Sheets

Abstract

To provide a sheet that can prevent shifting of bedding. [Solution] The sheet 10 comprises an upper covering portion 14 that covers the entire upper surface 12a of the bedding 12, a side covering portion 16 that covers the peripheral side surface 12c of the bedding 12, a lower covering portion 18 that covers the outer periphery of the lower surface 12b of the bedding 12, and an opening 20 that constitutes an opening Q for inserting and removing the bedding 12 from the space S formed by the upper covering portion 14, the side covering portion 16, and the lower covering portion 18. The side covering portion 16 is made of a material with poor elasticity, such as a natural fiber fabric. The lower covering portion 18 is made of a material with higher elasticity than the material of the side covering portion 16. In its natural state, when the bedding 12 does not cover its lower surface 12b, the outer edge of the lower covering portion 18 is positioned at a first position, which is inward from the outer edge of the upper covering portion 14 when viewed from the bottom. In its extended state, when the bedding 12 covers its lower surface 12b, the outer edge of the lower covering portion 18 is positioned at a second position P2, which is outward from the first position.

Description

TECHNICAL FIELD

[0001] The present invention relates to a sheet for covering mat-shaped bedding such as mattresses and futon mattresses. BACKGROUND ART

[0002] Patent Document 1 listed below discloses an example of a conventional sheet. This sheet includes a one-side covering surface that covers the surface (upper surface) of the bedding, and the other-side covering surface that covers the side surfaces of the bedding and wraps around from the side surfaces to the back surface (lower surface). The material forming the other-side covering surface has higher elasticity than the material forming the one-side covering surface. When the sheet is attached to the bedding, the one-side covering surface is positioned on the upper surface of the bedding by the other-side covering surface.

[0003] However, in this sheet, since the other-side covering surface that covers the side surfaces of the bedding has higher elasticity than the one-side covering surface that covers the surface (upper surface) of the bedding, there is a problem that the one-side covering surface easily moves on the upper surface of the bedding, and positional displacement of the sheet relative to the bedding tends to occur. PRIOR ART DOCUMENTS PATENT DOCUMENT

[0004] PATENT DOCUMENT 1 Japanese Patent No. 5339175 SUMMARY OF THE INVENTION

[0005] The present invention has been made to address the above problem, and an object thereof is to provide a sheet that can suppress positional displacement relative to bedding.

[0006] To achieve the above objective, the sheet according to the present invention is characterized by being a sheet that covers a mat-shaped bedding, comprising: an upper covering portion that covers the entire upper surface of the bedding; a side covering portion that covers the peripheral sides of the bedding; a lower covering portion that covers at least the outer periphery of the lower surface of the bedding; and an opening that constitutes an opening for inserting and removing the bedding from the space surrounded by the upper covering portion, the side covering portion, and the lower covering portion, wherein the side covering portion is made of a material with poor elasticity, and the lower covering portion is made of a material with higher elasticity than the material of the side covering portion, and the outer edge of the lower covering portion in its natural state without covering the lower surface of the bedding is positioned at a first position inward from the outer edge of the upper covering portion when viewed from below, and the outer edge of the lower covering portion in its extended state covering the lower surface of the bedding is positioned at a second position outward from the first position.

[0007] In this configuration, the side covering is made of a material with poor elasticity, so the top covering is less likely to move on the top surface of the bedding, thus suppressing the sheet from shifting position relative to the bedding. In addition, the bottom covering, when stretched, can pull the side covering downwards, thus suppressing the formation of wrinkles in the side covering. Furthermore, since the bottom covering is made of a material with higher elasticity than the material of the side covering, it is easier to put the sheet over the bedding.

[0008] Another feature of the sheet according to the present invention is that the top covering portion and the side covering portion are made of natural fibers that have a pleasant feel against the skin.

[0009] This configuration allows the sheets to have a luxurious appearance thanks to the pleasant feel of natural fibers.

[0010] Another feature of the sheet according to the present invention is that the side covering portion is formed of a woven fabric.

[0011] In this configuration, the side covering is formed from a woven natural fiber fabric with poor elasticity, which gives the sheet a luxurious appearance while suppressing the sheet from shifting position relative to the bedding.

