Orthopaedic pet mattress

Abstract

An orthopaedic mattress 100 for supporting a pet such as a cat or dog, the mattress defining a sleep region having a length of no greater than 145 cm and a width of no greater than 110 cm. The pet mat

Description

Field The present teachings relate to an orthopaedic pet mattress. 5 Background Orthopaedic pet mattresses are important in maintaining the health and well-being of pets (e.g. dogs and cats), particularly those that suffer from musculoskeletal conditions or are in the later stages of life. Specialised pet mattresses are required to provide comfort, support, and relief from the aches and pains associated with 10 joint issues, arthritis, and other orthopaedic problems. Traditional pet mattresses typically include a base surface for supporting the mattress on the ground and an arrangement of foam or cushioning material that defines a sleep region above the base surface upon which a pet is intended to rest. In conventional pet mattresses, the sleep region typically has a length of no greater 15 than 145 cm and a width of no greater than 110 cm, butare generally much smaller, to provide adequate support for a pet without occupying a significant area. It will be understood, therefore that conventional pet mattresses are of significantly smaller construction than mattresses for humans, and are unsuitable for use by adult humans. 20 While traditional pet mattresses provide some level of comfort, they do not address the unique needs of pets with orthopaedic issues. These conventional pet mattresses can aggravate existing problems or fail to prevent the development of such issues in the first place. One of the primary challenges in designing orthopaedic pet mattresses is providing 25 adequate support and comfort while avoiding the mattress becoming "bottomed out". A pet mattress is said to have bottomed out when the body of a pet, especially its weight-bearing joints, comes into contact with the base surface of the mattress. This occurs when the cushioning or padding in the pet mattress compresses or loses its supportive properties to the extent that the mattress no longer provides 30 adequate cushioning or support to keep the pet elevated and comfortable. 25 09 24 A bottomed out mattress can be problematic, especially for pets with orthopaedic issues. Contact of the body of a pet with the base surface of a mattress can lead to discomfort, increased pressure on sensitive areas like joints and bones, and potential exacerbation of existing musculoskeletal problems. Inadequate support 5 can also result in restless sleep, discomfort, and reduced overall quality of life for a pet. While orthopaedic pet mattresses have emerged in recent years, they are far from being universally effective or accessible. Existing orthopaedic pet mattress designs are often very basic and rely on repurposing mattress technology designed for 10 humans (e.g. a mattress made from lumps of memory foam). The failure to provide an orthopaedic pet mattress that is explicitly designed with pets in mind has resulted in these products providing lesser support and comfort to pets. As such, there exists a need for an orthopaedic pet mattress that can effectively provide support, comfort, and relief to a pet with orthopaedic issues. 15 The present teachings seek to overcome or at least mitigate one or more problems associated with the prior art. Summary In a first aspect of the invention, an orthopaedic pet mattress for supporting a pet (e.g. a dog, a cat) is provided, the pet mattress defining a longitudinal axis 20 and having a sleep region upon which a pet is intended to rest in use, the sleep region having a length of no greater than 145 cm and a width of no greater than 110 cm, the orthopaedic pet mattress comprising: a discrete first layer formed from a first foam material, the first layer comprising a base surface and an upper surface, the upper surface configured to define a first array comprising rows of alternating 25 peaks and troughs arranged in a grid extending above the base surface, the grid having a plurality of rows of alternating peaks and troughs extending in a parallel direction, a plurality of rows of alternating peaks and troughs extending in an orthogonal direction, and a plurality of rows of alternating peaks and troughs extending in a diagonal direction relative to the longitudinal axis; a discrete second 30 layer formed from a second foam material, the second layer comprising an upper surface configured to define the sleep region, and a lower surface configured to define a second array comprising rows of alternating peaks and troughs arranged in a grid extending beneath the sleep region, the grid having a plurality of rows of alternating peaks and troughs extending in a parallel direction, a plurality of rows 35 of alternating peaks and troughs extending in an orthogonal direction, and a 25 09 24 plurality of rows of alternating peaks and troughs extending in a diagonal direction relative to the longitudinal axis; wherein the first foam material and the second foam material have different properties; wherein the first layer and the second layer interdigitate with one another such that the peaks of the first array are received in 5 the troughs of the second array, and the peaks of the second array are received in the troughs of the first array, thereby defining an interdigitated area comprising the first foam material and the second foam material; and wherein the first layer and the second layer are configured such that air gaps are present between the first foam material and the second foam material in the interdigitated area. 10 The use of the arrayed (i.e. rows of peaks / troughs) profile has previously been found to be inappropriate for human use other than as a topper of a pre-existing mattress, in which a human would rest upon the arrayed profile. This is because the arrayed profile is not typically firm enough to support human mass and weight distribution without the peaks quickly becoming "bottomed out", i.e. compressed 15 to the extent that they no longer provide comfort. In order to avoid the mattress becoming bottomed out while still supporting a human body without an undermattress, it was found that the arrayed profile was required to be formed from a material that was so firm that it was no longer comfortable to lie on. In this way, the implementation of such an arrayed profile in a standalone mattress has not 20 previously been effective. The inventors of the present disclosure have found a means of implementing the arrayed profile in an orthopaedic mattress for pets without requiring a separate mattress below. Having a mattress made from the two layers results in an interdigitated area including rows of peaks and troughs (i.e. such that the pet does 25 not directly rest upon the peaks / troughs) extending in three directions. The arrangement of the layers has been found to result in a pet mattress providing excellent orthopaedic support and comfort to a pet without becoming bottomed out. Specifically, the arrayed profile improves weight distribution of a pet on the mattress, while the interdigitated area has been found to provide support for a 30 comfortable sleep region that is not at risk of becoming bottomed out. For pets with orthopaedic issues, such as joint pain or pressure-sensitive areas, improving their weight distribution while avoiding becoming bottomed out on the mattress can alleviate pressure points, reducing pressure on joints and reducing discomfort when resting on the mattress, thereby providing relief to areas that might otherwise 35 experience pain during sleep. 