NZ611938B - A support unit for use in a mattress or cushion - Google Patents

Abstract

support unit (100) for use in a mattress or cushion is disclosed. The support unit comprises an array of upright primary coil springs (110) arranged in a series of aligned rows (111) and columns (112) so as to define voids (117) between sets of four adjacent primary coil springs (110). Secondary support elements (120) are located in at least several of the voids (117). Then elements could be springs or foam columns. The support unit may be divided into zones characterised by different density or patterning’s of the secondary support elements. The lower ends of the primary coil springs and secondary support elements all lie substantially in a common plane, such that the upper ends of the secondary support elements lie in a plane below the plane of the upper ends of the primary coil springs. This results in the secondary support elements having no support effect until a load sufficient to compress the primary coil spring by an amount equal to the difference in heights between the primary coil springs and the secondary support elements is achieved. The additional support provided by the secondary support elements is thus only effectively achieved when the support unit is subjected to a heavy local load, either as a result of a heavier body mass of the person lying on the mattress or localised increased load resulting, for example, from a person sitting or standing in a localised area of the support unit. support elements (120) are located in at least several of the voids (117). Then elements could be springs or foam columns. The support unit may be divided into zones characterised by different density or patterning’s of the secondary support elements. The lower ends of the primary coil springs and secondary support elements all lie substantially in a common plane, such that the upper ends of the secondary support elements lie in a plane below the plane of the upper ends of the primary coil springs. This results in the secondary support elements having no support effect until a load sufficient to compress the primary coil spring by an amount equal to the difference in heights between the primary coil springs and the secondary support elements is achieved. The additional support provided by the secondary support elements is thus only effectively achieved when the support unit is subjected to a heavy local load, either as a result of a heavier body mass of the person lying on the mattress or localised increased load resulting, for example, from a person sitting or standing in a localised area of the support unit.

Description

A SUPPORT UNIT FOR USE IN A MATTRESS OR CUSHION Field The present invention relates to the field of support units for mattresses and cushions.

Background Mattresses used in beds, and cushions used in sofas, chairs and other forms of upholstered furniture, regularly incorporate support units, in the form of spring units, to provide cushioned support to a person lying or sitting on the mattress or cushion.

The spring units are typically formed as an array of upright coil springs formed in a rectangular array of rows and columns of coil springs. The individual coil springs are available in various specific forms, but are generally formed of a single length of high tensile wire, typically having a diameter of 1.4 to 2.2 mm, formed with multiple convolutions into the general shape of a barrel to form the spring. Spring units may be formed with varying degrees of stiffness, and thus support, that is generally determined by the thickness of wire and specific size and configuration of the coil.

The rectangular array of coil springs in the spring unit is usually of a uniform configuration with the coil springs aligned in uniform rows and columns. One typical form of spring unit has each individual row of coils inserted into a polypropylene fabric sleeve. An ultrasonic welding process is used to seal the sleeve between successive coil springs, thereby defining a pocket within which each coil spring is separately confined. The welds forming separate pockets are individually formed in the sleeve immediately following insertion of each successive coil spring into the sleeve, forming a continuous strand of pocketed coil springs. The continuous strands are then cut to length, ready for assembly side-by-side to form the separate rows of the spring unit. The individual strands of pocketed coil springs are glued together side- by-side with the coil springs of each row aligned, thereby forming the aligned columns of the spring unit.

Summary of Invention In a first aspect, the present invention provides a support unit for use in a mattress or cushion, said support unit comprising: (8196624_1):JAA an array of upright primary coil springs arranged in a series of aligned rows and columns of adjacent primary coil springs so as to define voids each bounded by a set of four adjacent primary coil springs, each of said voids being separated by said primary coil springs; a plurality of secondary support elements each located in one of said voids, wherein each of said secondary support elements has a height less than a height of each of the respective adjacent said primary coil springs.

Typically, each of said secondary support elements has a maximum diameter of between % and 50% of the maximum diameter of each of the respective adjacent said primary spring coils.

In one embodiment, the maximum diameter of each of said secondary support elements is 40% to 45% of the maximum diameter of each of the respective adjacent said primary coil springs.

In some embodiments, between at least one pair of adjacent said rows, said secondary support elements are located in each of said voids.

