chair

Abstract

To provide a seating tool of a safe and simple mechanism made sit in an easy posture and easily stand up.SOLUTION: In a seating tool 1 having a backrest, a seating fabric 4 composed of knitted fabric or woven fabric is supported at a seating surface part front edge 13 and a back surface part upper end 14 of a chair frame body 12. The seating tool 1 includes: a lateral rod body 10 which has a back and forth direction as a longitudinal direction at left and right ends below a seating surface part 5 of the seating fabric 4; and a support part 9 below the seating surface formed by arranging many elastic bands 8 stretched across the left and right lateral rod bodies 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a seating apparatus that provides a comfortable and easy sitting posture and enables the user to maintain it for a long period of time. That is, the present invention relates to a seating apparatus such as a chair or wheelchair that provides a comfortable and easy sitting posture and enables the user to maintain it for a long period of time. [Background technology]

[0002] It has traditionally been thought that the correct sitting posture for a typical chair is one in which you sit while maintaining the torso in the same position as when standing, with your back straight. Indeed, when standing, your head is on the vertical line of the spine, which forms a gentle S-shape, and your center of gravity is located on the vertical line of the contact surface with the ground, so the correct posture with an upright back can be said to be a natural posture from the perspective of your center of gravity.

[0003] Assuming this standing posture is the premise, let's explain the human trunk and lower limbs. The human trunk and lower limbs are connected via the pelvis. That is, the upper part of the pelvis is connected to the fifth lumbar vertebra by the base of the sacrum, and the lower part is connected to the femoral head by the acetabulum. The bones that make up the pelvis are the sacrum, coccyx, and left and right hip bones. The hip bones are further made up of three parts: the ilium, pubis, and ischium.

[0004] When a person is standing upright (the spine forms a double S-shape when viewed from the side), the pelvis is stable and vertical, with the ischium at the bottom. A beautiful, upright posture (the spine forms a double S-shape when viewed from the side) is when the ear holes, shoulders (acromion), greater trochanter (the bone at the base of the hip joint), slightly forward of the knees, and lateral malleolus (outer ankle) are all in a straight line.

[0005] Based on the same idea as standing, sitting posture also aims for a posture where, when a perpendicular line is dropped from the center of gravity of the body, the perpendicular line is located at the plane where the back of the thighs and the area around the sitting bones come into contact with the seat of the chair, or around the soles of the feet. In fact, there are many chairs that are designed to encourage this type of sitting with a straight spine. By devising the position and angle of the seat and backrest, chairs have been created that allow the user to maintain a straight spine, similar to an upright posture, even when sitting.

[0006] However, if one sits in this position, a large load is placed on the ischial bones, with the load being unevenly distributed on the part of the buttocks that is in contact with the seat. Furthermore, maintaining the same posture for a long period of time requires unnecessary muscle strength, as it creates an unnatural posture in terms of muscle balance. Therefore, rather than trying to replicate the traditionally ideal standing posture when sitting, it is necessary to explore a different approach.

[0007] Therefore, the inventor has considered the ergonomic difference between posture when standing upright and when sitting, in terms of the balance of tension between the skeleton and muscles, and has discovered that when sitting in a relaxed state, it is natural for the back to be rounded.

[0008] First, when a person is standing upright, the two muscles of the "iliopsoas muscles" on the lower abdominal side and the "gluteal muscles" on the buttocks side act as antagonistic muscles, and the tension they exert on each other across the unstable hip joint keeps the pelvis firmly and stably held in the "standing position" with the ischial bones positioned directly below. In other words, when standing upright, balance is maintained by the tension of the antagonistic muscles in the front and back, allowing you to maintain your posture easily without using much muscle strength.

[0009] However, when a person assumes a sitting position and the hip joint is bent nearly 90 degrees, the "iliopsoas muscles" on the lower abdominal side are brought closer to the lumbar vertebrae and femur, where the muscles are attached, and the tension on the muscles relaxes. On the other hand, the "gluteal muscles" on the buttocks side are stretched from the pelvis to the femur, wrapping around the outside, and are therefore under strong tension.