25 09 24 It should be understood that the mattress including the interdigitated area set forth is not suitable for use by an adult human. For example, the sleep region is not suitably dimensioned for an adult human to comfortably rest upon, and the interdigitated area would typically become bottomed out in response to use by an 5 adult human, thus failing to provide any form of orthopaedic support to an adult human. In contrast, pets typically weigh less than humans and rest with their weight more distributed about the mattress. The mattress can therefore effectively support a pet without becoming bottomed out, without having to be made from significantly firm material and without the inconvenience and cost of requiring an 10 additional mattress below. Advantageously, including air gaps allows the mattress to conform to the shape and weight of a pet (i.e. providing space into which the layers can move), providing improved comfort and pressure relief. This is preferable to a mattress made from a single block of foam, which has a reduced ability to conform to the shape of a pet. 15 The air gaps also facilitate flow of air (i.e. from the atmosphere around the mattress) through the mattress, which assists in removing moisture from the skin of a pet. Moisture build-up at the surface of the skin of a pet can cause increased risk of pressure injury and discomfort. In this way, the air gaps further assist in improving the comfort of a pet on the mattress is further increased. 20 In exemplary embodiments, wherein the first foam material has a greater hardness grade than the second foam material. Advantageously, the second layer can be seen as providing comfort to the pet, while the first layer provides structural support to the first layer, reducing the risk 25 of the mattress becoming bottomed out. The interdigitated area thus includes materials of varying hardness grades, resulting in a unique engagement between the peaks and troughs of the first and second layers. This has been found to further alleviate pressure points of pets using the mattress and reduce pain. In exemplary embodiments, the first foam material has a hardness grade in the 30 range of 135 N to 180 N. The second foam material has a hardness grade in the range of 80 N to 130 N. Advantageously, the selected range of hardness grades has been found to provide a balance between improving comfort felt by a pet on the mattress and reducing the risk of the mattress becoming bottomed out. Specifically, forming the layers 35 from the materials set forth has been found to assist in the comfort provided by the 25 09 24 interdigitated mattress, providing for a soft sleep region that is effectively supported by the first layer. It should be understood that the hardness grades set forth would cause the mattress with the interdigitated area to become bottomed out in response to 5 engagement with an adult human. As such, the mattress with such materials is not appropriate for providing orthopaedic support to an adult human. In exemplary embodiments, the first foam material has a hardness grade in the range of 140 N to 170 N. The second foam material has a hardness grade in the range of 90 N to 120 N. 10 In exemplary embodiments, the first foam material has a hardness grade of about 155 N. The second foam material has a hardness grade of about 105 N. Advantageously, the above hardness grades have been found to result in an 15 orthopaedic mattress that is capable of providing appropriate comfort and support to a pet, reducing the risk of the mattress becoming bottomed out. In exemplary embodiments, the second foam material has a greater density than the first foam material. 20 The second layer is thus formed from a denser foam material than the first layer. In this way, the second layer can be seen as having a more densely packed foam arrangement. The greater density second layer allows a pet to sink into the sleep region so as to absorb pressure from natural high pressure points. Moreover, the 25 higher density layer reduces residual deformation of the mattress, allowing the foam to preserve its size and shape over time. The lower density first layer provides support to the second layer, reducing the risk of the mattress becoming bottomed out. 30 In exemplary embodiments, the first foam material has a density in the range of 15 to 30 kg m-3. The second foam material has a density in the range of 31 to 45 kg nr3. Advantageously, the density of the foam materials has been found to result in a pet 35 bed that provides comfort and orthopaedic support to a pet, without being at risk of becoming bottomed out or deforming with use. The interdigitated area includes 25 09 24 materials having different properties, i.e. having materials that provide comfort and materials that provide support, further supporting the structural integrity and comfort provided by the bed. It should be understood that the combination of the above densities and hardness grades are not suitable for providing orthopaedic 5 support to an adult human, as the bed would simply become bottomed out in response to their weight and weight distribution. In exemplary embodiments, the first foam material has a density in the range of 20 to 30 kg m‘3. The second foam material has a density in the range of 31 to 40 10 kg nr3. In exemplary embodiments, the first foam material has a density of about 28 kg nr3. The second foam material has a density of about 35 kg m-3. 15 Advantageously, the utilisation of the above densities has been found to provide a high standard of comfort and orthopaedic support to a pet using the mattress, providing a balance between cost and comfort. In exemplary embodiments, the first foam material and / or the second foam 20 material are open cell polyurethane foam, preferably of the polyether type. Advantageously, this material has been found to provide a soft, cushioning feel to a pet resting on the mattress, while also being highly conformable and responsive to the pressure and contours of a pet body, thereby improving weight distribution 25 across the mattress. In exemplary embodiments, the first foam material and / or the second foam material are a combustion modified polyether type foam (CMP). 30 In exemplary embodiments, the first foam material is made from CMP28. In exemplary embodiments, the second foam material is made from CMP35. Advantageously, this material has been found to provide excellent support and 35 comfort, while meeting flammability requirements (e.g. in the UK) associated with domestic upholstery and soft furnishings. 