Multilayered pocketed bedding or seating product

Abstract

A multilayered bedding or seating product comprising a spring core made up of an upper layer and a lower layer of pocketed coil springs. Each layer comprises a plurality of parallel strings of springs joined to each other. Each of the strings of springs comprises a row of interconnected pocketed coil springs. The strings of springs of the upper and lower layers may be secured to at least one scrim sheet therebetween.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims priority to provisional patent application Ser. No. 60/401,476 filed Aug. 6, 2002 entitled “Multi-Layered Pocketed Bedding or Seating Product” which is fully incorporated by reference herein.

FIELD OF THE INVENTION

[0002] This invention relates to spring assemblies for mattresses, cushions and other bedding or seating products.

BACKGROUND OF THE INVENTION

[0003] Bedding and/or seating products are commonly made from strings of individually pocketed springs. Such strings of springs are combined in a parallel fashion to create a spring assembly. In such products, each of the coil springs of the string is generally contained within an individual pocket of fabric which extends from the top to the bottom of the spring. Typically, each of the springs within the string has identical features or characteristics. Consequently, bedding or seating products made from identical strings of pocketed springs have uniform characteristics throughout the bedding or seating product.

[0004] Published PCT patent application Ser. No. WO 99/35081 discloses a mattress having two layers of pocketed springs. Each of the springs in each layer is individually pocketed, and the springs of the upper layer are directly above the corresponding springs of the lower layer. A pair of such corresponding springs, one above the other, are enclosed in an external cover and separated from one another by a generally horizontal partition wall of the fabric which defines two pockets containing both the upper and lower springs. The springs of the upper layer are “softer” than the springs of the lower layer. Thus, this mattress is able to provide a soft upper layer and a harder or more firm lower supporting layer. According to the disclosure of this PCT application, using springs having different characteristics in the different layers of the mattress, differing degrees of firmness may be imparted to the mattress.

[0005] According to the disclosure of the above-identified PCT application, each row of pocketed springs is made up of pair of springs, one above the other, with one sheet of fabric folded or configured in a unique way such that each of the springs is individually pocketed within that single sheet. The effort and/or machinery required to individually pocket each spring in this manner requires very special machinery which increases the cost of manufacturing the mattress, and also the time required to manufacture it. Additionally, the upper spring may move sideways relative to the lower spring, causing the springs to move out of alignment with one another and create a bump, indentation or uneven spot in the mattress. Another possibility with such a mattress is that the spring of the upper layer may rotate relative to the spring of the lower layer, reducing the ability of the mattress to function as desired.

[0006] Therefore, it has been one objective of the present invention to provide a multilayered bedding or seating product made of individually pocketed springs wherein each coil spring is surrounded or pocketed within its own sheet of fabric but which may be relatively inexpensively manufactured on currently existing machinery and which is not subject to the misalignment problem described hereinabove.

[0007] Another objective of the present invention has been to provide a bedding or seating product made from a plurality of layers of similarly pocketed strings of pocketed springs joined together so as to locate one spring of each layer in axial alignment with a spring of the other layer or layers.

[0008] Still another objective of the present invention has been to provide a pocketed bedding or seating product which may be custom manufactured for a particular application.

SUMMARY OF THE INVENTION

[0009] The invention of this application which accomplishes these objectives comprises a pocketed spring bedding or seating product. The bedding or seating product comprises a multilayered spring core and an upholstered covering surrounding the spring core. Each layer of the spring core comprises a separate spring core assembly made from a plurality of parallel strings of pocketed springs joined together.

[0010] The spring core product made in accordance with this invention has an upper layer and a lower layer, each of the layers comprising a plurality of adhered or otherwise interconnected parallel strings of springs, each of the strings of springs comprising a row of interconnected, parallel coil springs. Each of the coil springs within each string of springs is surrounded and encased in its own fabric pocket. In contrast to the spring core described in the above-identified PCT application, the fabric used to pocket the springs of the upper layer in the practice of this invention is separate from the sheet of fabric used to pocket the springs of the lower layer. Each row of springs is formed into a string of pocketed springs formed from one sheet of fabric, as is conventional.

[0011] In one embodiment of the present invention, the characteristics of the springs of the upper layer are identical to the characteristics of the springs of the lower layer. However, the coil springs of the upper strings of springs may be different; i.e., they may have different characteristics than the coil springs of the lower strings of springs. However, it is envisioned that coil springs utilized in the practice of this invention may in at least one embodiment be conventional coil springs having the same physical properties or characteristics, i.e. pitch, coil diameter, wire thickness (gauge), heat treatment, etc., from top to bottom.