In some embodiments, said secondary support elements are only located in some of said voids.

In some embodiments, between at least one pair of adjacent said rows, said secondary support elements are located in every second or third said void.

In a preferred form, each said primary coil spring is located in a primary coil spring pocket.

Typically, each said row of primary coil springs comprises a strand of pocketed primary coil springs, a sleeve of fabric material having opposing sides being joined with a single weld between adjacent said primary coil springs so as to define said primary coil spring pockets.

Typically, adjacent said strands of pocketed primary coil springs are glued together.

In a preferred form, each of said secondary support elements is located in a secondary support pocket, each of said secondary support pockets being glued to one or more adjacent said primary coil spring pockets. (8196624_1):JAA In some embodiments, rows of said secondary support elements each comprise a strand of pocketed secondary support elements, a sleeve of fabric material having opposed sides being joined between adjacent said secondary support elements so as to define said secondary support pockets.

In a preferred form, each of said secondary support elements comprises an upright secondary coil spring.

In an alternate form, each of said secondary support elements comprises an upright column formed of a foam material.

The height of each of said secondary support elements may be between 70% to 80% of the height of each of the respective adjacent said primary coil springs.

In one embodiment, the height of each of said secondary support elements is approximately 70% of the height of each of the respective adjacent said primary coil springs.

In one form, said support unit is divided into multiple zones with the distribution of said secondary support elements varying between said zones.

Typically, each said row extends in a widthwise direction of said support unit and each said zone extends in the widthwise direction between at least one pair of adjacent said rows.

In some embodiments, in a first said zone, a said secondary support element is located in each of said voids and, in a second said zone, a said secondary support element is located in only some of said voids. (8196624_1):JAA In a second aspect, the present invention provides method of manufacturing a support unit for use in a mattress or cushion, said method comprising the steps of: (a) inserting a plurality of primary coil springs into a sleeve, joining opposing sides of said sleeve with a weld between adjacent said primary coil springs to form a strand of pocketed primary coil springs; (b) locating a plurality of secondary support elements against a side face of said strand of primary coil springs with each said secondary support element located in a recess between adjacent said primary coil springs; (c) inserting a further plurality of primary coil springs into a further sleeve, joining opposing sides of said sleeve with a weld between adjacent said primary coil springs to form a further strand of pocketed primary coil springs; (d) gluing said further strand of pocketed primary coil springs to said side face of said strand of pocketed primary coil springs with said primary coil springs of said strand each aligned with an adjacent said primary coil spring of said further strand, and defining voids each bounded, and separated, by a set of four adjacent primary coil springs, each said seconday support element being located in one of said voids; and (e) repeating steps (b) to (d) one or more times to form an array of upright primary coil springs arranged in a series of aligned rows and columns of adjacent primary coil springs. [0023a] Preferably, each of said secondary support elements has a height less than a height of each of the respective adjacent said primary coil springs. [0023b] Preferably, each of said secondary support elements is inserted into a secondary support pocket, each of said secondary support pockets being glued to one or more adjacent said strands of primary coil springs. [0023c] Preferably, each said secondary support element comprises an upright secondary coil spring. (8196624_1):JAA Brief Description of Drawings Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings wherein: Figure 1 is a schematic plan view of a support unit; Figure 2 is a schematic plan view of an alternate form of the support unit of Figure 1; Figure 3 is an isometric view of the support unit of Figure 1 in partly assembled form; Figure 4 is an isometric view of an alternate form of spring unit in partly assembled form; Figure 5 is an isometric view of a primary coil spring; Figure 6 is an isometric view of a secondary support element in the form of a secondary coil spring; and Figure 7 is an isometric view of a secondary support unit in the form of an upright column of foam material.

Description of Embodiments Referring firstly to Figure 1 of the accompanying representations, a support unit 100 for use in a mattress or cushion, is depicted. The support unit 100 includes an array of upright primary coil springs 110 arranged in a series of aligned rows 111 and columns 112. In the particular arrangement schematically depicted, there are three rows 111 and four columns 112, however for a typical mattress the array will be extended over a significantly greater number of rows and columns. For a queen mattress, there would typically be approximately 25 columns across the width of the mattress and 33 rows along the length of the mattress.

