mattress

Abstract

To provide a mattress capable of suitably exchanging a part with dirt and deteriorated mattress performance such as deteriorated cushion performance.SOLUTION: A mattress includes an upper layer part 4, an intermediate layer part 5, and a base part 2. The base part 2 includes; a lower layer part 6 extending in a longitudinal direction; and a pair of lateral side support parts 10 for supporting the lower layer part 6 from right and left sides. The base part 2 includes attachment parts 3 to which the intermediate layer part 5 is removably attached. The attachment part 3 has a fitting structure between an inner side surface of the lateral side support part 10 and a side surface of the intermediate layer part 5 opposing to the inner side surface of the lateral side support part 10.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a mattress composed of a plurality of layers in the vertical direction. In addition, it also relates to a mattress that can be preferably used for a bed equipped with a back-lifting and foot-lifting function.

Background Art

[0002] Conventionally, various configurations have been proposed to improve the body pressure dispersion function of mattresses. For example, Patent Document 1 discloses a mattress composed of a synthetic resin foam, in which the cross-sectional area of the base at the central portion in the longitudinal direction of the mattress is formed larger than the cross-sectional area of the protrusion at the end portion in the longitudinal direction of the mattress. With such a configuration, the relative hardness at the central portion of the mattress can be increased, and the central portion in the longitudinal direction of the body such as the chest and hips can be supported. Therefore, it is described that these parts can be kept from sinking deeply, without burden on the spine, and one can sleep soundly. In addition, some conventional mattresses are divided into three parts: a central part, a dorsal part, and a foot part, and are configured to be foldable if necessary.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] <F However, since the conventional mattresses described above were a single, integrated unit, if a decrease in elasticity (change in hardness) or sagging occurred in any part of the synthetic resin foam, it was necessary to replace the entire mattress. While the degree of deterioration such as sagging varies depending on how the mattress is used by the user, it inevitably occurs after a certain period of use, and even if other parts are in like-new condition, the entire mattress may have to be replaced. Even if a portion of a mattress was heavily soiled by liquids such as sweat, urine, coffee, or tea, the user might still choose to purchase a new mattress due to the smell of the liquid or other reasons.

[0005] Furthermore, some conventional mattresses, due to their structure, cannot be placed on beds with back-raising and leg-raising functions. Even mattresses divided into three parts—central, back, and foot—still had issues such as discomfort and unease caused by abdominal pressure and tension when the back or legs were raised.

[0006] This invention was made to solve the above-mentioned problems. The first objective of the present invention is to provide a mattress in which parts of the mattress that have deteriorated due to soiling or reduced cushioning can be replaced as needed. Another object of the present invention is to provide a mattress suitable for beds that are durable and have back-raising and leg-raising functions. [Means for solving the problem]

[0007] The inventors of the present invention have found that the above problems can be solved by providing an upper layer and an intermediate layer, which are parts that are prone to deterioration such as soiling and sagging, and a base that detachably supports these upper and intermediate layers, and by configuring the upper layer and intermediate layer to be detachably attached to the base, and have completed the present invention.

[0008] A mattress according to the first aspect of the present invention is A mattress having an upper layer portion, an intermediate layer portion, and a base portion, wherein the base portion has a lower layer portion extending in the longitudinal direction and a pair of lateral support portions that support the lower layer portion from the left and right lateral sides, the base portion has an attachment portion to which the intermediate layer portion is detachably attached, the attachment portion has a fitting structure between the inner surface of the lateral support portion and the side surface of the intermediate layer portion facing the inner surface of the lateral support portion and is characterized by the above. death, The intermediate layer is divided into multiple mat sections in the longitudinal direction, and each mat section has a back mat section, an intermediate mat section, and a foot mat section. The size of the back-side protrusion provided on the upper surface of the back-side mat portion is made larger than the size of the foot-side protrusion provided on the upper surface of the foot-side mat portion.

[0009] A second aspect of the present invention is A mattress having an upper layer, an intermediate layer, and a base, The base portion has a lower layer portion extending in the longitudinal direction and a pair of lateral support portions that support the lower layer portion from the left and right sides. The base portion has a mounting portion to which the intermediate layer portion is detachably attached. The mounting portion has a fitting structure between the inner surface of the lateral support portion and the side surface of the intermediate layer portion facing the inner surface of the lateral support portion. The intermediate layer is divided into multiple mat sections in the longitudinal direction, and each mat section has a back mat section, an intermediate mat section, and a foot mat section. The lower layer is characterized by having multiple slits extending in the left-right direction on its upper and lower surfaces, extending over the longitudinal range to which the back mat section, the intermediate mat section, and the foot mat section are attached.

