Abstract
A pocketed spring assembly comprises a plurality of parallel strings of individually pocketed springs. A dimensionally stabilizing substrate is secured to at least some of the strings on one of the top and bottom surfaces of the strings. A scrim sheet is secured to at least some of the strings on an opposed surface of the strings to maintain the positions of the strings. The dimensionally stabilizing substrate is laterally rigid enough to maintain length and width dimensions of the coil spring assembly. However, the dimensionally stabilizing substrate is flexible enough to allow the pocketed spring assembly to be roll packed for shipping.
Claims
1. A bedding or seating product comprising: a pocketed spring assembly comprising a plurality of parallel strings of springs joined together to form a pocketed spring assembly core; a dimensionally stabilizing substrate secured to one of top and bottom surfaces of the pocketed spring assembly core, said dimensionally stabilizing substrate comprising a sheet being made from a continuous filament, needled polyester with a resin binder; a scrim sheet secured to the other of the top and bottom surfaces of said at least some of the strings of the pocketed spring assembly, wherein said dimensionally stabilizing substrate has a density at least twice the density of the scrim sheet and is more rigid than the scrim sheet; cushioning materials; and an upholstered covering encasing said pocketed spring assembly and cushioning materials.
2. A bedding or seating product comprising: a pocketed spring assembly comprising a plurality of parallel strings of springs joined together to form a pocketed spring assembly core; a dimensionally stabilizing substrate secured to one of top and bottom surfaces of the pocketed spring assembly core, said dimensionally stabilizing substrate comprising a sheet having a weight of at least two ounces per square yard; a scrim sheet secured to the other of the top and bottom surfaces of the pocketed spring assembly core; wherein said dimensionally stabilizing substrate has a density at least twice the density of the scrim sheet and is more rigid than the scrim sheet, the dimensionally stabilizing substrate being flexible enough in the height of the pocketed spring assembly to allow the pocketed spring assembly to be roll packed.
3. The product of claim 2 wherein said scrim sheet is made of a non-woven polypropylene fabric.
4. The product of claim 2 wherein said scrim sheet is flexible in the X, Y and Z axis directions.
5. The product of claim 2 wherein the dimensionally stabilizing substrate resists being shorted in the Y axis direction when subject to a compressive force in the direction of the Y axis.
6. The product of claim 2 wherein the dimensionally stabilizing substrate is made from a continuous filament, needled polyester with a resin binder.
7. The product of claim 6 wherein the scrim sheet is made of a non-woven polypropylene fabric.
8. The product of claim 2 wherein the dimensionally stabilizing substrate comprising a sheet having a density of at least 3.4 ounces per square yard.
9. The product of claim 2 wherein some of the individually pocketed springs are different than other individually pocketed springs of the pocketed spring assembly.
10. A pocketed spring assembly comprising: a pocketed spring assembly core comprising parallel strings of springs joined together, each of said strings comprising a plurality of individually pocketed springs, each of said strings comprising a piece of fabric joined along a longitudinal seam, first and second opposed plies of fabric being on opposite sides of the springs, a plurality of pockets being formed along a length of said string by transverse seams joining said first and second plies, at least one spring being positioned in each said pocket; a dimensionally stabilizing substrate made from a continuous filament, needled polyester with a resin binder and being secured to a portion of pocketed spring assembly core with adhesive, said dimensionally stabilizing substrate having a weight of at least two ounces per square yard; and a scrim sheet secured to another portion of the pocketed spring assembly core with adhesive to facilitate handling of the pocketed spring assembly, the dimensionally stabilizing substrate having a density at least twice the density of the scrim sheet and being more rigid than the scrim sheet, but bendable for purposes of roll packing the pocketed spring assembly.
11. The pocketed spring assembly of claim 10 wherein said dimensionally stabilizing substrate is flexible in the direction of the Z axis only.