[0012] In alternative embodiments of this invention the coil springs of each string of springs may have at least two distinctly different portions in order to posturize the product into regions of differing firmnesses. In these embodiments, each portion of a string of springs has different physical characteristics than at least one other portion of the string of springs.

[0013] Thus the bedding or seating product is multilayered, each layer comprising a plurality of pocketed springs, each of the pockets containing a coil spring.

[0014] The bedding or seating product typically has a longitudinal dimension and a transverse dimension, the longitudinal dimension being greater than the transverse dimension. However, the longitudinal dimension and transverse dimension may be identical in a square bedding or seating product. In the invention of the present application, the strings of springs may extend longitudinally or transversely, depending upon the desired effect.

[0015] Adjacent strings of springs of the bedding or seating product are preferably glued together but may be otherwise secured to each other. At least one border wire may extend around the perimeter of the bedding or seating product and is secured to selected outermost pocketed coil springs. Preferably, a first or lower border is secured to the lower end turns of the coil springs of the outermost springs of the lower layer and a second or upper border wire is secured to the upper end turns of the coil springs of the outermost springs of the upper layer. The border wires provide stability to the completed assembly.

[0016] In one embodiment of the present invention, the strings of springs of the upper spring core assembly are adhered or otherwise joined together. The strings of springs of the lower spring core assembly, instead of being adhered or otherwise joined together, are glued, fastened or otherwise secured to upper and lower scrim sheets. The upper scrim sheet is secured to the tops of the strings of springs of the lower layer and the lower scrim sheet is secured to the bottoms of the strings of springs of the lower layer. The upper spring core assembly, once assembled, is secured to the upper scrim sheet by gluing, ultrasonic welding or any other suitable method. In this manner, the upper and lower spring core assemblies are joined to a common scrim sheet or multiple scrim sheets located therebetween.

[0017] These and other objects and advantages of the present invention will be more readily apparent from the following detailed description of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a perspective view of a bedding product made in accordance with the invention of this application comprising a plurality of longitudinally extending strings of springs surrounded by a pair of generally rectangular border wires.

[0019] FIG. 2 is a side elevational view, partially broken away, taken along the view line 2-2 of FIG. 1 but with the border wires removed.

[0020] FIG. 3 is a side elevational view, partially broken away, taken along the view line 3-3 of FIG. 1, again with the border wires removed.

[0021] FIG. 4 is a block diagram illustrating the process for manufacturing the bedding product illustrated in FIG. 1.

[0022] FIG. 5 is a perspective view of an alternative embodiment of the present invention comprising a plurality of longitudinally extending strings of springs surrounded by a pair of generally rectangular border wires.

[0023] FIG. 6 is a side elevational view, partially broken away, taken along the view line 6-6 of FIG. 5 but with the border wires removed.

DETAILED DESCRIPTION OF THE DRAWINGS

[0024] Referring to the drawings, and particularly to FIG. 1, there is illustrated a bedding or seating product 10 comprising a spring core 12, padding 14 and an upholstered covering 16 surrounding the padding 14 and spring core 12. The spring core 12 has an upper layer 18 and a lower layer 19, each layer 18, 19 comprising a separate spring core assembly 20, 22, respectively, The upper spring core assembly 20 comprises a plurality of strings of springs 24 joined together. Likewise the lower spring core assembly 22 comprises a plurality of strings of springs 26 joined together.

[0025] As illustrated in FIG. 2, each of the upper strings of springs 24 has a longitudinal dimension or length 28 and a height 30. Each upper string of springs 24 comprises a row of interconnected fabric pockets 32 formed from one sheet of fabric, each pocket 32 containing an upper coil spring 34. The combination of the upper coil spring 34 and the fabric pocket 32 is considered a pocketed coil spring 35. As is known in the art, each string of springs 24 comprises a piece of fabric folded over on itself encapsulating a plurality of parallel coil springs 34. Opposite sides or plies of the fabric are welded, glued, sewn or otherwise secured together at spaced intervals to create a pair of outermost vertical seams 36 and internal seams 40. Together with a top seam 38, the vertical seams 36, 40 form spring containing pockets, each one of which contains at least one coil spring 34. Although the seams 36, 38 and 40 are each illustrated as being a plurality of spaced, linear welded segments, these seams may as well comprise continuous lines or a series of dots of glue or sewn continuous seams as well without departing from the spirit of this application.