[0010] A third aspect of the present invention is A mattress having an upper layer, an intermediate layer, and a base, The base portion has a lower layer portion extending in the longitudinal direction and a pair of lateral support portions that support the lower layer portion from the left and right sides. The base portion has a mounting portion to which the intermediate layer portion is detachably attached. The mounting portion has a fitting structure between the inner surface of the lateral support portion and the side surface of the intermediate layer portion facing the inner surface of the lateral support portion. The intermediate layer is divided into multiple mat sections in the longitudinal direction, and each mat section has a back mat section, an intermediate mat section, and a foot mat section. The upper layer is characterized by having multiple slits extending in the left-right direction on its upper and lower surfaces, extending over the longitudinal range to which the back mat section, the intermediate mat section, and the foot mat section are attached.

[0011] An aspect of the present invention is the mattress according to the above 4 aspect, wherein the upper layer portion is housed in a cylindrical sheet, and the cylindrical sheet is formed of a material such that the frictional resistance between the cylindrical sheet and the intermediate layer portion and the lateral support portion is lower than the frictional resistance between the upper layer portion and the intermediate layer portion and the lateral support portion, and is characterized by the above. 3 An aspect of the present invention is 5 the above 4The mattress according to the aspect, wherein the height position of the upper surface of the lateral support portion, the height position of the upper surface of the intermediate mat portion, the height position of the dorsal convex portion of the dorsal mat portion, and the height position of the foot-side convex portion of the foot-side mat portion are set to be flush. A sixth aspect of the present invention is a mattress according to any of the first to fifth aspects, characterized in that a longitudinally extending recessed groove is provided on the inner surface of the lateral support portion, a longitudinally extending protruding portion is provided on the side surface of the intermediate layer portion, and the recessed groove and the protruding portion constitute the fitting structure. 。

Advantages of the Invention

[0012] According to the present invention, it is possible to provide a mattress in which portions with deteriorated mattress performance such as dirt and cushioning properties can be appropriately replaced. In addition, it is possible to provide a mattress having durability and suitable for a bed equipped with a back-raising and foot-raising function.

Brief Description of the Drawings

[0013] [Figure 1] It is a perspective view seen from the upper right of the foot side in a state where the mattress according to the present embodiment is covered with an outer cover. [Figure 2] In the mattress according to the present embodiment, it is a perspective view seen from the upper right of the upper layer portion wrapped with a cylindrical sheet with the outer cover removed. [Figure 3] In the mattress according to the present embodiment, it is a perspective view seen from the upper right of the intermediate layer portion composed of a dorsal mat portion, an intermediate mat portion, and a foot-side mat portion and the lateral support portion with the upper layer portion removed. [Figure 4] It is a schematic exploded perspective view of the mattress according to the present embodiment. [Figure 5] In the mattress according to the present embodiment, it is a perspective view seen from the upper left of the base portion and the intermediate layer portion in the mattress. [Figure 6] In the mattress according to the present embodiment, it is a perspective view seen from the upper left of a state where only the foot-side mat portion is placed on the base portion with the intermediate layer portion removed. [Figure 7] It is a view showing an example of the dorsal mat portion, where (a) is a plan view, (b) is a view seen from the foot side, and (c) is a side view. [Figure 8]This diagram shows an example of an intermediate mat section, where (a) is a plan view, (b) is a view from the foot side, and (c) is a side view. [Figure 9] This diagram shows an example of the foot-side mat section, with (a) being a plan view, (b) being a view from the foot side, and (c) being a side view. [Figure 10] (a) is a view of the mattress according to this embodiment from the foot side, (b) is a side view of the mattress, and (c) is a bottom view showing only the lateral support portion. [Modes for carrying out the invention]

[0014] Hereinafter, with reference to the drawings, a mattress according to one embodiment of the present invention will be described. The mattress according to this embodiment is placed on a bed 20 (see Figure 1) equipped with back-raising and leg-raising functions, and is a mattress that can provide a good sleeping experience by suppressing uncomfortable movements such as abdominal pressure and leg stiffness even when the back-raising and leg-raising operations are performed.