[0010] Therefore, when the antagonistic muscles supporting the pelvis, such as the iliopsoas and gluteal muscles, try to balance tension during a sitting position, the pelvis, which is in a vertical "standing position" with the ischial bones positioned downwards when standing, tilts, pushing the ischial bones forward, and assumes a "tilted position." In other words, the muscle tension in the standing position that stabilizes the pelvis in a vertical, upright position acts as muscle tension in the sitting position that tilts the pelvis around the hip joints.

[0011] When this happens, the pelvis, which serves as the base, is tilted, and the spine, including the lumbar vertebrae located above it, requires extra muscle strength to maintain a straight, S-shaped posture.In other words, when the position of the pelvis and lumbar vertebrae is such that the ischial bones are downwards and the bottom of the ischial bones are horizontal, as when standing upright, extra muscle strength is required.

[0012] Therefore, whether you're a healthy person or a disabled person, when you sit in a relaxed position, your pelvis naturally tilts, and your back curves accordingly. For these reasons, the ideal sitting posture shouldn't be one that's close to an upright posture; rather, it's more comfortable for your pelvis to tilt your sitting bones slightly forward, so that the base of your sitting bones is in a "tilted position." Being able to sit comfortably in a hunched, rounded, curved posture means you don't exert unnecessary strain, and it's natural and comfortable, so you won't get tired even if you sit for long periods of time.

[0013] Therefore, the inventor has invented a seat cushion for a sitting aid that is hung from the back of a chair with a backrest, as a sitting aid that makes it easier to form a comfortable posture (see Patent Documents 1 and 2). Because it hangs from the backrest, it can be easily adjusted to fit the person when sitting, and it properly induces the desired comfortable posture.

[0014] The inventor has also proposed a seating aid that can be placed on the seat of a chair, has a simple structure that does not need to be fixed to the backrest, and makes it easier to stand up from the chair while in a seated position (see Patent Document 3).

[0015] The inventor also initially proposed a chair with a tiltable and rotatable lumbar support as a seating device suitable for both able-bodied and physically disabled people, which would enable the head of the person to be comfortably maintained in a posture in which the head faces directly forward and the person can naturally look straight ahead, while assuming that the pelvis is in an inclined position when seated. This seating device is designed so that the fulcrum axis connecting the left and right rotation axes of the lumbar support is positioned within 2 cm of the intervertebral disc plane between the second and third lumbar vertebrae of the seated person, thereby ensuring close contact with the lumbar of the seated person (see Patent Document 4). The proposed method involves pivoting the lumbar support plate of the chair so that it can rotate and tilt from the left and right, supporting the lower back at an appropriate angle and position, allowing the user to sit in a relaxed and comfortable posture.However, it was necessary to position the chair within 2 cm of the intervertebral disc plane between the second and third lumbar vertebrae of the human body. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-41358 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-70465 [Patent Document 3] Japanese Patent Application Publication No. 2019-141539 [Patent Document 4] Patent No. 6112768 Summary of the Invention [Problem to be solved by the invention]

[0017] When trying to sit with the pelvis tilted and taking into account the balance of muscle strength so that it can be relaxed when sitting, it is desirable for the buttocks to move forward, resulting in a posture of, so to speak, a hunched over posture. However, because this results in sitting towards the front of the chair, if one were to sit in this position on a chair with a normal backrest, the weight of the back would be placed heavily on the seat. Furthermore, placing a large weight on only one part of the seat would result in a sitting posture that is unsuitable for long periods of use, and so sitting in a relaxed posture for long periods of time was difficult in the first place.

[0018] Therefore, in order to sit in a comfortable, so-called slumped-over position, with the pelvis tilted, it is necessary to adopt a different posture from when the spine is S-shaped when standing upright. As this changes the way the weight is distributed compared to when standing upright, it becomes necessary to use a special seating device or seating aid.

