Cushion structure and bathroom chair equipped therewith

Abstract

The present invention provides a cushion structure and a bathroom chair equipped therewith that can absorb deformation even if the cushion shrinks due to changes over time, and prevent slippage relative to the main body even when subjected to horizontal force. [Solution] According to the present invention, a cushion structure is provided comprising a chair body and a cushion part detachably attached to the chair body, wherein the chair body has a support part and two or more openings extending radially from near the center of the support part, and the cushion part has a top plate part and two or more protruding parts extending radially from near the center of the top plate part, and the protruding parts are arranged to align and fit with the openings, the width dimension of the protruding parts is approximately the same as the width dimension of the openings, and the longitudinal dimension of the protruding parts is approximately the same as the longitudinal dimension of the openings, or shorter than the longitudinal dimension of the openings, and a bathroom chair equipped therewith is provided.

Description

Technical Field

[0001] The present invention relates to a cushion structure and a bathroom chair provided with the same, and particularly includes a main body portion of a seat or a backrest of the chair and a cushion portion detachably attached to the main body portion. By aligning and fitting an opening portion of the main body portion and a rib portion of the cushion portion, it absorbs expansion due to heat and shrinkage over time, and relates to a cushion structure in which the cushion portion does not easily shift with respect to the main body portion and a bathroom chair provided with the same.

Background Art

[0002] With the advent of an aging society, in order to assist the movements of the elderly and care recipients in the bathroom and bathtub, for example, as described in Japanese Unexamined Patent Application Publication No. 2011-67448 (Patent Document 1) and Japanese Unexamined Patent Application Publication No. 2020-175225 (Patent Document 2), there are known bathroom chairs and bathroom stools provided with a cushion structure in which a cushion portion (cover main body) made of foamed resin is attached to a main body portion such as a seat portion or a backrest portion.

[0003] By the way, many of the foamed materials used for the cushion portion expand with heat and often deform due to long-term use such as shrinking over time, so they must be replaced in a timely manner. Therefore, in Patent Document 2, in order to fit the protrusion of the cushion portion, a fitting hole provided in the seat main body portion is made into a long hole directed in the central direction in which the cushion portion shrinks, enabling the movement of the protrusion within the fitting hole and absorbing the deformation of the cushion portion and the displacement of the protrusion. A technique is disclosed.

[0004] However, the bathtub stool described in Patent Document 2 does not control the contraction direction of the cushion portion by the fitting between the protrusion of the cushion portion and the fitting hole of the seat main body portion. So, if the contraction direction of the cushion portion does not coincide with the direction of the long hole of the fitting hole and is slightly displaced, particularly when the cushion portion shrinks greatly, friction occurs between the protrusion and the fitting hole, and the cushion portion floats or undulates from the main body portion, and there is a problem that the deformation of the cushion portion and the displacement of the protrusion cannot be sufficiently absorbed.

[0005] Furthermore, in the bathtub seat described in Patent Document 2, the fitting hole provided in the seat body is an elongated hole, while the protrusion provided in the cushion is cylindrical. As a result, the protrusion can only make contact with the edge of the fitting hole over a small area, and there is a problem that the protrusion cannot be sufficiently restrained within the fitting hole. Therefore, for example, when a user sits on the chair, if the cushion is subjected to a horizontal force, it can easily slide sideways and detach from the seat body. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2011-67448 [Patent Document 2] Japanese Patent Publication No. 2020-175225 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Therefore, the present invention aims to provide a cushion structure and a bathroom chair equipped therewith, which has a main body portion of the seat or backrest of a chair and a cushion portion that is detachably attached to the main body portion, and which can control the direction of deformation and absorb deformation even if the cushion portion undergoes thermal expansion or contraction due to changes over time, and can prevent the cushion portion from sliding sideways and detaching from the main body portion even if it is subjected to a horizontal force. [Means for solving the problem]

[0008] The inventors of the present invention have conducted extensive research on the structure of the cushion portion and the structure of the main body of the seat and backrest of the chair to which the cushion portion is attached. As a result, they have found that the above problems can be solved by arranging convex ridges and openings that contact the cushion portion and the main body radially from an arbitrary base point and making them movable, rather than providing columnar protrusions and elongated fitting holes that contact the cushion portion and the main body as lines (points in a plan view). This has led to the completion of the present invention.