25 09 24 In exemplary embodiments, the air gaps extend through the interdigitated area in a parallel, an orthogonal and a diagonal direction with respect to the longitudinal axis. Advantageously, the pet mattress can conform to the shape and weight of a pet in three directions, providing improved comfort to the pet irrespective of the orientation and position with which they lie on the sleep region. In exemplary embodiments, the first layer has a depth in the range of about 5 cm to 12 cm. The second layer has a depth in the range of about 5 cm to 8 cm. In exemplary embodiments, the mattress has a depth in the range of about 7.5 cm to 16 cm. Advantageously, the depths as set forth have been found to provide effective support to the interdigitated area, reducing the risk of the mattress becoming bottomed out in response to a pet resting on the sleep region. In a second aspect of the invention, an orthopaedic pet mattress for supporting a pet (e.g. a dog, a cat) is provided, the pet mattress defining a longitudinal axis and having a sleep region upon which a pet is intended to rest in use, the orthopaedic pet mattress comprising: a discrete first layer formed from a first foam material, the first layer comprising a base surface and an upper surface, the upper surface configured to define a first array comprising rows of alternating peaks and troughs arranged in a grid extending above the base surface, the grid having a plurality of rows of alternating peaks and troughs extending in a parallel direction, a plurality of rows of alternating peaks and troughs extending in an orthogonal direction, and a plurality of rows of alternating peaks and troughs extending in a diagonal direction relative to the longitudinal axis; a discrete second layer formed from a second foam material, the second layer comprising an upper surface configured to define the sleep region, and a lower surface configured to define a second array comprising rows of alternating peaks and troughs arranged in a grid extending beneath the sleep region, the grid having a plurality of rows of alternating peaks and troughs extending in a parallel direction, a plurality of rows of alternating peaks and troughs extending in an orthogonal direction, and a plurality of rows of alternating peaks and troughs extending in a diagonal direction relative to the longitudinal axis; wherein the first layer and the second layer interdigitate with one another such that 25 09 24 the peaks of the first array are received in the troughs of the second array, and the peaks of the second array are received in the troughs of the first array, thereby defining an interdigitated area comprising the first foam material and the second foam material. 5 In exemplary embodiments, the sleep region has a length of no greater than 145 cm and a width of no greater than 110 cm. In exemplary embodiments, the first foam material and the second foam material 10 have different properties. Brief Description of the Drawings Embodiments will now be described with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a first layer according to an embodiment of the 15 disclosure; Figure 2 is a cross-sectional view of the first layer of Figure 1; Figure 3 is an exploded view of a pet mattress according to an embodiment of the disclosure; Figure 4 is a perspective view of a pet mattress according to an embodiment of the 20 disclosure; Figure 5 is a cross-sectional view of the pet mattress of Figure 4. Detailed Description of the Embodiment(s) The present disclosure relates to an orthopaedic pet mattress 100. The pet mattress 100 provides support to a pet (e.g. a dog or a cat) who can rest, lie, and sleep on 25 a sleep region of the mattress 100. The pet mattress 100 is configured to reduce pressure on joints of pets, reducing discomfort and providing relief to areas that might otherwise experience pain during sleep. The sleep region is dimensioned for supporting a pet without occupying excessive amounts of floor area. The pet mattress 100 set forth has a sleep region with a 30 length of no greater than 145 cm and a width of no greater than 110 cm. In some embodiments, the sleep region has a length of no greater than 85 cm and a width of no greater than 85 cm. In another embodiment, the sleep region has a length of 25 09 24 no greater than 75 cm and a width of no greater than 75 cm. In some embodiments, the sleep region has a length of no greater than 55 cm and a width of no greater than 55 cm. As will be discussed, the orthopaedic pet mattress 100 is configured for providing 5 orthopaedic support to pets only and is not suitable for use by an adult human. For example, a standard adult single mattress (i.e. the smallest mattress intended for use by an adult human) has a length of 190 cm and a width of 90 cm. As such, even the smallest mattress intended for adult human use requires a larger sleep region than the largest embodiment of the pet mattress 100. In view of this, the 10 pet mattress 100 would not be considered suitable for use by an adult human, particularly not in providing orthopaedic support. Moreover, as will be discussed in more detail, the material and profile of the pet mattress 100 have been specifically selected for supporting the weight and weight-distribution of a pet and would not be capable of providing orthopaedic support to an adult human. 15 The pet mattress 100 includes two discrete layers, a first layer 102 and a second layer 104. It should be understood that the term "discrete" refers to the layers being provided as separate from each other prior to assembly of the pet mattress 100. The first layer 102 will firstly be discussed with reference to Figures 1 and 2. As will be discussed, the second layer 104 is configured in much the same way as 20 the first layer 102. Figure 1 indicates a perspective view of the first layer 102, while Figure 2 indicates a cross-sectional view of the first layer 102 through line 2-2. The first layer 102 defines a longitudinal axis A. The first layer 102 includes a base surface 106, intended to rest upon the ground, floor, or any suitable surface and 25 an upper surface 108. In the illustrated embodiment, the base surface 106 is substantially planar. In general use, the base surface 106 is positioned on a substantially planar region of the ground such that an interface between the base surface 106 and the ground is substantially planar. In this way, a pet resting on the mattress 100 can rest in a 30 generally parallel orientation relative to the ground, improving their comfort and reducing the likelihood of the pet falling from the mattress 100. It will be understood from the drawings that the upper surface 108 is configured to define a profile having a general appearance similar to that of an "egg-box" or "egg 25 09 24 crate". Put another way, the upper surface 108 is configured to define a first array of peaks 110a and troughs 112a. The peaks 110a are arranged so as to be distributed across the upper surface 108 so as to form rows. The troughs 112a are arranged in between neighbouring peaks 110a so as to be arranged in the rows 5 across the upper surface 108. In this way, the first array can be seen as being an arrangement of rows of alternating peaks 110a and troughs 112a that form a grid arrangement of alternating peaks and troughs. In exemplary embodiments, the peaks 110a and troughs 112a are evenly distributed across the upper surface 108 so as to form a uniform grid arrangement of alternating peaks and troughs. Put 10 another way, as can be seen in Figure 1, a peak 110a in the first array defines a centre point relative to four troughs 112a that are arranged at a uniform spacing around the peak. In this way, four troughs 112a and peak 110a in the array can be seen as forming a cross or cruciform shape, with a peak 110a forming the centre of the cross or cruciform. 