[0019] It is true that the sitting aids proposed by the inventor in Patent Documents 1 and 2 can provide a comfortable posture when seated, and once seated, it is easy to maintain a comfortable posture. However, these sitting aids need to be set on a chair with a backrest, and so the seating surface of the sitting aid is formed at a position slightly higher than the seating surface of the chair itself, which means that the seating surface tends to be slightly higher than the original chair.

[0020] In addition, the seat of the seating aid placed on the seat of a chair tends to slide back and forth, so if it slides forward too much when sitting, the original comfortable posture formed by the back of the knees, buttocks, lower back, and back is lost, and the back of the chair may not fit properly.

[0021] Furthermore, if the seating surface is made up of only a piece of cloth that is hung like a hammock, the sitter will slide forward and the back of the chair will not fit properly, making it difficult to maintain the desired comfortable posture.

[0022] Also, once you sit down, the chair has a strong effect of maintaining your posture, so you end up feeling completely seated, which makes it difficult to stand up. To stand up, you first have to tilt your head forward significantly, then move your center of gravity forward significantly, and use the recoil to stand up.

[0023] Therefore, the problem to be solved by this invention is to provide a seating device with a backrest that tilts the pelvis and relaxes the muscles, making it easy to form and maintain a comfortable and desirable sitting posture, and a seating device with a simple mechanism that makes it easy to stand up.The object is to provide a seating device mechanism that can easily form a line that suits the sitter from the back of the knees to the back, without using unnecessary cushioning material, etc. [Means for solving the problem]

[0024] The first means for solving the problems of the present invention is A seating device having a backrest, in which a seating fabric made of knitted or woven fabric is supported on the front end of the seat surface and the upper end of the back surface of a chair frame body, Horizontal rods with their longitudinal direction in the front-to-back direction are attached to the left and right ends of the seat fabric under the seat surface, The seating device is provided with an under-seat support portion formed by arranging a number of elastic bands stretched between the left and right horizontal rods in order.

[0025] The elastic band can be tensioned by fastening the left and right ends of a belt-like band to a horizontal bar. Alternatively, a ring-shaped elastic band can be used by passing the left and right horizontal bars through the rings of the elastic band, stretching the elastic band to the left and right.

[0026] The second means is a seating device as described in the first means, in which the horizontal rod body is a rod body bent in a "U" shape when viewed from the longitudinal direction, and the seat surface at the front end of the support part under the seat is lower in front than the seat surface at the rear part.

[0027] The third method is a front shaft that pivotally supports the front ends of the left and right horizontal rods on the chair frame body; A connecting rod connecting the rear ends of the left and right horizontal rod bodies; The chair is provided with an elastic suspension support part that suspends and supports the connecting rod from the upper rear part of the chair frame body, and the support part under the seat is an under-seat support part whose rear part can sink slightly downward with its front end as an axis. The seating device according to the first or second aspect is characterized by the above.

[0028] The fourth means is a seating device according to any one of the first to third means, characterized in that some of the multiple elastic bands have higher elasticity than the other elastic bands.

[0029] The fifth means is a seating device described in any one of the first to fourth means, characterized in that the elastic bands are ring-shaped bands, and the ring length of some of the multiple elastic bands is different from the ring circumference of the other elastic bands.

[0030] The sixth aspect of the present invention is a seating tool according to any one of the first to fifth aspects, characterized in that the seating fabric has a gripping portion in the center of the long side.

[0031] The seventh means is a seating device described in any one of the first to sixth means, characterized in that elastic strings provided in the center of the long sides of the seating fabric are fastened to the left and right armrests of the chair frame body.

[0032] The eighth aspect of the present invention is a chair as a seating device according to any one of the first to seventh aspects.

[0033] The ninth aspect of the present invention is a wheelchair that is a seating apparatus according to any one of the first to seventh aspects.