[0009] In other words, the present invention provides a cushion structure comprising a main body that constitutes the base of the seat or backrest of a chair, and a cushion that is detachably attached to the main body, wherein the main body has a flat support portion and two or more openings that are open on the surface of the support portion and extend radially from a first base point located near the center of the support portion, and the cushion portion has a top plate portion supported by the support portion and two or more convex portions that are positioned on each of two or more displacement lines that protrude toward the back surface of the top plate portion toward the center of the top plate portion and extend radially from a second base point located near the center of the top plate portion, wherein the convex portions are arranged to align and fit with the openings of the main body to which the cushion portion is attached, the width dimension of the convex portions is approximately the same as the width dimension of the openings on the surface of the support portion, and the longitudinal dimension of the convex portions is approximately the same as the longitudinal dimension of the openings on the surface of the support portion, or shorter than the longitudinal dimension of the openings on the surface of the support portion. Furthermore, it is sufficient if there are two or more openings and two or more ridges in the radial direction, and there are no particular restrictions on their number or radial angle.

[0010] In the cushion structure of the present invention, the main body is provided with a bottomed groove-shaped or slit-shaped opening penetrating both the front and back surfaces, extending radially from near the center of the main body (first base point). The cushion portion is provided with a convex ridge on a displacement line extending radially from near the center of the cushion portion (second base point), and the convex ridge is fitted into the opening so as to be movable in the longitudinal direction (radial direction) of the opening. Therefore, the contraction direction of the cushion portion is controlled (guided) in the longitudinal direction (radial direction) of the opening and the corresponding longitudinal direction (radial direction) of the convex ridge, and the deformation of the cushion portion is reliably absorbed. For this reason, resin materials such as EVA exhibiting the above-mentioned properties can be suitably used as the material for the cushion portion.

[0011] Furthermore, in the cushion structure of the present invention, the protruding portion of the cushion and the opening of the main body have a certain length, and their respective sides can contact each other with a contact area larger than the contact area between the columnar projection and the elongated fitting hole. Therefore, the protruding portion is strongly restrained so as not to rotate, especially in the horizontal plane within the opening, and even if the cushion is subjected to a horizontal force, it is prevented from sliding sideways and detaching from the main body.

[0012] Furthermore, the protruding parts of the cushion only need to be able to make contact with the main body so that the cushion does not rotate within the opening of the main body. Therefore, the number of protruding parts and the number of bars in the opening do not necessarily need to be the same. If there are three or more bars in the opening, it is sufficient for there to be two or more protruding parts, and the number of protruding parts may even be less than the number of bars in the opening.

[0013] In the cushion structure of the present invention, the opening of the main body extends radially, including the vicinity of the center of the main body (first base point), whereas the protruding portion of the cushion only needs to be positioned on a displacement line extending radially from the vicinity of the center of the cushion (second base point), and does not necessarily need to extend including the vicinity of the center (second base point) like the opening. For this reason, the protruding portion may start at a position away from the vicinity of the center of the cushion (second base point), but in order to more strongly control (guide) the contraction direction of the cushion and more strongly prevent the cushion from sliding laterally and detaching from the main body, it is preferable that it extends radially, including the vicinity of the center of the cushion (second base point), similar to the opening of the main body.

[0014] In the cushion structure of the present invention, the opening of the main body may be formed by two openings extending in radial directions 180 degrees apart, thereby forming what appears to be a single straight opening, and the protruding portion of the cushion may also be formed by two protruding portions extending in radial directions 180 degrees apart, thereby forming what appears to be a single straight protruding portion.

