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

A mattress assembly is provided that includes a mattress core having a bottom surface and a top surface opposite the bottom surface, and a mattress topper positioned adjacent to the top surface of the mattress core. The mattress topper includes a plurality of coil springs, an upper fabric layer extending above the plurality of coil springs, and a lower fabric layer extending below the plurality of coil springs. The lower fabric layer is 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. The mattress topper further includes a padded layer positioned atop the upper fabric layer, with the padded layer connected to the upper fabric layer by ultrasonic welds and/or tufts. Methods of producing a mattress topper for connection to a mattress core are further provided.

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'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'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.

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 toFIG. 1, in one exemplary embodiment of the present invention, an exemplary mattress assembly10is provided that includes a mattress core20and a mattress topper30positioned atop the mattress core20. In particular, the mattress core20has a bottom surface22and a top surface24opposite the bottom surface22, and the mattress topper30is positioned adjacent to the top surface24of the mattress core20.

The mattress topper30includes a plurality of coil springs40arranged in a matrix, an upper fabric layer54extending above the plurality of coil springs40, and a lower fabric layer52extending below the plurality of coil springs40. The lower fabric layer52is connected to the upper fabric layer54around each coil spring40such that the upper fabric layer54and the lower fabric layer52collectively form a fabric pocket encasing each coil spring40.

With respect to each of the coil springs40and referring still toFIG. 1, each exemplary coil spring40shown inFIG. 1is made of a continuous wire that extends from a lower end convolution42to an upper end convolution44opposite the lower end convolution42. In the coil spring40, there are six intermediate convolutions46that helically spiral between the lower end convolution42and the upper end convolution44, such that the coil spring40is made of a total of eight convolutions or turns. Furthermore, each of the coil springs40has a height defined from the lower end convolution42to the upper end convolution44with each of the convolutions of the coil spring40having a diameter. The height of the coil spring40can range from about one-half (½) inches to about three (3) inches and the diameter of each of the convolutions of the coil spring40can range from about three-fourths (¾) inches to about three (3) inches. In the particular embodiment shown inFIG. 1, the height of the coil springs40is 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 layer54and the lower fabric layer52and referring still toFIG. 1, the lower fabric layer52is connected to the upper fabric layer54in between each of the coil springs40about midway up the height of the coil springs40. In this regard, the upper fabric layer54and the lower fabric layer52shown inFIG. 1are generally made of a non-woven textile which are joined together by an ultrasonic weld70to form such a structure. For example, suitable fabrics that can be used for the upper fabric layer54and the lower fabric layer52can 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 layer52can be connected to the upper fabric layer54by 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 layer54and the lower fabric layer52, however, by connecting the upper fabric layer54and the lower fabric layer52around each coil spring40, not only is it possible to impart a desired level of pre-compression, stability, and/or stretchability to the coil spring40, but each of the coil springs40is able to compress at least partially independently of the other coil springs40while still being held in position relative to the other coil springs40, as further discussed below.

Referring still toFIG. 1, the exemplary mattress topper30further includes a padded layer60positioned atop the upper fabric layer54. The padded layer60is configured to provide a sufficiently soft surface upon which a portion of a user's body can rest, and as such, the padded layer60is 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 layer60comprising 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 inFIG. 1, the padded layer60of the mattress topper30is 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 layer60can 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 layer60of the mattress topper30has a density of no less than about 30 kg/m3to no greater than about 150 kg/m3. In some embodiments, the density of the visco-elastic foam used in the padded layer60of the mattress topper30is about 30 kg/m3, about 40 kg/m3, about 50 kg/m3, about 60 kg/m3, about 70 kg/m3, about 80 kg/m3, about 90 kg/m3, about 100 kg/m3, about 110 kg/m3, about 120 kg/m3, about 130 kg/m3, about 140 kg/m3, or about 150 kg/m3. 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 layer60need 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 layer60is 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 layer60is comprised of, in the exemplary mattress topper30, the padded layer60is connected to the upper fabric layer54. More specifically, in the mattress topper30shown inFIG. 1the padded layer60is connected to the upper fabric layer54by an adhesive which allows the padded layer60to extend across the plurality of coil springs40with the padded layer60staying substantially flat such that the mattress topper30is a smooth top mattress topper, as further discussed below.