[0034] The tenth means is the wheelchair described in the ninth means, characterized in that the left and right crossbar bodies are connected to the upper ends of the wheelchair's cross pipes provided under the seat. [Effects of the Invention]

[0035] The seating fabric is, for example, a rectangular piece of knitted or woven fabric, and its four corners are supported by the left and right edges of the front end of the seat and the left and right edges of the upper back of the chair frame. The seating fabric completely envelops the occupant from their thighs to their back, dispersing body pressure and supporting them while naturally encouraging a tilted pelvic posture. When seated, the seating surface of the seating fabric abuts against the under-seat support portion located below the seat, and the elastic bands stretch to provide support. The stretching of the elastic bands over the occupant's ischial bones firmly holds the ischial bones in place, preventing the seating fabric from sliding forward and allowing the occupant to maintain a comfortable sitting posture.

[0036] Therefore, when the seating device of the present invention is installed on a chair or wheelchair, a seated person, either able-bodied or disabled, can easily assume a comfortable, relaxed sitting posture by tilting their pelvis so as to push the ischial bones forward, allowing them to maintain the seated posture for a long period of time. Furthermore, the exterior body abuts against the back and lumbar region of the seated person from the back portion to the rear of the seat, enveloping them, so that the weight of the seated person can be distributed widely and the weight can be prevented from concentrating in one area, making it less tiring to sit for long periods of time.

[0037] By bending the horizontal rod body in a V-shape, the front elastic band forms a surface that is slightly more forward inclined than the central and rear elastic bands, so the front end of the support part under the seat is lower in front than the rest of the seat, and when the occupant stands up, it is easier to move the area in front of the knees downward and shift weight, so it is less likely to get caught in the seating fabric and the occupant can stand up easily.

[0038] Furthermore, if the rear part of the under-seat support can sink in more than horizontally, with the front end as the axis, it becomes easier to maintain the position of the sitting bones properly and to form a comfortable posture. In this case, if the rear end is suspended from above by an elastic suspension support, it will provide an appropriate cushion according to the load. Furthermore, when standing up, the elastic suspension support contracts, which pushes up the buttocks from below, making it easier to transfer the load and stand up.

[0039] The tension of the elastic bands can be changed for each band, so the seating fabric can be supported from below the seat while adjusting the tension so that body pressure can be distributed appropriately depending on the area.If the elastic bands are ring-shaped, the tension of the bands can be adjusted by changing the length of the rings of the elastic bands, making it easy to adjust to the desired tension.

[0040] If elastic cords such as rubber cords are attached to the armrests of the chair frame from around the center of the left and right sides of the rectangular seating fabric, the rubber cords that extend from the waist to the armrests will form a bucket shape when the occupant sits down, wrapping around the body from both sides of the seating fabric. This firmly holds the greater trochanters of the hip joints of the occupant, further improving posture maintenance.

[0041] When the present invention is used in a wheelchair, the elastic band stretches under the load of the opposing ischial bones and receives it from the front, making it difficult for the chair to slip forward and stabilizing posture. Also, the backrest can be tilted slightly backward to allow for a relaxed posture, so the center of gravity of the head is positioned backward, making it difficult for the body to be thrown forward by inertia even when the chair suddenly stops.

[0042] In addition, the wheelchair can be folded by using a cross pipe under the seat of the frame. When a person sits down, the weight of the support part under the seat is applied to the horizontal bar connected to the upper end of the cross pipe, so the cross pipe is guided in the direction of expansion, and the wheelchair can be used without folding. [Brief explanation of the drawings]

[0043] [Figure 1] 1 is an exploded schematic view of a chair of a seating apparatus according to an embodiment of the present invention, in which the four corners of the upper seating fabric are placed on and locked to the lower chair frame body. [Figure 2] 1 is a diagram showing a state in which the occupant is seated on the seating device according to an embodiment of the present invention, in which the elastic belt in the position that rests on the ischial bones is bent further downward, making it difficult for the occupant to slip forward. [Figure 3] 1 is a diagram showing how the under-seat support portion of the chair of the seating device of one embodiment of the present invention rotates around the front end of the horizontal bar as a fulcrum and lowers from the position shown by the dotted line when the user sits down. FIG. [Figure 4] FIG. 10 is a side view of a wheelchair according to another embodiment of the present invention. [Figure 5] This figure explains the difference in sitting postures when sitting on a conventional high-back chair, showing the orientation of the lumbar vertebrae, pelvis, and ischium base of the human body when (a) sitting with the back in line and (b) sitting in a relaxed posture. DETAILED DESCRIPTION OF THE INVENTION

[0044] Hereinafter, an embodiment of the seating device of the present invention will be described, first using an example in which it is applied to a chair, with appropriate reference to Figures 1 to 4. The seating device of the present invention can be applied to both chairs and wheelchairs.