[0015] However, in order to allow the movement of the protruding portion of the cushion within the opening of the main body and to strongly prevent the cushion from sliding sideways relative to the main body, it is preferable that the opening is formed from two or more openings that intersect at least near the center of the main body (first base point), such as being bent in a V-shape, and similarly, it is preferable that the protruding portion is formed from two or more protruding portions that intersect at least near the center of the cushion (second base point), such as being bent in a V-shape.

[0016] In the cushion structure of the present invention, the opening of the main body may be formed as a slit that penetrates the front and back surfaces of the support portion, or as a groove with a bottom.

[0017] Furthermore, in order to further prevent the cushion from shifting or detaching from the main body, the opening of the main body may be provided with a narrow opening formed adjacent to the surface of the support portion, having a width dimension approximately the same as the width dimension of the protruding part of the cushion in a vertical cross-section perpendicular to the longitudinal direction of the opening, and a wide opening formed adjacent to the narrow opening, having a width dimension wider than the width dimension of the narrow opening. Additionally, the protruding part of the cushion may be provided with a neck portion formed adjacent to the back surface of the top plate portion, having a width dimension approximately the same as the width dimension of the opening on the surface of the support portion of the main body in a vertical cross-section perpendicular to the longitudinal direction of the protruding part, and a widening portion formed adjacent to the neck portion, having a width dimension wider than the width dimension of the neck portion. [Effects of the Invention]

[0018] Thus, according to the present invention, a cushion structure is provided comprising a main body that constitutes the base of the seat or backrest of a chair, and a cushion that is detachably attached to the main body, wherein the main body has a flat support portion and two or more openings that are open on the surface of the support portion and extend radially from a first base point located near the center of the support portion, and the cushion portion has a top plate portion supported by the support portion and two or more convex portions that protrude on the back surface of the top plate portion toward the direction away from the top plate portion and are arranged on two or more displacement lines that extend radially from a second base point located near the center of the top plate portion, and the convex portions are arranged to align and fit with the openings of the main body to which the cushion portion is attached, the width dimension of the convex portions is approximately the same as the width dimension of the openings on the surface of the support portion, and the longitudinal dimension of the convex portions is approximately the same as the longitudinal dimension of the openings on the surface of the support portion, or shorter than the longitudinal dimension of the openings on the surface of the support portion.

[0019] According to the cushion structure of the present invention and the bathroom chair provided with the same, a bottomed groove-shaped or slit-shaped opening extending radially from near the center (first base point) of the main body portion is provided in the main body portion, and a convex strip portion is provided on a displacement line extending radially from near the center (second base point) of the cushion portion. Since the convex strip portion is fitted into the opening so as to be movable in the longitudinal direction (radial direction) of the opening, the contraction direction of the cushion portion is controlled (guided) in the longitudinal direction of the opening of the main body portion and the longitudinal direction (radial direction) of the convex strip portion that coincides with it, and the deformation of the cushion portion can be reliably absorbed.

[0020] Further, according to the cushion structure of the present invention and the bathroom chair provided with the same, the convex strip portion of the cushion portion and the opening of the main body portion have a certain length, and the side surfaces of each contact with a contact area larger than the contact area between the columnar protrusion and the long hole-shaped fitting hole. Therefore, the convex strip portion is strongly constrained so as not to rotate particularly in the horizontal plane in the opening, and even if the cushion portion receives a force in the horizontal direction, it is prevented from slipping sideways or disengaging with respect to the main body portion.

