GB2524228A - Pocketed springs - Google Patents

Abstract

A pocketed spring unit 30, suitable for an upholstered article or such, comprises a plurality of coil springs 32 each encased in its own individual pocket 34 formed between two sheets 36 and 38 of material. The sheets 36, 38 are welded at points between the springs, so as to form the pockets. The material from which the sheets are made is woven polypropylene, which is weldable, breathable and also substantially transparent so that the springs 32 are visible within the pockets. Such pocketed, or encased, springs are used in a variety of upholstered articles such as mattresses, in which the independently acting springs conform to the shape of a person's body.

Description

Pocketed Springs.

The present invention relates to pocketed springs for an upholstered article or similar.

S

Pocketed springs, sometimes referred to as encased springs, are used in a variety of upholstered articles, such as mattresses. Mattresses in which the springs are encased in pockets of fabric are generally held to be more comfortable and luxurious than conventionally sprung mattresses. This is partly because discrete, independently acting pocketed springs are more able to conform to the shape of a person's body than a mesh of interconnected springs in which the springs are unable to deform without affecting their neighbours. Also, the presence of the fabric pocket between adjacent springs lessens the likelihood that the springs will rub together, which can generate an unwelcome level of noise in what is meant Lo be a quiet environment.

Broadly, there are two common types of pocketed spring unit. The first is of the type described in our PCT Patent application, published as WO 2007/031774, in which coil springs are located beLween axially spaced sheets of material, which sheets are welded or otherwise attached together at points between the springs to encapsulate the springs in individual pockets. This method produces an array of individually pocketed springs as a pocketed spring unit.

The other type is made by encasThg each spring in a pocket formed by folding a sheet of material and then welding or otherwise attaching together the leaves of the folded sheet along the side of the spring. The thus formed strings of springs are then stacked alongside one another and are glued at their ends, axially above and below the springs, to further sheets of material to form a pocketed spring unit.

Various types of material are used in the manufacture of the above-described pocketed springs, and particularly conunon is the use of non-woven, spun-bonded polyester, as this can readily be welded to itself using electrical welding apparatus.

The present invention is defined in the attached independent claims, to which reference should now be made.

Further, preferred features may bc found in the sub-cl aims appended thereto.

According to another aspect of the present invention, there is provided a pocketed spring comprising a spring encased in a pocket at least partly formed from a non-opaque, weldable material.

According to another aspect of the present invention, there is provided a pocketed spring comprising a spring encased in a pocket at least partly formed from a woven, weldable material.

According to yet another aspect of the present invention, there is provided a pocketed spring comprising a spring encased in a pocket at least partly fomued from a woven, non-opaque material.

The invention also includes a pocketed spring unit comprising a plurality of springs encased in pockets

according to any statement herein.

In a preferred arrangement at least some of the poc]ceted springs are attached at least at their one ends to a common sheet of weldable material.

The pocketed springs may be attached at their one ends to a first common sheet and may be attached at their second ends to a second common sheet.

The non-opaque maLerial may comprise substantially translucent material, and/or substantially transparent material.

At leasL some of Lhe pockets may be famed from material that is woven and weldable.

The invention also includes a pocketed spring unit comprising a plurality of springs encapsulated in one or more pockets formed between first and second sheets of material, which maLarial is non-opaque and weldable.

The invention also includes a pocketed spring uniL comprising a plurality of springs encapsulated in one or more pockets formed between first and second sheets of material, which material is woven and weldable.

The invention also inc]udes a pocketed spring unit comprising a plurality of springs encapsulated in one or more pockets formed between first and second sheets of material, which material is non-opaque and woven.

The first and second sheets may be bonded, welded or otherwise joined together at spaced locations to form the pockets for the springs.

The springs may comprise coil springs and may be of wire.

At least some of the springs may have coils of different diameters at opposed ends.

Preferably, in respect of at least some of the springs, the diameter of at least one of the coils is greater than the axial length of the spring in the pocket. For at least some of the springs the first and second layers may be joined together at a position that is closer to one end of the spring than the other.

the first and second layers may be welded together, for example ultrasonically or thermally. The weld may form a join that may be wider than it is tall, and is preferably substantially flat. In a preferred arrangement the pockets are formed from only the first and second sheets.

For at least some springs the first and second layers of material may be joined at a position that is closer to an end of the spring having a coil of larger diameter.

Preferably substantially the same area of material is arranged to cover each end of the spring.

In a preferred arrangement the unit is also at least partly compressible in at least one direction transverse to the axis of the springs.

Preferably at least somo of the springs are held under..

compression in their pockets.

The springs ar..e preferably wire and are more preferably of steel, aluminium or titanium, or of an alloy thereof.

