Patent Publication Number: US-11026517-B2

Title: Mattress assembly with a mattress topper that includes pocketed coil springs and methods of producing the same

Description:
TECHNICAL FIELD 
     The present invention relates to mattress assemblies having a mattress topper. In particular, the present invention includes mattress assemblies with a mattress topper that has a plurality of integrated pocketed coil springs and that is positioned atop a mattress core. 
     BACKGROUND 
     Mattress toppers are oftentimes connected to a mattress core to form the uppermost support surface of a traditional innerspring mattress assembly. These mattress toppers generally consist of one or more layers of textiles, foam, and/or fiber fill which are bonded together, typically by sewing a quilted pattern through the layers. As such, mattress toppers therefore provide additional padding between the innerspring mattress core and the body of a user positioned on the mattress assembly. However, the foam and/or fiber fill used in mattress toppers can lose resilience over time, which commonly leads to an indentation where a user&#39;s body lays on the uppermost support surface of the mattress. Such an indentation is not only unattractive, but it also provides the user with less cushioning and support, which can lead to poor sleep quality and/or having to replace the mattress entirely. Accordingly, a mattress topper that provides better cushioning and support throughout the life of the mattress would be both highly desirable and beneficial. 
     SUMMARY 
     The present invention includes a mattress assembly having a mattress topper. In particular, the present invention includes mattress assemblies with a mattress topper that has a plurality of integrated pocketed coil springs and that is positioned atop a mattress core. 
     In one exemplary embodiment of the present invention, a mattress assembly is provided that includes a mattress core and a mattress topper positioned atop the mattress core. The mattress topper includes a plurality of coil springs arranged in a matrix, an upper fabric layer extending above the plurality of coil springs, and a lower fabric layer extending below the plurality of coil springs with the lower fabric layer connected to the upper fabric layer around each coil spring such that the upper fabric layer and the lower fabric layer collectively form a fabric pocket encasing each coil spring. Specifically, the lower fabric layer is typically connected to the upper fabric layer in between each of the coil springs by an ultrasonic weld. 
     The exemplary mattress topper further includes a padded layer positioned atop the upper fabric layer. The padded layer is configured to provide a sufficiently soft surface upon which a portion of a user&#39;s body can rest, and as such, the padded layer is comprised of a visco-elastic foam, a fibrous material, or both a visco-elastic foam and a fibrous material. Regardless of the particular material which the padded layer is comprised of, however, in the exemplary mattress topper, the padded layer is connected to the upper fabric layer. The exemplary mattress topper further includes a textile layer positioned atop and connected to the padded layer as well as a backing layer positioned below and connected to the lower fabric layer. In one embodiment of the present invention, the padded layer, textile layer and backing layer are connected to the respective underlying layers by an adhesive. 
     In another embodiment of the present invention, the backing layer, padded layer, and textile layer are all connected by the same ultrasonic weld that connects the lower fabric layer to the upper fabric layer. In particular, not only is the upper fabric layer connected to the lower fabric layer by the ultrasonic weld, but the backing layer is connected to the lower fabric layer by the ultrasonic weld, the padded layer is connected to the upper fabric layer by the ultrasonic weld, and the textile layer is connected to the padded layer by the ultrasonic weld. The backing layer, the lower fabric layer, the upper fabric layer, the padded layer, and the textile layer are brought together between each of the coil springs and connected by the ultrasonic weld such that each of the coil springs is completely surrounded by a respective ultrasonic weld, as further discussed below. 
     In yet other embodiments of the present invention, the backing layer, the lower fabric layer, the upper fabric layer, the padded layer, and the textile layer are connected by a plurality of tufts that extend through all of the layers of the mattress topper. In particular, in this exemplary mattress topper, the plurality of coil springs are arranged in a rectangular matrix with a tuft positioned at an intersection point equidistant to four adjacent coil springs such that each coil spring is bordered by four tufts which connect all of the layers of the mattress topper around each coil spring to collectively form a fabric pocket encasing the coil spring. 