[0015] In this specification, as shown in Figure 1, the longitudinal direction of the mattress 1, that is, the direction from head to toe, is referred to as the front-to-back direction (indicated as the X direction in Figure 1), the width direction perpendicular to the longitudinal direction is referred to as the lateral direction or left-to-right direction (indicated as the Y direction in Figure 1), and the direction perpendicular to both the front-to-back direction and the lateral direction is referred to as the height direction or vertical direction (indicated as the Z direction in Figure 1).

[0016] Figure 1 is a perspective view of the mattress from the upper right foot end; Figure 2 is a perspective view of the upper layer of the mattress, wrapped in a cylindrical sheet, from the upper right, with the outer cover of the mattress partially removed; Figure 3 is a perspective view of the mattress with the upper layer removed, showing the intermediate layer consisting of the back mattress section, middle mattress section, and foot mattress section, along with a pair of lateral support sections; and Figure 4 is a schematic exploded perspective view of the mattress.

[0017] As shown in Figure 4, the mattress 1 according to this embodiment has an intermediate layer 5 and an upper layer 4 placed on the base 2 from bottom to top, and the entire structure, consisting of the base 2, intermediate layer 5, and upper layer 4, is covered with an outer cover 8 (see Figure 1). The base 2, intermediate layer 5, and upper layer 4 are all made of elastic materials such as polyurethane foam or other synthetic resin foam.

[0018] <Base section> As shown in Figures 3, 4, and 10(a), the base portion 2 has a receiving structure in which a lower layer portion 6 extending in the longitudinal direction is fixed by a pair of lateral support portions 10, 10 that also extend in the longitudinal direction, sandwiching it from the sides. As shown in Figures 4 and 10(a), when the base portion 2 is viewed from the foot side, it has a concave shape in which the height position of the central part in the left-right direction is low, and the height position of the upper surfaces 10J, 10J of the lateral support portions 10, 10 on both sides is high, and the concave central part is the mounting portion 3 of the intermediate layer portion 5 (see Figure 4). The intermediate layer portion 5 is a component that constitutes the mattress portion at the middle position in the left-right direction of the mattress. In the rectangular region containing the intermediate layer 5, there is a three-layer structure consisting of the lower layer 6, the intermediate layer 5, and the upper layer 4, in that order from bottom to top. In this embodiment, the intermediate layer 5 is composed of a total of three mat sections, arranged in order from the head side to the foot side, as shown in Figure 3: a back mat section 12, an intermediate mat section 13, and a foot mat section 14. The intermediate layer 5 will be described later.

[0019] (Side support part) Figure 5 is a perspective view illustrating the fitting structure between the base and the intermediate layer of the mattress, while Figure 6 is a perspective view showing the mattress with the intermediate layer removed and only the foot-side mat placed on the base. The lateral support section 10 is made of a material such as urethane foam, which has a relatively higher hardness compared to the intermediate layer 5 and the upper layer 4. The material used for the lateral support section 10 can also be a material with the same hardness as, or identical to, the lower layer 6. The hardness of the lateral support section 10 is often set higher than that of the upper layer 4, intermediate layer 5, and lower layer 6. The lateral support section 10 is often the hardest part among the various elastic material components, such as urethane foam, used in the construction of a mattress. As shown in Figure 5, the lateral support section 10 is composed of a pair of columnar sections that are approximately square in shape in the vertical cross-section when viewed from the foot side, and are provided in the left-right direction. The outer surfaces 6B on both the left and right sides of the lower layer section 6 and the lower inner surface 10W in the left-right direction of the lateral support section 10 are abutted against each other on their surfaces and are firmly fixed by means of adhesive or other means.

[0020] The bottom surface 10D of the lateral support portion 10 is flush with the bottom surface 6D of the lower layer portion 6, forming the bottom surface of the mattress 1. The outer surface 10P of the lateral support portion 10, which faces outward in the left-right direction, constitutes the lateral outer edge surface of the mattress 1. The top surface 10J of the lateral support portion 10 functions as a support surface that supports the bottom surface 4D of the upper layer portion 4 shown in Figures 4 and 10(b), in cooperation with the top surface 12E of the back mattress portion 12, the top surface 13E of the intermediate mattress portion 13, and the top surface 14E of the foot mattress portion 14, as shown in Figures 7 to 9. The top surface 10J of the lateral support portion 10, the top surface 12E of the back mattress portion 12, the top surface 13E of the intermediate mattress portion 13, and the top surface 14E of the foot mattress portion 14 are formed at the same height (flush). In this specification, "flush" means that the heights are not significantly different and are generally perceived as not being a step.