12. The pocketed spring assembly of claim 10 wherein said resin is corn starch.
13. The pocketed spring assembly of claim 10 wherein the scrim sheet is made of a non-woven polypropylene fabric.
14. The pocketed spring assembly of claim 10 wherein said springs are coil springs.
15. A pocketed spring assembly having a length, width and height, said pocketed spring assembly comprising: a plurality of parallel strings of springs joined together, each of said strings comprising a plurality of individually pocketed springs, each of said strings comprising a piece of fabric joined along a longitudinal seam, first and second opposed plies of fabric being on opposite sides of the springs, a plurality of pockets being formed along a length of said string by transverse seams joining said first and second plies, at least one spring being positioned in each said pocket; a dimensionally stabilizing substrate secured directly to either a top surface or a bottom surface of at least some of the strings; a scrim sheet secured directly to the other surface of the top and bottom surfaces of said at least some of the strings, said dimensionally stabilizing substrate having a density at least twice as dense as the scrim sheet, wherein said dimensionally stabilizing substrate does not bunch upwardly and form an irregular pattern as the scrim sheet does when subjected to the same force.
16. The pocketed spring assembly of claim 15 wherein the dimensionally stabilizing substrate is made from a continuous filament, needled polyester with a resin binder.
17. The pocketed spring assembly of claim 16 wherein said resin is corn starch.
18. The pocketed spring assembly of claim 15 wherein said dimensionally stabilizing substrate has a weight of 2.0 ounces per square yard.
19. The pocketed spring assembly of claim 15 wherein the scrim sheet is flexible in the direction of the length and width of the coil spring assembly.
20. The pocketed spring assembly of claim 15 wherein the scrim sheet and the fabric of the strings of springs are both made of non-woven polypropylene fabric.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 is a perspective view, partially broken away, of a bedding or seating product incorporating a pocketed spring assembly according to the principles of the present invention.
(2) FIG. 2 is a perspective view, partially broken away, of the pocketed spring assembly of the mattress of FIG. 1.
(3) FIG. 3 is a perspective view, partially broken away, of a bedding or seating product incorporating another pocketed spring assembly according to the principles of the present invention.
(4) FIG. 4 is a cross-sectional view, partially broken away, taken along the line 4-4 of FIG. 2.
(5) FIG. 4A is a cross-sectional view, partially broken away, taken along the line 4A-4A of FIG. 2.
(6) FIG. 5A is a perspective view of a dimensionally stabilizing substrate being compressed in the direction of the Y-axis.
(7) FIG. 5B is a perspective view of a dimensionally stabilizing substrate being compressed in the direction of the X-axis.
(8) FIG. 6A is a perspective view of a scrim sheet being compressed in the direction of the Y-axis.
(9) FIG. 6B is a perspective view of a scrim sheet being compressed in the direction of the X-axis.
(10) FIG. 7 is a side elevational view of a method of making a pocketed spring assembly in accordance with the present invention.
(11) FIG. 8 is side elevational view of a method of roll packing multiple pocketed spring assemblies in accordance with the present invention.
(12) FIG. 9 is a chart of data from a first test comparing a standard pocketed spring assembly having two scrim sheets to a pocketed spring assembly having one scrim sheet and one a dimensionally stabilizing substrate.
(13) FIG. 9A is a perspective view of a person measuring a queen size pocketed spring assembly which resulted in the data shown in FIG. 9.
(14) FIG. 10 is a graph of data from another test comparing a standard pocketed spring assembly having two scrim sheets to a pocketed spring assembly having one scrim sheet and one a dimensionally stabilizing substrate.
(15) FIG. 11 is a chart of data from another test comparing a standard pocketed spring assembly having two scrim sheets to a pocketed spring assembly having one scrim sheet and one a dimensionally stabilizing substrate.
(16) FIG. 11A is a perspective view illustrating how the data shown in FIG. 11 was obtained.
(17) FIG. 12 is a chart of data from another test comparing a standard pocketed spring assembly having two scrim sheets to a pocketed spring assembly having one scrim sheet and one a dimensionally stabilizing substrate.