Each individual primary coil spring 110 will typically be of a standard configuration, being formed of a single length of high tensile wire, with a diameter of 1.4 to 2.2 mm, formed with multiple convolutions into the general shape of a barrel. An example of such a primary coil (8196624_1):JAA spring 110 is depicted in Figure 5. Each of the primary coil springs will also typically be located in a primary coil spring pocket 113. The primary coil spring pockets 113 may be formed separately, with a single primary coil spring 110 located within each primary coil spring pocket 113. Alternatively, and more typically, individual primary coil spring pockets 113 may be defined by individual pockets formed in a polypropylene fabric sleeve 114 by ultrasonically forming welds 115 between opposing sides of the fabric sleeve 114 in the manner described above. In this configuration, each row 111 of primary spring coils 110 comprises a strand 116 of pocketed primary coil springs 110.

The aligned rows 111 and columns 112 of primary coil springs 110 define voids 117 between each set of four adjacent primary coil springs 110. Each such set is formed by primary coil springs 110 in two adjacent rows 111 and columns 112, with the void 117 formed in the centres. A secondary support element 120 is located in each of at least several of the voids 117.

Each of the secondary support elements 120 will typically be in the form of an upright secondary coil spring 120, as depicted in Figure 6, but it is also envisaged that the secondary support elements 120 may each take the form of an upright column 120’ formed of a foam material, such as high density polyurethane foam or high density viseoelastic foam, or polyethylene. Such a column 120’ is depicted in Figure 7.

In the form depicted in Figure 1, a secondary support element 120 is located in each of the voids 117. Configurations are envisaged, however, where secondary support elements 120 are only located in some of the voids 117 and the distribution of secondary support elements 120 may vary across different regions of the mattress. For example, secondary support elements 120 may be located in each of the voids 117 between at least one pair of adjacent rows 111 in zones of the bed that require the greatest support, such as areas intended to support the hips and shoulders of a person lying on the mattress. In zones requiring lesser support, secondary support elements 120 might be located in every second or third void 117 between at least one pair of adjacent rows 111 in such zones. For other zones, requiring even less support, there may be no secondary support elements 120. Accordingly, the support characteristics of the support unit 100 may be readily varied across the extent of the support unit 100 by varying the frequency of location of secondary support elements 120. Figure 2 schematically depicts a specific alternative arrangement to that of Figure 1, where secondary support elements 120 are located in every second void 117, with the secondary support elements 120 offset between successive pairs of rows 111 of primary coil springs 110. (8196624_1):JAA Each of the secondary support elements 120 will generally have a maximum diameter less than that of the adjacent primary spring coils 110, which will typically each be of an identical configuration and thus maximum diameter. Typically, each of the secondary support elements 120 will have a maximum diameter of between 35% and 50% of the maximum diameter of each of the primary coil springs 110. In particular arrangements, the maximum diameter of each of the secondary support elements 120 will be 40% to 45% of the maximum diameter of each of the primary coil springs 110. In some arrangements, each of the secondary support elements 120 may have a maximum diameter of 30 to 35 mm whilst each of the primary coil springs 110 may have a maximum diameter of 70 to 80 mm.

Each of the secondary support elements 120 will typically have a height less than the height of each of the adjacent primary coil springs 110. The primary coil springs 110 will typically have a fixed height across the extent of the spring unit 100, with the secondary support elements also having a fixed, lesser, height across the extent of the support unit 100. The height of each of secondary support elements 120 will typically be between 70% to 80% of the height of the primary coil springs 110. In particular arrangements, the height of each of the secondary support elements 120 is approximately 70% of the height of the primary coil springs 110. In some arrangements, each of the secondary support elements 120 may have a height of 130 to 180 mm whilst each of the primary coil springs 110 may have a height of 180 to 230 mm.