     In one exemplary implementation of a method for producing the mattress toppers described herein, an array of coils is first provided and positioned between an upper fabric layer and a lower fabric layer. After positioning the array of coil springs between the upper fabric layer and the lower fabric layer, the lower fabric layer is then connected to the upper fabric layer between each of the coil springs. In some embodiments, the lower fabric layer is connected to the upper fabric layer by ultrasonically welding the lower fabric layer to the upper fabric layer. As would be recognized by those of skill in the art, such ultrasonic welds are formed by compressing the fabric layers together between two irons and then running an electric current through the irons to melt the material of the two fabric layers together. In one exemplary embodiment, the lower fabric layer is ultrasonically welded to the upper fabric layer by compressing the fabric layers between two substantially circular irons which fit around each coil spring such that the irons simultaneously form an ultrasonic weld that completely surrounds the respective coil spring. 
     After connecting the lower fabric layer to the upper fabric layer, a padded layer is then connected to the upper fabric layer. In some implementations of the methods of the present invention, the padded layer is connected to the upper fabric layer by an adhesive. In some other implementations of the methods of the present invention, the padded layer is connected to the upper fabric layer with an ultrasonic weld. In still other implementations of the methods of the present invention, the padded layer is connected to the upper fabric layer by forming a plurality of tufts that extend through the lower fabric layer, the upper fabric layer, and the padded layer. 
     Further features and advantages of the present invention will become evident to those of ordinary skill in the art after a study of the description, figures, and non-limiting examples in this document. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side sectional view of an exemplary mattress assembly made in accordance with the present invention and including a mattress topper; 
         FIG. 2  is a side sectional view of another exemplary mattress assembly made in accordance with the present invention and including a mattress topper; 
         FIG. 3  is a partial top view of the mattress assembly of  FIG. 2  showing ultrasonic welds around each of a plurality of coil springs arranged in a matrix; and 
         FIG. 4  is a partial top view of another mattress assembly showing a plurality of tufts between each of a plurality of coil springs arranged in a matrix. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The present invention includes a mattress assembly having a mattress topper. In particular, the present invention includes mattress assemblies with a mattress topper that has a plurality of integrated pocketed coil springs and that is positioned atop a mattress core. 
     Referring first to  FIG. 1 , in one exemplary embodiment of the present invention, an exemplary mattress assembly  10  is provided that includes a mattress core  20  and a mattress topper  30  positioned atop the mattress core  20 . In particular, the mattress core  20  has a bottom surface  22  and a top surface  24  opposite the bottom surface  22 , and the mattress topper  30  is positioned adjacent to the top surface  24  of the mattress core  20 . 
     The mattress topper  30  includes a plurality of coil springs  40  arranged in a matrix, an upper fabric layer  54  extending above the plurality of coil springs  40 , and a lower fabric layer  52  extending below the plurality of coil springs  40 . The lower fabric layer  52  is connected to the upper fabric layer  54  around each coil spring  40  such that the upper fabric layer  54  and the lower fabric layer  52  collectively form a fabric pocket encasing each coil spring  40 . 
     With respect to each of the coil springs  40  and referring still to  FIG. 1 , each exemplary coil spring  40  shown in  FIG. 1  is made of a continuous wire that extends from a lower end convolution  42  to an upper end convolution  44  opposite the lower end convolution  42 . In the coil spring  40 , there are six intermediate convolutions  46  that helically spiral between the lower end convolution  42  and the upper end convolution  44 , such that the coil spring  40  is made of a total of eight convolutions or turns. Furthermore, each of the coil springs  40  has a height defined from the lower end convolution  42  to the upper end convolution  44  with each of the convolutions of the coil spring  40  having a diameter. The height of the coil spring  40  can range from about one-half (½) inches to about three (3) inches and the diameter of each of the convolutions of the coil spring  40  can range from about three-fourths (¾) inches to about three (3) inches. In the particular embodiment shown in  FIG. 1 , the height of the coil springs  40  is about seven-eighths (⅞) inches and the diameter of each of the convolutions is about one and one-fourth (1¼) inches. Of course, various other springs, such as coil springs having a different number of convolutions, different height, and/or different diameter, could also be used in an exemplary pocket coil spring assembly without departing from the spirit and scope of the present invention. 
