Pocketed bedding or seating product having pockets of differing heights

FIELD OF THE INVENTION

[0001] This invention relates generally to spring assemblies for mattresses, cushions and other bedding or seating products and, more particularly, to a pocketed coil spring assembly and associated method of manufacturing such an assembly.

BACKGROUND OF THE INVENTION

[0002] A well known type of bedding or seating product comprises a spring assembly which includes a number of discrete coil springs, each of which is enclosed in a fabric pocket in a length of folded fabric material. Longitudinal axes of the coil springs are generally parallel with one another so that the top and bottom end turns of the coil springs define top and bottom faces of the spring assembly. A row of such pocketed springs is known in the industry as a string of pocketed springs. A bedding or seating product can be fabricated from such strings of pocketed springs by binding or adhering the individual rows or strings of pocketed springs together to form a spring assembly which may be padded and encased in an upholstered covering. U.S. Pat. No. 6,143,122, which is fully incorporated herein, discloses one such method of adhesively bonding strings of pocketed springs together to form a spring assembly.

[0003] This type of spring assembly is commonly referred to as a pocketed spring unit due to the fact that each spring is contained within an individual pocket of fabric material. The construction of strings of pocketed coil springs in each pocket is well known in the art and, for example, is disclosed in U.S. Pat. No. 4,439,977 which is hereby incorporated by reference in its entirety. The system disclosed in that patent includes a spring coiler which forms a coil spring which is subsequently compressed and inserted between the plies of folded pocketing fabric material. Other systems for manufacturing pocketed coil spring assemblies are disclosed in PCT Patent Application No. WO 94/18116 and U.S. Pat. No. 6,101,697, each of which are expressly incorporated herein by reference.

[0004] Pocketed spring assemblies are generally recognized to have a unique and particular luxurious feel to them and mattresses manufactured of such pocketed spring assemblies provide a feeling of softness without lacking spring resilience or support. Mattresses and similar articles constructed of pocketed spring assemblies are often considered a high-end type of product because of the added benefits and features of the pocketed coil springs. Mattresses and the like of this type can be more costly to manufacture and assemble as a result of the considerable amount of time and labor which is involved in their manufacture, together with the fact that the method of fabrication and assembly of such pocketed spring assemblies can be complicated, particularly in an automated process.

[0005] One particular aspect of pocketed spring assemblies and the associated mattresses or the like is that the resulting product may have a “hard” feel due to the fact that all of the coil springs are identical and compressed to the same degree in individual pockets. Usually, the firmness of such a product is uniform across the width and along the length of the product.

[0006] Additionally, while pocketed spring assemblies are desirably provide a combination of softness and support, the ability to economically posturize a spring assembly or mattress of pocketed spring coils has heretofore been difficult. Posturization provides multiple zones or sections of differing firmnesses within a product such as a mattress. For example, the middle regions of the mattress, which typically support a person's torso, often require a firmer more resilient support while other areas of the mattress which support the feet and head of a person require a softer feel.

[0007] One known method of posturizing a pocketed spring unit has been to incorporate springs made of different gauge wire into the strings of springs. For example, the springs incorporated into the strings of springs within certain sections or zones of the spring assembly are made of a larger gauge wire than the springs incorporated into the strings of springs of the other sections or zones of the spring assembly. U.S. Pat. No. 6,173,464 discloses this concept, albeit with continuous bands of springs as opposed to individual springs.

[0008] Therefore, there is a need for a pocketed spring assembly which has an initial soft feel but the firmness necessary to support heavy loads.

[0009] There is further a need for a posturized pocketed spring assembly and associated method of manufacture which offers the advantages of posturization of the spring assembly without the higher manufacturing costs, production difficulties and inefficiencies associated with known posturized pocketed spring assemblies.

SUMMARY OF THE INVENTION

[0010] The invention of this application which accomplishes these objectives comprises a pocketed bedding or seating product and associated method of manufacture. The bedding or seating product comprises a pocketed spring assembly, one or more pads and an upholstered covering surrounding the pocketed spring assembly and pads.

[0011] The pocketed spring assembly comprises a plurality of parallel strings of springs joined together. Each of the strings of springs comprises a row of interconnected pocketed coil springs. Each of the pocketed coil springs comprises a coil spring surrounded with a pocket of fabric, as is conventional. Each of the coil springs has an upper end turn, a lower end turn and a plurality of central convolutions between the end turns. Although coil springs are preferably used in the present invention, other types of springs may be used in accordance with the present invention.