[0012] Another feature of the sheet according to the present invention is that the shape and size of the top covering portion are the same as the shape and size of the top surface of the bedding, the width of the side covering portion is wider than the thickness of the bedding, and when the side covering portion covers the peripheral surface of the bedding, the lower end of the side covering portion is folded under the bedding.

[0013] In this configuration, the lower end of the side covering portion that extends beyond the periphery of the bedding is folded under the bedding, so that the periphery of the bedding can be reliably covered by the side covering portion.

[0014] Another feature of the sheet according to the present invention is that a suture portion for sewing the upper covering portion and the side covering portion together is provided linearly and continuously along the entire length of the boundary portion.

[0015] In this configuration, the top covering portion and the side covering portion are clearly separated by a linear seam, making it easy to position the top covering portion and the side covering portion relative to the top surface and circumferential sides of the bedding.

[0016] Another feature of the sheet according to the present invention is that the opening is provided in the center of the lower covering portion.

[0017] In this configuration, the inner circumference of the opening is formed from a part of the expandable lower covering, allowing the inner circumference of the opening to be stretched in all directions, making it easy to cover bedding with a sheet.

[0018] Another feature of the sheet according to the present invention is that the lower surface of the bedding is formed in a rectangular shape, and the lower covering portion is formed by sewing together a first covering piece formed in a rectangle so as to face the portion along one long side of the lower surface, a second covering piece formed in a rectangle so as to face the portion along the other long side of the lower surface, a third covering piece formed so as to face the portion along one short side of the lower surface, and a fourth covering piece formed so as to face the portion along the other short side of the lower surface, the first and second covering pieces are sewn to the side covering portion at both ends in the longitudinal direction and one end in the short direction, and the other end in the short direction of the first and second covering pieces is provided with an elasticity-restricting portion that has less elasticity than the other parts of the first and second covering pieces.

[0019] In this configuration, the stretch-resisting portions provided on the first and second covering pieces can suppress the displacement of the sheet in the longitudinal direction of the bedding.

[0020] Another feature of the sheet according to the present invention is that it is provided with a connecting portion that detachably connects the longitudinal center of the first covering piece and the longitudinal center of the second covering piece.

[0021] In this configuration, the connecting portion that links the longitudinal center of the first covering piece and the longitudinal center of the second covering piece can suppress the displacement of the sheet in the short direction of the bedding.

[0022] Another feature of the sheet according to the present invention is that the connecting portion comprises a flexible linear first connecting piece provided in the longitudinal center of the first covering piece, a flexible linear second connecting piece provided in the longitudinal center of the second covering piece, a first hook-and-loop fastener piece provided on the first connecting piece, and a second hook-and-loop fastener piece provided on the second connecting piece and detachably connected to the first hook-and-loop fastener piece.

[0023] In this configuration, the entire connecting section is formed flexibly, which prevents the connecting section from damaging other parts. [Brief explanation of the drawing]

[0024] [Figure 1] This is a diagram showing the usage state of the sheet according to the first embodiment, where (A) is a perspective view seen from the flat surface side, and (B) is a perspective view seen from the bottom surface side. [Figure 2] This is a perspective view showing the configurations of the sheet and the bedding according to the first embodiment. [Figure 3] This is a diagram showing the configuration of the sheet according to the first embodiment, where (A) is a plan view, and (B) is a bottom view. [Figure 4] (A) is a bottom view showing the configuration of the sheet according to the second embodiment, and (B) is a bottom view showing the configuration of the sheet according to the third embodiment. [Figure 5] (A) is a perspective view seen from the bottom surface side showing the usage state of the sheet according to the fourth embodiment, and (B) is a perspective view seen from the bottom surface side showing the usage state of the sheet according to the fifth embodiment. [Figure 6] This is a plan view showing the top surface covering portion and the side surface covering portion in the sheet according to a modification of the present invention. [Modes for Carrying Out the Invention]

[0025] Hereinafter, the sheet according to the present invention will be described with reference to the drawings.