15 The first array of peaks 110a and troughs 112a are arranged to extend above the base surface 106. In some embodiments, the entire upper surface 108 is arranged to define the first array, e.g. such that the rows of peaks 110a and troughs 112a extend across the entire upper surface 108. In an alternative arrangement, only a region of the upper surface 108 is configured to define the first array, preferably 20 the region of the upper surface 108 configured to define the first array is positioned beneath the sleep region when the mattress 100 is assembled. In exemplary embodiments, the peaks 110a are in the form of projections that extend upwardly in a direction away from the base surface 106. The troughs 112a are defined as voids between respective peaks 110a. In the illustrated embodiment, 25 the troughs 112a include a concavity in the upper surface 108, e.g. that extends inwardly in a direction toward the base surface 106. In some embodiments, the peaks 110a of the first array are substantially identical to one another, e.g. defining a substantially identical height and width. The troughs 112a of the first array may be substantially the same as one another. Peaks and troughs of varying dimensions 30 may be implemented in alternative embodiments. As can be seen, the first array is arranged such that the grid has rows of alternating peaks 110a and troughs 112a that extend in multiple directions relative to the longitudinal axis A. In Figure 1, the grid includes a plurality of rows that extend in a parallel direction, 35 a plurality of rows that extend in an orthogonal direction and a plurality rows that 25 09 24 extend in a diagonal direction relative to the longitudinal axis. In this way, each row of the first array extends in either an orthogonal, a parallel or a diagonal direction relative to the longitudinal axis. In the figures, the rows of alternating peaks 110a and troughs 112a can be seen as extending over the base surface 106 5 in three directions relative to the longitudinal axis A. It will be appreciated that a given peak and / or trough may form part of multiple rows, e.g. a peak or trough in a central region of the first array will be part of a row that extends in a parallel direction, a row that extends in an orthogonal direction and a row that extends in a diagonal direction relative to the longitudinal axis A. 10 It should be understood that the term "diagonal" relates to a row that defines an angle of less than 90° relative to the longitudinal axis A. For example, in one embodiment, a diagonal row of alternating peaks 110a and troughs 112a may intersect the longitudinal axis A so as to define an angle of less than about 90° therebetween. In the illustrated embodiment, the diagonal row of alternating peaks 15 110a and troughs 112a defines an angle of about 45° relative to the longitudinal axis A. The term "about" in the context of the above angles is intended to cover minor deviations that may arise during manufacturing of the mattress. Figure 2 indicates two rows of alternating peaks 110a and troughs 112a extending in a direction orthogonal to the longitudinal axis. As can be seen, the rows are 20 alternating in that each peak 110a is directly adjacent to a trough 112a. It should be understood that a cross-sectional view taken across a line parallel to the longitudinal axis A would be substantially the same as that shown in Figure 2 (e.g. the total number of peaks 110a and troughs 112a, and thus the total length, may be different, but the alternating arrangement is substantially the same). 25 Such arrayed or "egg-box" profile have previously been used as a mattress topper for humans, in which a human would rest upon the array of peaks and troughs that was placed on top of a mattress. The use of an "egg-box" topper without a preexisting mattress has not previously been considered, since the array of peaks and troughs quickly becomes "bottomed out" when used without an under-mattress, 30 i.e. peaks become compressed to the extent that they no longer provide comfort. In order to avoid the mattress 100 becoming bottomed out while still supporting a human body without an under-mattress, it was found that the arrayed profile was required to be formed from a material that was so firm that it was no longer comfortable to lie on. In this way, the use of such an arrayed profile as a standalone 25 09 24 mattress for humans or animals has not previously been considered effective or worthwhile, particularly in an orthopaedic field. The second layer 104 will now be discussed with reference to Figure 3 in combination with Figures 1 and 2. Figure 3 indicates an exploded view of the pet mattress 100, which includes the discrete first layer 102 of Figures 1 and 2, and a discrete second layer 104. The second layer 104 defines a longitudinal axis B. The longitudinal axis B of the second layer 104 is preferably co-axial with the longitudinal axis A of the first layer 102 when the mattress 100 is assembled. The second layer 104 includes an upper surface 114. The upper surface 114 is configured to define a sleep region upon which a pet is intended to rest in use. In the illustrated embodiment, the sleep region is defined by the entire upper surface 114 (i.e. a pet can rest upon any part of the upper surface 114). In some embodiments, regions of the upper surface 114 may not be intended for the pet to rest. In Figure 3, the upper surface 114 and thus the sleep region is substantially planar prior to use. The provision of a planar sleep region allows the mattress 100 to suitably conform with the body of a pet in any position, providing comfort irrespective of the orientation with which the pet rests on the upper surface 114. It should be understood that, in some embodiments, the upper surface 114 may not be substantially planar. For example, the upper surface 114 may include side walls (e.g. padded side walls or bumpers) that extend around the perimeter of the upper surface 114, creating a raised edge to secure a pet on the mattress 100, and / or upon which a pet can rest its head. In some embodiments, the upper surface 114 may have a wavy, or undulating, upper profile. The second layer 104 has a length defined in the longitudinal direction, and a width defined in a direction transverse to the longitudinal axis B. The second layer 104 is configured such that the sleep region has a length of no greater than 145 cm and a width of no greater than 110 cm. Such a configuration has been found