[0026] Similarly, each of the lower strings of springs 26 has a longitudinal dimension or length 28 and a height 42. Each lower string of springs 26 comprises a row of interconnected fabric pockets 44, each containing a lower coil spring 46. Although the lengths of the upper and lower strings of springs 22, 24 are illustrated as being identical, they may vary from each other. As illustrated, the height 30 of the upper strings of springs 22 is greater than the height 32 of the lower strings of spring 24, due primarily to the difference in the heights of the coil springs 34, 46. However, the heights of the coil springs 34, 46 may be identical, the lower coil springs 46 being further compressed than the upper coil springs 34 due primarily to the size of the pockets in which they are respectively located. Alternatively, the upper and lower coil springs may have different characteristics such as pitch, heat treatment, coil diameter, etc. In addition, springs other than coil springs may be incorporated into the present invention.

[0027] Referring to FIG. 2, each of the upper and lower coil springs 34, 46 has an upper end turn 50, a lower end turn 52 and a plurality of central convolutions 54 therebetween. In one embodiment, each of the upper coil springs 34 has the same physical properties as those of the lower coil springs 46. In another embodiment of the present invention, each of the upper coil springs 34 has different physical characteristics such as different thicknesses, coil pitches, coil diameters, heat treatments than those of the lower coil springs 46. Preferably, the upper coil springs 34 are “softer” or less firm than the lower coil springs 46, to give the product an initial soft feel and more cushioning ability.

[0028] Referring to FIG. 1, the bedding or seating product 10 has a longitudinal dimension L and a transverse dimension W, the longitudinal dimension L being greater than the transverse dimension W. As illustrated in FIG. 1, the strings of springs 24, 26 may extend longitudinally (parallel the longitudinal dimension L). Alternatively, the strings of springs 24, 26 may extend transversely (parallel the transverse dimension W).

[0029] As illustrated in FIG. 1, a least one border wire may extend around the perimeter of the spring core 12. FIG. 1 illustrates a lower border wire 80 secured to the lower end turns of the outermost lower coil springs 46 of the lower layer 26 of the spring core 12. FIG. 1 also illustrates an upper border wire 82 surrounding the spring core 12.

[0030] With reference now to FIG. 4, there is illustrated the process by which the spring product illustrated in FIG. 1 is manufactured. Basically, that process comprises separately manufacturing the upper spring assembly 20 and the lower spring assembly 22 and then after those two assemblies are completed, placing the upper assembly atop the lower assembly and gluing or otherwise permanently securing the two assemblies together.

[0031] In order to manufacture the upper spring assembly 20, the springs 34 of the upper spring assembly 20 are serially formed in a conventional spring-forming machine, after which those springs are serially formed into a continuous string of pocketed springs as illustrated, for example, in the Thompson U.S. Pat. No. 3,668,816 or the Stumpf U.S. Pat. Nos. 4,439,977 and 4,986,518. After formation of that continuous string of pocketed springs, individual strings of springs are then cut with the requisite number of pocketed springs in the string. Those individual strings are then assembled and glued or otherwise secured together to form the upper spring assembly as, for example, illustrated and described in the Suenens et al. U.S. Pat. No. 5,126,604. The disclosure of these patents are hereby incorporated by reference for purposes of completing the disclosure of this application.

[0032] The same process described hereinabove for forming the upper spring assembly 20 is followed for manufacturing the lower spring assembly 22; that is, the springs of the lower spring assembly are formed, placed in a continuous string of pocketed springs, that continuous string is then cut into individual strings of springs, which are then assembled and glued or otherwise secured together to form the lower spring assembly 22.

[0033] After formation of those two spring assemblies, the upper spring assembly 20 is then placed atop the lower spring assembly 22 and the two assemblies permanently secured together as, for example, by gluing the bottom of the upper spring assembly 20 to the top surface of the lower spring assembly 22. Thereafter, the complete spring product may be completed by placement of border rods 80 and 82 around the periphery of the assembly and attachment of those border rods to the spring assembly as, for example, by utilizing hog rings (not shown) wrapped around the border rod and the outermost ones of the pocketed springs of the upper spring assembly to connect the upper border rod to the product and by utilizing hog rings wrapped around the lower border rod and the bottom turn of the edgemost springs of the lower spring assembly.

[0034] The border rods may be omitted from the spring product since the complete assembly is permanently secured as a consequence of the strings of pocketed springs being glued or otherwise secured together in each assembly and the two assemblies being secured together. In the illustrated preferred embodiment of the invention, the coil springs of the upper spring assembly are axially aligned with and of the same diameter coil springs of the lower spring assembly. Consequently, all of the coil springs in the lower spring assembly are axially aligned with the coil springs of the upper spring assembly in this illustrated preferred embodiment. Of course, that colinear alignment of the springs is not always necessary but is preferred in most applications of this invention in order to create a product which has a softer initial feel upon compression of the product.

