elsewhere in the mattress to provide different levels of firmness.

S$ A large variety of elongate springs can be used in constructing an inner spring mattress. Each spring type is used for a particular reason, such as cost of manufacture, ease of reproducibility, longevity of function, ease of fixing adjacent springs, their compression characteristics and length.

Springs of different elongate length are used to construct mattresses of different heights, however as the height of the mattress and hence the length of the spring increases, the mattress in its constructed form can become unstable and uncomfortable to use. In particular the upper surface of a tall inner spring mattress tends to move very easily relative to its lower surface making use of the mattress uncomfortable for some users.

Furthermore, long springs are less likely to maintain their compression characteristics over time, and thus produce uneven sag in the mattress. It is also apparent that a long spring will have a longer period of resonance and be less damped than a shorter spring which can induce uncomfortable conditions for users of the mattress.

Also as the height of the inner spring mattress increases it is also preferable to decrease the amount of movement the upper surface makes relative to the lower surface as well as reduce the extent of the collapse of the sides of the mattress while a ",user rests upon or moves onto and/or off the mattress.

15 It is the aim of this invention to minimise or eliminate the instability of relatively a high mattresses using a novel inner spring assembly and side support arrangement.

BRIEF DESCRIPTION OF THE INVENTION According to one aspect of the invention, an inner spring mattress assembly 20 comprises a first array of springs having a topmost edge support means, a second array of springs located below said first array of springs and having a lowermost edge support means, a load spreading means located between said first and second a *a° array of springs, and an intermediate edge support means connected to both said a.

first and second array of springs.

According to another aspect of the invention, there is provided an inner spring mattress assembly further comprising at least one resilient connection between said topmost edge support means and said intermediate edge support means, and at least one resilient connection means between said intermediate edge support means and said lowermost edge support means wherein said resilient connections spread load between said edge support means in conjunction with said upper and lower arrays of springs.

A specific embodiment of the invention will now be described in some further detail with reference to and as illustrated in the accompanying figures. This embodiment is illustrative only and not meant to be restrictive of the scope of the invention.

BRIEF DESCRIPTION OF THE FIGURES Fig 1 depicts a perspective view of a typical inner spring arrangement for a mattress; Fig 2 depicts a perspective view of an upper and lower inner spring array and an intermediate load spreader means ready for assembly; Fig 3 depicts a perspective view of a double layer inner spring arrangement and load spreader means according to an aspect of the invention; Fig 4 depicts a partial section view of a double layer inner spring arrangement; ooo I Fig 5 depicts a partial side view of a side support means for a double layer inner spring arrangement; Fig 6 depicts offset side support means used in a double layer inner spring 20 arrangement according to the invention; S

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Fig 7 pictorially represents a force applied to the central top most area of the upper SS S inner spring and the manner in which the force is spread in a double layer inner spring arrangement according to the invention as depicted in perspective view in Fig 9; Fig 8 pictorially represents a force applied and the manner in which the force is spread in an offset side support means used in a double layer inner spring arrangement; and Fig 9 depicts a perspective view of a force applied to the top most area of the upper inner spring array.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION Fig 1 depicts a typical inner spring arrangement for a mattress consisting of a single layer 10 of an array of elongate spiral springs 12 which are fixed in side to side relation to each other by known means and surrounded at the upper and lower periphery of the array by edge support wires 14 and 16 having a rectangular shape to suit a bedding application.

Fig 2 depicts a first (upper) single layer 18 of elongate springs which are fixed in relation to one another by known means.

The springs could be continuous wire springs, single springs which are assembled into cloth pockets and fixed into adjacent relationship by glue, clips, wire thread and other known means or single springs which are fixed into the assembly by the S15 application of coiled wire connecting pieces or connecting devices as is known in the *9*9a* 9 9 Fig 2 also depicts a second (lower) single layer 20 of elongate springs constructed in the same or similar manner to that of the first single layer 18.

Edge support wires 22 and 24 hold the peripheral edges of the top and bottom of the first and second single layers respectively.

During construction the second single layer is located on a construction surface and a load spreading layer 26 is located thereon as shown pictorially in Fig 2. The first single layer 18 is then located on top of the load spreading layer 26 which is also substantially over the top of the lower second single layer.

Preferably the load spreading layer 26 comprises a hard wearing non-stretch material such as geotextile fabric. This fabric although commonly used for road construction, civil engineering and environmental engineering applications has properties which are very advantageous in this particular application.

Geotextile fabric is very inelastic, hard wearing and impenetrable to the springs above and below. In this new application, geotextile fabric provides load spreading characteristics over the lifetime of the mattress, and since it is a fabric, it is able to bend and spread load at the same time. Thus in the configuration disclosed in the specification the first layer of springs react in concert with a greater spread of springs in the second layer of springs while being physically separated by the geotextile fabric layer providing consistent spring characteristics for a relatively high mattress.