to provide a sleep region suitable for pets of various sizes, but without being so large to the extent that the mattress 100 occupies an inconvenient amount of space, or that material is wasted, and manufacturing costs are unnecessarily increased. The second layer 104 includes a lower surface 116. The lower surface 116 of the second layer 104 is similar to the upper surface 108 of the first layer 102 (e.g. having an appearance similar to that of an "egg-box" or "egg-crate"). The lower surface 116 of the second layer 104 is configured to define a second array of peaks 110b and troughs 112b. The peaks 110b extend outwardly in a direction away from 25 09 24 the upper surface 114. The troughs 112b may include a concavity in the lower surface 116, e.g. that extends inwardly in a direction toward the upper surface 114. It should be understood that second array includes rows of alternating peaks 110b and troughs 112b that are arranged much like the rows of the first array illustrated 5 in Figures 1 to 3. As can be seen in Figure 3, the second array includes a rows arranged in a grid arrangement, the grid including rows of alternating peaks 110b and troughs 112b extending in an orthogonal and a parallel direction relative to the longitudinal axis B. Although not shown, the grid also includes rows of alternating peaks 110b and troughs 112b extending in a diagonal direction relative to the 10 longitudinal axis B. In this way, the second array can be seen as defining an arrangement of peaks 110b and troughs 112b similar to that of the first array, but rotated 180° about the longitudinal axis A (i.e. peaks 110b project in a generally downward direction instead of in a generally upward direction). It should be appreciated that any features described in relation to the first array may be applied 15 to the second array. As is represented by arrows in the exploded view of Figure 3, the pet mattress 100 is formed by the engagement of the first layer 102 and the second layer 104. Specifically, the pet mattress 100 is formed by bringing the lower surface 116 of the second layer 104 and the upper surface 108 of the first layer 102 (i.e. the first 20 and second arrays) into contact with one another, as can be seen in Figures 4 and 5. Referring now to Figures 4 and 5, the assembled pet mattress 100 is illustrated. Figure 4 is a perspective view of the pet mattress 100, while Figure 5 is a cross-sectional view of the pet mattress 100 through line 3-3. The pet mattress 100 25 defines a longitudinal axis L. In exemplary embodiments, the second layer 104 is arranged to overlay the first layer 102. The two layers 102, 104 may preferably be arranged relative to each other such that the longitudinal axis L of the pet mattress 100 is coaxial with the longitudinal axis A, B of the respective layers 102, 104. As is illustrated, the second layer 104 and the first layer 102 interdigitate with one 30 another such that the peaks 110a of the first array are received in the troughs 112b of the second array, and the peaks 110b of the second array are received in the troughs 112a of the first array. In a preferred embodiment, each layer 102, 104 is configured such that the peaks 110a, 110b of each array nest in the troughs 112a, 112b of the other array. Put another way, the two layers 102, 104 can be seen as 25 09 24 being "jigsawed" together via the array of peaks 110a, 110b and troughs 112a, 112b. The interdigitated arrangement of the first and second layers 102, 104 secures the two layers 102, 104 together, e.g. via friction of the two foam materials when they 5 are brought into contact with each other. This allows for a slight movement of the layers 102, 104 in respect to each other. It should be understood that the friction between the two layers 102, 104 is such that neither layer will "slide off" the other. It should be understood that the layers 102, 104 are arranged or configured such that the respective arrays are complimentary to each other. For example, the 10 arrangement of peaks 110a, 110b and troughs 112a, 112b on each layer 102, 104 may be opposite to each other, such that a peak 110a, 110b is present on one layer where there is a trough 112a, 112b on the other layer in an equivalent position. The peaks 110a, 110b and troughs 112a, 112b of each layer 102, 104 may be dimensioned such that the peaks 110a, 110b nest within the troughs 112a, 112b. 15 The relative arrangement of the first layer 102 and the second layer 104 results in the formation of an interdigitated area 118, e.g. formed from the first layer 102 and the second layer 104. The interdigitated area 118 Is located between the upper surface 114 of the second layer 104 and the base surface 106 of the first layer 102. In this way, the interdigitated area 118 can be seen as defining a central layer of 20 the mattress 100 that includes the first layer 102 and the second layer 104. The interdigitated area 118 can be seen as being defined by the grid of peaks 110a, 110b of each layer 102, 104 when received in the respective troughs 112a, 112b. The interdigitated area 118 may be defined as a grid (e.g. rows) of interdigitated peaks 110a, 110a and troughs 112a, 112b of the base and second layers 102, 104, 25 which extend in a parallel, an orthogonal, and a diagonal direction relative to the longitudinal axis L of the pet mattress 100. The first layer 102 is formed from a first foam material. The second layer 104 is formed from a second foam material. In this way, the interdigitated area 118 includes both the first foam material and the second foam material. The first and 30 second foam materials may be different in exemplary embodiments, i.e. the materials may have different properties. In this way, the interdigitated area 118 includes two different materials. 25 09 24 The provision of a mattress 100 having an interdigitated area 118 that includes rows of peaks 110a, 110b and troughs 112a, 112b extending in three directions has been found to assist in distributing body weight of a pet more evenly across the mattress 100. For pets with orthopaedic issues, such as joint pain or pressure-5 sensitive areas, improving the weight distribution of the pet can alleviate pressure points and reduce discomfort or pain when engaging with the mattress 100. Moreover, the interdigitated area 118 has been found to provide an improved cushioning effect to reduce pressure on joints, providing relief to areas that might otherwise experience pain during sleep. 