Brief Description of the Drawings

[0021] [Figure 1] It is a perspective view of the cushion structure according to an embodiment of the present invention and the bathroom chair provided with the same, viewed from above. [Figure 2] It is a perspective view of the bathroom chair shown in FIG. 1, viewed from below. [Figure 3A] Among the seat cushion structures according to the first embodiment shown in FIG. 1, it is a perspective view of only the seat cushion portion, viewed from below. [Figure 3B] Among the seat cushion structures according to the first embodiment, it is a perspective view of only the seat main body portion, viewed from above. [Figure 4A] Among the seat cushion structures according to the second embodiment, it is a perspective view of only the seat cushion portion, viewed from below. [Figure 4B] Among the seat cushion structures according to the second embodiment, it is a perspective view of only the seat main body portion, viewed from above. [Figure 5A] Of the seat cushion structure according to the third embodiment, it is a perspective view of only the seat cushion portion seen from below. [Figure 5B] Of the seat cushion structure according to the third embodiment, it is a perspective view of only the seat main body portion seen from above. [Figure 6A] Of the seat cushion structure according to the fourth embodiment, it is a perspective view of only the seat cushion portion seen from below. [Figure 6B] Of the seat cushion structure according to the fourth embodiment, it is a perspective view of only the seat main body portion seen from above. [Figure 7] It is a longitudinal sectional view in the width direction schematically showing the fitting state between the opening of the main body portion and the rib portion of the cushion portion. In (a), the opening and the rib portion have a constant width form, in (b), the opening has a constant width and the rib portion has a widened portion, in (c), the opening and the rib portion have a widened portion in a stepped shape, and in (d), the opening and the rib portion have a widened portion in a trapezoidal (tapered) shape.

Mode for Carrying Out the Invention

[0022] Hereinafter, a cushion structure according to an embodiment of the present invention and a bathroom chair provided with the same will be described in detail with reference to the drawings. Note that the present invention is not limited to the examples shown below, and various modifications are possible without departing from the technical idea of the present invention.

[0023] ]> <Bathroom chair provided with a cushion structure> FIG. 1 shows a perspective view of a seat cushion structure 2, a backrest cushion structure 5 according to an embodiment of the present invention, and a bathroom chair 1 provided with the same seen from above, and FIG. 2 shows a perspective view of the bathroom chair 1 shown in FIG. 1 seen from below.

[0024] The seat cushion structure 2 and back cushion structure 5 of this embodiment are suitably used in a bathroom chair 1 to assist the movements of the elderly and those requiring care in humid bathrooms and bathtubs. Therefore, this embodiment mainly describes the seat cushion structure 2 used in the bathroom chair 1, but the usage of the cushion structures 2 and 5 of the present invention is not limited to this.

[0025] As shown in Figures 1 and 2, the bathroom chair 1 of this embodiment consists of a seat cushion structure 2, a back cushion structure 5, armrests 8, and legs 9. The legs 9 include a pair of front leg frames 90 that extend upward from below and support the back of the back cushion structure 5, and a pair of rear leg frames 91 that are rotatably connected to the front leg frames 90 and extend upward from below to rotatably support the back of the seat cushion structure 2. An armrest 8 is also rotatably attached to each of the pair of front leg frames 90.

[0026] The front leg frame 90 and the rear leg frame 91 are both formed from hollow metal pipes, but the material is not limited to this. Sleeve-shaped movable front leg parts 900 and 910 are slidably mounted on the outer circumference of the front leg portion of the front leg frame 90 and the outer circumference of the rear leg portion of the rear leg frame 91, respectively, and are configured to allow adjustment of the length of the legs of the front leg frame 90 and the rear leg frame 91, in other words, the height of the seat cushion structure 2. In addition, a resin cap 911 is attached to the tip of the movable rear leg part 910 to prevent scratching the floor and slipping, and a resin cap 901 with a roller is attached to the movable front leg part 900, which has a contact surface and rollers to prevent scratching the floor and slipping, as well as to facilitate opening and closing the legs of the bathroom chair 1.