     With respect to the upper fabric layer  54  and the lower fabric layer  52  and referring still to  FIG. 1 , the lower fabric layer  52  is connected to the upper fabric layer  54  in between each of the coil springs  40  about midway up the height of the coil springs  40 . In this regard, the upper fabric layer  54  and the lower fabric layer  52  shown in  FIG. 1  are generally made of a non-woven textile which are joined together by an ultrasonic weld  70  to form such a structure. For example, suitable fabrics that can be used for the upper fabric layer  54  and the lower fabric layer  52  can include one of various thermoplastic fibers known in the art, such as non-woven polymer-based fabric, non-woven polypropylene material, or non-woven polyester material. Of course, the lower fabric layer  52  can be connected to the upper fabric layer  54  by any number of means, including a tuft, a staple, stitches, clamps, hook-and-loop fasteners, and the like. Regardless of the particular method of connecting the upper fabric layer  54  and the lower fabric layer  52 , however, by connecting the upper fabric layer  54  and the lower fabric layer  52  around each coil spring  40 , not only is it possible to impart a desired level of pre-compression, stability, and/or stretchability to the coil spring  40 , but each of the coil springs  40  is able to compress at least partially independently of the other coil springs  40  while still being held in position relative to the other coil springs  40 , as further discussed below. 
     Referring still to  FIG. 1 , the exemplary mattress topper  30  further includes a padded layer  60  positioned atop the upper fabric layer  54 . The padded layer  60  is configured to provide a sufficiently soft surface upon which a portion of a user&#39;s body can rest, and as such, the padded layer  60  is typically comprised of a visco-elastic foam, a fibrous material, or both a visco-elastic foam and a fibrous material. In the case of the padded layer  60  comprising a flexible foam, such flexible foams include, but are not limited to, latex foam, reticulated or non-reticulated visco-elastic foam (sometimes referred to as memory foam or low-resilience foam), reticulated or non-reticulated non-visco-elastic foam, polyurethane high-resilience foam, expanded polymer foams (e.g., expanded ethylene vinyl acetate, polypropylene, polystyrene, or polyethylene), and the like. In the embodiment shown in  FIG. 1 , the padded layer  60  of the mattress topper  30  is comprised of visco-elastic foam. Generally, such visco-elastic foam has a hardness of at least about 10 N to no greater than about 80 N, as measured by exerting pressure from a plate against a sample of the material to a compression of at least 40% of an original thickness of the material at approximately room temperature (i.e., 21° C. to 23° C.), where the 40% compression is held for a set period of time as established by the International Organization of Standardization (ISO) 2439 hardness measuring standard. In some embodiments, the visco-elastic foam has a hardness of about 10 N, about 20 N, about 30 N, about 40 N, about 50 N, about 60 N, about 70 N, or about 80 N to provide a desired degree of comfort and body-conforming qualities. 
     The visco-elastic foam described herein for use in the padded layer  60  can also have a density that assists in providing a desired degree of comfort and body-conforming qualities, as well as an increased degree of material durability. In some embodiments, the density of the visco-elastic foam used in the padded layer  60  of the mattress topper  30  has a density of no less than about 30 kg/m 3  to no greater than about 150 kg/m 3 . In some embodiments, the density of the visco-elastic foam used in the padded layer  60  of the mattress topper  30  is about 30 kg/m 3 , about 40 kg/m 3 , about 50 kg/m 3 , about 60 kg/m 3 , about 70 kg/m 3 , about 80 kg/m 3 , about 90 kg/m 3 , about 100 kg/m 3 , about 110 kg/m 3 , about 120 kg/m 3 , about 130 kg/m 3 , about 140 kg/m 3 , or about 150 kg/m 3 . Of course, the selection of a visco-elastic foam having a particular density will affect other characteristics of the foam, including its hardness, the manner in which the foam responds to pressure, and the overall feel of the foam, but it is appreciated that a visco-elastic foam having a desired density and hardness can readily be selected for a particular application or mattress topper as desired. 
     As mentioned above, the padded layer  60  need not be comprised of flexible foam at all, but can alternatively be comprised of a fibrous material. Such a fibrous material can include natural fibers, such as cotton or silk fibers, synthetic fibers, such as polyester fibers, or combinations thereof. Furthermore, in some embodiments, the padded layer  60  is comprised of a plurality of layers with each layer being made of a visco-elastic foam, a fibrous material, or both a visco-elastic foam and a fibrous material. 