[0012] Preferably, each string of springs is made of one piece of fabric folded and welded into a plurality of pockets, each of the pockets containing a coil spring. Opposed plies of fabric of the string of springs may be joined together by sewing, gluing or sonic welding, as known in the art. Adjacent pockets within a string of springs are separated by generally vertically oriented lines of attachment or seams of the opposed plies to each other. The height of the pocket is determined by the distance between the bottom of the pocket and one longitudinal segment of attachment or seam of the opposed plies to each other. Alternatively, the height of the pocket may be determined by the distance between top and bottom seams of the pocket.

[0013] In several preferred embodiments of the present invention, each string of springs has pockets of alternating heights along its length. In these strings of springs, every other one of the pockets of fabric is shorter than the adjacent pockets of fabric so that the springs in the shorter pockets are compressed more than the springs in the adjacent taller pockets. Preferably, the coil springs are identical although they may be different, i.e. have different physical characteristics.

[0014] The concept of the present invention may also be used to posturize a bedding or seating product, i.e., make certain regions or portions firmer than other areas or portions of the bedding or seating product. This is accomplished by grouping together multiple strings of springs having identical characteristics in one region of a bedding or seating product. The strings of springs of the other regions have different characteristics so as to impart different firmnesses to the different regions.

[0015] In one of these embodiments of the present invention, at least one portion of a string of springs has pockets of alternating heights. In others of these embodiments, the entire length of select strings of springs has pockets of alternating heights. In these portions of the strings of springs, every other one of the pockets of fabric is shorter than the adjacent pockets of fabric so that the springs in the shorter pockets are compressed more than the springs in the adjacent pockets. Again, the coil springs are preferably identical although they may be different in some regard.

[0016] 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.

[0017] 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 pocketed spring assembly of the bedding or seating product and be secured to select outermost pocketed coil springs. A first or lower border may be secured to the lower end turns of the coil springs of the outermost strings. A second or upper border wire may be secured to the upper end turns of the coil springs of the outermost strings or, alternatively, either border wire may be secured to intermediate convolutions of the coil springs of the outermost strings of springs.

[0018] Due to every other coil spring or selected ones of the coil springs being compressed less than the coil springs immediately adjacent to it in at least one section of the pocketed spring assembly, at least one section of the pocketed spring assembly has a “soft” feel when a load is placed thereon. Once the taller pocketed coil springs are compressed to the level of the shorter pocketed coil springs, the pocketed spring assembly has a uniform firmness.

[0019] One method of manufacturing the pocketed spring assembly of the present invention comprises inserting at least one spring into each of the pockets of a string of springs. The pockets are then closed such that every other pocket or selected pockets within the string of springs is of a height less than the adjacent pockets in the string of springs. The strings of springs are then joined together to form the pocketed spring assembly and the pocketed spring assembly encased in an upholstered covering.

[0020] The method of manufacturing the posturized spring assembly of the present invention varies depending upon the desired posturization. However, in each of the applications of the present invention whenever pockets of differing heights are incorporated into a portion of a string of springs, that region or section of the pocketed spring assembly has an initial “soft” feel when a load is placed thereon.

[0021] In each of the embodiments of the present invention, incorporating pockets of different heights into at least a portion of at least several strings of springs results in a pocketed spring assembly after multiple strings of springs are joined to each other. Such a product may be made in accordance with a customer's needs and desires quickly and easily.

[0022] These and other objects and advantages of the present invention will be more readily apparent from the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023]FIG. 1 is a perspective view of a bedding product made in accordance with the invention of this application comprising a pocketed spring assembly having a plurality of longitudinally extending strings of springs surrounded by generally rectangular border wires;

[0024]FIG. 1A is a perspective view of a bedding product made in accordance with the present invention, the strings of springs of the pocketed spring assembly extending transversely;

[0025]FIG. 2 is a side elevational view, partially broken away, of a string of springs made in accordance with the present invention;

[0026]FIG. 3 is a side elevational view, partially cut away, of a portion of the string of springs of FIG. 2;

[0027]FIG. 4 is a top plan view of an alternative embodiment of pocketed spring assembly made in accordance with the present invention;

[0028]FIG. 5 is a top plan view of another alternative embodiment of pocketed spring assembly made in accordance with the present invention.