[0027] By adopting the above configuration, the bathroom chair 1 of this embodiment can open and close the front leg frame 90 and the rear leg frame 91 between an open leg state where they are spaced apart from each other and a closed leg state where they are close together. In conjunction with the movement of the front leg frame 90 and the rear leg frame 91, the seat cushion structure 2 can rotate between a substantially horizontal unfolded state and a substantially vertical folded state. It should be noted that the bathroom chair 1 of this embodiment is merely an example, and the seat cushion structure 2 may also include a seat main body 3 and a seat cushion 4 that can be detachably attached to the seat main body 3, even if it does not have a backrest cushion structure 5, or a bath chair that is normally used by being immersed in a bathtub.

[0028] <Cushion structure> As shown in Figures 1 and 2, the seat cushion structure 2 used in the bathroom chair 1 of this embodiment consists of a seat body 3 and a seat cushion 4 that is detachably attached to the surface of the seat body 3. The backrest cushion structure 5 used in the bathroom chair 1 of this embodiment consists of a backrest body 6 and a backrest cushion 7 that is detachably attached to the surface of the backrest body 6.

[0029] <First Embodiment> Figure 3A shows a perspective view from below of only the seat cushion portion 4a of the seat cushion structure 2 according to the first embodiment shown in Figure 1, and Figure 3B shows a perspective view from above of only the seat body portion 3a of the seat cushion structure 2 according to the first embodiment.

[0030] In the seat cushion structure 2 of the first embodiment, the seat body 3a is a hollow component formed from a hard resin such as PE (polyethylene) or PP (polypropylene) considering water resistance and chemical resistance, but the material is not limited to these.

[0031] As shown in Figure 3B, the seat body 3a has a support portion 30 with a flat surface, and four openings 31a, 31b, 31c, and 31d that open on the surface of the support portion 30 and extend in four different radial directions from a first base point a located near the center of the support portion 30. Therefore, in the first embodiment, the openings 31a to 31d of the seat body 3a are formed in an X shape that intersects at the first base point a, and are also formed in a bottomed groove shape. The openings 31a to 31d may also be formed in a slit shape that penetrates the surface and back surface of the seat body 3a (support portion 30) (not shown).

[0032] Furthermore, although not shown in the figures, the surface of the seat body 3a (support portion 30) may have a "V" shaped drainage groove that is aligned to communicate with the drainage holes provided in the seat cushion portion 4a when the seat cushion portion 4a is attached, and drainage holes that communicate with the drainage groove and penetrate the seat body 3a may be provided at both ends thereof. In addition, the rear part of the seat body 3a (the side closer to the back cushion structure 5) may be provided with a roughly square-shaped handle cut out for gripping when carrying the bathroom chair 1.

[0033] In this invention, "flat" on the surface of the support portion 30 does not mean a perfectly flat surface in the strict sense. For the seat cushion structure 2, it is sufficient if it is flat enough to distribute the body pressure transmitted to the user's buttocks and support it across a surface. For the backrest cushion structure 5, it is sufficient if it is flat enough to distribute the body pressure transmitted to the user's back and support it across a surface. Therefore, "flat" means that as long as it is flat as described above, it may be curved overall, form a curved surface such as a mortar, or have localized irregularities or openings.

[0034] The seat cushion portion 4a is made from EVA resin (ethylene vinyl acetate copolymer resin) to provide high flexibility and water resistance, but the material is not limited to this. Other materials that can be used for the seat cushion portion 4a include PP (polypropylene) resin, PE (polyethylene) resin, AS (acrylonitrile / styrene) resin, or urethane resin, which have elasticity imparted by foaming conditions and compounding composition.

[0035] On the other hand, as shown in Figure 3A, the seat cushion portion 4a has a top plate portion 40 supported by a support portion 30 of the seat body portion 3a, and four convex portions 41a, 41b, 41c, and 41d that protrude from the back surface 400 of the top plate portion 40 in a direction away from the top plate portion 40 and are positioned on each of four imaginary upper displacement lines P that extend in four different radial directions from a second base point b located near the center of the top plate portion 40. Therefore, in the first embodiment, the convex portions 41a to 41d of the seat cushion portion 4a are formed in an X shape that intersects at the second base point b.