[0045] First, the seating device (1) of the present invention is a chair (2) for the seating device (1) to be used in a relaxed sitting position where the seated person (21) is not sitting with the ischial bones in a position straight down as in an upright pelvis (see the position in Figure 5(a)), but with the pelvis (29) slightly tilted so that the ischial bones (23) are at an angle (see Figure 5(b) where the position (17) of the bottom of the ischial bones is tilted backward rather than horizontal). Even when sitting in the position shown in Figure 5(b) with a conventional chair like the one in Figure 5, it is difficult to maintain the position because the person simply slides forward as if they have fallen. Therefore, the present invention is a seating device (1) that allows the seated person (21) to sit properly in the position shown in Figure 5(b).

[0046] The chair (2) has a rectangular knitted (or woven) seating fabric (4) with its long sides in the front-to-back direction attached to the front end (13) of the seat and the upper end (14) of the back of the chair frame body (12), and the seated person (21) leans their body against the seating fabric (4). Therefore, in the present invention, the elastic band (8) can stretch to form the surface of the under-seat support part (9) so that it faces the bottom surface (17) of the ischial bones.

[0047] The seating fabric (4) is 40-45 cm wide, with a long side length of, for example, 85-95 cm, longer than the diagonal distance (65-70 cm) between the front end (13) of the seat and the top end (14) of the back, and is made of a slack fabric. Therefore, when the seating fabric (4), whose upper and lower ends are fastened to the chair frame (12), is supported from above and below (for example, by supporting the four corners), it hangs down in a curved shape like a hammock fastened at an angle. For example, the four corners of the seating fabric (4) are provided with opening pockets (24) that can be inserted into the vertically oriented chair frame (12) at the upper and lower ends (26) and (25), respectively, and are supported by being inserted into the frame and fastened. The fastening parts (24) at the four corners of the seating fabric (4) can be supported by being inserted into the frame body (12) or by being fastened to the frame body (12) with strings provided at the four corners. It is also possible to hook the seat fabric (4) onto the frame body (12) with hooks provided at the four corners.

[0048] The seating fabric (4) can be made of any woven or knitted fabric, as long as it is strong enough to withstand the weight of a person. For example, a double-Russell knitted fabric can provide cushioning and breathability. The back surface (6) and seating surface (5) of the seating fabric (4) can be reinforced from the rear surface as needed. For example, polypropylene straps approximately 2 to 4 cm wide are sewn in a Y-shape from the upper left and right edges of the back surface to the center of the back surface where weight is applied, or straps are sewn in an inverted Y-shape from the front left and right edges of the seat surface toward the center. In the embodiment shown in the drawings, a pair of straps are sewn from the four corners to the center of the backrest to reinforce the back surface of the seating fabric (4), from the upper end of the backrest to the tip of the seat surface. The seating fabric (4) may be made of a thin sheet material, which may be combined with a cushion material to cover it.

[0049] However, if one were to sit on the seating fabric (4) alone, the fabric would be stretched too tight, and the occupant's (21) upper body would easily slide forward, making it difficult to maintain a comfortable, desired posture and making it easier for the occupant to lose their posture. Therefore, in the present invention, an under-seat support portion (9) formed by stretching multiple elastic bands (8) in the left and right directions is provided under the seat portion (5) of the seating fabric (4), which supports the buttocks of the occupant (21) and makes it easier for the occupant to maintain an ideal posture.

