Liquid cushion

Abstract

To provide a cushion that uniformly supports along a hip shape as well as improving motility and handleability.SOLUTION: A liquid cushion is composed of a top-covering sheet, a side face, and an undersurface. The top is an elastic sheet having a modulus of longitudinal elasticity of 10 MPa or less. A filling liquid height is 1 / 16 or less and 1 / 38 or more of the maximum inside dimension in the lateral direction of the cushion. The elastic sheet is fastened in the end part and is a sheet of high extensibility with the central part free from sinking and with the entire hip part uniformly supported. By making the liquid height necessary lowest with no bottom out in a quietly seated state, weight increase and swing are suppressed. Also, in the event that a large weight is imposed, bottoming takes place to prevent sheet breakage.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cushion filled with liquid and placed on the seat of a chair or the like. [Background technology]

[0002] Conventionally, there have been cushions that use flexible materials or fluids to prevent pain in the buttocks and the development of bedsores. In particular, cushions have been provided that are designed to disperse pressure generated in the ischial and coccygeal regions, where bedsores are likely to develop, and promote blood circulation, as a measure against bedsores.

[0003] For example, cushions made of flexible materials such as soft urethane may initially distribute body pressure, but over time the pressure gradually concentrates on the ischial and coccygeal areas. In addition, the buttocks sink and become fixed, restricting body movement and impeding blood circulation. Hard urethane allows for easier body movement, but is inferior to soft urethane in dispersing body pressure. It is necessary to select a material that has both advantages and disadvantages.

[0004] On the other hand, cushions that use fluids, in principle, hold the buttocks with even pressure regardless of time, and have excellent features in terms of dispersing body pressure and accommodating body movement, as the buttocks are not fixed. Fluid cushions are broadly divided into those that use air, which is a gas, and those that use liquids such as water.

[0005] While air cushions are lightweight, inexpensive, and easy to use, air tends to shrink, so air pressure must be increased to prevent bottoming out, and the surface material is always under high tension, limiting the surface material's ability to stretch when sitting, resulting in poor pressure dispersion. Highly compressed air also escapes easily, so air must be frequently replenished to maintain the same condition. Furthermore, the rebound caused by air pressure can be uncomfortable when sitting down or moving.

[0006] Cushions that use liquid include a type in which liquid is filled inside a bag-shaped flexible material as in Patent Document 1, and a type in which a flexible material is welded to a base material and then filled with liquid, taking into consideration the position of the fluid part and water flow according to the shape of the buttocks as in Patent Document 2. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2002-300940 A [Patent Document 2] Patent No. 4996169 Summary of the Invention [Problem to be solved by the invention]

[0008] The cushion described in Patent Document 1 uses a polymer elastic gel to reduce shaking and inserts a core material to prevent bottoming out, and supports pressure with the liquid and the core material, but since it is bag-shaped and the ends of the upper surface of the seat are not fixed, when pressure is applied to the center of the seat, the ends move toward the center and the depression is amplified. This is similar to how the lower back sinks significantly in a hammock where the ends are not fixed laterally. To prevent this depression, a honeycomb-structured core material is inserted, but supporting with the core material means that the even pressure caused by the liquid pressure will be uneven. Furthermore, to prevent bottoming out, the liquid layer is made thick and a soft synthetic resin that is flexible but difficult to stretch is used, but making the liquid layer thicker increases the weight of the cushion, and using a material that is difficult to stretch reduces the effect of supporting the body evenly along the body. The measures to prevent bottoming out due to the depression in the center affect the original utility and convenience.

[0009] Generally, air mattresses, air cushions, water mattresses, and water cushions are made by welding soft synthetic resins such as soft polyvinyl chloride, which has less stretchability but excellent flexibility compared to rubber, etc. This is to prevent bottoming out due to stretching under pressure, and because highly stretchable rubber materials are difficult to bond in a way that can withstand fluid pressure, but the material is selected in order to prioritize the effect of stretching to support the body evenly.

[0010] The cushion described in Patent Document 2 is designed to take into consideration the shape of the buttocks, and to consider the position of the fluid to be filled to avoid pressure concentration on the ischial and coccygeal regions, while also providing an orifice to gradually move the fluid to areas with less pressure. However, there are many cases where ideal pressure distribution is not achieved due to the shape of the buttocks, the sitting position, the use of bandages or nursing pants, etc. In addition, the existence of the orifice itself worsens the balance of uniform pressure, and the risk of breakage increases because high pressure is frequently generated in the orifice. In addition, as mentioned above, a synthetic resin with poor elongation is used in order to prioritize bonding strength, so there is a drawback in that the original body pressure distribution effect of the fluid along the buttocks shape cannot be obtained.

[0011] The present invention has been made in view of the above-mentioned problems in the conventional art, and has as its object to provide a cushion which uniformly supports the buttocks in accordance with their contours, and which also improves body movement and ease of handling. [Means for solving the problem]

[0012] The present invention relates to a cushion that is filled with liquid such as water and that is seated on a flexible, highly extensible seat with a fixed upper end.