[0026] (Configuration of the sheet according to the first embodiment) Figure 1 is a diagram showing the usage state of the sheet 10 according to the first embodiment, where Figure 1(A) is a perspective view seen from the flat surface side, and Figure 1(B) is a perspective view seen from the bottom surface side. Figure 2 is a perspective view showing the configurations of the sheet 10 and the bedding 12. Figure 3 is a diagram showing the configuration of the sheet 10, where Figure 3(A) is a plan view, and Figure 3(B) is a bottom view. Note that in Figure 1(B) and Figure 3(B), the portion formed of a stretchable material, that is, the lower surface covering portion 18, is indicated by hatching.

[0027] The sheet 10 shown in Figures 1(A) and 1(B) is a cloth-like bedding item that covers a mat-shaped bedding item 12 such as a mattress or futon, and is formed in a bag shape to form a space S that accommodates the mat-shaped bedding item 12. As shown in Figure 2, the bedding item 12 is made of a cushioning material with a uniform thickness, and the upper surface 12a and lower surface 12b of the bedding item 12 are formed as rectangular flat surfaces in a plan view. The length L1, width W1, and thickness T1 of the bedding item 12 are not particularly limited, but in this embodiment, the length L1 is set to 1940 mm, the width W1 to 1000 mm, and the thickness T1 to 55 mm.

[0028] As shown in Figure 1(A), the sheet 10 comprises a fabric-like upper covering portion 14 that covers the entire upper surface 12a of the bedding 12 (Figure 2), and a fabric-like side covering portion 16 that covers the entire peripheral surface 12c of the bedding 12. Also, as shown in Figure 1(B), the sheet 10 comprises a fabric-like lower covering portion 18 that covers the outer periphery of the lower surface 12b of the bedding 12, an opening 20 provided in the center of the lower covering portion 18, and a connecting portion 22.

[0029] The top covering portion 14 shown in Figure 3(A) is made of various fabrics (including knitted, woven, or nonwoven fabrics) of natural fibers, synthetic fibers, synthetic leather, or fur that have a pleasant feel against the skin. In this embodiment, the top covering portion 14 is made of a woven natural fiber fabric that has a pleasant feel against the skin. The shape and size of the top covering portion 14 are determined to be approximately the same as the shape and size of the top surface 12a of the bedding 12 (Figure 2). In other words, the top covering portion 14 in this embodiment is formed as a rectangle with a length L2 of 1940 mm and a width W2 of 1000 mm. Examples of natural fibers that form the top covering portion 14 include plant fibers such as cotton and linen, and animal fibers such as silk and wool, but in this embodiment, cotton is used.

[0030] The side covering portion 16 shown in Figure 3(B) is made of various fabrics (including knitted, woven, or nonwoven fabrics) of natural fibers, synthetic fibers, synthetic leather, or fur that have a pleasant feel against the skin, similar to the top covering portion 14. In this embodiment, the side covering portion 16 is made of a woven natural fiber fabric that has a pleasant feel against the skin. At the boundary between the top covering portion 14 and the side covering portion 16, a stitching portion 24 is provided linearly and continuously along the entire length of the boundary, and decorative piping is applied to the stitching portion 24.

[0031] In this embodiment, since the bedding 12 (Figure 2) is formed in a rectangular shape in plan view, the side covering portion 16 has a first portion 16a that covers one end face in the longitudinal direction of the bedding 12, a second portion 16b that covers the other end face in the longitudinal direction of the bedding 12, a third portion 16c that covers one end face in the short direction of the bedding 12, and a fourth portion 16d that covers the other end face in the short direction of the bedding 12.

[0032] Natural fiber fabrics are materials with poor elasticity. Therefore, the side covering portion 16 formed from natural fiber fabric has poor elasticity, and by covering the entire peripheral surface 12c of the bedding 12 (Figure 2), displacement of the top covering portion 14 on the top surface 12a of the bedding 12 is suppressed. Examples of natural fibers that form the side covering portion 16 include plant fibers such as cotton and linen, and animal fibers such as silk and wool, but in this embodiment, cotton is used, just as with the top covering portion 14.