10 It has been found that by providing the interdigitated area 118 with peaks / troughs that extend in three directions as a central layer of the mattress 100, rather than as an upper surface upon which the user rests (as in the traditional "egg-box" mattress cover), and by forming the respective layers 102, 104 from different materials, the advantageous effects noted above can be obtained without the pet 15 mattress 100 being at risk of becoming bottomed out in response to a pet resting thereon. Specifically, the first and second arrays have been found to improve weight distribution of a pet across the mattress 100, while arranging the arrays to form the interdigitated area 118 has been found to provide and a comfortable sleep region that is not at risk of becoming bottomed out. 20 It should be understood that the mattress including the interdigitated area 118 set forth is not suitable for use by an adult human. For example, as discussed above, the sleep region is not suitably sized for an adult human to comfortably rest upon. Moreover, the interdigitated area 118 would typically cause the mattress 100 to become bottomed out in response to use by an adult human. In this way, the 25 mattress 100 is not suitable for providing any form of orthopaedic support to an adult human. In contrast, pets typically weigh less than humans, meaning the interdigitated area 118 is suitable for providing comfort and capable of supporting their weight. The weight distribution of pets and humans tends to vary significantly, further 30 making the mattress 100 unsuitable for providing orthopaedic support to an adult human. For example, while humans tend to lie in the same position each night (e.g. with an end of a mattress dedicated to positioning the head upon every use), pets do not have a consistent orientation on a pet mattress, meaning their weight is less likely to be consistently concentrated in a specific area of the mattress 100. 35 Moreover, when resting in lateral recumbency on a mattress (i.e. lying on their 25 09 24 side), the weight of an adult human has been found to be primarily applied to the mattress through contact with the pelvis / thigh region. In contrast, when an animal (e.g. a dog) is resting in lateral recumbency on a mattress, their weight has been found to be applied to the mattress through contact with the shoulder, chest wall, 5 and thigh regions. As such, it should be understood that while the pet mattress 100 set forth is suitably configured to support the distributed weight of a pet, the mattress 100 would becoming bottomed out in response to the concentrated load from an adult human. In view of this, the mattress 100 can effectively provide orthopaedic support to a pet without becoming bottomed out, without having to be 10 made from significantly firm material and without requiring an additional mattress below. In exemplary embodiments, the first and second foam materials have different hardness grades. In the present context, the term "hardness grade" should be understood to relate to the firmness of the material (i.e. the greater the hardness 15 grade, the firmer or harder the foam will feel). In some embodiments, the hardness grade relates to the force in Newtons required to compress a material by 40%. The first foam material preferably has a greater hardness grade than that of the second foam material. In this way, the first layer can be seen as providing comfort to the pet, while the second layer provides structural support to the first layer, 20 reducing the risk of the mattress becoming bottomed out. The interdigitated area thus includes materials of varying hardness grades, resulting in a unique engagement between the peaks and troughs of the first and second layers which further alleviates pressure points of pets using the mattress and reduces pain. In exemplary embodiments, the first foam material has a hardness grade in the 25 range of about 135 N to 180 N, preferably in the range of about 140 N to 170 N (e.g. 140, 145, 150, 155, 160, 165, or 170 N). In a preferred embodiment, the first foam material has a hardness grade of about 155 N. The second foam material preferably has a hardness grade in the range of 80 N to 130 N, preferably in the range of about 90 N to 120 N (e.g. 90, 95, 100, 105, 110, 30 115, or 120 N). In a preferred embodiment, the first foam material has a hardness grade of about 105 N. The selected range of hardness grades has been found to provide a balance between improving comfort felt by a pet on the mattress 100 and reducing the risk of the mattress (i.e. the interdigitated area 118) becoming bottomed out. The above 25 09 24 hardness grades in combination with the interdigitated mattress 100 provides excellent orthopaedic support to a pet, but would be unsuitable for providing any form of orthopaedic comfort to an adult human. In exemplary embodiments, the second foam material has a greater density than the first foam material. In this way, the second layer 104 has a more densely packed foam arrangement when compared with the first layer 102. This has been found to assist the second layer 104 in absorbing pressure from a pet on the sleep region, while also reducing the risk that the foam in the second layer loses its size and shape over time. The first foam material preferably has a density in the range of about 15 to 30 kg m-3, more preferably in the range of about 20 to 30 kg m-3 (e.g. 20, 21, 22, 23, 24 25, 26, 27, 28, 29, or 30kg m-3). The first foam material has a density of about 28 kg m-3 in exemplary embodiments. The second foam material preferably has a density in the range of about 31 to 45 kg m 3, more preferably in the range of about 31 to 40 kg m 3 (e.g. 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 kg m3). The second foam material has a density of about 35 kg m 3 in exemplary embodiments. The combination of the hardness grades and densities set forth results in an interdigitated area 118 that includes materials having both support and comfort properties. The interrelationship of the different foam materials in this area 118 has been found to improve the structural integrity and comfort provided by the mattress 100, improving conformity of the sleep region with the shape of the pet. In exemplary embodiments, at least one of the first foam material and the second foam material includes or is an open cell polyurethane foam, preferably of the polyether type. In exemplary embodiments, both the first and second foam materials include or are open cell polyurethane foam, preferably of the polyether type. This material has been found to provide effective cushioning, while also being conformable to the contours of a pet body, improving weight distribution across the mattress 100. In exemplary embodiments, at least one of the first foam material and the second foam material includes or is a combustion modified polyether type foam (CMP). In exemplary embodiments, both the first and second foam materials include or are CMP. CMP advantageously provides the desired support and comfort to a pet, while 25 09 24 also having enhanced fire resistance, allowing the mattress 100 to meet flammability requirements associated with domestic upholstery and soft furnishings. Preferably, the first foam material is made from or is CMP28 (i.e. CMP having a 5 density of 28 kg m 3). The second foam material is preferably CMP35 (i.e. CMP having a density of 35 kg nr3). Advantageously, the combination of CMP28 and CMP35 alongside the above mentioned hardness grades (particularly a hardness grade of 155 N and 105 N respectively) allows a pet to sink into the second layer 104, which can absorb pressure from high pressure points and avoid significant 10 deformation of the layer. Forming the first layer 102 as set forth provides for a firmer layer that provide structure and support to the second layer 104, thereby protecting the mattress 100 from becoming bottomed out. In this way, the material can be seen as facilitating the use of the arrayed interdigitated area 118 without requiring an under-mattress. 