Cushion

Abstract

To provide a cushion allowing a user to stretch the muscle of back and improve the posture.SOLUTION: A cushion has a cushion body layer, an upper cushion layer, and a lower cushion layer. The cushion body layer is in a thick plate shape for forming the body part of the cushion, and having both upper and lower principal surfaces. The upper cushion layer is in a thin plate shape for covering the upper principal surface of the cushion body layer. The lower cushion layer is in a thin plate shape for covering the lower principal surface of the cushion body layer. The cushion body layer has, in a rear portion for supporting the pelvis of a seated user, a relatively soft cushion layer having a cavity penetrating into both upper and lower principal surfaces, and a relatively hard cushion layer arranged so as to fill the cavity. The soft cushion layer is softer than the upper cushion layer and the lower cushion layer, and the hard cushion layer is harder than the upper cushion layer and the lower cushion layer.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a cushion for use when sitting. [Background technology]

[0002] Cushions used when sitting are known to have been designed to improve comfort. For example, Patent Document 1 discloses a cushion that prevents pressure on the ischial bones when the user sits, thereby preventing pain in the buttocks even when used for long periods of time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-325270 Summary of the Invention [Problem to be solved by the invention]

[0004] When a person sits using a regular cushion, the pelvis tends to rotate backward, which can lead to poor posture. This problem is particularly severe for elderly people, whose pelvises tend to be loose and unstable. The inventors of the present application, who have extensive experience as caregivers, noticed this through their work and have experimented with various cushions. Cushions such as those in Patent Document 1, which aim to prevent pressure on the ischial bones, are not a viable solution. The present invention was made as a result of these experiments by the inventors, and aims to provide a cushion that straightens the user's spine and improves posture. [Means for solving the problem]

[0005] To achieve the above object, a first aspect of the present invention provides a cushion comprising a cushion main body layer, an upper cushion layer, and a lower cushion layer. The cushion main body layer forms the main body of the cushion and is a thick plate having upper and lower main surfaces. The upper cushion layer is a thin plate covering the upper main surface of the cushion main body layer. The lower cushion layer is a thin plate covering the lower main surface of the cushion main body layer. The cushion body layer has a cavity penetrating both the upper and lower main surfaces in a rear portion supporting the pelvis of a seated user, and includes a relatively soft cushion layer and a relatively hard cushion layer arranged to fill the cavity. Furthermore, the soft cushion layer is softer than the upper and lower cushion layers, and the hard cushion layer is harder than the upper and lower cushion layers.

[0006] With this configuration, the rear portion supporting the user's pelvis is relatively hard, while the front portion supporting the thighs is relatively soft, making it easier for the pelvis to rotate forward due to the weight of the thighs. As a result, the user's back straightens and posture improves. Both the upper and lower main surfaces of the cushion body layer, which is divided into a soft cushion layer and a hard cushion layer, are covered by the upper and lower cushion layers, and the upper and lower cushion layers have a hardness between that of the soft cushion layer and the hard cushion layer, so the difference in hardness felt by the user at the boundary between the soft cushion layer and the hard cushion layer is alleviated. [Effects of the Invention]

[0007] As described above, according to the present invention, a cushion that straightens the user's back and improves posture is realized. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view illustrating an example of the appearance of a cushion according to an embodiment of the present invention; [Figure 2] FIG. 2 is an exploded perspective view illustrating the configuration of the cushion of FIG. 1. [Figure 3]FIG. 10 is a schematic explanatory diagram illustrating the effect of a conventional cushion as a comparative example. [Figure 4] 2 is a schematic explanatory view illustrating the effect of the cushion of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1 is a perspective view illustrating the appearance of a cushion according to one embodiment of the present invention. This cushion 101 has a cushion body layer 1, an upper cushion layer 3, and a lower cushion layer 5. In the illustrated example, the planar shape of cushion 101 is rectangular, and in particular, square.

[0010] The cushion main body layer 1 is the central part that forms the main body of the cushion 101, and its thickness accounts for the majority of the thickness of the cushion 101. The cushion main body layer 1 is in the shape of a thick plate, and has upper and lower main surfaces. The upper cushion layer 3 is arranged so as to cover the upper main surface of the cushion main body layer 1. The other lower cushion layer 5 is arranged so as to cover the lower main surface of the cushion main body layer 1. In this way, the cushion main body layer 1, upper cushion layer 3, and lower cushion layer 5 are stacked one on top of the other to form layers.

[0011] The cushion main body layer 1 and the upper cushion layer 3, and the cushion main body layer 1 and the lower cushion layer 5 are connected by, for example, an adhesive or heat fusion. Both the upper cushion layer 3 and the lower cushion layer 5 are thinner than the cushion main body layer 1 and are thin plates.