As also shown inFIG. 1, the exemplary mattress topper30further includes a textile layer64positioned atop the padded layer60and which is also connected to the padded layer60by an adhesive. In the embodiment shown inFIG. 1, the textile layer64is the uppermost layer of the mattress topper30and so the textile layer64is 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 layer64can include a decorative pattern on its top surface, such as a quilted pattern, as desired.

Referring still toFIG. 1, the exemplary mattress topper30further includes a backing layer62positioned below the lower fabric layer52and which is connected to the lower fabric layer52by an adhesive. In the embodiment shown inFIG. 1, the backing layer62is 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 inFIG. 1is a smooth top mattress topper30in which the padded layer60extends substantially flat across the plurality of coil springs40. By comparison, in another embodiment of the present invention, and referring now toFIGS. 2 and 3, the padded layer160is configured such that it rises and falls across the plurality of coil springs140, thereby forming a pattern across the mattress topper130and such that the mattress topper130is in the form of a quilted top mattress topper. Specifically, as perhaps best shown inFIG. 2, a mattress assembly110is provided that includes a mattress core120having a bottom surface122and a top surface124opposite the bottom surface122, and a mattress topper130positioned adjacent to the top surface124of the mattress core120. Similar to the mattress topper30described above with respect toFIG. 1, the mattress topper130shown inFIG. 2includes a plurality of coil springs140arranged in a matrix, an upper fabric layer154extending above the plurality of coil springs140, and a lower fabric layer152extending below the plurality of coil springs140. The lower fabric layer152is connected to the upper fabric layer154by an ultrasonic weld170around each coil spring140, such that the upper fabric layer154and the lower fabric layer152collectively form a fabric pocket encasing each coil spring140. Furthermore, the mattress topper130also includes a backing layer162positioned below the lower fabric layer152, a padded layer160positioned atop the upper fabric layer154, and a textile layer164positioned atop the padded layer160, which are each substantially similar to the backing layer62, padded layer60, and textile layer64shown inFIG. 1, except that the backing layer162, padded layer160, and textile layer164in the exemplary embodiment shown inFIGS. 2 and 3are all connected by the same ultrasonic weld170that connects the lower fabric layer152to the upper fabric layer154.

In particular, as shown inFIG. 2, not only is the upper fabric layer154connected to the lower fabric layer152by the ultrasonic weld170, but the backing layer162is connected to the lower fabric layer by the ultrasonic weld170, the padded layer160is connected to the upper fabric layer154by the ultrasonic weld170, and the textile layer164is connected to the padded layer160by the ultrasonic weld170. Each of the layers of the mattress topper130(i.e., the backing layer162, the lower fabric layer152, the upper fabric layer154, the padded layer160, and the textile layer164) are brought together between each of the coil springs140and connected about midway up the height of the coil springs140. Furthermore, as shown inFIG. 3, each of the coil springs140is completely surrounded by a respective ultrasonic weld170, as further discussed below. Accordingly, the padded layer160and overlaying textile layer164rise and fall across the plurality of coil springs140such that, as described above, the mattress topper130is a quilted top mattress topper.

As shown inFIG. 3, the coil springs140and ultrasonic welds170are positioned such that one substantially circular ultrasonic weld170surrounding one coil spring140overlaps with another ultrasonic weld170surrounding another adjacent coil spring140. Furthermore, since the ultrasonic welds170shown inFIG. 3are substantially circular, the ultrasonic welds170only partially overlap with each other. It is, of course, contemplated though that increasing the spacing of the coil springs140or 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 toFIG. 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 topper230shown inFIG. 4, the layers of the mattress topper230are connected by a plurality of tufts280that extend through all of the layers of the mattress topper230. In particular, the exemplary mattress topper230shown inFIG. 4also includes a plurality of coil springs240arranged in a matrix similar to the mattress toppers30,130described above with reference toFIGS. 1-3. Furthermore, although not shown in theFIG. 4, the mattress topper230inFIG. 4also includes an upper fabric layer extending above the plurality of coil springs240, a lower fabric layer extending below the plurality of coil springs240, 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 toFIGS. 1-3. As shown inFIG. 4, however, the plurality of coil springs240are arranged in a rectangular matrix with a tuft280positioned at an intersection point equidistant to four adjacent coil springs240such that each coil spring240is bordered by four tufts280which connect all of the layers of the mattress topper230around each coil spring240to collectively form a fabric pocket encasing the coil spring240similar to the fabric pockets described above with respect toFIGS. 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 toppers30,130,230described 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 layer54and the lower fabric layer52described above with respect toFIG. 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 toFIG. 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.