     Regardless of the particular material that the padded layer  60  is comprised of, in the exemplary mattress topper  30 , the padded layer  60  is connected to the upper fabric layer  54 . More specifically, in the mattress topper  30  shown in  FIG. 1  the padded layer  60  is connected to the upper fabric layer  54  by an adhesive which allows the padded layer  60  to extend across the plurality of coil springs  40  with the padded layer  60  staying substantially flat such that the mattress topper  30  is a smooth top mattress topper, as further discussed below. 
     As also shown in  FIG. 1 , the exemplary mattress topper  30  further includes a textile layer  64  positioned atop the padded layer  60  and which is also connected to the padded layer  60  by an adhesive. In the embodiment shown in  FIG. 1 , the textile layer  64  is the uppermost layer of the mattress topper  30  and so the textile layer  64  is comprised of a material which is resilient to wear, while still providing a comfortable top surface on which to rest. Such materials can be comprised of natural fibers, such as cotton or silk fibers, synthetic fibers, such as polyester fibers, or combinations thereof. Furthermore, although not expressly shown, it is contemplated that the textile layer  64  can include a decorative pattern on its top surface, such as a quilted pattern, as desired. 
     Referring still to  FIG. 1 , the exemplary mattress topper  30  further includes a backing layer  62  positioned below the lower fabric layer  52  and which is connected to the lower fabric layer  52  by an adhesive. In the embodiment shown in  FIG. 1 , the backing layer  62  is comprised of a non-woven textile such as non-woven polymer-based fabric, non-woven polypropylene material, or non-woven polyester material, but the backing layer can be comprised of a variety of other materials as well without departing from the spirit and scope of the present invention. 
     As mentioned above, the exemplary embodiment shown in  FIG. 1  is a smooth top mattress topper  30  in which the padded layer  60  extends substantially flat across the plurality of coil springs  40 . By comparison, in another embodiment of the present invention, and referring now to  FIGS. 2 and 3 , the padded layer  160  is configured such that it rises and falls across the plurality of coil springs  140 , thereby forming a pattern across the mattress topper  130  and such that the mattress topper  130  is in the form of a quilted top mattress topper. Specifically, as perhaps best shown in  FIG. 2 , a mattress assembly  110  is provided that includes a mattress core  120  having a bottom surface  122  and a top surface  124  opposite the bottom surface  122 , and a mattress topper  130  positioned adjacent to the top surface  124  of the mattress core  120 . Similar to the mattress topper  30  described above with respect to  FIG. 1 , the mattress topper  130  shown in  FIG. 2  includes a plurality of coil springs  140  arranged in a matrix, an upper fabric layer  154  extending above the plurality of coil springs  140 , and a lower fabric layer  152  extending below the plurality of coil springs  140 . The lower fabric layer  152  is connected to the upper fabric layer  154  by an ultrasonic weld  170  around each coil spring  140 , such that the upper fabric layer  154  and the lower fabric layer  152  collectively form a fabric pocket encasing each coil spring  140 . Furthermore, the mattress topper  130  also includes a backing layer  162  positioned below the lower fabric layer  152 , a padded layer  160  positioned atop the upper fabric layer  154 , and a textile layer  164  positioned atop the padded layer  160 , which are each substantially similar to the backing layer  62 , padded layer  60 , and textile layer  64  shown in  FIG. 1 , except that the backing layer  162 , padded layer  160 , and textile layer  164  in the exemplary embodiment shown in  FIGS. 2 and 3  are all connected by the same ultrasonic weld  170  that connects the lower fabric layer  152  to the upper fabric layer  154 . 
     In particular, as shown in  FIG. 2 , not only is the upper fabric layer  154  connected to the lower fabric layer  152  by the ultrasonic weld  170 , but the backing layer  162  is connected to the lower fabric layer by the ultrasonic weld  170 , the padded layer  160  is connected to the upper fabric layer  154  by the ultrasonic weld  170 , and the textile layer  164  is connected to the padded layer  160  by the ultrasonic weld  170 . Each of the layers of the mattress topper  130  (i.e., the backing layer  162 , the lower fabric layer  152 , the upper fabric layer  154 , the padded layer  160 , and the textile layer  164 ) are brought together between each of the coil springs  140  and connected about midway up the height of the coil springs  140 . Furthermore, as shown in  FIG. 3 , each of the coil springs  140  is completely surrounded by a respective ultrasonic weld  170 , as further discussed below. Accordingly, the padded layer  160  and overlaying textile layer  164  rise and fall across the plurality of coil springs  140  such that, as described above, the mattress topper  130  is a quilted top mattress topper. 