[0021] As shown in Figure 5, on the inner surface of the lateral support portion 10, between the upper surface 6J of the lower layer portion 6 and the upper surface 10J of the lateral support portion 10, a recessed groove portion 16 is formed in the intermediate area when viewed from the vertical direction, having an insertion opening 10K, and extending in depth from the inside to the outside in the left-right direction. The recessed groove portion 16 is formed at the same height position in the three mat portions: the back mat portion 12, the intermediate mat portion 13, and the foot mat portion 14, and extends over the entire longitudinal area of ​​the lateral support portion 10.

[0022] Furthermore, the inner surface of the lateral support portion 10 has an upper inner surface 10V provided above the recessed groove portion 16 and a lower inner surface 10W provided below the recessed groove portion 16. The lower surface 16A of the recessed groove portion 16 is set to be higher by a height t than the upper surface 6J of the lower layer portion 6.

[0023] Figure 10(a) is a view of the mattress according to this embodiment from the foot side, with the outer cover and the cylindrical sheet described later omitted; Figure 10(b) is a side view of the mattress according to this embodiment; and Figure 10(c) is a bottom view showing only the lateral support section. As shown in Figures 10(b) and 10(c), the bottom surface 10D of the lateral support portion 10 is provided with slits 10S extending in the left-right direction. The slits 10S are provided over a longitudinal range including the back mattress portion 12, the intermediate mattress portion 13, and the foot mattress portion 14, to allow for compression and expansion of the bottom surface 10D that occurs in conjunction with back-raising and leg-raising operations. These slits 10S promote the natural deformation of the lateral support portion 10, making the movement of the mattress 1 smoother during back-raising and leg-raising operations.

[0024] (Lower layer) As shown in Figure 4, the lower layer 6 is made of a synthetic resin foam such as urethane foam, which has a relatively higher hardness compared to the middle layer 5 and the upper layer 4, and is a rectangular base plate that is long in the front-to-back direction and supports the back mat section 12, the middle mat section 13, and the foot mat section 14. The width of the lower layer 6 is formed to be approximately equal to the width of each mat section. Because the lower layer 6 is made of high-hardness urethane foam, it suppresses excessive sinking of the user's body when lying down, and the mattress 1 can provide a firm side-lying surface that makes it easy to turn over.

[0025] Furthermore, as shown in Figure 4, the upper and lower (not shown) surfaces of the lower layer 6 have multiple slits 6C extending in the left-right direction, within the longitudinal range of the back-side mat section 12, the intermediate mat section 13, and the foot-side mat section 14. Note that the slits 6C are not provided at regular intervals throughout the entire longitudinal range, but rather there are flat sections 6H where no slits 6C are provided to facilitate the deformation of the lower layer 6 when the backrest and footrest are raised. In this embodiment, the flat sections 6H on the upper surface of the lower layer 6 are provided in a configuration of two between the front end surface and the rear end surface. The length of the flat portion 6H provided on the upper surface of the lower layer 6 is such that the rear (foot side) flat portion 6H is larger than the front (back side) flat portion 6H. By providing the slit 6C during back-raising and leg-raising movements, the lower layer 6 can be easily folded at the slit 6C, enabling smooth back-raising and leg-raising movements.

[0026] <Upper layer> The upper layer 4 is made of a synthetic resin foam such as urethane foam, which has a relatively lower hardness than the intermediate layer 5, the lower layer 6, and the lateral support parts 10. As shown in Figures 2 and 4, the upper layer 4 is wider than the intermediate layer 5 and is formed in a long, narrow rectangular shape in plan view so that it can cover not only the width range to which the back mat part 12, the intermediate mat part 13, and the foot mat part 14 are attached, but also the upper surface range of the lateral support parts 10, 10.

[0027] As shown in Figure 10(b), the upper layer 4 has multiple slits 4C extending in the left-right direction on both the upper surface 4A and the lower surface 4D, covering almost the entire length X. By providing a slit 4C in the upper layer 4, the lower layer 6 can easily bend at the slit 4C during back-raising and leg-raising movements, enabling smooth back-raising and leg-raising. Furthermore, as this is the uppermost layer that supports the body, the slit 4C allows the contact surface to deform in accordance with the body's movements, resulting in a comfortable sleeping experience.