[0050] The elastic band (8) of the under-seat support portion (9) is a wide (flat cross section) rubber band (flat rubber) with a width of, for example, 5 cm, and can be made of woven or knitted rubber. The elastic band (8) is stretched between left and right horizontal bars (10, 10) arranged at the left and right ends of the underside of the seat portion (5) with the longitudinal direction extending in the front-to-back direction. The elastic band (8) can be stretched by engaging both ends with the horizontal bars (10, 10). For example, the horizontal bars (10) can be provided with hook holes for hooking hooks, and the hooks on both ends of the elastic band (8) can be inserted into the hook holes of the horizontal bars (10) to stretch the elastic band.

[0051] In addition, the elastic modulus of the elastic band (8) stretched across the under-seat support part (9) may be changed at different positions by changing the material, such as the tension of the elastic thread, or the way it is stretched. For example, an elastic band with higher elasticity may be placed around the buttocks.

[0052] Furthermore, in addition to the structure of hooking both ends with hooks, a ring-shaped elastic band (8) can also be used to fasten the elastic band (8). The ring-shaped elastic band (8) is hung on the left and right horizontal bars (10) and stretched to the left and right by the left and right horizontal bars (10, 10) passed through the ring of the elastic band (8). Since the elastic band (8) that has already been sewn into a ring shape is simply passed through the horizontal bars (10), the process is easy to do. In addition, the elastic modulus can be easily adjusted by adjusting the circumference of the ring, etc.

[0053] In the present invention, the under-seat support portion (9) is made up of multiple elastic bands (8) stretched across the left and right sides and arranged in parallel to form a surface. The elastic bands (8) of the under-seat support portion (9) that support the seating fabric (4) stretch to support the seating fabric so that they face the inclination of the seat bones (the direction of the bottom of the seat bones) of the seated person (21). As a result, as shown in Figure 2, the seat bones lightly bite into the opposing elastic bands (8) of the under-seat support portion (9), preventing forward sliding and allowing the person to maintain a comfortable posture without sliding forward. Therefore, the body of the seated person (21) is firmly supported by the back part (6) and seat part (5) of the seating aid (1) of the present invention, and is held comfortably, allowing the body pressure to be distributed comfortably and allowing the person to sit for long periods of time.

[0054] The horizontal bars (10) arranged on the left and right sides are, for example, 55 cm long steel bars. Furthermore, these horizontal bars (10) may be bent slightly at about 15 degrees about 12 to 15 cm from the front end to form a V-shape. When the horizontal bars (10) are bent in a V-shape, the elastic bands (8) stretched over the front bent portions (11) lean slightly forward compared to the elastic bands (8) stretched from the center to the rear. This causes the front of the under-seat support portion (9) to lean forward. This causes the area behind the knees to lean forward when seated, facilitating weight transfer when standing up and reducing the strain on the body when standing up. In the present invention, the seating fabric (4) itself is not provided with any irregularities, but the seating fabric (4) follows the seat under support part (9) that supports it from below. Therefore, by tilting the front of the horizontal bar body (10) in a V-shape, the surface of the elastic band (8) stretched on it tilts forward, and the front end of the seating fabric (4) tilts forward along the seat under support part (9).

[0055] Furthermore, as shown in Figure 3, by pivotally supporting the front end of the horizontal bar (10) on the rotation axis (27) of the chair frame (12), the rear end can sink slightly downward when sitting down, and the rear end can be pushed up from behind when standing up. This improves both cushioning and standing up. Therefore, the front end of the horizontal bar (10) can be pivotally supported on the chair frame, and the rear ends of the left and right horizontal bars (10) can be connected by a connecting rod (20). This connecting rod (20) can be suspended from above the back of the chair frame (12) by an elastic hanging support (18) made of an elastic band. This allows the rear of the under-seat support (9) to sink. For example, using two flat rubber bands as the connecting rods (20) allows the rear ends of the under-seat support (9) to sink evenly when sitting, making it easier to achieve an ideal posture. When the seated person (21) leans his / her body forward to shift the weight in an attempt to stand up, the rear end of the support part (9) under the seat is pushed up, making it easier for the person to stand up.

[0056] Furthermore, by adjusting the length and tension of the flat elastic, the balance between cushioning and support can be adjusted, so it can be adjusted to suit the expected weight of the user and the condition of the user, whether they are able-bodied or disabled.The flat elastic may be stretched from the connecting rod to the upper part of the back of the frame and then further stretched downward to be fixed to the frame.