[0033] As shown in Figure 3(B), the width W3 of the side covering portion 16 is the same in each portion 16a to 16d and is set to be wider than the thickness T1 of the bedding 12 (55 mm in this embodiment). Therefore, as shown in Figure 1(B), when the sheet 10 is placed over the bedding 12, the lower end portion 16e of the side covering portion 16 protrudes downward from the peripheral surface 12c of the bedding 12, and this lower end portion 16e is pulled by the extended lower covering portion 18 and folded downwards from the bedding 12.

[0034] The width W3 of the side covering portion 16 is not particularly limited, but in this embodiment it is set to 60 mm. Therefore, the width of the lower end portion 16e that protrudes downward from the circumferential surface 12c is 5 mm.

[0035] The lower covering portion 18 shown in Figure 3(B) is the part that stretches outward when the sheet 10 is placed over the bedding 12, and pulls the side covering portion 16 with its elastic restoring force. At the boundary between the side covering portion 16 and the lower covering portion 18, a suture portion 26 is provided linearly and continuously along the entire length of the boundary, which sews them together (i.e., stitches them together with thread). This lower covering portion 18 is made of a fabric that is more elastic than the upper covering portion 14 or the side covering portion 16.

[0036] As shown in Figure 3(B), the bottom covering portion 18 of this embodiment has a first covering piece 28 formed in the shape of a rectangle so as to face the portion along one long side of the bottom surface 12b of the bedding 12 (Figure 2), and a second covering piece 30 formed in the shape of a rectangle so as to face the portion along the other long side of the bottom surface 12b. The bottom covering portion 18 also has a third covering piece 32 formed in the shape of a rectangle so as to face the portion along one short side of the bottom surface 12b, and a fourth covering piece 34 formed in the shape of a rectangle so as to face the portion along the other short side of the bottom surface 12b. Note that the shapes of the third covering piece 32 and the fourth covering piece 34 are not limited to rectangles, but may be squares or other shapes.

[0037] Each covering piece 28, 30, 32, and 34 is made of a material with higher elasticity than the material forming the side covering portion 16, and an annular lower covering portion 18 is formed by sewing each covering piece 28, 30, 32, and 34 together. The elastic material forming the lower covering portion 18 is not particularly limited, but in this embodiment, a knitted fabric (tricot fabric) using polyurethane elastic yarn is used.

[0038] The first covering piece 28 shown in Figure 3(B) is positioned between the first portion 16a and the second portion 16b of the side covering portion 16, and is sewn to the side covering portion 16 at both longitudinal edges and one transverse edge. The other transverse edge of the first covering piece 28, i.e., the first edge 28a, is provided with a linear stretch-restricting portion 36a that has less stretchability than the other parts of the first covering piece 28, extending along its entire length.

[0039] The stretch-restraining portion 36a is formed by folding and suturing the first edge 28a, and the third covering piece 32 and the fourth covering piece 34 are sutured to the first covering piece 28 at the stretch-restraining portion 36a.

[0040] The second covering piece 30, shown in Figure 3(B), is positioned between the first portion 16a and the second portion 16b of the side covering portion 16, away from the first covering piece 28, and is sewn to the side covering portion 16 at both longitudinal edges and one transverse edge. The other transverse edge of the second covering piece 30, i.e., the second edge 30a, is provided with a linear stretch-resisting portion 36b that has less stretchability than the rest of the second covering piece 30, extending along its entire length.

[0041] The stretch-restricting portion 36b is formed by folding and suturing the second edge 30a, and the third covering piece 32 and the fourth covering piece 34 are sutured to the second covering piece 30 at the stretch-restricting portion 36b.

[0042] The third covering piece 32 shown in Figure 3(B) is positioned between the first covering piece 28 and the second covering piece 30, and is sewn to the first covering piece 28 and the second covering piece 30 at both longitudinal edges, and to the first portion 16a of the side covering portion 16 at one of its short edges. The other short edge of the third covering piece 32, i.e., the third edge 32a, is provided with a linear stretch-restricting portion 36c that has less stretchability than the rest of the third covering piece 32, extending along its entire length. The stretch-restricting portion 36c is formed by folding and sewing the third edge 32a.