[0036] Furthermore, although not shown in the figures, the seat cushion portion 4a (top plate portion 40) may be provided with a roughly rectangular handle recess at a position aligned with the handle portion provided on the seat body portion 3a. In addition, the rear part of the seat body portion 3a (the side closer to the backrest cushion structure 5) may be provided with drainage holes to allow water accumulated on the surface of the top plate portion 40 to escape.

[0037] In the first embodiment, the seat cushion portion 4a is attached so as to cover the seat body portion 3a (Figure 1). At that time, the protrusions 41a to 41d are positioned on the back surface 400 of the top plate portion 40 so as to align with and fit with the openings 31a to 31d of the seat body portion 3a to which the seat cushion portion 4a is attached. Furthermore, the width dimension of the protrusions 41a to 41d of the seat cushion portion 4a is approximately the same as the width dimension of the openings 31a to 31d on the surface of the support portion 30 of the seat body portion 3a, and the longitudinal dimension of the protrusions 41a to 41d is approximately the same as the longitudinal dimension of the openings 31a to 31d on the surface of the support portion 30, or is formed to be shorter than the longitudinal dimension of the openings 31a to 31d on the surface of the support portion 30.

[0038] Thus, in the first embodiment, the seat body 3a is provided with bottomed groove-shaped openings 31a to 31d extending radially from near the center of the seat body 3a (first base point a), and the seat cushion 4a is provided with protruding portions 41a to 41d on a virtual displacement line P extending radially from near the center of the seat cushion 4a (second base point b), so that the protruding portions 41a to 41d are fitted into the openings 31a to 31d so as to be movable in the longitudinal direction (radial direction) of the openings 31a to 31d.

[0039] Therefore, the contraction direction of the seat cushion portion 4a is controlled (guided) toward the longitudinal direction of the openings 31a to 31d and the longitudinal direction (radial direction) of the convex portions 41a to 41d that coincide with it, and the deformation of the seat cushion portion 4a is reliably absorbed. As a result, the seat cushion portion 4a contracts toward the second base point b of the convex portions 41a to 41d that extend in the radial direction (the first base point a of the openings 31a to 31d that coincides with it), so that the second base point b forms the center or vicinity of the center of the contraction of the seat cushion portion 4a.

[0040] Furthermore, in the first embodiment, the protrusions 41a to 41d of the seat cushion portion 4a and the openings 31a to 31d of the seat body portion 3a have a certain length, and their respective sides contact each other with a contact area larger than the contact area between the columnar protrusion and the elongated fitting hole. Therefore, the protrusions 41a to 41d are strongly restrained so as not to rotate, especially in the horizontal plane within the openings 31a to 31d. Thus, even if the seat cushion portion 4a is subjected to a horizontal force, it is prevented from sliding sideways and detaching from the seat body portion 3a.

[0041] In this invention, it is sufficient for the width dimensions of the protrusions 41a to 41d of the seat cushion portion 4a to be "approximately the same" as the width dimensions of the openings 31a to 31d of the seat body portion 3a because the seat cushion portion 4a is softer than the seat body portion 3a, and the protrusions 41a to 41d can move while deforming even if their width dimensions are slightly wider or narrower than the width dimensions of the openings 31a to 31d. Therefore, the width dimensions of the protrusions 41a to 41d do not need to be exactly the same as the width dimensions of the openings 31a to 31d in a strict sense; they may be slightly wider or narrower than the width dimensions of the protrusions 41a to 41d as long as they are large enough to move even when fitted into the openings.