[0057] Furthermore, gripping parts (16) may be provided near the center (15) of the long side of the seating fabric (4), i.e., on both ends around the waist of the seated person. Because the under-seat support part (9) and the seating fabric (4) are independent, the gripping parts (16) can be grasped and lifted. In this way, when the caregiver stands up, they can place both hands on the seating fabric (4) and pull it, rather than holding the person, so that the entire back is pushed against, allowing for smooth assistance with less strain, making it suitable for use by disabled people.

[0058] In addition, the rubber cords of the elastic cord body (17) provided near the center (15) of the long side of the seating fabric (4) may be fastened to the armrest portions (22) on the left and right sides of the upper seat surface of the chair frame body (12). When the seated person (21) sits on the seating fabric (4), the seating fabric (4) on the left and right sides of the waist is pulled by the elastic cord body and pulled up toward the armrests, so that the seated person (21) sits with the seating fabric (4) enveloping the waist from both sides. This makes the seated person (21)'s posture more stable. This makes the chair (2) suitable for both able-bodied people and physically disabled people.

[0059] When the seating device of the present invention is used in a chair, not only able-bodied people but also physically handicapped people can sit in a wide range of comfortable positions. The mechanism of this seating device can also be used in wheelchairs.

[0060] Therefore, another embodiment of the present invention will be described below in which the present invention is used in a wheelchair. The wheelchair of the present invention is provided with a seating fabric (4) that is fastened to the upper end of the frame of the backrest of the wheelchair (3) and the front end of the seat, and an under-seat support part (9) that is made up of a number of elastic bands (8) that are arranged in order and stretched between left and right horizontal rods (10) under the seat part (5) to support the seating fabric (4).

[0061] The elastic band (8) can be stretched and taut by passing the ring-shaped elastic band through horizontal rods (10, 10). The elastic modulus can be changed appropriately by changing the circumference of the ring, so the hardness of the elastic band (8) can be changed depending on the position.

[0062] The back frame of the wheelchair (3) is not upright but tilted backward by about 10°, and the horizontal axis rod (10) supporting the under-seat support part (9) is also tilted backward by about 10 to 20°. On the other hand, since the horizontal axis rod (10) is bent in a V-shape, the front part is tilted forward by about 2 to 5°. Therefore, the front part of the under-seat support part (9) near the knees is tilted forward slightly, while the part from the thighs to the buttocks is tilted backward.

[0063] Therefore, in Figure 4, the rubber cords of the elastic cord body (17) provided near the center (15) of the long side of the seating fabric (4) are engaged with the armrest portions (22) on the left and right upper sides of the seat surface of the chair frame body (12) on the left and right, respectively, so that when standing up, the seating fabric (4) near the waist can easily move upward, making it easier to stand up.

[0064] Alternatively, since the under-seat support part (9) and the seating fabric (4) are independent, a grip part may be provided in the center of the long side of the seating fabric (4). In this way, when the caregiver facing the seated person stands up from the wheelchair, by pulling on this grip part, only the seating fabric (4) is pulled up, and the seating fabric (4) can be used to lift up the seated disabled person.

[0065] As shown in Figure 4, the chair frame body (12) of the wheelchair (3) has two cross pipes (23) at the front and rear, which connect the left and right frames in a foldable manner. When the X links of these cross pipes (23) are narrowed so that they are vertically long, the wheelchair is folded, and when sitting, the load of the horizontal rods is applied to the upper left and right ends of the X, pushing the wheelchair outward, allowing the person to sit stably.

[0066] When a person sits on the wheelchair (3) of the present invention, he or she can easily assume a comfortable, relaxed posture by tilting the pelvis so as to push the ischium forward, thereby making it possible to sit comfortably. In addition, since the occupant is sitting in a hunched posture, the head and upper body are tilted slightly backward, and the center of gravity is directed backward, which helps to prevent the occupant (21) from being thrown forward due to inertia when the wheelchair (3) suddenly stops. In addition, the elastic band (8) that contacts the sit bones lowers, so the seat supports the sit bones from the front, making it less likely for the body to slip forward, and even in the event of a sudden stop, it is less likely for the body to slip forward and be thrown out.