[0043] The fourth covering piece 34, shown in Figure 3(B), is positioned between the first covering piece 28 and the second covering piece 30, away from the third covering piece 32. It is sewn to the first covering piece 28 and the second covering piece 30 at both longitudinal edges, and to the second portion 16b of the side covering piece 16 at one of its short edges. The other short edge of the fourth covering piece 34, i.e., the fourth edge 34a, has a linear stretch-restricting portion 36d that extends along its entire length and has less stretchability than the rest of the fourth covering piece 34. The stretch-restricting portion 36d is formed by folding and sewing the fourth edge 34a.

[0044] As shown in Figure 3(B), in its natural state, when the lower covering portion 18 does not cover the lower surface 12b of the bedding 12 (Figure 2), the outer edge, i.e., the suture portion 26, is positioned at a first position P1, which is inward from the outer edge of the upper covering portion 14 when viewed from the bottom. As shown in Figure 1(B), in the stretched state, when the lower covering portion 18 covers the lower surface 12b of the bedding 12, the outer edge, i.e., the suture portion 26, is positioned at a second position P2, which is outward from the first position P1 (Figure 3(B)). Therefore, the stretched lower covering portion 18 tries to return to the first position P1 due to its elastic restoring force.

[0045] As shown in Figure 3(B), the length L3 of the bottom covering portion 18 is set to be twice as short as the width W3 of the side covering portion 16 compared to the length L2 of the top covering portion 14 (Figure 3(A)), and the width W4 of the bottom covering portion 18 is set to be twice as short as the width W3 of the side covering portion 16 compared to the width W2 of the top covering portion 14. In other words, the length L3 of the bottom covering portion 18 is set to satisfy the equation "L3 = L2 - W3 × 2", and the width W4 of the bottom covering portion 18 is set to satisfy the equation "W4 = W2 - W3 × 2".

[0046] Therefore, the entire side covering portion 16 and the bottom covering portion 18 can be naturally overlapped with the top covering portion 14 without causing wrinkles, making it easy for the user to fold the sheet 10. In this embodiment, L2 is set to 1940 mm, W2 to 1000 mm, and W3 to 60 mm, so L3 is set to 1820 mm and W4 to 880 mm.

[0047] The opening 20 shown in Figure 3(B) is the part that constitutes the opening Q for inserting and removing bedding 12 (Figure 2) into the space S enclosed by the upper covering portion 14, the side covering portion 16, and the lower covering portion 18. In this embodiment, the opening 20 is formed in an annular shape in the central part of the lower covering portion 18 by the first covering piece 28, the second covering piece 30, the third covering piece 32, and the fourth covering piece 34, and the inner circumference of the opening 20 is reinforced while ensuring elasticity by expansion and contraction suppressing portions 36a, 36b, 36c, and 36d.

[0048] The connecting portion 22 shown in Figure 3(B) is a member that detachably connects the longitudinal center of the first covering piece 28 and the longitudinal center of the second covering piece 30. The connecting portion 22 has a flexible linear first connecting piece 38 provided on the longitudinal center of the first covering piece 28, a flexible linear second connecting piece 40 provided on the longitudinal center of the second covering piece 30, a first hook-and-loop fastener piece 42 provided on the first connecting piece 38, and a second hook-and-loop fastener piece 44 provided on the second connecting piece 40.

[0049] In this embodiment, one end of the first connecting piece 38 is sewn to the stretch-restraining portion 36a at the longitudinal center of the first covering piece 28, and one end of the second connecting piece 40 is sewn to the stretch-restraining portion 36b at the longitudinal center of the second covering piece 30. The first hook-and-loop fastener piece 42 and the second hook-and-loop fastener piece 44 are detachably connected to each other.

[0050] (Method of using the sheet according to the first embodiment) When a user uses the sheet 10, they first separate the first hook-and-loop fastener piece 42 and the second hook-and-loop fastener piece 44 of the connecting part 22 shown in Figure 3(B) to open the opening Q, and then insert the bedding 12 (Figure 2) into the space S through the opening Q while stretching the inner circumference of the opening 20.

[0051] Next, as shown in Figure 1(A), the top covering portion 14 is positioned on the top surface 12a of the bedding 12, using the stitched portion 24 provided at the boundary between the top covering portion 14 and the side covering portion 16 as a guide. Then, as shown in Figure 1(B), the first hook-and-loop fastener piece 42 and the second hook-and-loop fastener piece 44 are connected to each other to prevent the sheet 10 from shifting relative to the bedding 12 (Figure 2).