Geotextile can comprise either woven or non-woven filaments of polypropylene which when constructed or bonded by heating or cooling processes into a fabric can resist surface intrusion in all directions. This characteristic has the advantageous effect of physically isolating the layers of springs while allowing them to advantageously cooperate.

Geotextile fabric resists sagging in isolated spots thereby providing an even load distribution mechanism for loads applied to the upper surface of the upper single layer of springs over the lifetime of the mattress.

20 Geotextile fabric products have the following characteristics which particularise S. some of the preferable features of a load spreading layer.

High tensile strength at low elongations (high tensile modulus) S: Grab tensile strength Grab elongation High Puncture strength Mullen Burst Trapezoidal tear.

Furthermore geotextiles are vapour permeable thereby allowing movement of air and vapour between layers as required.

Clearly a stiff timber board would have some of the abovementioned characteristics and in certain circumstances could be used as a load spreading layer. However, it has been found that a fabric such as geotextile is preferable because it bends and spreads load at the same time resulting in a more comfortable result for most users of the mattress.

Other polypropylene and polyethylene based products could be used to create both woven and non-woven fabric suitable for the load spreading layer.

The load spreading layer 26 may also comprise fibres assembled into a composite material formed by melting a secondary material to maintain a finished composite material having a fixed and permanent state upon solidification or drying of the secondary material. However, it may also comprise fibres needled into a composite assembly with either synthetic or natural fibres formed into a sheet of a size and shape to fit between the first and second single layers of the spring assembly for a mattress. Preferably, the characteristics of long lived even load spreading is provided by the abovementioned load spreading layer material.

Furthermore, the load spreading layer may comprise a synthetic foam plastic. The 20 load spreading layer may also comprise a solid sheet material, woven materials and 6-60 either man made or naturally occurring materials or fibres assembled, either, with a glue medium to construct a permanent material having low stretch and load spreading characteristics or fixed by other permanent means.

It is not essential for each spring 12 in the first single layer to be located immediately above a corresponding spring in the second single layer as is depicted pictorially in Figs 2, 3 and 4.

Referring to Fig 3, the first and second single layers are depicted one above the other with the load spreading layer 26 therebetween but this figure does not depict an intermediate edge support means located around the periphery of the bottom of the first single layer and the top of the second single layer. Preferably an intermediate edge wire of suitable strength can be fitted so as to couple the layers by known means and act as an intermediate edge support means. Other edge support means could be used to meet the requirements of this coupling of two layers of inner spring arrays which may conceivably comprise the close coupling of two intermediate edge support means connected to respective layers.

Fig 4 depicts a partial internal side view of the first and second single layers of springs which are located immediately adjacent to the edge support wires 22, 24 and the intermediate edge wire 28.

As discussed previously it is preferable but not essential for an upper spring 30 to be above a lower spring 32. The upper peripheral edge of the spring 30 is connected in known manner to the edge support wire 22 and similarly attached to the intermediate edge wire 28 at its lower end. The upper peripheral edge of the spring 15 32 is attached to the intermediate edge wire 28 and the lower peripheral edge of the °osoo spring 32 is attached to the lower edge support wire 24, thereby in this preferable embodiment, coupling at least the adjacent peripheral edges of the upper and lower layers.

20 The load spreading layer 26 is located slightly inwards of the intermediate edge support wire 28. This is merely a preferable position and occurs only at the edge of the spring assembly. Also shown in Fig 4 is spring 34 located above spring 36 separated by the intermediate load spreading layer 26 which extends (not shown) across the width and length of the final spring assembly.

Fig 4 also pictorially depicts side views of preferable side support means 42 and 48 in the form of single 900 spring coil.

Fig 5 depicts a side view of a side support means for a double layer inner spring arrangement showing edge support wires 22 and 24 and an intermediate edge support wire 28, as well as side views of springs 30, 32, 38, 40, 50 and 52. Side support means which are preferably single coil springs 42 and 48, are located in offset relationship to each other in the first and second single layers respectively as are springs 48 and 46 as is also depicted from the front in Fig 4 and side-on in Fig 4.

Side support means may comprise a device which is arranged or has characteristics which recover from compression and which are attachable between the upper and intermediate edge support wires and intermediate and lower support wires respectively.