(18) FIG. 12A is a perspective view illustrating how the data shown in FIG. 12 was obtained.
DETAILED DESCRIPTION OF THE INVENTION
(19) FIG. 1 illustrates a bedding product in the form of a double-sided mattress 10 incorporating the principles of the present invention. This product or mattress 10 comprises a pocketed spring assembly 12 over the top of which lays conventional padding or cushioning layers 14, 16 which may be foam, fiber, gel, a pocketed spring blanket or any other suitable materials or any combination thereof. Similarly, conventional padding or cushioning layers 14, 16 lie below the pocketed spring assembly 12. An upholstered cover 20 surrounds the pocketed spring assembly 12 and conventional padding or cushioning layers 14, 16.
(20) If desired, any of the padding or cushioning layers may be omitted in any of the embodiments shown or described herein. The novel features reside in the pocketed spring assembly.
(21) As shown in FIG. 1, fully assembled, the product 10 has a length “L” defined as the linear distance between opposed end surfaces 22 (only one being shown in FIG. 1). Similarly, the assembled product 10 has a width “W” defined as the linear distance between opposed side surfaces 24 (only one being shown in FIG. 1). In the product shown in FIG. 1, the length is illustrated as being greater than the width. However, it is within the scope of the present invention that the length and width may be identical, as in a square product.
(22) As shown in FIGS. 1 and 2, pocketed spring assembly 12 comprises a pocketed spring assembly core 34, a scrim sheet 36 and a dimensionally stabilizing substrate 38. The pocketed spring assembly core 34 is manufactured from multiple strings 26 of pocketed springs 28 joined together in any known manner, such as by gluing for example. Although pocketed springs 28 are typically metal coil springs 18 (as shown in FIG. 4), the springs may be any resilient members including foam, for example. Although the strings 26 of pocketed springs 28 are commonly arranged in transversely extending rows 30 and longitudinally extending columns 32, as shown in FIGS. 1 and 2, they may be offset, as is known in the art. The present invention is not intended to limit the configuration or type of pocketed spring assembly core 34 to those illustrated. FIG. 3 illustrates an alternative pocketed spring assembly core 34a, as one example.
(23) As best shown in FIG. 2, each string 26 extends longitudinally or from head-to-foot along the full length of the pocketed spring assembly core 34. Although the strings 26 are illustrated as extending longitudinally or from head-to-foot in the pocketed spring assembly 12 of FIGS. 1 and 2, they may extend transversely or from side-to-side as is known in the art. In any of the embodiments shown or described herein, the strings may extend either longitudinally (from end-to-end) or transversely (from side-to-side).
(24) As best shown in FIGS. 4 and 4A, each string 26 of pocketed spring assembly core 34 comprises a piece of fabric joined along a longitudinal seam 40 shown in FIG. 1, first and second opposed plies of fabric 42, 44 being on opposite sides of the springs 18, a plurality of pockets 46 being formed along a length of said string 26 by transverse seams 48 joining said first and second plies, at least one spring 18 being positioned in each pocket 46. Although one type of spring 18 is shown, any spring may be incorporated into any of the pockets 46.
(25) As best shown in FIG. 4A, each string 26 of pocketed spring assembly core 34 has an upper surface 68 and a lower surface 70. As best shown in FIG. 4A, the upper surfaces 68 of the strings 26 of pocketed spring assembly core 34 are generally co-planar in an upper plane P1 and the lower surfaces 70 of the strings 26 of pocketed spring assembly core 34 are generally co-planar in a lower plane P2. The linear distance between upper and lower surfaces 68, 70 of the strings 26 of pocketed spring assembly core 34 is defined as the height “H” of the pocketed spring assembly core 34 because all the strings 26 are the same height.