[0012] FIG. 2 is an exploded perspective view illustrating the configuration of the cushion 101. The cushion main body layer 1 has a soft cushion layer 7 and a hard cushion layer 9. A cavity 11 is formed in the soft cushion layer 7, penetrating both the upper and lower main surfaces, in a rear portion that supports the pelvis of a seated user. The hard cushion layer 9 is arranged to fill this cavity 11. The inner wall of the cavity 11 and the hard cushion layer 9 may be connected by adhesive, heat fusion, or the like, or the hard cushion layer 9 may simply be arranged to fill the cavity 11.

[0013] The hard cushion layer 9 is harder than the soft cushion layer 7. The soft cushion layer 7 is softer than both the upper cushion layer 3 and the lower cushion layer 5, and the hard cushion layer 9 is harder than both the upper cushion layer 3 and the lower cushion layer 5. The upper cushion layer 3, the lower cushion layer 5, the soft cushion layer 7, and the hard cushion layer 9 all have elasticity and are made of, for example, a urethane resin. "Soft" means that the elastic deformation is large for the same load, and "hard" means, conversely, that the elastic deformation is small.

[0014] The upper cushion layer 3 and the lower cushion layer 5 are mostly made up of a soft cushion layer 7, which serves to maintain the shape of the cushion main body layer 1, which is also a composite with a hard cushion layer 9, and also serves to reduce the sense of difference in hardness felt by the user at the boundary between the soft cushion layer 7 and the hard cushion layer 9.

[0015] FIG. 3 is a schematic explanatory diagram illustrating the effect of a conventional cushion as a comparative example. In the illustrated example, a conventional cushion 50 is placed on the seat 15 of a chair 13 placed on a floor 12. The cushion 50 is a standard type that is uniformly soft throughout. When a user 60 sits on the cushion 50, their weight causes their pelvis to sink into the cushion 50, and their thighs are lifted by the elasticity of the cushion 50. As a result, the pelvis tends to rotate backward, as indicated by the arrow in the figure. When the pelvis rotates backward, the spine becomes rounded, resulting in poor posture. This also applies to cushions with hollowed-out areas for the ischial bones to rest on, as in Patent Document 1. Note that in FIG. 3, the body of the user 60 is depicted only schematically.

[0016] FIG. 4 is a schematic diagram illustrating the effect of cushion 101. In the illustrated example, cushion 101 is placed on seat 15 of chair 13. When user 60 sits on cushion 101, the rear portion of cushion 101 that supports user 60's pelvis is relatively hard, while the front portion that supports the user's thighs is relatively flexible. This makes it easier for the pelvis to rotate forward due to the weight of the thighs, as indicated by the arrow in the figure. As a result, user 60 straightens his or her spine and maintains good posture. The results of this verification experiment have been confirmed by a physical therapist. As such, cushion 101 is highly effective in correcting the posture of user 60, and is therefore also suitable for use as a posture correction training cushion.

[0017] FIG. 2 shows an example in which the cavity 11 is provided in the soft cushion layer 7, and the hard cushion layer 9 that fills it has two upright cylindrical sections of the same size lined up on the left and right, and a bridge section connecting them. The width of the bridge section is set smaller than the diameter of the cylindrical sections. The cylindrical sections of the hard cushion layer 9 support the left and right pelvises of the user 60, and the bridge section functions to maintain the distance between the left and right cylindrical sections. However, the cavity 11 and the hard cushion layer 9 that fills it can also have a different shape. It is sufficient that the cavity 11 and the hard cushion layer 9 that fills it are provided in the rear section of the cushion main body layer 1 that supports the pelvis of the seated user 60. [Explanation of symbols]

[0018] 1 cushion body layer, 3 upper cushion layer, 5 lower cushion layer, 7 soft cushion layer, 9 hard cushion layer, 11 cavity, 12 floor surface, 13 chair, 15 seat board, 50 cushion, 60 user, 101 cushion.

Claims

[Claim 1] A cushion, a thick-plate-shaped cushion body layer that forms the main body of the cushion and has both upper and lower main surfaces; a thin-plate-shaped upper cushion layer covering the upper main surface of the cushion body layer; a thin plate-shaped lower cushion layer covering the lower main surface of the cushion body layer, The cushion body layer is a relatively soft cushion layer having a cavity penetrating both the upper and lower main surfaces at a rear portion supporting the pelvis of a seated user; a relatively hard cushion layer disposed to fill the cavity; the soft cushion layer is softer than the upper cushion layer and the lower cushion layer; The hard cushion layer is harder than the upper cushion layer and the lower cushion layer.

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