As best depicted in Figure 3, showing a support unit 100 in a partly assembled form, the lower ends of the primary coil springs 110 and secondary support elements 120 all lie substantially in a common plane, such that the upper ends of the secondary support elements 120 lie in a plane below the plane of the upper ends of the primary coil springs 110. This results in the secondary support elements 120 having no support effect until a load sufficient to compress the primary coil springs 110 by an amount equal to the difference in heights between the primary coil springs 110 and the secondary support elements 120 is achieved. The additional support provided by the secondary support elements 120 is thus only effectively achieved when the support unit 100 is subjected to a heavy local load, either as a result of a heavier body mass of the person lying on the mattress or localised increased load resulting, for example, from a person sitting or standing in a localised area of the support unit 100. This configuration allows two people lying on a common support unit 100, and having significantly different body weights, to be afforded differing amounts of support as dictated by their body weights. That is, a heavier person lying on one side of a mattress incorporating the support unit 100 will be provided the (8196624_1):JAA additional support of the secondary support elements 120, whilst a lighter person lying on the opposing side of the mattress might only be provided with support from the primary coil springs 110.

As with the primary coil springs 110, each of the secondary support elements 120 may be located within a secondary support pocket 123. The secondary support pockets 123 may be formed separately, with a single secondary support element 120 located within each secondary support pocket 123 as depicted in the arrangements of Figures 4.

Alternatively, as depicted in the arrangement of Figures 1 and 3, individual secondary support pockets 123 may be defined by individual pockets formed in a polypropylene fabric sleeve 124 by ultrasonically forming welds 125 between opposing sides of the fabric sleeve 124 in the same manner that the primary coil spring pockets 123 are formed. In this configuration, each row of secondary support elements 120 comprises a strand 126 of pocketed secondary support elements 120. As the secondary support elements 120 will be spaced from each other, as compared to the closely adjacent primary coil springs 110, it is envisaged that two vertically extending welds 125 may be formed in the sleeve 124 between each secondary support element 120, with each of the welds 125 being located adjacent one of the secondary support elements 120. This will particularly be the case where the secondary support elements 120 are only located in every second or third void 117.

The support units 100 may be manufactured utilising relatively standard equipment currently utilised to manufacture pocketed coil spring support units. The process will now be described with reference to Figure 3.

A continuous strand of pocketed primary coil springs 110 is manufactured in the usual manner by inserting individual primary coil springs 110 into a continuous polypropylene fabric sleeve 114 and ultrasonically forming a weld 115 between opposing sides of the fabric sleeve 114 adjacent the last primary coil spring 110 inserted, before inserting the next primary coil spring 110 and ultrasonically forming the next weld 115 so as to provide individual primary coil spring pockets 113. The continuous strand of pocketed primary coil springs 110 is then cut to individual lengths corresponding to the length of each row 111 of the support unit 100 forming cut-to-length strands 116 of pocketed primary coil springs 110. (8196624_1):JAA A continuous strand of pocketed secondary support elements 120 is formed in the same manner utilising the same machinery, set up to process the smaller size of the secondary support elements 120 and appropriately smaller sized continuous sleeve 124. The machine is also configured to form two spaced welds 225 after inserting each secondary support element 120, so as to provide the necessary spacing between successive secondary elements 120 such that the secondary support elements 120 will align with the voids 117 between rows 111 of primary coil springs 110. The continuous strand of pocketed secondary support elements 120 is also cut to individual lengths, forming cut-to-length strands 126 of pocketed secondary support elements 120.

A standard pocket assembly machine may then be utilised to assemble the individual strands 116 of pocketed primary coil springs 110 and strands 126 of secondary support elements 120. A first strand 116 of pocketed primary coil springs 110 is first placed in the pocket assembly machine and a glue head traverses across the length of the strand 116 to apply one or more lines of glue 130 across the side face of the strand 116, as depicted in Figure 3. Rather than immediately placing the next strand 116 of primary coil springs to form the next row of primary coil springs 110 against the first strand 116, a strand 126 of pocketed secondary support elements 120 is located in the pocket assembly machine adjacent the first strand 116 of pocketed primary coil springs 110, positioned such that the secondary support elements 120 are located in the recesses between individual primary coil springs 110. The glue 130 holds the secondary support elements 120 in place. The glue head again traverses to place one or more further lines of glue 130 on the side face of the strand 126 of secondary support elements 120 and a further strand of primary coil springs 110 is then located against the preceding strands 116,126, aligning the primary spring coils 110 with those of the first strand 116, such that the secondary support elements 120 are held captive in the void 117 between sets of four adjacent primary coil springs 110. The process is then repeated.