     As shown in  FIG. 3 , the coil springs  140  and ultrasonic welds  170  are positioned such that one substantially circular ultrasonic weld  170  surrounding one coil spring  140  overlaps with another ultrasonic weld  170  surrounding another adjacent coil spring  140 . Furthermore, since the ultrasonic welds  170  shown in  FIG. 3  are substantially circular, the ultrasonic welds  170  only partially overlap with each other. It is, of course, contemplated though that increasing the spacing of the coil springs  140  or changing the size and/or shape of the ultrasonic welds would result in different patterns of the ultrasonic welds that could be produced without departing from the spirit and scope of the present invention. 
     Referring now to  FIG. 4 , in another embodiment of the present invention that includes a mattress topper, rather than connecting all of the layers of the mattress topper with an ultrasonic weld, in the mattress topper  230  shown in  FIG. 4 , the layers of the mattress topper  230  are connected by a plurality of tufts  280  that extend through all of the layers of the mattress topper  230 . In particular, the exemplary mattress topper  230  shown in  FIG. 4  also includes a plurality of coil springs  240  arranged in a matrix similar to the mattress toppers  30 ,  130  described above with reference to  FIGS. 1-3 . Furthermore, although not shown in the  FIG. 4 , the mattress topper  230  in  FIG. 4  also includes an upper fabric layer extending above the plurality of coil springs  240 , a lower fabric layer extending below the plurality of coil springs  240 , a backing layer positioned below the lower fabric layer, a padded layer positioned atop the upper fabric layer, and a textile layer positioned atop the padded layer similar to the corresponding layers described above with reference to  FIGS. 1-3 . As shown in  FIG. 4 , however, the plurality of coil springs  240  are arranged in a rectangular matrix with a tuft  280  positioned at an intersection point equidistant to four adjacent coil springs  240  such that each coil spring  240  is bordered by four tufts  280  which connect all of the layers of the mattress topper  230  around each coil spring  240  to collectively form a fabric pocket encasing the coil spring  240  similar to the fabric pockets described above with respect to  FIGS. 1 and 2 . 
     Of course, rather than connecting all of the layers of the mattress topper with an ultrasonic weld or with a tuft, one or more of the layers of the mattress topper can be connected by an ultrasonic weld or tuft while the other layers are connected by an alternative means including, for example, a tuft, an adhesive, a staple, stitches, clamps, hook-and-loop fasteners, and the like. For example, in some embodiments, a lower fabric layer, an upper fabric layer, and a padded layer are all connected by an ultrasonic weld around each coil spring, but a backing layer and a textile layer are connected by an adhesive to the respective underlying layers. Similarly, in other embodiments, a lower fabric layer, an upper fabric layer, and a padded layer are all connected by a tuft extending through the lower fabric layer, upper fabric layer, and padded layer, but a backing layer and a textile layer are connected by an adhesive to the respective underlying layers. 
     Regardless of how the various layers of the mattress topper are connected, in the mattress toppers of the present invention, the coil springs are integrated into the mattress topper such that they are held in position relative to the layers of the mattress topper as well as the other coil springs. Furthermore, the mattress topper itself is securely connected to the mattress core by means well known in the art. In this regard, the coils remain in place relative to the mattress core even when the mattress assembly is moved or otherwise manipulated. For example, in embodiments of the present invention where the mattress topper is positioned atop an adjustable mattress base, when the mattress assembly is actuated into, for example, a reclined position, each of the coil springs remains in place relative to the mattress core and continues to provide the same support to a user positioned on the mattress assembly. 
     Further provided by the present invention are methods for producing a mattress topper. In one exemplary implementation of a method for producing a mattress topper, such as the mattress toppers  30 ,  130 ,  230  described above, an array of coils is first provided. Each of the coils in the array is made of a continuous wire that extends from a lower end convolution to an upper end convolution opposite the lower end convolution. The array of coils is then positioned between an upper fabric layer and a lower fabric layer. In particular, the upper fabric layer is positioned such that it extends across the upper end convolutions of the coils and the lower fabric layer is positioned such that it extends across the lower end convolutions of the coils. 