The compression recovery side support means may comprise springs which are shaped so as to project inwards of the spring assembly, an example of which is the 900 spring which is pictorially represented in Figs 4, 5 and 6. Other types of compression recovery device may comprise springs which operate and are contained S within the same plane as the perimeter edge of the spring assembly but which are arranged not to extend externally of the edge support wires which circumscribe the 15 edge of the spring assembly. Additionally the compression recovery device may comprise blocks of foam plastic (man made) or foam latex (natural material) or arrangements of fibres fixed together by secondary melted medium and compressed °during solidification to assume a compressed state with a resilient compression recovery property or alternatively solid items which have an inherent compression 20 recovery characteristic which are available in man made or naturally occurring materials.

The side support means are arranged so as to evenly distribute loads acting on the upper surface of the upper layer across its total surface area and in particular those loads acting on the edges of the mattress such as when a user is sleeping near the edge of the mattress. In particular it is preferable for the side support means to be arranged so that the firmness at the edge of the mattress is similar to the firmness elsewhere on the mattress so that a user located on its top surface and inwards of a longitudinal edge thereof is supported evenly or in the same manner as though they were elsewhere on the mattress.

Fig 7 pictorially depicts the manner in which the spring assembly described and depicted in Fig 9 reacts to a load when it is applied to the top surface of the upper single layer of the spring assembly. As the springs in the upper layer are compressed the load spreading means distributes forces transferred through the upper layer of springs across not only the spring or springs in the lower layer of the spring assembly immediately below the load, but those adjacent to it.

The large thick arrow above the first layer depicts a large force and the smaller thinner arrows depict the way in which that force is dissipated across more than one of the springs in the second lower layer of the spring assembly.

The cross-section of the spring assembly depicted in Fig 7 and its reaction to a force exerted from above only shows one dimension whereas distribution of an actual force on a mattress is distributed radially outwards from the force (Fig 9) thus spreading the force across a broader base than would be the case without a load 0 spreading means located intermediate the first and second layers of springs, or using only a single layer of springs.

Fig 8 pictorially depicts similar spreading of load which is distributed by the side 20 support means when a force is exerted on the upper edge support wire. The one or more side support means laterally spread the load along the length of the intermediate support wire, the side support means between it and the lower edge support wire as well as the springs adjacent thereto as well as compensate for the absence of springs beyond the edge of the assembly.

This spreading of the load also results in a reduction in the transverse movement of the upper edge support wire relative to the lower edge support wire resulting in a more stable use, entry and exit of a user of a mattress constructed using the spring assembly and side support arrangement of the invention.

It will be appreciated by those skilled in the art, that the invention is not restricted in its use to the particular application described, nor is it restricted to the feature of the preferred embodiment as described herein. It will be appreciated that various modifications can be made without departing from the principles of the invention, therefore the invention should be understood to include all such modifications within its scope.

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Claims (13)

1. An inner spring mattress assembly comprising a first array of springs having a topmost edge support means, a second array of springs located below said first array of springs and having a lowermost edge support means, a load spreading means located between said first and second array of springs, and an intermediate edge support means connected to both said first and second array of springs.

2. An inner spring mattress assembly according to claim 1 wherein said load •0 -spreading means is a substantially planar fabric material. 1:

3. An inner spring mattress assembly according to claim 2 wherein said load spreading means comprises geotextile fabric material.

4. An inner spring mattress assembly according to claim 2 wherein said load Sspreading means comprises fibres assembled into a composite fabric material. 2 o

5. An inner spring mattress assembly according to claim 2 wherein said load spreading means comprises fibres needled into a composite assembly of synthetic •and natural fibres formed into a sheet.

6. An inner spring mattress assembly according to claim 1 wherein said load spreading means comprises synthetic foam material.

7. An inner spring mattress assembly according to claim 1 wherein said load spreading means comprises latex rubber material.

8. An inner spring mattress assembly according to claim 1 wherein said load spreading means comprises a solid sheet material.

9. An inner spring mattress assembly according to claim 1 further comprising at least one resilient connection between said topmost edge support means and said intermediate edge support means, and at least one resilient connection means between said intermediate edge support means and said lowermost edge support means wherein said resilient connections spread load between said edge support means in conjunction with said upper and lower arrays of springs.

An inner spring mattress assembly according to claim 9 wherein said intermediate edge support means connected to said topmost edge support means are not vertically aligned with intermediate edge support means connected to said lowermost edge support means. 'oo.

11. An inner spring mattress assembly according to claims 9 or 10 wherein a said S: 15 resilient connection comprises a spring. 0 0 oooeo

12. An inner spring mattress assembly according to claim 11 wherein said spring •is a 900 spring located between respective edge support means and within said respective spring assemblies. S

13. An inner spring mattress assembly as described in the specification and as illustrated in the attached Figs 2 to 8. Dated this 29th day of July, 1997. SLEEP HAVEN BEDDING CO PTY LTD By its Patent Attorneys MADDERNS All