[0035] FIGS. 5 and 6 illustrate an alternative embodiment of the present invention. For the sake of simplicity, like parts will be designed with like numerals but with an “a” designation. The embodiment illustrated in FIGS. 5 and 6 comprises a bedding product 10a comprising a spring core 12a, padding 14a and an upholstered covering 16a surrounding the padding 14a and spring core 12a. The spring core 12a has an upper layer 18a and a lower layer 19a. The upper layer 18a comprises an upper spring core assembly 20a comprising a plurality of upper strings of springs 24a joined together. Similarly, the lower layer 19a comprises an lower spring core assembly 22a comprising a plurality of lower strings of springs 26a.

[0036] Each of the upper strings of springs 24a is joined to at least one other upper strings of springs 24a along the sides thereof, such as taught in U.S. Pat. No. 6,176,960, which is fully incorporated by reference herein. Other means of attaching the upper strings of springs 24a to each other may be used without departing from the spirit of this invention. The group of upper strings of springs 24a joined together form the upper spring assembly 20a.

[0037] Each of the lower strings of springs 26a is not generally joined directly to adjacent strings of springs 26a, but instead is joined to an upper scrim sheet 86 and a lower scrim sheet 88 by adhesive and/or any other fastening method. As best illustrated in FIG. 6, the upper scrim sheet 86 is glued or otherwise secured to the upper surfaces 90 of each of the lower strings of springs 26a. Similarly, the lower scrim sheet 88 is glued or otherwise secured to the lower surfaces 92 of each of the lower strings of springs 26a. The lower strings of springs 26a with the upper and lower scrim sheets 86, 88 secured together is considered the lower spring core assembly 22a for purposes of this application.

[0038] Once the lower spring core assembly 22a is constructed, the upper spring core assembly 20a is placed on top of the upper scrim sheet 86 and secured thereto with adhesive and/or any other fastening method. Thereafter, the complete spring product 12a may be completed by placement of border rods 80a and 82a around the periphery of the assembly and attachment of those border rods to the spring assembly as, for example, by utilizing hog rings (not shown) wrapped around the border rod and the outermost ones of the pocketed springs of the upper spring assembly to connect the upper border rod to the product and by utilizing hog rings wrapped around the lower border rod and the bottom turn of the edgemost springs of the lower spring assembly.

[0039] The upper and lower scrim sheets 86, 88 are preferably made of a nonwoven fabric material but may be made of any flexible sheet material. In addition, several scrim sheets may be joined together before being secured to the upper and lower strings of springs 24a, 26a.

[0040] In this alternative embodiment illustrated in FIGS. 5 and 6 of the present invention, as with the embodiment illustrated in FIGS. 1-3 and described above, either or both of the upper and lower spring core assemblies may be posturized to provide multiple regions of differing firmness. Such posturization may be achieved numerous ways, such as for example, changing the characteristics of springs in the different regions or changing the amount of compression of the pocketed springs within different regions.

[0041] Although I have described several preferred embodiments of our invention, I do not intend to be limited except by the scope of the following claims.

Claims

1. A bedding or seating product comprising:

a spring core having an upper layer and a lower layer, each of said layers comprising a separate spring core assembly comprising a plurality of parallel strings of springs, each of said strings of springs being secured to at least one adjacent string of springs and comprising a row of interconnected pocketed coil springs,

said layers being joined together, one on top of the other, the springs of each layer being located in axial alignment with the springs of the other layer, and

an upholstered covering surrounding said spring core.

2. A bedding or seating product comprising:

a spring core having an upper layer and a lower layer, each of said layers comprising a separate spring core assembly comprising a plurality of parallel strings of springs, each of said strings of springs being secured to at least one adjacent string of springs and comprising a row of interconnected pocketed coil springs,

said layers being joined together, one on top of the other, the springs of each layer being located in axial alignment with the springs of the other layer.

3. The bedding or seating product of claim 2 wherein each of said strings of springs made with one sheet of fabric.

4. The bedding or seating product of claim 2 wherein said product has a longitudinal dimension and a transverse dimension, said longitudinal dimension being greater than said transverse dimension, said strings of springs extending longitudinally.

5. The bedding or seating product of claim 2 wherein said product has a longitudinal dimension and a transverse dimension, said longitudinal dimension being greater than said transverse dimension, said strings of springs extending transversely.