[0028] In this embodiment, as shown in Figure 2, the upper layer 4 is housed within a cylindrical sheet 9 made of synthetic resin or the like, and placed on the upper surface 10J of the lateral support 10 (see Figure 10(a)) and the intermediate layer 5. The cylindrical sheet 9 may be bag-shaped. By using a material with low frictional resistance (e.g., coefficient of friction) for the cylindrical sheet 9 and housing the upper layer 4 within the cylindrical sheet 9, the frictional resistance can be significantly reduced compared to the case where the urethane foam on the lower surface 4D of the upper layer 4 and the urethane foam on the upper surface 10J of the lateral support 10 and the upper surface of the intermediate layer 5 are in direct contact. This allows the upper layer 4 to move relatively freely relative to the upper surface 10J of the lateral support 10 and the upper surface of the intermediate layer 5. Furthermore, this configuration allows for better movement of the upper layer 4, which bears the user's weight, even during back-raising and leg-raising movements. As a result, the durability of the mattress 1 can be improved, and a mattress 1 that allows for smooth back-raising and leg-raising movements can be provided.

[0029] By housing the upper layer 4 within a waterproof cylindrical sheet 9, odors such as sweat from the user can be prevented from adhering to the upper layer 4. Furthermore, even if liquids such as sweat, urine, tea, or coffee are spilled onto the mattress 1, the outer cover 8 prevents the upper layer 4, middle layer 5, and side support parts 10 from being soiled by these liquids, thereby improving the durability of the mattress 1. In addition, housing the upper layer 4 within the cylindrical sheet 9 also has the effect of suppressing wear and deformation of the upper layer 4.

[0030] <Middle class> The intermediate layer 5 provided in the mattress 1 has at least one detachable mat section. As described above, in this embodiment, the intermediate layer 5 is composed of three mat sections: a back mat section 12, an intermediate mat section 13, and a foot mat section 14.

[0031] (Composition of the back mat section) First, the shapes of the back mattress section 12, the middle mattress section 13, and the foot mattress section 14 shown in Figures 3 to 6 differ from the shapes of the back mattress section 12, the middle mattress section 13, and the foot mattress section 14 shown in Figures 7 to 9. This indicates that the detailed configuration and surface shapes of the back mattress section 12, the middle mattress section 13, and the foot mattress section 14 can be changed or selected as appropriate, depending on the configuration of each mattress 1 manufactured for a predetermined purpose and the requests of the user, etc. Furthermore, the hardness (elasticity) of the materials used for the back mat section 12, the middle mat section 13, and the foot mat section 14 can be set to be the same, and the tactile characteristics of each mat section can be adjusted by varying the shape of the bumps and the size of the protrusions. Conversely, to accommodate the needs of various users, such as those who prefer to sleep on a firm mattress, those who prefer a mattress that provides a sinking, enveloping feel, and those looking for a mattress that can reduce the pain of bedsores, a configuration can be adopted in which the hardness of the three (or more) mattress sections—the back mattress section 12, the middle mattress section 13, and the foot mattress section 14—is appropriately varied. As an example of such a configuration, as shown in Figure 3, the back mat section 12 and the foot mat section 14 are made of the same material, while only the intermediate mat section 13 uses a material with different hardness specifications. Another configuration involves setting the hardness of each section in the order of back mat section 12, intermediate mat section 13, and foot mat section 14, from hardest to softest. Yet another configuration involves setting the hardness of each section in the order of intermediate mat section 13, back mat section 12, and foot mat section 14, from hardest to softest.

[0032] Figure 7 shows an example of the dorsal mat section, where (a) is a plan view, (b) is a view from the foot side, and (c) is a side view. As shown in Figure 7, the back mat portion 12 is approximately square or rectangular in plan view, and the back convex portion 12A is formed by providing grooves 12C extending in the left-right direction at regular intervals on the upper and lower surfaces of the back mat portion 12. In the configuration shown in Figure 7, only grooves 12C extending in the left-right direction are shown as an example, but as shown in Figures 3 and 4, it is also possible to provide grooves 12B extending in the longitudinal direction to create a back convex portion 12A with a smaller area than the configuration shown in Figure 7.