As discussed above, configurations are envisaged where the secondary support elements 120 are not arranged in strands 126, but are instead in separated individual pockets 123 (or not pocketed at all), as depicted in Figures 2 and 4. Referring to Figure 4, in this configuration, the secondary support elements 120 are individually placed in the recesses between adjacent primary coil springs 110 of each successive strand 116 of primary coil springs 110, with the lines of glue 130 applied at the side face of the strand 116 of pocketed primary coil springs 110 serving both to hold each individual secondary support element 120 (either pocketed or not) and to (8196624_1):JAA subsequently fix the next strand 116 of pocketed primary coil springs 110 by virtue of that portion of the lines of glue 130 located on the first strand 116 of pocketed primary coil springs 110 between the individual secondary support elements 120. Configurations are also envisaged where the primary coil springs 110 are not arranged in strands 116, but are also in separated individuals pockets (or not pocketed at all). (8196624_1):JAA I/WE

Claims (18)

CLAIM 1.:

1. A support unit for use in a mattress or cushion, said support unit comprising: an array of upright primary coil springs arranged in a series of aligned rows and columns of adjacent primary coil springs so as to define voids each bounded by a set of four adjacent primary coil springs, each of said voids being separated by said primary coil springs; a plurality of secondary support elements each located in one of said voids, wherein each of said secondary support elements has a height less than a height of each of the respective adjacent said primary coil springs.

2. The support unit of claim 1, wherein each of said secondary support elements has a maximum diameter of between 35% and 50% of the maximum diameter of each of the respective adjacent said primary spring coils.

3. The support unit of claim 2, wherein the maximum diameter of each of said secondary support elements is 40% to 45% of the maximum diameter of each of the respective adjacent said primary coil springs.

4. The support unit of any one of claims 1 to 3, wherein each said primary coil spring is located in a primary coil spring pocket.

5. The support unit of claim 4, wherein each said row of primary coil springs comprises a strand of pocketed primary coil springs, a sleeve of fabric material having opposing sides being joined with a single weld between adjacent said primary coil springs so as to define said primary coil spring pockets.

6. The support unit of claim 4, wherein adjacent said strands of pocketed primary coil springs are glued together.

7. The support unit of any one of claims 4 to 6, wherein each of said secondary support elements is located in a secondary support pocket, each of said secondary support pockets being glued to one or more adjacent said primary coil spring pockets. (8196624_1):JAA

8. The support unit of claim 7, wherein rows of said secondary support elements each comprise a strand of pocketed secondary support elements, a sleeve of fabric material having opposed sides being joined between adjacent said secondary support elements so as to define said secondary support pockets.

9. The support unit of any one of claims 1 to 8, wherein between at least one pair of adjacent said rows, said secondary support elements are located in each of said voids.

10. The support unit of any one of claims 1 to 8, wherein said secondary support elements are only located in some of said voids.

11. The support unit of any one of claims 1 to 8, wherein between at least one pair of adjacent said rows, said secondary support elements are located in every second or third said void only.

12. The support unit of any one of claims 1 to 11, wherein each of said secondary support elements comprises an upright secondary coil spring.

13. The support unit of any one of claims 1 to 11, wherein each of said secondary support elements comprises an upright column formed of a foam material.

14. The support unit of any one of claims 1 to 14, wherein the height of each of said secondary support elements is between 70% to 80% of the height of each of the respective adjacent said primary coil springs.

15. The support unit of any one of claims 1 to 13 wherein said support unit is divided into multiple zones with a distribution of said secondary support elements varying between said zones.

16. The support unit of claim 15 wherein each said row extends in a widthwise direction of said support unit and each said zone extends in the widthwise direction between at least one pair of adjacent said rows. (8196624_1):JAA

17. The support unit of claim 16 wherein, in a first said zone, a said secondary support element is located in each of said voids and, in a second said zone, a said secondary support element is located in only some of said voids.

18. A support unit for use in a mattress or cushion, said support unit being substantially as hereinbefore described with reference to any one of the embodiments of the support unit, as that support unit is generally represented in the accompanying drawings.