DETAILED DESCRIPTION

[0029] Referring to the drawings, and particularly to FIG. 1, there is illustrated a bedding or seating product in the form of a mattress <b>10</b>. Although a mattress <b>10</b> is illustrated, the present invention may be used to construct any bedding or seating product. The mattress <b>10</b> comprises a pocketed spring assembly <b>12</b> having a generally planar top surface <b>14</b> in a top plane P<b>1</b> and a parallel generally planar bottom surface <b>16</b> in a bottom plane P<b>2</b>. Covering pads <b>18</b> (only one being shown) may be located on the top and bottom surfaces <b>14</b>, <b>16</b> of the pocketed spring assembly <b>12</b>. An upholstered covering <b>20</b> encases the pocketed spring assembly <b>12</b> and the covering pads <b>18</b>.

[0030] The mattress <b>10</b> has a height H defined as the distance between the top and bottom surfaces <b>14</b>, <b>16</b> of the spring assembly <b>12</b>. Similarly, the mattress <b>10</b> has a transverse dimension or width W defined between opposed side surfaces <b>22</b> and a longitudinal dimension or length L defined as the distance between the opposed end surfaces <b>24</b> of the mattress <b>10</b>. The longitudinal dimension is illustrated as being larger than the transverse dimension of the mattress <b>10</b> although it is within the contemplation of the present invention that the longitudinal and transverse dimensions be identical, such as in a square product.

[0031] If desired, at least one border wire may be secured to the pocketed spring assembly <b>12</b> with hog rings or any other conventional fastener <b>13</b>. FIG. 1 illustrates an upper border wire <b>26</b> and a lower border wire <b>28</b>, both of which are generally rectangular, secured to the pocketed spring assembly <b>12</b>. However, only one border wire may be used, if desired or none at all, as shown in FIG. 1A.

[0032] The pocketed spring assembly <b>12</b> comprises a plurality of longitudinally extending strings of springs <b>30</b> joined to each other. Adjacent strings of springs are preferably glued together as shown in U.S. Pat. No. 6,143,122, but may be joined to each other using any known technology.

[0033] Referring to FIGS. 2 and 3, each string of springs <b>30</b> has a top surface <b>31</b> and a bottom surface <b>33</b>, the distance between which defines the height H<b>1</b> of the string of springs <b>30</b>. Each string of springs <b>30</b> comprises a row of interconnected fabric pockets <b>32</b>, each fabric pocket <b>32</b> containing a coil spring <b>34</b>. As best illustrated in FIG. 3, each coil spring <b>34</b> has an upper end turn <b>36</b>, a lower end turn <b>38</b> and a plurality of central convolutions <b>40</b> between the end turns <b>36</b>, <b>38</b>.

[0034] Preferably, only one piece of fabric is used to form a string of springs <b>30</b>, the piece of fabric being folded over onto itself around the coil springs <b>34</b> to create a first ply <b>42</b> and a second ply <b>44</b>. As illustrated in FIG. 3, the first ply <b>42</b> is behind the second ply <b>44</b>. As is known in the art, opposite sides or plies of the fabric are sewn, welded or otherwise secured together in order to create a pair of outermost seams <b>46</b>, a plurality of internal seams <b>48</b> and a plurality of longitudinal seams <b>50</b> and <b>52</b>. The internal seams <b>48</b> separate adjacent pockets <b>32</b> and therefore adjacent coil springs <b>34</b>. Although the seams <b>46</b>, <b>48</b>, <b>50</b> and <b>52</b> are illustrated as being a plurality of spaced, linear segments <b>54</b>, they may comprise continuous lines or a series of dots or other arrangement without departing from the spirit of this application.

[0035] As best illustrated in FIG. 3, each string of springs <b>30</b> has alternating tall pockets <b>56</b> of a first height H<b>2</b> and short pockets <b>58</b> of a second height H<b>3</b> less than the first height H<b>2</b>. The height H<b>2</b> of each of the tall pockets <b>56</b> is preferably substantially identical and defined by the distance between the bottom surface <b>33</b> of the string of springs <b>30</b> and one of the longitudinal seams <b>50</b>. On the other hand, the height H<b>3</b> of each of the short pockets <b>56</b> is preferably substantially identical and defined by the distance between the longitudinal seams <b>52</b> which are inwardly spaced from the top and bottom surfaces <b>31</b>, <b>33</b>, respectively of the string of springs <b>30</b>.