[0042] Furthermore, in the present invention, it is sufficient that the longitudinal dimension of the protrusions 41a to 41d of the seat cushion portion 4a is approximately the same length as the longitudinal dimension of the openings 31a to 31d of the seat body portion 3a, or shorter than the longitudinal dimension of the openings 31a to 31d, because the seat cushion portion 4a is softer than the seat body portion 3a, so even if the initial longitudinal dimension of the protrusions 41a to 41d is slightly longer than the longitudinal dimension of the openings 31a to 31d, they can fit into the openings 31a to 31d and contract towards the first base point a (second base point b) within the openings 31a to 31d.

[0043] Therefore, if the longitudinal dimension of the protruding sections 41a to 41d is shorter than the longitudinal dimension of the openings 31a to 31d, it is preferable to bring the tip of the protruding section 41a to 41d on the side furthest from the second base point b into contact with the tip of the opening 31a to 31d on the side furthest from the first base point a, and to create a gap between the base end of the protruding section 41a to 41d on the side closer to the second base point b and the first base point a of the openings 31a to 31d to maximize the shrinkage allowance of the seat cushion section 4a.

[0044] In the first embodiment, the protruding portions 41a to 41d of the seat cushion portion 4a only need to be able to contact the seat cushion portion 4a within the openings 31a to 31d of the seat body portion 3a so that the seat cushion portion 4a does not rotate relative to the seat body portion 3a. Therefore, the number of protruding portions and the number of grooves in the openings do not necessarily need to be the same. For four grooves in the openings 31a to 31d, it is sufficient to have two or more protruding portions, and the number of protruding portions may be less than the number of grooves in the openings 31a to 31d (not shown).

[0045] Furthermore, in the first embodiment, the openings 31a to 31d of the seat body 3a extend radially, including the vicinity of the center of the seat body 3a (first base point a), whereas the protruding portions 41a to 41d of the seat cushion 4a only need to be positioned on a displacement line P extending radially from the vicinity of the center of the seat cushion 4a (second base point b), and do not necessarily need to extend including the vicinity of the center (second base point b) like the openings 31a to 31d. For this reason, although not shown, the protruding portion may have a protruding shape that begins at a position away from the vicinity of the center of the seat cushion 4a (second base point b).

[0046] <Second Embodiment> Figure 4A shows a perspective view from below of only the seat cushion portion 4b of the seat cushion structure 2 according to the second embodiment, and Figure 4B shows a perspective view from above of only the seat body portion 3b of the seat cushion structure 2 according to the second embodiment.

[0047] The seat cushion portion 4b and seat body portion 3b of the second embodiment shown in Figures 4A and 4B differ from the seat cushion portion 4a and seat body portion 3a of the first embodiment in the shape of the protruding portion and the shape of the opening.

[0048] As shown in Figure 4B, the seat body 3b has a support portion 30 with a flat surface, and two openings 31a and 31b that open on the surface of the support portion 30 and extend in two radial directions 180 degrees apart from a first base point a located near the center of the support portion 30. That is, in the second embodiment, the two openings 31a and 31b of the seat body 3b are formed to appear as a single straight opening 31a and 31b by extending in radial directions 180 degrees apart. In the second embodiment, the openings 31a and 31b are formed as bottomed grooves, but they may also be formed as slits that penetrate the surface and back surface of the seat body 3b (support portion 30) (not shown).

[0049] On the other hand, as shown in Figure 4A, the seat cushion portion 4b has a top plate portion 40 supported by a support portion 30 of the seat body portion 3b, and two convex portions 41a, 41b that protrude from the back surface 400 of the top plate portion 40 toward the top plate portion 40 and are positioned on two imaginary upper displacement lines P that extend in two radial directions 180 degrees apart from a second base point b located near the center of the top plate portion 40. That is, in the second embodiment, the two convex portions 41a, 41b of the seat cushion portion 4b are formed to appear as a single straight convex portion 41a, 41b by extending in radial directions 180 degrees apart.