[0052] (Effects of the sheet according to the first embodiment) According to the first embodiment, the above configuration can achieve the following effects. Specifically, since the side covering portion 16 shown in Figures 1(A) and (B) is made of a material with poor elasticity, the top covering portion 14 is less likely to move on the top surface 12a of the bedding 12, and displacement of the sheet 10 relative to the bedding 12 can be suppressed.

[0053] As shown in Figure 1(B), the extended lower covering portion 18 can pull the side covering portion 16 downwards, thus preventing wrinkles from forming in the side covering portion 16. Furthermore, since the lower covering portion 18 is made of a material with higher elasticity than the material of the side covering portion 16, it is easy to cover the bedding 12 with the sheet 10.

[0054] Since the top covering portion 14 and the side covering portion 16 shown in Figure 1(A) are made of natural fibers that have a pleasant feel against the skin, the appearance of the sheet 10 can be made to look luxurious.

[0055] The shape and size of the top covering portion 14 shown in Figure 3(A) are the same as the shape and size of the top surface 12a of the bedding 12 (Figure 2), and the width W3 of the side covering portion 16 shown in Figure 3(B) is set to be wider than the thickness T1 of the bedding 12. Therefore, the lower end portion 16e of the side covering portion 16 that protrudes from the peripheral surface 12c of the bedding 12 can be folded downwards. Thus, the peripheral surface 12c of the bedding 12 can be reliably covered by the side covering portion 16.

[0056] As shown in Figure 1(A), the top covering portion 14 and the side covering portion 16 are clearly separated by a linear suture portion 24, making it easy to position the top covering portion 14 and the side covering portion 16 relative to the top surface 12a and peripheral surface 12c of the bedding 12.

[0057] As shown in Figure 3(B), the inner circumference of the opening 20 is formed from a part of the expandable lower covering portion 18, allowing the inner circumference of the opening 20 to be stretched in all directions, making it easy to cover the bedding 12 with the sheet 10.

[0058] As shown in Figure 3(B), the stretch-resisting portions 36a and 36b suppress the stretching of the first covering piece 28 and the second covering piece 30 in the longitudinal direction, thereby suppressing displacement of the sheet 10 in the longitudinal direction of the bedding 12.

[0059] As shown in Figure 3(B), the connecting portion 22 connects the longitudinal center of the first covering piece 28 and the longitudinal center of the second covering piece 30, thereby suppressing displacement of the sheet 10 in the short direction of the bedding 12.

[0060] The connecting portion 22 shown in Figure 3(B) is flexibly formed by a flexible linear first connecting piece 38, a flexible linear second connecting piece 40, a first hook-and-loop fastener piece 42, and a second hook-and-loop fastener piece 44, thus preventing the connecting portion 22 from damaging other parts.

[0061] (modified version) In carrying out the present invention, the invention is not limited to the first embodiment described above, and various modifications are possible as long as they do not depart from the purpose of the invention.

[0062] In the sheet 10 shown in Figure 1(A), the top covering portion 14 is made of the same poorly elastic material as the side covering portion 16. However, the top covering portion 14 may be made of a material with higher elasticity than the side covering portion 16. Also, the top covering portion 14 may be made of a non-woven fabric material (such as knitted fabric).

[0063] Furthermore, the sheet 10 according to the above embodiment is a single size, specifically with a length L1 of 1940 mm, a width W1 of 1000 mm, and a thickness T1 of 55 mm. However, the size or shape of the sheet 10 can be appropriately set according to the shape of the bedding 12. Therefore, the sheet 10 can be made in semi-double size, double size, queen size, or king size. In addition, the sheet 10 can be made in shapes other than a rectangle in plan view, such as a circle, ellipse, polygon, or irregular shape. Furthermore, the sheet 10 can also be configured as a sheet for nursing care.