15 As is best shown in Figure 5, the first layer 102 and the second layer 104 are configured such that air gaps 120 are present between the layers 102, 104 in the interdigitated area 118. The air gaps 120 may be formed, for example, by configuring the layers 102, 104 such that the peaks 110a, 110b and troughs 112a, 112b are not perfectly complimentary (i.e. the troughs may be slightly larger than 20 the peaks intended to be received therein). In this way, a series of voids or gaps 120 are present in the interdigitated area 118. The gaps 120 may extend through the interdigitated area 118 so as to permit a flow of air (i.e. from the atmosphere) through a central region of the mattress 100 via the gaps 120. The air gaps 120 have been found to provide multiple advantages. Firstly, the air 25 gaps 120 improve the flexibility and conformity of the mattress 100 by providing space for the two layers 102, 104 to move relative to one another. In this way, the mattress 100 can provide improved cushioning at the sleep region compared with mattresses made of a block of foam, since the second layer 104 can move into the air gaps 120 in response to the weight of a pet. 30 While some of the air gaps 120 will be naturally eradicated via the compression of the second layer 104 as the mattress 100 is utilised, the air gaps 120 facilitate the presence of air pockets throughout the structure of the mattress 100 when a pet is on the sleep region. These pockets are advantageous in allowing movement of air through the mattress 100. The flow of air assists in removing moisture from the 35 mattress 100 that may have built up from contact with the body of a pet. Reducing 25 09 24 the build-up of moisture in the mattress can improve skin health of a pet while also reducing the risk of pressure injury. Moreover, the presence of air in the structure of the mattress 100 while a pet is resting thereon has been found to provide a thermal barrier, helping prevent heat 5 from being conducted from the sleep region to the ground upon which the mattress 100 is placed. This improves heat retention of a pet resting on the mattress 100, preventing significant amounts of heat from escaping a pet and thus maintaining the warmth of a pet using the mattress 100. In exemplary embodiments, the layers 102, 104 are configured relative to each 10 other such that the air gaps 120 extend through the interdigitated area in a parallel, an orthogonal and a diagonal direction with respect to the longitudinal axis L of the mattress 100. In this way, the air gaps 120 are present in various directions throughout the grid, facilitating improved cushioning of the mattress irrespective of the orientation and position of a pet on the mattress 100. 15 The pet mattress 100 includes a cover 122 in some embodiments. The cover 122 is configured to at least partially encase the first layer 102 and the second layer 104 in some embodiments. The cover 122 is preferably configured to envelop and shield the layers 102, 104 so as to protect the first and second foam materials from wear and tear, while providing additional comfort to a pet (e.g. by forming the cover 20 from a pleasant material). The cover 122 can also assist in preventing the two layers 102, 104 from becoming disconnected if the mattress 100 is turned upside down or on its side. The cover 122 may be formed of any suitable material, for example, cotton, polyester, microfibre or the like. In a preferred embodiment, the cover 122 is a vinyl water-resistant cover. The cover 122 may not be present in 25 some embodiments. Each layer 102, 104 defines a depth. The depth of the first layer 102 is defined by a vertical distance between the base surface 106 and the upper surface 108 of the first layer 102 (e.g. the distance between the base surface 106 and the highest point or crest of a peak 110a). The depth of the second layer 104 is defined by a 30 vertical distance between the upper surface 114 of the second layer 104 and lower surface 116 of the second layer 104 (e.g. the distance between the upper surface 114 and the highest point or crest of a peak 110b). In the figures, the depth of the first layer 102 is substantially the same as the depth of the second layer 104. It should be appreciated that the depths of the two layers 102, 104 may be different 35 in some embodiments. Preferably, the first layer 102 has a greater depth than the 25 09 24 second layer 104, so as to provide effective support against the mattress 100 becoming bottomed out. The total depth of the mattress 100 is defined as the vertical distance between the base surface 106 and the upper surface 114 when the two layers 102, 104 have interdigitated with one another. 5 In exemplary embodiments, the first layer 102 has a depth in the range of about 5 cm to 12 cm. The second layer 104 preferably has a depth in the range of about 5 cm to 8 cm. The mattress 100 preferably has a depth in the range of about 7.5 cm to 16 cm. The depths of the respective layers 102, 104 has been found to facilitate effective orthopaedic support of an animal, while facilitating the advantageous 10 implementation of the peaks 110a, 110b and troughs 112a, 112b (i.e. by reducing the likelihood of the mattress 100 becoming bottomed out). The combination of the depths of the respective layers 102, 104 with the interdigitated area 118 and foam materials discussed above has resulted in a pet mattress 100 that provides excellent orthopaedic support to a pet, but it should be appreciated that the depth 15 of the layers 102, 104 would not make the mattress suitable for human use (because the mattress 100 would quickly become bottomed out in response to a human's weight and weight-distribution). The term "about" in the context of the above hardness grades, densities and mattress dimensions is intended to cover the given value + / - 5% or + / - 2% or + / -20 1%. It should be understood that the pet mattress 100 may be configured differently to support different types of pets. For example, for larger pets, the depth of the respective layers and the length and width of the sleep area will be increased. The foam depth and the length and width of the sleep area may be reduced to 25 accommodate smaller pets, thereby reducing the cost of manufacturing the mattress 100. While the pet mattress 100 in the figures defines a generally cuboidal shape, having a rectangular sleep area, it should be appreciated that the pet mattress 100 may be any suitable shape. For example, the pet mattress 100 may define a 30 substantially circular sleep area in some embodiments, or a substantially square sleep area. The pet mattress 100 may define an irregularly shaped sleep area in some embodiments, e.g. a T-shaped or an L-shaped sleep area. Although the teachings have been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope as defined in the appended claims. 25 09 24 25 09 24