[0033] As shown in Figures 5 and 7, on both the left and right sides of the back mat portion 12, protruding ridges 17, 17 are provided in the middle of the vertical direction, extending outward in the longitudinal direction. An upper cut-out surface 12F is provided above the protruding ridges 17, and a lower cut-out surface 12G is provided below the protruding ridges 17. The height (vertical width) of the lower cut-out surface 12G is set to approximately the same height as the height t in Figure 5, and is formed so that when the lower surface of the lower cut-out surface 12G is brought into contact with the upper surface 6J of the lower layer portion 6 and moved in the left and right outward directions, the protruding ridges 17 can easily fit into the recessed groove portion 16.

[0034] (Composition of the intermediate mat section) Figure 8 shows an example of an intermediate mat section, where (a) is a plan view, (b) is a view from the foot side, and (c) is a side view. As shown in Figure 8, the intermediate mat section 13 is approximately square or rectangular in plan view, and both its top and bottom surfaces are flat. Furthermore, on both the left and right sides of the back mat section 12, protruding ridges 17, 17 are provided in the middle section in the vertical direction, extending outward in the longitudinal direction. An upper cut surface 13F is provided above the protruding ridges 17, and a lower cut surface 13G is provided below the protruding ridges 17.

[0035] (Composition of the foot-side mat section) Figure 9 shows an example of the foot-side mat section, where (a) is a plan view, (b) is a view from the foot side, and (c) is a side view. As shown in Figure 9, the foot-side mat portion 14 is configured as a rectangle in plan view, with the horizontal direction being longer and the front-to-back direction (the longitudinal direction of the mattress 1) being shorter. On both the left and right sides of the foot-side mat portion 14, protruding portions 17, 17 are provided that extend outward in the longitudinal direction. An upper cut surface 14F is provided above the protruding portions 17, and a lower cut surface 14G is provided below the protruding portions 17. The pitch of the grooves 14C and 14B in the foot-side mat section 14 is set to be shorter than the respective pitches of the back-side mat section 12 shown in Figure 3 or Figure 4. Therefore, the size of the foot-side protrusion 14A formed on the upper surface of the foot-side mat section 14 is smaller than the back-side protrusion 12A of the back-side mat section 12.

[0036] Specifically, the area of ​​the foot-side protrusion 14A and the protrusion height of the foot-side protrusion 14A, with the recesses 14C and 14B that serve as the base for the protrusion of the foot-side protrusion 14A as the base, are set to be smaller than the area of ​​the dorsal-side protrusion 12A and its protrusion height.

[0037] This configuration allows for the support of large, heavy areas of the body, such as the back, by using the back-side protrusion 12A, which has a large surface area and protruding height. This suppresses excessive sagging from the surface of the back-side mattress 12, resulting in a mattress that provides stable support without discomfort or unease for areas such as the head and back.

[0038] On the other hand, in the foot-side mat section 14, by supporting the left and right feet with the foot-side protrusions 14A, which have a small surface area and protrusion height, the feet, which have a smaller weight per unit area and a larger curvature compared to the head or back, can be well supported, thus creating a mattress that improves the user's comfort for their feet.

[0039] Furthermore, the ratio of the back-side mat section 12, the intermediate mat section 13, and the foot-side mat section 14 in the front-to-back direction (longitudinal direction) is set to correspond to the back-raising change region and the foot-raising change region of the back-raising and foot-raising type bed on which it is expected to be placed. In other words, the positions where the mat section is divided into the three mat sections, the back-side mat section 12, the intermediate mat section 13, and the foot-side mat section 14, in the longitudinal direction are set to correspond to the back-raising change region and the foot-raising change region in a way that is preferable. The slits 6C, which are spaced apart in the lower layer 6, are also provided based on the same concept.

[0040] Note that the number of grooves and protrusions in the foot-side mat section 14 and back-side mat section 12 shown in each figure are merely examples. By appropriately changing the number of grooves and protrusions, and the depth of the grooves, it is possible to set the desired hardness and degree of sinking when supporting the human body.

[0041] (Attachment to the mounting part of the mat) When attaching the intermediate layer 5 (each mat portion) to the mounting portion 3 of the base portion 2, for example, one end of the intermediate layer 5 (for example, the left side) is placed inside the mounting portion 3, the left convex portion 17 is positioned opposite the left concave groove portion 16, and the convex portion 17 is biased to be pushed into the concave groove portion 16, while the other end (for example, the right side) convex portion 17 is biased to be pushed into the right concave groove portion 16. Here, since the intermediate layer 5 (each mat portion) and the base portion 2 are made of deformable elastic material, for example, the intermediate layer 5 can be bent, or the concave groove portion 16 of the lateral support portion 10 can be deformed to be widened vertically, allowing each mat portion to be easily attached to the mounting portion 3.