[0036] Preferably, all of the coil springs <b>34</b> within a string of springs <b>30</b> are all the same height before being compressed and inserted into the pockets <b>32</b> of the strings of springs <b>30</b>. Due to the difference in the heights of the short and tall pockets, <b>58</b>, <b>56</b>, respectively, the coil springs <b>34</b> located in the short pockets <b>58</b> are further compressed or loaded than are the coil springs <b>34</b> located in the tall pockets <b>56</b>. For example, coil springs having an uncompressed height of eight inches might be compressed to a height of six inches in the tall pockets <b>56</b> and compressed to a height of four inches inside the short pockets <b>58</b>.

[0037] The practical result of each of the strings of springs <b>30</b> being made of alternating tall and short pockets <b>56</b>, <b>58</b>, each pocket containing a coil spring is that the pocketed spring assembly <b>12</b> has a checkerboard pattern. Consequently, the mattress <b>10</b> has an initial“soft” feel when a load is placed thereon due to the coil springs <b>34</b> in the tall pockets <b>56</b> initially compressing before the coil springs <b>34</b> in the short pockets <b>58</b> are affected. For example, when a person initially lays on the mattress <b>10</b>, the coil springs <b>34</b> in the tall pockets <b>56</b> compress a first distance to the height H<b>2</b> of the coil springs <b>34</b> in the short pockets <b>58</b>. Then, all of the coil springs <b>34</b> which are placed under a load regardless of which pocket they are in compress a second distance.

[0038]FIG. 1A illustrates an alternative embodiment of the present invention comprising a mattress <b>10</b><i>a. </i>The mattress <b>10</b><i>a </i>comprises a pocketed spring assembly <b>12</b><i>a </i>having a generally planar top surface <b>14</b><i>a </i>in a top plane P<b>1</b> and a parallel generally planar bottom surface <b>16</b><i>a </i>in a bottom plane P<b>2</b>. Covering pads <b>18</b><i>a </i>(only one being shown) may be located on the top and bottom surfaces <b>14</b><i>a, </i><b>16</b><i>a </i>of the pocketed spring assembly <b>12</b><i>a. </i>An upholstered covering <b>20</b><i>a </i>encases the pocketed spring assembly <b>12</b><i>a </i>and the covering pads <b>18</b><i>a. </i>

[0039] The pocketed spring assembly <b>12</b><i>a </i>comprises a plurality of transversely extending strings of springs <b>30</b><i>a </i>joined to each other. Adjacent strings of springs <b>30</b><i>a </i>are preferably glued together but may be joined to each other using any known technology. The strings of springs <b>30</b><i>a </i>are similar to those described above with regard to the embodiment shown in FIG. 1 and made in same manner. Like the embodiment of FIG. 1, this embodiment has a uniform composition or construction along its length and width.

[0040]FIG. 4 illustrates an alternative embodiment of the present invention in which the mattress <b>10</b><i>b </i>is posturized, the mattress <b>10</b><i>b </i>having multiple regions of differing firmness. In this embodiment, the mattress <b>10</b><i>b </i>has a pocketed spring assembly <b>12</b><i>b </i>which is divided into multiple regions or sections as one moves longitudinally down the side of the mattress. At least one border wire <b>64</b> is secured to the pocketed spring assembly <b>12</b><i>b. </i>Around the perimeter of the mattress <b>10</b><i>b </i>is an edge portion <b>60</b> surrounding an internal portion <b>62</b>. The edge portion <b>60</b> comprises two longitudinally extending strings of springs <b>30</b><i>b</i>′ on each side of the mattress <b>10</b><i>b. </i>Each of these strings of springs <b>30</b><i>b</i>′has a uniform composition along its length because each of the pockets in each string of springs <b>30</b><i>b</i>′ is the same height. In other words, each string of springs <b>30</b><i>b</i>′ does not have alternating pockets of differing heights but rather all the pockets are tall pockets <b>66</b>.