Claims

1. An orthopaedic pet mattress for supporting a pet (e.g. a dog, a cat), the pet mattress defining a longitudinal axis and having a sleep region upon which a pet is intended to rest in use, the sleep region having a length of no greater than 145 cm5 and a width of no greater than 110 cm, the orthopaedic pet mattress comprising:a discrete first layer formed from a first foam material, the first layer comprising a base surface and an upper surface, the upper surface configured to define a first array comprising rows of alternating peaks and troughs arranged in a grid extending above the base surface, the grid having a plurality of rows of 10 alternating peaks and troughs extending in a parallel direction, a plurality of rows of alternating peaks and troughs extending in an orthogonal direction, and a plurality of rows of alternating peaks and troughs extending in a diagonal direction relative to the longitudinal axis;a discrete second layer formed from a second foam material, the second15 layer comprising an upper surface configured to define the sleep region, and a lower surface configured to define a second array comprising rows of alternating peaks and troughs arranged in a grid extending beneath the sleep region, the grid having a plurality of rows of alternating peaks and troughs extending in a parallel direction, a plurality of rows of alternating peaks and troughs extending in an orthogonal20 direction, and a plurality of rows of alternating peaks and troughs extending in a diagonal direction relative to the longitudinal axis;wherein the first foam material and the second foam material have different properties;wherein the first layer and the second layer interdigitate with one another25 such that the peaks of the first array are received in the troughs of the second array, and the peaks of the second array are received in the troughs of the first array, thereby defining an interdigitated area comprising the first foam material and the second foam material; andwherein the first layer and the second layer are configured such that air gaps30 are present between the first foam material and the second foam material in the interdigitated area.

2. An orthopaedic pet mattress according to claim 1, wherein the first foam material has a greater hardness grade than the second foam material.25 09 243. An orthopaedic pet mattress according to claim 2, wherein the first foam material has a hardness grade in the range of 135 N to 180 N and the second foam material has a hardness grade in the range of 80 N to 130 N.

4. An orthopaedic pet mattress according to claim 3, wherein the first foam material has a hardness grade in the range of 140 N to 170 N, and the second foam material has a hardness grade in the range of 90 N to 120 N.

5. An orthopaedic pet mattress according to claim 4, wherein the first foam material has a hardness grade of about 155 N and the second foam material has a hardness grade of about 105 N.

6. An orthopaedic pet mattress according to any preceding claim, wherein the second foam material has a greater density than the first foam material.

7. An orthopaedic pet mattress according to claim 6, wherein the first foam material has a density in the range of 15 to 30 kg m 3 and wherein the second foam material has a density in the range of 31 to 45 kg m 3.

8. An orthopaedic pet mattress according to claim 7, wherein the first foam material has a density in the range of 20 to 30 kg m-3, and wherein the second foam material has a density in the range of 31 to 40 kg m-3.

9. An orthopaedic pet mattress according to claim 8, wherein the first foam material has a density of about 28 kg m'3, and wherein the second foam material has a density of about 35 kg m-3.

10. An orthopaedic pet mattress according to any preceding claim, wherein the first foam material and the second foam material are open cell polyurethane foam, preferably of the polyether type.

11. An orthopaedic pet mattress according to any preceding claim, wherein the first foam material and the second foam material are a combustion modified polyether type foam (CMP), said first foam material made from CMP28 and said second foam material made from CMP35.

12. An orthopaedic pet mattress according to any preceding claim, wherein the air gaps extend through the interdigitated area in a parallel, an orthogonal and a diagonal direction with respect to the longitudinal axis.5 13. An orthopaedic pet mattress according to any preceding claim, wherein thefirst layer has a depth in the range of about 5 cm to 12 cm and the second layer has a depth in the range of about 5 cm to 8 cm.

14. An orthopaedic pet mattress according to claim 13, wherein the mattress 10 has a depth in the range of about 7.5 cm to 16 cm.1525 09 24

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