(26) As best shown in FIG. 4, scrim sheet 36 is secured to an upper surface 68 of at least some of the strings 26 of pocketed spring assembly core 34 with adhesive/glue. Similarly, dimensionally stabilizing substrate 38 is secured to the lower surface 70 of at least some of the strings 26 of pocketed spring assembly core 34 with adhesive. Although not shown, the dimensionally stabilizing substrate 38 may be secured to the upper surface 68 of at least some of the strings 26 of pocketed spring assembly core 34 with adhesive and the scrim sheet 36 secured to the lower surface 70 of at least some of the strings 26 of pocketed spring assembly core 34 with adhesive. In some applications, the scrim sheet may be omitted.
(27) As best shown in FIG. 2, scrim sheet 36 has a length “L1” defined as the linear distance between opposed end edges 52 (only one being shown in FIG. 2). Similarly, the scrim sheet 36 has a width “W1” defined as the linear distance between opposed side edges 54. In the pocketed spring assembly 12 shown in FIG. 2, the length is illustrated as being greater than the width. However, it is within the scope of the present invention that the length and width may be identical, as in a square pocketed spring assembly. As shown in FIG. 4, the scrim sheet 36 has a thickness “T1” defined as the linear distance between opposed top and bottom surfaces 60, 62, respectively. In one embodiment, the thickness T1 of the scrim sheet 36 is 0.009 inches, but may be any desired thickness. Scrim sheet 36 is preferably made of a non-woven polypropylene fabric which is commonly the material from which the strings 26 of pocketed spring assembly core 34 are made.
(28) As best shown in FIGS. 6A and 6B, scrim sheet 36 is elastic or flexible in the directions of the X axis, Y axis and Z axis. On the other hand, as best shown in FIGS. 6A and 6B, dimensionally stabilizing substrate 38 is elastic or flexible in the direction of the Z axis only.
(29) Referring to FIG. 6A, when a compressive force is exerted on the scrim sheet 36 in the direction of the Y axis, as illustrated by the arrows in FIG. 6A, the scrim sheet 36 bunches upwardly and forms an irregular pattern. In other words, the scrim sheet 36 is easily shortened in the direction of the Y axis when subject to a compressive force in the direction of the Y axis.
(30) Referring to FIG. 6B, when a compressive force is exerted on the scrim sheet 36 in the direction of the X axis, as illustrated by the arrows in FIG. 6B, the scrim sheet 36 bunches upwardly and forms an irregular pattern. In other words, the scrim sheet 36 is easily shortened in the direction of the X axis when subject to a compressive force in the direction of the X axis.
(31) Similarly, as best shown in FIG. 2, dimensionally stabilizing substrate 38 has a length “L1” defined as the linear distance between opposed end edges 56. Similarly, the dimensionally stabilizing substrate 38 has a width “W1” defined as the linear distance between opposed side edges 58 (only one being shown in FIG. 2). In the pocketed spring assembly 12 shown in FIG. 2, the length is illustrated as being greater than the width. However, it is within the scope of the present invention that the length and width may be identical, as in a square pocketed spring assembly. As shown in FIG. 4, the dimensionally stabilizing substrate 38 has a thickness “T2” defined as the linear distance between opposed top and bottom surfaces 64, 66, respectively. In one embodiment, the thickness T2 of the dimensionally stabilizing substrate 38 is 0.032 inches, but may be any desired thickness.
(32) Referring to FIG. 5A, when a compressive force is exerted on the dimensionally stabilizing substrate 38 in the direction of the Y axis, as illustrated by the arrows in FIG. 5A, the dimensionally stabilizing substrate 38 bows either upwardly as shown in solid lines or downwardly as shown in dashed lines in the direction of the Z axis. The dimensionally stabilizing substrate 38 does not bunch upwardly and form an irregular pattern as the scrim sheet 36 does when subjected to the same force as shown in FIG. 6A. In other words, the dimensionally stabilizing substrate 38 resists being shortened in the direction of the Y axis when subject to a compressive force in the direction of the Y axis.