[0013] The mattress top surface is an elastic sheet with a modulus of elasticity of 10MPa or less, the sides and bottom are rigid, and the elastic sheet is tightly bonded to the sides and bottom. Fluid is enclosed inside the mattress to make the top surface flat. Furthermore, the height of the liquid is between 1 / 16 and 1 / 38 of the maximum internal dimension of the cushion in the lateral direction.

[0014] The upper surface is an elastic sheet with a low modulus of longitudinal elasticity, and the ends are fixed, so that when you sit down, the parts of the sheet that are subjected to the load stretch and sink, while the parts that are not subjected to the load stretch and swell, providing uniform support over a wide area while conforming to the buttocks.

[0015] The height of the liquid varies depending on body type and weight, but if it is about the height difference between the lowest part of the tailbone and the hip joints when in a sitting position, the person can sit without bottoming out. The liquid height that will not bottom out when sitting quietly, but will bottom out and protect the seat from damage when excessive pressure is applied, is between 1 / 16 and 1 / 38 of the maximum horizontal internal dimension of the cushion. If the liquid height is lower than this, the seat will often bottom out even when sitting quietly, and if the liquid height is higher than this, there is a higher risk of the seat being damaged before bottoming out, such as when standing on the cushion with your feet.

[0016] In this invention, the liquid height is shown as a ratio to the maximum internal horizontal dimension of the cushion, but this is because there are circular, elliptical and trapezoidal cushions other than the common rectangular shape, and because there are cushions with a width of 30 cm or less for infants and 50 cm or more for adults. In addition, the sides and bottom are made rigid, which means that the material has a hardness that does not affect the stretching of the elastic sheet due to stress from the elastic sheet or the liquid. Effect of the Invention

[0017] In this invention, the buttocks are supported uniformly over a wide area by the highly stretchable elastic sheet with fixed ends and the liquid pressure, and the center does not sink more than necessary, so even if the liquid level is kept low, the user can continue to sit without hitting the bottom. By keeping the liquid level low, the weight is reduced and handling during transportation and cleaning is improved. Furthermore, while the buttocks are firmly supported, the lower part is liquid, so body movement is easy.

[0018] In addition, because the sheet expands on the top while suppressing the fluid height, if excessive pressure is applied, such as when someone stands on it, the sheet will bottom out, suppressing the generation of excessive stress on the sheet and making it less likely to break. The simple structure of simply joining a member with a recess to a rectangular elastic sheet, and the structure that suppresses the generation of large stress, makes it possible to use an elastic sheet that is less easy to process and bond than conventional materials such as polyvinyl chloride.

[0019] Generally, in bag-type water beds with a thick liquid layer, the liquid can create waves that can cause bothersome swaying, and similarly in cushions that use liquid, if the liquid layer is thick, the swaying can be bothersome; however, in the case of this invention, the liquid layer is thin, so there is less swaying.

[0020] In this way, the present invention provides ideal low pressure distribution by providing wide and even support along the buttocks, allowing body movement but allowing stable sitting, and makes it possible to provide a cushion that is easy to handle and effective in relieving buttock pain and bedsores. [Brief description of the drawings]

[0021] [Figure 1] FIG. 2 is a partially cutaway perspective view of the mattress. [Diagram 2] FIG. 1 is an image of a lateral cross section in a sitting position. [Diagram 3] This is an image of the cross section when you stand on it. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the accompanying drawings. As shown in FIG. 1, the cushion according to this embodiment is used by putting a liquid such as water into a watertight space.

[0023] The mattress is composed of an elastic sheet 1 covering the upper surface, side surfaces 2, a lower surface 3, supply and drainage holes 4, supply and drainage plugs 5, and a fluid 6.

[0024] The elastic sheet 1 is made of a material with a modulus of elasticity of 10 MPa or less so that it stretches along the buttocks when seated. Soft resins such as polyvinyl chloride, which are commonly used, have a modulus of elasticity of 100 MPa or more, and do not provide sufficient elongation, so if they stretch too much, permanent deformation remains. However, general rubber materials have a modulus of elasticity of 10 MPa or less, and are easy to stretch and have high recovery performance, making them suitable as materials that support the body. However, there are no materials with a modulus of elasticity in the range of 10 MPa to 100 MPa that are suitable for the present invention in terms of function, manufacturing, and price.

[0025] The side surface 2 and the bottom surface 3 are made of a material such as resin so that even if liquid pressure or tensile force from the sheet is applied, only negligible deflection occurs. The side surface 2 and the bottom surface 3 may be separate materials, but are tightly bonded to the elastic sheet 1 with an adhesive or the like.