[0042] In addition to the above-described mounting operation, for example, the front or rear end of each mat portion may be placed against the front or rear end of the base portion 2, the protruding end 17 of each mat portion on the insertion end side of the mat portion may be inserted into the recessed groove portion 16, and each mat portion may be inserted by sliding it within the recessed groove portion 16. However, in order to adopt this mounting method, the size of the recessed groove portion 16 must be larger than the protruding end 17, and there must be enough clearance for the protruding end 17 to slide within the recessed groove portion 16 without significant resistance.

[0043] (Outer cover) The outer cover 8 is a cover that covers the outer shape of the mattress 1, and its material and shape are not particularly limited as long as it provides the user with a pleasant feel to the touch and is durable. As an example of the outer cover 8, the central part of the longitudinal side and the central part of the short side (front end or rear end) can be opened, and the components consisting of the upper layer 4, the intermediate layer 5 and the base 2 can be inserted and removed through these openings. The openings are formed to be closable with various sealing devices, which can be fasteners, strings, hooks, safety pins, etc. Although not shown in the illustration, the outer cover 8 has two carrying handles on its side.

[0044] (Advantages of detachably supporting the intermediate layer with a fitting structure in the base) By adopting a configuration in which the intermediate layer 5 (mattress section) is attached by engaging it with the mounting section 3 of the base section 2, it is possible to replace only the "sagging" part, the part of the mat section soiled with liquid, etc., the upper layer 4, or only the base section 2 with a new one, while the other parts can be used as is, thus having the advantage of continuing to be used as a good mattress 1 without incurring additional costs. Since each mat section can be removed from the base section 2, maintenance such as cleaning and disinfection is also easy. Furthermore, for example, if a mattress 1 consisting of a back mattress section 12, a middle mattress section 13, and a foot mattress section 14 is initially delivered to a user, it becomes possible to replace each individual mattress section after delivery, changing the hardness, degree of unevenness, etc., of the back mattress section 12, middle mattress section 13, and foot mattress section 14 according to the user's sleeping style and preferences. This offers the advantage of being able to provide a mattress configuration that is optimal for the diverse preferences of users, according to their requests.

[0045] Furthermore, in this embodiment, the upper layer 4 can be wrapped in a waterproof cylindrical sheet 9 made of synthetic resin or the like. This reduces the likelihood of liquid stains, sweat, odors, etc., reaching the lower intermediate layer 5 or base 2. This enhances the advantage of being able to reuse usable parts and replace only the parts that need replacing. Consequently, it becomes possible to increase the likelihood of using a single mattress unit 1 for a long period of time while keeping costs down.

[0046] The intermediate layer 5 is supported by the convex portion 17 and the concave groove portion 16 on the base portion 2 side. Compared to a mattress in which the lower layer 6, intermediate layer 5, and upper layer 4 are laminated and fixed together in that order from the bottom, this structure allows the intermediate layer 5, consisting of the back mat portion 12, intermediate mat portion 13, and foot mat portion 14, to slide slightly along the concave groove portion 16 relative to the base portion 2, depending on the degree of weight applied by the user during back-raising and leg-raising movements. Therefore, it is possible to reduce the feeling of pressure on the abdomen and tension in the legs, etc., that occur during back-raising movements. Furthermore, this effect can be synergistically enhanced by the upper layer 4 being wrapped in a cylindrical sheet 9 made of a material with low frictional resistance.

[0047] <Variation> A modified example of the mattress 1 according to this embodiment will be described below. In this embodiment, a configuration is shown in which a recessed groove 16 is provided on the lateral support portion 10 and a raised groove 17 is provided on each mat portion. However, depending on the type of mattress, a configuration in which a raised groove 17 is provided on the lateral support portion 10 and a recessed groove 16 is provided on each mat portion can also be adopted. It is also possible to provide multiple convex ridges 17 at intervals from each other, and to provide concave grooves 16 corresponding to the intervals between them. Furthermore, if necessary, the fitting structure is not limited to a configuration of convex and concave grooves, but can also employ various concave and convex fitting shapes. The aforementioned intermediate layer 5 can also be configured with one or two units. Furthermore, the present invention can be similarly applied to beds with complex back-raising and leg-raising movements, or to mattress specifications that are placed on beds with special structures, even if the number of units shipped is not large, when the mattress is composed of four or more mattress units.