(33) Referring to FIG. 5B, when a compressive force is exerted on the dimensionally stabilizing substrate 38 in the direction of the X axis, as illustrated by the arrows in FIG. 5B, the dimensionally stabilizing substrate 38 bows either upwardly as shown in solid lines (or downwardly as shown in dashed lines) in the direction of the Z axis. The dimensionally stabilizing substrate 38 does not bunch upwardly and form an irregular pattern as the scrim sheet 36 does when subjected to the same force as shown in FIG. 6B. In other words, the dimensionally stabilizing substrate 38 resists being shortened in the direction of the X axis when subject to a compressive force in the direction of the X axis.
(34) One material which has proven effective for the dimensionally stabilizing substrate 38 is a continuous filament, needled polyester with a resin binder with a weight of at least two ounces per square yard. The resin may be corn starch. A weight of at least 3.5 ounces per square yard has proven to perform well. This material may be purchased from Hanes Companies of Conover, N.C., a division of Leggett & Platt, Incorporated.
(35) FIG. 3 illustrates an alternative pocketed spring assembly 12a having a different pocketed spring assembly core 34a. The pocketed spring assembly core 34a includes a border 50 made of pocketed coil springs 51 (only a portion being shown in FIG. 3). The border 50 surrounds a central portion 72 (only a portion being shown in FIG. 3) comprising strings 26 of individually pocketed springs 28, as described herein. The pocketed springs 51 of border 50 are narrower than the pocketed springs 28 of the central portion 72 of pocketed spring assembly core 34a. Although one type of border 50 is illustrated, the border may assume other forms or shapes of pocketed coil springs. Alternatively, the border 50 may be omitted in this embodiment or any embodiment described or shown herein.
(36) Strings of pocketed springs 26 and any other strings of springs described or shown herein, may be connected in side-by-side relationship as, for example, by gluing the sides of the strings together in an assembly machine, to create an assembly or matrix of springs having multiple rows and columns of pocketed springs bound together as by gluing, welding or any other conventional assembly process commonly used to create pocketed spring cores or assemblies.
(37) FIGS. 7 and 8 illustrate a method of making the pocketed spring assembly in accordance with the present invention. Referring to FIG. 7, in an assembler 74 strings 26 of individually pocketed springs 28 are glued together to form a continuous pocketed spring web 92. Nozzles 75 apply adhesive/glue 76 to top and bottom surfaces 78, 80 of the pocketed spring web 92 as the pocketed spring web 92 is moving downstream (to the right in FIG. 7). A roll 82 comprising a web 84 of non-woven polypropylene fabric or scrim material is unwound and placed upon the top surface 78 of the pocketed spring web 92 as the pocketed spring web 92 is moving downstream (to the right in FIG. 7). Similarly, a roll 86 comprising a web 88 of dimensionally stabilizing substrate material is unwound and placed upon the bottom surface 80 of the pocketed spring web 92 as the pocketed spring web 92 is moving downstream (to the right in FIG. 7). The combination of the web 84 of non-woven polypropylene fabric or scrim material, the pocketed spring web 92 and the web 88 of dimensionally stabilizing substrate material secured together will be called a continuous finished web 94 for purposes of this document.
(38) As shown in FIG. 7, blades 90 move to cut the continuous finished web 94 to a desired size to form a pocketed spring assembly 96. Although two blades 90 are shown, any number of blades including only one blade may be used.
(39) As shown in FIG. 8, pocketed spring assembly 96 is moved further downstream between two conveyor belts 98 to compress the pocketed spring assembly 96 for roll packing. The compressed pocketed spring assembly 96 is moved further downstream as indicated by the arrow 99 shown in FIG. 8. A web 100 of packaging material stored on a roll 102 is laid on the compressed pocketed spring assembly 96 and then rolled around a tube 104 into a roll-pack 106 for shipment.