6. The bedding or seating product of claim 2 further comprising at least one border wire secured to select outermost pocketed coil springs.

7. The bedding or seating product of claim 2 wherein said upper layer is adhesively secured to said lower layer.

8. The product of claim 2 wherein said coil springs of said upper layer have different characteristics than the characteristics of the coil springs of the lower layer.

9. The product of claim 2 wherein the coil springs of said upper layer are less firm than the coil springs of the lower layer.

10. A method of manufacturing a spring product which comprises:

forming a first plurality of coil springs,

pocketing that first plurality of coil springs in a first continuous string of spring-containing fabric pockets,

cutting that first continuous string of spring-containing fabric pockets into a first series of multiple strings of spring-containing fabric pockets,

assembling and permanently securing together the first series of strings of spring-containing fabric pockets to create a first spring assembly,

forming a second plurality of coil springs,

pocketing that second plurality of coil springs in a second continuous string of spring-containing fabric pockets,

cutting the second continuous string of spring-containing fabric pockets into a second series of multiple strings of spring-containing fabric pockets,

assembling and permanently securing together the second series of spring-containing fabric pockets to create a second spring assembly,

placing the first spring assembly atop the second spring assembly and permanently securing these two assemblies together to create a spring product.

11. The method of claim 10 wherein the first series of strings of pocketed springs are permanently secured together by gluing and the second series of pocketed springs are secured together by gluing.

12. The method of claim 10 wherein the first spring assembly is permanently secured atop the second spring assembly by gluing.

13. The method of claim 10 wherein the first spring assembly is placed atop the second spring assembly with the axes of the springs of the first spring assembly in colinear alignment with the axes of the springs of the second spring assembly.

14. A bedding or seating product comprising:

a spring core having an upper layer and a lower layer, each of said layers comprising a separate spring core assembly comprising a plurality of parallel strings of springs, each of said string of springs comprising a row of interconnected pocketed coil springs, said strings of springs of said upper layer being secured to at least one adjacent string of springs,

said strings of springs of said lower and upper layers being secured to at least one scrim sheet located between said layers such that said spring core assemblies are joined together, one on top of the other, and

an upholstered covering surrounding said spring core.

15. A bedding or seating product comprising:

a spring core having an upper layer and a lower layer, each of said layers comprising a separate spring core assembly comprising a plurality of parallel strings of springs, each of said string of springs comprising a row of interconnected pocketed coil springs, each of said strings of springs of said upper layer being secured to at least one adjacent string of springs,

said strings of springs of said lower and upper layers being secured to at least one scrim sheet located between said layers such that said spring core assemblies are joined together, one on top of the other.

16. A bedding or seating product comprising:

a spring core having an upper layer and a lower layer, said upper layer of said spring core comprising an upper spring core assembly comprising a plurality of parallel strings of springs, each of said string of springs comprising a row of interconnected pocketed coil springs, each of said strings of springs of said upper layer being secured to at least one adjacent string of springs in said upper layer,

said lower layer of said spring core comprising an lower spring core assembly comprising plurality of parallel strings of springs, each of said string of springs comprising a row of interconnected pocketed coil springs, each of said strings of springs of said lower layer being secured to upper and lower scrim sheets, said upper scrim sheet being located between said layers and said lower scrim sheet being located below said lower layer, said strings of springs of said upper and lower layers being secured to said upper scrim sheet such that said spring core assemblies are joined together, one on top of the other, and

an upholstered covering surrounding said spring core.

17. A bedding or seating product comprising:

a spring core having an upper layer and a lower layer, said upper layer of said spring core comprising an upper spring core assembly comprising a plurality of parallel strings of springs, each of said string of springs comprising a row of interconnected pocketed coil springs, each of said strings of springs of said upper layer being secured to at least one adjacent string of springs in said upper layer,

said lower layer of said spring core comprising an lower spring core assembly comprising plurality of parallel strings of springs, each of said string of springs comprising a row of interconnected pocketed coil springs, each of said strings of springs of said lower layer being secured to upper and lower scrim sheets, said upper scrim sheet being located between said layers and said lower scrim sheet being located below said lower layer, said strings of springs of said upper and lower layers being secured to said upper scrim sheet such that said spring core assemblies are joined together, one on top of the other.

18. A method of manufacturing a spring product which comprises:

forming a plurality of upper strings of springs,

joining said upper strings of springs into an upper spring core assembly,

forming a plurality of lower strings of springs,

joining said lower strings of springs to at least one scrim sheet, and

placing the upper spring core assembly atop the lower spring core assembly and permanently securing these two assemblies together to create a spring product.