     After positioning the array of coil springs between the upper fabric layer and the lower fabric layer, the lower fabric layer is then connected to the upper fabric layer between each of the coil springs. In particular, the lower fabric layer is connected to the upper fabric layer by ultrasonically welding the lower fabric layer to the upper fabric layer. As would be recognized by those of skill in the art, such ultrasonic welds are formed by compressing the fabric layers together between two irons and then running an electric current through the irons to melt the material of the two fabric layers together. In this regard, the upper fabric layer and the lower fabric layer are preferably made of a non-woven textile similar to the upper fabric layer  54  and the lower fabric layer  52  described above with respect to  FIG. 1 . Typically, ultrasonic welds are formed along a linear path with only a portion of the weld formed at any given moment. In some embodiments of the present invention, however, the step of ultrasonically welding the lower fabric layer to the upper fabric layer is performed by compressing the fabric layers between two substantially circular irons which fit around each coil spring such that the irons simultaneously form an ultrasonic weld that completely surrounds the respective coil spring. 
     After connecting the lower fabric layer to the upper fabric layer, a padded layer is then connected to the upper fabric layer. In some implementations of the method of the present invention, the padded layer is connected to the upper fabric layer by applying an adhesive to the upper fabric layer and then positioning the padded layer atop the upper fabric layer. For example, in some embodiments, this process is performed by roll feeding the array of coil springs positioned between the lower fabric layer and the upper fabric layer through a roll coater to roll coat the adhesive onto the upper fabric layer and then position the padded layer atop the upper fabric layer in one continuous process. 
     In some other implementations of the method of the present invention, the padded layer is connected to the upper fabric layer with an ultrasonic weld. For example, after connecting the lower fabric layer to the upper fabric layer, a padded layer is positioned atop the upper fabric layer and the lower fabric layer. The lower fabric layer, the upper fabric layer, and the padded layer are then compressed around each coil spring, and the lower fabric layer, the upper fabric layer, and the padded layer are ultrasonically welded around each coil spring. Of course, rather than connecting the padded layer to the upper fabric layer with an ultrasonic weld in a separate step performed after connecting the lower fabric layer to the upper fabric layer, the padded layer can be connected to the upper fabric layer with an ultrasonic weld simultaneously with the above described step of ultrasonically welding the lower fabric layer to the upper fabric layer. 
     In still other implementations of the methods of the present invention, the padded layer is connected to the upper fabric layer by forming a plurality of tufts that extend through the lower fabric layer, the upper fabric layer, and the padded layer. As would be recognized by those of skill in the art, in forming such tufts, a large needle is pushed through the lower fabric layer, the upper fabric layer, and the padded layer. According to some implementations of the method of the present invention, the needle is pushed through the lower fabric layer, the upper fabric layer, and the padded layer between each of the coils in order to form each of the plurality of tufts. It is contemplated that while pushing the needle through the lower fabric layer, the upper fabric layer, and the padded layer, unintended contact between the large needle and a coil spring may occur. Advantageously, the large needle will simply push the coil spring out of the way during insertion rather than bending or breaking the needle. 
     Regardless of the particular method utilized to connect the padded layer, it is contemplated that upon connecting the padded layer, the resulting mattress topper can then be connected to a mattress core as part of a mattress assembly. Furthermore, it should be understood that additional steps of connecting more layers, such as the backing layer and textile layer described above with respect to  FIG. 1 , may also be included in the implementations of the methods of the present invention. Such additional layers may be connected by adhesives, ultrasonic welds, or tufts by methods substantially similar to the methods of connecting the padded layer described above. 
     One of ordinary skill in the art will recognize that additional embodiments are also possible without departing from the teachings of the present invention or the scope of the claims which follow. This detailed description, and particularly the specific details of the exemplary embodiments disclosed herein, is given primarily for clarity of understanding, and no unnecessary limitations are to be understood therefrom, for modifications will become apparent to those skilled in the art upon reading this disclosure and may be made without departing from the spirit or scope of the claimed invention.