[0026] A hole 4 for supplying and draining liquid that connects to the inside is drilled in the side 2 and plugged with a supply and drain plug 5. When in use, the supply and drain plug 5 is removed and liquid 6 is poured inside so that the elastic sheet 1 is held flat, and the supply and drain plug 5 is used to secure it in place to prevent leakage. Note that there is no restriction on the method as long as it is possible to supply and drain the liquid.

[0027] The height of the space for putting liquid should be less than 1 / 16 and more than 1 / 38 of the maximum inner dimension of the cushion in the lateral direction so that it will not bottom out when the person is sitting quietly, but will bottom out when excessive pressure is applied, preventing excessive stress on the seat, and further suppressing unnecessary shaking during body movement. If it is smaller than this value, the seat will easily bottom out even when the person is sitting quietly, and if it is larger, the load on the seat will increase when the person places their feet on it, making it more likely to break, and the weight of the cushion will increase, making it harder to handle and causing more shaking.

[0028] This mattress can be used alone, but by combining it with a soft cover or urethane cushion, the feeling when sitting is improved and the elastic sheet is protected. It is also effective when you are concerned about the movement of liquids or the temperature of liquids.

[0029] Figure 2 is an image of a cross section when seated. The seat in the areas where weight is applied stretches and sinks, while the seat in the areas where weight is not applied stretches and bulges, providing wide and uniform support for the entire buttocks without bottoming out.

[0030] Figure 3 is an image of the cross section of the cushion when one foot is placed on it. When a large body weight is placed on the mattress with a relatively small area, the bottom is touched and the support sheet underneath is prevented from breaking. The maximum horizontal inner dimension is indicated by the symbol 7, and the liquid height is indicated by the symbol 8. [Explanation of symbols]

[0031] 1 Elastic sheet 2. Side 3 Bottom surface 4 Supply / discharge hole 5 Supply / drain valve 6 fluid 7 Maximum horizontal inner dimension 8 Liquid Height EXAMPLES

[0032] A specific embodiment of this patent will be described with reference to Figure 1. The mattress is composed of an upper elastic sheet 1, a side surface 2 including water supply and drainage holes 4 and a water supply and drainage valve 5, and a lower surface 3, and is filled with water containing a preservative so that the upper surface of the elastic sheet is flat.

[0033] The elastic sheet 1 is a silicone rubber sheet with a thickness of 1 mm and a modulus of longitudinal elasticity of 3 MPa, which is tightly and securely bonded to the upper part of the side surface 2 with a silicone adhesive. The thickness of the elastic sheet is preferably about 1 mm from the viewpoints of both ease of stretching and prevention of breakage. Since the elastic sheet is used for long periods of time in close proximity to the body, it is made of silicone rubber, which is excellent in terms of health and safety, but this material is not the only option as long as there are no problems with elasticity, adhesion, strength, etc.

[0034] The sides 2 are made of polystyrene foam resin with an upper frame width of 20 mm, a lower frame width of 60 mm, and a height of 1.6 mm, while the bottom surface 3 is made of 3 mm thick aluminum composite plate, which are tightly bonded with adhesive. Polystyrene was selected because it adheres well with silicone rubber, is lightweight and easy to process, and aluminum composite plate is lightweight and has high bending strength. However, the material selection is not limited to these.

[0035] The size of the cushion is 40cm square, the maximum inside dimension is 36cm, the thickness is 2cm, and the liquid height is 1.6cm. 40cm square is a standard size, but it is advisable to adjust it to fit your body type.

[0036] The water supply hole 4 opened on the side 2 is φ8 mm and a silicone tube with an inner diameter of 6 mm and an outer diameter of 8 mm is inserted watertightly, and a small coupler with a valve is connected to the tip as a water supply and drainage valve 5. When using, water containing a preservative is poured in and the air is removed at the end.

[0037] The liquid can be highly viscous, such as gel. However, it must be a liquid with flowability. Viscosity can also be used to adjust the degree of shaking during body movement.

[0038] The cushion in this embodiment weighs approximately 1.8 kg, which is comparable in weight to a typical cushion, even though it uses liquid. [Industrial Applicability]

[0039] Because it is effective in preventing bedsores, it is intended for use in hospital chairs, nursing chairs, wheelchairs, etc. It can also be used on chairs that require sitting for long periods of time, such as chairs as furniture, chairs in vehicles such as cars and airplanes, and chairs indoors and outdoors in various facilities. Because it can be made of materials that do not cause problems when wet, it is also effective for use outdoors, in bathrooms, saunas, etc.

Claims

[Claim 1] A liquid cushion having a space therein for filling with a liquid such as water, the cushion consisting of an upper surface, sides, and a lower surface, the sides and lower surface being rigid bodies, the upper surface being an elastic sheet having a longitudinal elastic modulus of 10 MPa or less, and the height of the space being 1 / 16 or less and 1 / 38 or more of the maximum internal dimension of the mattress in the longitudinal direction.

Images