Preferably the unit is flexible in at least one lateral direction, generally perpendicular to the axis of the springs.

The material may be translucent or transparent and is preferably breathable. More preferably at least a portion of the material may comprise holes or perforaLions.

rn a preferred arrangement the material comprises a woven polymeric fibre such as polypropylene.

The invention may include any combina Lion of the features or limitations referred to herein, excepL such a combination of features as are mutually exclusive, or mutually inconsistent.

A preferred embodiment of the present invention will now be described. By way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 shows in schematic perspective view a first embodiment of pocketed spring unit according to the present invention; Figure 2 shows the pocketed spring unit of Figure 1 in schematic sectional view; and Figure 3 shows in schematic perspective view a second embodiment of pocketed spring unit according to the pesent invention.

Turning to Fiqures 1 and 2, there is shown generally at 10 a pocketed spring unit comprising a plurality of coil springs 12 each encased in its own individual pocket 14 formed between Lwo sheets 16 and 1.8 of material. The sheets 16 and 18 have been welded at points 20 between the springs, so as to form the pockets.

One method for forming such a pocketed spring unit is described in our PCT patent application, published as Wa 2007/031774, the entire contents of which are incorporated herein by reference.

In the embodiment shown, the material from which the sheets arc made is polypropylonc which in this case is woven. The material is weldable and breathable and in this example is also substantially transparent so that the springs 12 are visible within their pockets.

In this embodiment the upper layer is also perforated with holes to allow air to circulate freely within the spring unit. In an alternative embodiment (not shown) the lower layer may be perforated, or both layers may he perforated.

Figure 3 shows another common type of pocketed spring unit, generally at 30. A plurality of individual coil springs 32 are each encased within an individual pocket 34 formed of the material described above in relation to the embodiment of Figures 1 and 2. A number of the pocketed springs 32 are formed togebher as a linear string of springs and the strings are then placed together and joined at upper and lower ends by sheets 36 and 38 of material by gluing or preferably welding the material of the sheets 36, 38 to the material of the pockets 34.

Again, he upper sheet 36 or lower sheet 38, or both sheets, may be perforated.

The welding may be ultrasonic or thermal welding.

The material, being woven, helps to deaden the noise made by the movement of the springs in use. In addition, as iLL is substantially transparent, the springs themselves are vi sible, which may be of interest to a purchaser.

One or both of the sheets 16, 18 or 36, 38 may be non-opaque, such as translucent or transparent, or only a portion of at least one of these sheets may be non-opaque.

The upper and lower layers, or as the case may be sheets, may have different properties or characteristics, and may be combined in various ways. Examples include but are not limited to differenccs between the layers in respect of thermal characteristics, waterproofing, weight, density, water absorption or repelience, visual appearance, tactile properties, structural differences such as woven or non-woven, knitted, felted, wear characteristics, elasticity, antibacterial, anti-static, properties of flavour and/or fragrance and flame-retardance.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance, it should be understood that the applicant claims protection in respect of any patentable feature or combination of features referred to herein, and/or shown in the drawings, whether or not particular emphasis has been placed thereon.

Claims (13)

1. CLAIMS1. A pocketed spring comprising a spring encased in a pocket at least partly formed from a non-opaque, weldable material.
2. 2. A pocketed spring unit comprising a plurality of springs encased in pockets, wherein at least some of the pocketed springs are attached at least at their one ends to a common sheet of non-opaque, weldable material.
3. 3. A unit according to Claim 2, wherein Lhe pocketed springs are attached at their one ends to a first common sheet and are atlLached at their second ends to a second common sheet.
4. 4. A unit according to Claim 2 or 3, wherein at least some of the pockets are formed from material that is woven.
5. 5. A pocketed spring unit comprising a plurality of springs encapsulated in one or more pockets formed between first and second sheets of material, which material is non-opaque and weldable.
6. 6. A unit according to Claim 5, wherein the first and second sheets are bonded, welded or otherwise joined together at spaced locations to form the pockets for the springs.
7. 7. A unit according to any of the preceding claims, wherein the springs comprise coil springs.
8. 8. A unit according to Claim 7, wherein at least some of the springs have coils of different diameters at opposed ends.
9. 9. A unit according to Claim 5, wherein the first and second sheets are welded together ultrasonically or thermally.
10. 10. A unit according to any of the preceding claims, wherein the material is translucent or transparent.
11. 11. A unit according to any of the preceding claims, wherein the material is breathable.
12. 12. A unit according to any of the preceding claims, wherein the material comprises holes or perforations.
13. 13. A unit according to any of the preceding claims, wherein the material comprises a woven polymeric fibre such as polypropylene.