[0064] Figure 4(A) is a bottom view showing the configuration of the sheet 46 according to the second embodiment. Figure 4(B) is a bottom view showing the configuration of the sheet 48 according to the third embodiment. In the sheet 10 shown in Figure 3(B), the first covering piece 28 and the second covering piece 30 are arranged between the first portion 16a and the second portion 16b of the side covering portion 16, and the third covering piece 32 and the fourth covering piece 34 are arranged between the first covering piece 28 and the second covering piece 30. However, the positional relationship and shape of each covering piece 28, 30, 32, and 34 may be changed as appropriate.

[0065] For example, as shown in Figure 4(A) of the sheet 46, the third covering piece 32 and the fourth covering piece 34 may be positioned between the third portion 16c and the fourth portion 16d of the side covering portion 16, and the first covering piece 28 and the second covering piece 30 may be positioned between the third covering piece 32 and the fourth covering piece 34.

[0066] Alternatively, as shown in Figure 4(B), the sheet 48 may be formed such that the outer corners of both longitudinal ends of the first covering piece 28, the second covering piece 30, the third covering piece 32, and the fourth covering piece 34 form a 45-degree angle, and these longitudinal ends are sewn together to form a lower covering portion 18 with a 90-degree corner.

[0067] Figure 5(A) is a perspective view from the bottom side showing the sheet 50 in use according to the fourth embodiment. In the sheet 10 shown in Figure 1(B), the width W3 of the side covering portion 16 (Figure 3(B)) is set to be wider than the thickness T1 of the bedding 12 (Figure 2). However, as in the sheet 50 shown in Figure 5(A), the width W3 of the side covering portion 16 may be set to be the same as the thickness T1 of the bedding 12.

[0068] In the sheet 10 shown in Figure 1(B), the connecting portion 22 has a first hook-and-loop fastener piece 42 and a second hook-and-loop fastener piece 44, but the first hook-and-loop fastener piece 42 and the second hook-and-loop fastener piece 44 may be omitted, and the first connecting piece 38 and the second connecting piece 40 may be directly connected. Also, as in the sheet 50 shown in Figure 5(A), the connecting portion 22 may be omitted.

[0069] Figure 5(B) is a perspective view from the bottom side showing the sheet 52 in use according to the fifth embodiment. In the sheet 10 shown in Figure 1(B), the bottom covering portion 18 is formed to cover the outer periphery of the bottom surface 12b (Figure 1(B)) of the bedding 12. However, the bottom covering portion 18 only needs to be formed to cover at least the outer periphery of the bottom surface 12b, and may be formed to cover the entire bottom surface 12b, for example, as in the sheet 52 shown in Figure 5(B).

[0070] In the sheet 10 shown in Figure 1(B), the opening 20 is located in the center of the bottom covering portion 18. However, the opening 20 may be located at a position away from the center of the bottom covering portion 18. Alternatively, the opening 20 may be provided in a straight line along one of the four sides of the bottom covering portion 18. For example, as in the sheet 52 shown in Figure 5(B), it may be provided in a straight line along one of the longer sides of the bottom covering portion 18. In this case, a fastener (not shown) may be provided in the opening 20.

[0071] In the sheet 10 shown in Figure 1(A), the top covering portion 14 and the side covering portion 16 are connected via a seam 24 on all four sides, but at least one of the four sides may be directly connected without a seam 24. That is, in the above embodiment, the sheet 10 is configured by preparing the top covering portion 14 and the side covering portion 16 as separate parts and sewing them together via a seam 24 to form a single unit. However, the sheet 10 can also have the side covering portion 16 integrally formed with the fabric constituting the top covering portion 14.

[0072] Specifically, as shown in Figure 6, the sheet 10 can be formed with side covering portions 16a to 16d extending integrally (continuously) from each of the four sides of the fabric constituting the top covering portion 14 (the portion enclosed by the dashed line), which is formed in a rectangular shape in plan view. In this case, the side covering portion 16 is formed in a state that hangs down from the top covering portion 14 by sewing the ends 17a and 17b of the side covering portion 16a to the ends 17e and 17g of the side covering portions 16c and 16d, respectively, and sewing the ends 17c and 17d of the side covering portion 16b to the ends 17f and 17h of the side covering portions 16c and 16d, respectively. Then, the bottom covering portion 18 (first covering piece 28, second covering piece 30, third covering piece 32, fourth covering piece 34) is sewn to the side covering portion 16 configured in this way to form the sheet 10. [Explanation of Symbols]