[0067] (Inertial velocity impact test) A (skeletal specimen) and b (infant model) were placed on the seat of A (a general type wheelchair) or B (a wheelchair with the mechanism of the present invention), and the wheelchair was allowed to move forward 180 cm without holding the hands on a slope with an inclination angle of 5°.Then the wheelchair was allowed to move horizontally at its inertial speed for 140 cm and then collided with a wall in front of it.The displacement of the buttocks was measured five times and the average value was recorded.The results are shown below.

[0068] a: Skeletal specimen (170cm, 9kg) A (general wheelchair) - a (skeleton specimen): 22.8 cm B (the wheelchair of the present invention)-a (skeleton specimen): 0.2cm

[0069] b: Infant model (76cm, 7kg) A (standard wheelchair) - b (child model): 8.1cm B (the wheelchair of the present invention) - b (child model): 1.4 cm

[0070] These test results also confirmed that the wheelchair of the present invention allows the user to sink in around the sitting bones to stabilize posture and the backrest can be tilted slightly backward, so in addition to being able to sit more stably than a regular type of wheelchair, it is also safer as it is less likely to jump out or slip forward when making a sudden stop. [Explanation of symbols]

[0071] 1 Seating equipment 2 chairs 3. Wheelchair 4 Seating fabric 5 Seat part 6 Back section 7. Ischial contact position 8 elastic bands 9 Under-seat support 10 Horizontal bar body 11 Bend 12 Chair frame 13 Front end of seat part 14 Top edge of back section 15 Center of long side 16 Gripping part 17 Elastic string 18 Elastic hanging support 19 Rear crossbeam 20 Connecting rod 21 Seated Person 22 Armrest section 23 Cross Pipe 24 Locking part 25 Front end of seat part 26 Top edge of back section 27 Rotation axis 28 Orientation of the base of the ischial bones 29 Pelvis 30 Sciatica

Claims

1. A seating device having a backrest, in which a seating fabric made of knitted or woven fabric is supported on the front end of the seat surface part and the upper end of the back surface part of a chair frame body, is Horizontal rods with their longitudinal direction in the front-to-back direction are attached to the left and right ends of the seat fabric under the seat surface, A support portion under the seat formed by arranging a number of elastic bands stretched between the left and right horizontal rod bodies in order; It is equipped with a front shaft that pivotally supports the front ends of the left and right horizontal rods on the chair frame body; A connecting rod connecting the rear ends of the left and right horizontal rod bodies; The chair is provided with an elastic suspension support part that suspends and supports the connecting rod from the upper rear part of the chair frame body, and the support part under the seat is an under-seat support part whose rear part can sink slightly downward with its front end as an axis. A seating device characterized by:

2. 2. The seating device according to claim 1, wherein the horizontal rod is a rod bent in a V-shape when viewed from the longitudinal direction, and the front end seat surface of the under-seat support portion is lower in front than the rear seat surface.

3. 3. The seating device according to claim 1 or 2, wherein some of the multiple elastic bands have higher elasticity than the other elastic bands.

4. The elastic bands are ring-shaped bands, and the circumferential lengths of some of the rings of the multiple elastic bands are different from the ring lengths of the other elastic bands; The seating device according to any one of claims 1 to 3, characterized in that

5. The seating fabric has a grip portion at the center of the long side; The seating device according to any one of claims 1 to 4, characterized in that

6. A seating device according to any one of claims 1 to 5, characterized in that an elastic cord provided in the center of the long side of the seating fabric is fastened to the left and right armrest portions of the chair frame body.

7. A chair that is the seating device according to any one of claims 1 to 6.

8. A wheelchair that is the seating device according to any one of claims 1 to 6.

9. 9. The wheelchair according to claim 8, wherein the left and right cross bars are connected to the upper ends of cross pipes of the wheelchair provided below the seat.

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