[0041] In this embodiment, the internal portion <b>62</b> of the pocketed spring assembly <b>12</b><i>b </i>is the posturized portion of the mattress <b>10</b><i>b. </i>The internal portion <b>62</b> of the pocketed spring assembly <b>12</b><i>b </i>comprises a plurality of longitudinally extending strings of springs <b>30</b><i>b </i>secured to each other in a known manner. The two pockets <b>68</b> at each end of each string of springs <b>30</b><i>b </i>are tall pockets and make up part of the edge portion <b>60</b> of the pocketed spring assembly <b>12</b><i>b. </i>The remaining pockets of each string of springs <b>30</b><i>b </i>between the outermost pockets <b>68</b> contain both tall and short pockets <b>70</b>, <b>72</b>, respectively in a manner as described below.

[0042] The internal portion <b>62</b> of the pocketed spring assembly <b>12</b><i>b </i>has a head section <b>74</b>, immediately adjacent head section <b>74</b> is an upper lumbar section <b>76</b>, immediately adjacent upper lumbar section <b>76</b> is center section <b>78</b>, immediately adjacent center section <b>78</b> is a lower lumbar section <b>80</b> and at the other end of the internal portion <b>62</b> of the pocketed spring assembly <b>12</b><i>b </i>is a foot section <b>82</b>.

[0043] The practical result of this configuration of pocketed spring assembly <b>12</b><i>b </i>is that the head section <b>74</b>, center section <b>78</b> and foot section <b>82</b> have a checkerboard pattern which results in an initial“soft” feel when a load is placed thereon. The portions of each string of springs <b>30</b><i>b </i>in the head section <b>74</b>, center section <b>78</b> and foot section <b>82</b> have alternating tall and short pockets <b>70</b>, <b>72</b>.

[0044] On the other hand, the portions of each string of springs <b>30</b><i>b </i>in the upper and lower lumbar sections <b>76</b>, <b>80</b> contain only tall pockets <b>70</b>. Therefore, the upper and lower lumbar sections <b>76</b>, <b>80</b> have a “softer” firmness when compared to the head section <b>74</b>, center section <b>78</b> and foot section <b>82</b>.

[0045] Although the strings of springs <b>30</b><i>b </i>and <b>30</b><i>b</i>′are illustrated as being longitudinally extending, this embodiment of the present invention may also be accomplished with transversely extending strings of springs. If the strings of springs were transversely extending, each string of springs in the upper and lower lumbar sections <b>58</b>, <b>62</b> would have only tall pockets and each string of springs in the head, center and foot sections <b>74</b>, <b>78</b> and <b>82</b> would have alternating short and tall pockets, except the outermost pockets which form part of the edge portion.

[0046]FIG. 5 illustrates an alternative embodiment of the present invention. In this embodiment, the mattress <b>10</b><i>c </i>has a pocketed spring assembly <b>12</b><i>c </i>comprising longitudinally extending strings of springs <b>30</b><i>c, </i><b>30</b><i>c</i>′ joined to each other in a conventional manner. The pocketed spring assembly <b>12</b><i>c </i>has an edge portion <b>60</b><i>c </i>around the perimeter of an internal portion <b>62</b><i>c. </i>The edge portion <b>60</b><i>c </i>comprises two longitudinally extending strings of springs <b>30</b><i>c</i>′ on each side of the mattress <b>10</b><i>b. </i>Each of these strings of springs <b>30</b><i>c</i>′has a uniform composition along its length because each of the pockets in each string of springs <b>30</b><i>c</i>′is a short pocket having the same height. On the other hand, each string of springs <b>30</b><i>c </i>has two short pockets <b>72</b><i>c </i>at each end thereof and alternating pockets of differing heights therebetween. The short pockets <b>72</b><i>c </i>make up part of the edge portion <b>60</b><i>c </i>while the pockets therebetween alternate between short and tall pockets <b>72</b><i>c, </i><b>70</b><i>c, </i>respectively.

[0047] Although the strings of springs <b>30</b><i>c, </i><b>30</b><i>c</i><b>4</b> are longitudinally extending, this embodiment of the present invention may also be manufactured with transversely extending strings of springs.

[0048] Although we have described several preferred embodiments of our invention, we do not intend to be limited except by the scope of the following claims.