[0048] Although the present invention has been described above with examples of embodiments, the technical scope of the present invention is not limited to the configurations described in the above embodiments. The technical scope of the present invention should be determined based on the description in the claims, and it goes without saying that various modifications, additions of configurations, or improvements can be made within that scope. [Explanation of Symbols]

[0049] 1: Mattress 2: Base 3: Mounting part 4: Upper layer 4A: Top surface of the upper layer 4D: Lower surface of the upper layer 4C: Slit 5: Middle Class 6: Lower layer 6J: Upper surface of the lower layer 6D: Lower surface of the lower layer 9: Cylindrical sheet 10: Side support part 10J: Upper surface of the lateral support section 12: Backside mattress section (intermediate layer) 12A: Dorsal protrusion 12E: Top surface of the backrest mattress 13: Intermediate mat section (intermediate layer section) 13E: Top surface of the intermediate mat section 14: Foot side mat section (intermediate layer) 14A: Foot-side protrusion 14E: Top surface of the foot side mat 16: Recessed groove 17: Convex part X: Front-to-back direction (longitudinal direction) Y: Horizontal direction (left and right direction) Z: Height direction (vertical direction)

Claims

1. A mattress having an upper layer, an intermediate layer, and a base, The base portion has a lower layer portion extending in the longitudinal direction and a pair of lateral support portions that support the lower layer portion from the left and right sides. The base portion has a mounting portion to which the intermediate layer portion is detachably attached. The mounting portion has a fitting structure between the inner surface of the lateral support portion and the side surface of the intermediate layer portion facing the inner surface of the lateral support portion. The intermediate layer is divided into multiple mat sections in the longitudinal direction, and each mat section has a back mat section, an intermediate mat section, and a foot mat section. A mattress characterized in that the size of the back-side protrusion provided on the upper surface of the back-side mat portion is larger than the size of the foot-side protrusion provided on the upper surface of the foot-side mat portion.

2. A mattress having an upper layer, an intermediate layer, and a base, The base portion has a lower layer portion extending in the longitudinal direction and a pair of lateral support portions that support the lower layer portion from the left and right sides. The base portion has a mounting portion to which the intermediate layer portion is detachably attached. The mounting portion has a fitting structure between the inner surface of the lateral support portion and the side surface of the intermediate layer portion facing the inner surface of the lateral support portion. The intermediate layer is divided into multiple mat sections in the longitudinal direction, and each mat section has a back mat section, an intermediate mat section, and a foot mat section. A mattress characterized in that a plurality of slits extending in the left-right direction are provided on the upper and lower surfaces of the lower layer, extending over the longitudinal range to which the back mat portion, the intermediate mat portion, and the foot mat portion are attached.

3. A mattress having an upper layer, an intermediate layer, and a base, The base portion has a lower layer portion extending in the longitudinal direction and a pair of lateral support portions that support the lower layer portion from the left and right sides. The base portion has a mounting portion to which the intermediate layer portion is detachably attached. The mounting portion has a fitting structure between the inner surface of the lateral support portion and the side surface of the intermediate layer portion facing the inner surface of the lateral support portion. The intermediate layer is divided into multiple mat sections in the longitudinal direction, and each mat section has a back mat section, an intermediate mat section, and a foot mat section. A mattress characterized in that a plurality of slits extending in the left-right direction are provided on the upper and lower surfaces of the upper layer, extending over the longitudinal range to which the back mat portion, the intermediate mat portion, and the foot mat portion are attached.

4. The mattress according to claim 3, wherein the upper layer is housed within a cylindrical sheet, and the cylindrical sheet is formed of a material such that the frictional resistance between the cylindrical sheet and the intermediate layer and the lateral support portion is lower than the frictional resistance between the upper layer and the intermediate layer and the lateral support portion.

5. The mattress according to claim 4, characterized in that the height position of the upper surface of the lateral support portion, the height position of the upper surface of the intermediate mat portion, the height position of the back side protrusion of the back side mat portion, and the height position of the foot side protrusion of the foot side mat portion are set to be flush with each other.

6. The mattress according to any one of claims 1 to 5, characterized in that a longitudinally extending recessed groove is provided on the inner surface of the lateral support portion, a longitudinally extending convex portion is provided on the side surface of the intermediate layer portion, and the recessed groove and the convex portion constitute the fitting structure.

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