(40) FIG. 9 illustrates the results of a test in which two queen size pocketed spring assemblies were compared. FIG. 9A illustrates how the test was performed. One pocketed spring assembly labelled “Standard” had dimensions in the X and Y axis directions of 79 inches by 56 inches before two scrim sheets of non-woven polypropylene fabric having a density of one ounce per square yard were attached to the top and bottom surfaces, respectively, of the pocketed spring assembly. A second pocketed spring assembly labelled “Substrate” had dimensions in the X and Y axis directions of 79 inches by 56 inches before one scrim sheet of non-woven polypropylene fabric having a density of one ounce per square yard was attached to one the top and bottom surfaces of the pocketed spring assembly and a dimensionally stabilizing substrate was attached to the other of the top and bottom surfaces of the pocketed spring assembly. Each unit was placed in the same position shown in FIG. 9A with each spring axis being horizontally oriented and the scrim sheet(s) generally vertically oriented. The strings extending from head to foot extended generally vertically when the units were measured. The data shown in FIG. 9 shows the pocketed spring assembly with the dimensionally stabilizing substrate was taller compared to the “Standard” unit without any load applied. FIG. 9A shows a person 108 using a tape measure 110 to obtain the data shown in FIG. 9.
(41) FIG. 10 illustrates the results a test in which two mini-samples of pocketed spring assemblies were compared, each mini-sample comprising six strings, each string having six pocketed coil springs. Each barrel-shaped coil spring was eight inches tall with five convolutions and a maximum diameter of 77 millimeters. The mini-sample labelled “Standard” had two scrim sheets of non-woven polypropylene fabric having a density of one ounce per square yard attached to the top and bottom surfaces, respectively, of the mini-sample. A mini-sample labelled “Substrate” had one scrim sheet of non-woven polypropylene fabric having a density of one ounce per square yard attached to one the top and bottom surfaces of the mini-sample and a dimensionally stabilizing substrate was attached to the other of the top and bottom surfaces of the mini-sample. The mini-samples were put into an Admet testing machine. The chart shown in FIG. 10 shows a greater force was required to deflect the “Substrate” mini-sample a predetermined distance.
(42) FIG. 11 illustrates the results a test in which 12 inch by 4 inch pieces of material were pushed along a flat surface with incrementally increasing weights placed on one end of the piece of material. FIG. 11A illustrates how the test was performed. The weight 112 shown in FIG. 11A and listed in the chart of FIG. 11 is the weight at which the piece of material 114 shown in FIG. 11A buckled during the test. The piece of material labelled “Standard” was made of non-woven polypropylene fabric having a density of one ounce per square yard. The piece of material labelled “Substrate” was a dimensionally stabilizing substrate material having a density of four ounces per square yard. As the chart shows, much more weight was required to make the dimensionally stabilizing substrate material buckle.
(43) FIG. 12 illustrates the results a test in which 12 inch by 4 inch pieces of material were compressed using an Admet testing machine having two clamps 118 shown in FIG. 12A. FIG. 12A illustrates how the test was performed. The force listed in the chart of FIG. 12 is the weight at which the piece of material 116 buckled during the test. The piece of material labelled “Standard” was made of non-woven polypropylene fabric having a density of one ounce per square yard. The piece of material labelled “Substrate” was a dimensionally stabilizing substrate material having a density of four ounces per square yard. As the chart shows, much more weight was required to make the dimensionally stabilizing substrate material buckle.
(44) The various embodiments of the invention shown and described are merely for illustrative purposes only, as the drawings and the description are not intended to restrict or limit in any way the scope of the claims. Those skilled in the art will appreciate various changes, modifications, and improvements which can be made to the invention without departing from the spirit or scope thereof. The invention in its broader aspects is therefore not limited to the specific details and representative apparatus and methods shown and described. Departures may therefore be made from such details without departing from the spirit or scope of the general inventive concept. The invention resides in each individual feature described herein, alone, and in all combinations of any and all of those features. Accordingly, the scope of the invention shall be limited only by the following claims and their equivalents.