[0073] L1... Length of bedding, W1... Width of bedding, T1... Thickness of bedding, L2... Length of top covering, W2... Width of top covering, L3... Length of bottom covering, P1... First position, P2... Second position, Q... Opening, S... Space, W3... Width of side covering, W4... Width of bottom covering, 10... Sheet, 12... Bedding, 12a... Top surface, 12b... Bottom surface, 12c... Peripheral side, 14... Top covering, 16... Side covering, 16a... First part, 16b... Second part, 16c... Third part, 16d... Fourth part, 16e ...Lower end of side covering, 18...Bottom covering, 20...Opening, 22...Connecting part, 24...Sutured part, 26...Sutured part, 28...First covering piece, 28a...First edge, 30...Second covering piece, 30a...Second edge, 32...Third covering piece, 32a...Third edge, 34...Fourth covering piece, 34a...Fourth edge, 36a,36b,36c,36d...Stretch-restricting parts, 38...First connecting piece, 40...Second connecting piece, 42...First hook-and-loop fastener piece, 44...Second hook-and-loop fastener piece, 46,48,50,52...Sheets.

Claims

1. A sheet that covers a mat-shaped bedding, The upper covering portion covers the entire upper surface of the bedding, A side covering portion that covers the peripheral surface of the bedding, A lower covering portion that covers at least the outer periphery of the lower surface of the bedding, The space enclosed by the upper covering portion, the side covering portion, and the lower covering portion includes an opening that forms an opening for inserting and removing the bedding, The aforementioned side covering portion is formed of a material with poor elasticity. The lower covering portion is formed of a material having higher elasticity than the material of the side covering portion. A sheet in which, in its natural state when not covering the underside of the bedding, the outer edge of the underside covering portion is positioned at a first position inward from a bottom view of the outer edge of the upper covering portion, and in an extended state when covering the underside of the bedding, the outer edge of the underside covering portion is positioned at a second position outward from the first position.

2. The sheet according to claim 1, wherein the top covering portion and the side covering portion are made of natural fibers that have a pleasant feel against the skin.

3. The sheet according to claim 2, wherein the side covering portion is made of a woven fabric.

4. The shape and size of the upper covering portion are determined to be the same as the shape and size of the upper surface of the bedding, and the width of the side covering portion is determined to be wider than the thickness of the bedding. The sheet according to claim 1, wherein when the side covering portion covers the peripheral side surface of the bedding, the lower end of the side covering portion is folded downwards toward the bedding.

5. The sheet according to claim 1, wherein a suture portion for sewing the upper covering portion and the side covering portion together is provided linearly and continuously along the entire length of the boundary portion.

6. The sheet according to claim 1, wherein the opening is provided in the center of the lower covering portion.

7. The lower surface of the bedding is formed in a rectangular shape. The lower covering portion is formed by sewing together a first covering piece formed in the shape of a rectangle so as to face the portion along one long side of the lower surface, a second covering piece formed in the shape of a rectangle so as to face the portion along the other long side of the lower surface, a third covering piece formed so as to face the portion along one short side of the lower surface, and a fourth covering piece formed so as to face the portion along the other short side of the lower surface. The first covering piece and the second covering piece are sewn to the side covering portion at both ends in the longitudinal direction and one end in the short direction. The sheet according to claim 6, wherein the other edge of the first covering piece and the second covering piece in the short direction is provided with an expansion / contraction suppressing portion that has less expansion / contraction than the other parts of the first covering piece and the second covering piece.

8. The sheet according to claim 7, further comprising a connecting portion that detachably connects the longitudinal center of the first covering piece and the longitudinal center of the second covering piece.

9. The sheet according to claim 8, wherein the connecting portion comprises a flexible linear first connecting piece provided in the longitudinal center of the first covering piece, a flexible linear second connecting piece provided in the longitudinal center of the second covering piece, a first hook-and-loop fastener piece provided on the first connecting piece, and a second hook-and-loop fastener piece provided on the second connecting piece and detachably connected to the first hook-and-loop fastener piece.

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