[0050] In the second embodiment, the seat body 3b and seat cushion 4b have a significantly smaller number of openings 31a, 31b and protrusions 41a, 41b compared to other embodiments. This allows for efficient control (guidance) of the contraction direction of the seat cushion 4b in the longitudinal direction of the openings 31a, 31b of the seat body 3b and the longitudinal direction (radial direction) of the protrusions 41a, 41b that coincide with them, thereby reliably absorbing the deformation of the seat cushion 4b.

[0051] Furthermore, according to the seat body 3b and seat cushion 4b of the second embodiment, the protrusions 41a and 41b are strongly restrained so as not to move in a direction perpendicular to the longitudinal direction of the openings 31a and 31b, or to rotate within the horizontal plane of the openings 31a and 31b. In particular, even if the seat cushion 4b is subjected to force in a direction perpendicular to the longitudinal direction of the protrusions 41a and 41b, it is prevented from sliding laterally and detaching from the seat body 3b. For this reason, the shape of the protrusions 41a and 41b and the openings 31a and 31b in the second embodiment can be suitably used in the back cushion 7 and back cushion body 6 of the back cushion structure 5, which are often subjected to force in one direction (vertical direction).

[0052] Note that the seat cushion portion 4b and seat body portion 3b of the second embodiment shown in Figures 4A and 4B are the same as the seat cushion portion 4a and seat body portion 3a of the first embodiment in terms of their other features and effects, except for the difference in the shape of the protruding portion and the shape of the opening described above, so a detailed explanation is omitted here.

[0053] <Third Embodiment> Figure 5A shows a perspective view from below of only the seat cushion portion 4c of the seat cushion structure 2 according to the third embodiment, and Figure 5B shows a perspective view from above of only the seat body portion 3c of the seat cushion structure 2 according to the third embodiment.

[0054] The seat cushion portion 4c and seat body portion 3c of the third embodiment shown in Figures 5A and 5B differ from the seat cushion portion 4a and seat body portion 3a of the first embodiment in the shape of the protruding portion and the shape of the opening.

[0055] As shown in Figure 5B, the seat body 3c has a support portion 30 with a flat surface, and two openings 31a and 31b that open on the surface of the support portion 30 and intersect at a first base point a located near the center of the support portion 30. That is, in the third embodiment, the two openings 31a and 31b of the seat body 3c bend in a V-shape near the center of the seat body 3c (first base point a) and extend in two different radial directions. In the third embodiment, the openings 31a and 31b are formed as bottomed grooves, but they may also be formed as slits that penetrate the surface and back surface of the seat body 3c (support portion 30) (not shown).

[0056] On the other hand, as shown in Figure 5A, the seat cushion portion 4c has a top plate portion 40 supported by a support portion 30 of the seat body portion 3c, and two convex portions 41a and 41b that protrude from the back surface 400 of the top plate portion 40 toward the direction away from the top plate portion 40 and intersect at a second base point b located near the center of the top plate portion 40. That is, in the third embodiment, the two convex portions 41a and 41b of the seat cushion portion 4c are bent in a V-shape near the center of the top plate portion 40 (second base point b) and are positioned on two different imaginary upper displacement lines P extending in two different radial directions.

[0057] In the third embodiment, the seat body 3c and seat cushion 4c have a significantly smaller number of openings 31a, 31b and protrusions 41a, 41b compared to the other embodiments. This allows for efficient control (guidance) of the contraction direction of the seat cushion 4c in the longitudinal direction of the openings 31a, 31b of the seat body 3c and the longitudinal direction (radial direction) of the protrusions 41a, 41b that coincide with them, thereby reliably absorbing the deformation of the seat cushion 4c.

[0058] Furthermore, according to the seat body 3c and seat cushion 4c of the third embodiment, the protruding parts 41a and 41b are more strongly restrained than in the second embodiment so as not to rotate in the horizontal plane within the openings 31a and 31b. In particular, even if the seat cushion 4c is subjected to a horizontal force, it is prevented from sliding sideways and detaching from the seat body 3c.

[0059] Note that the seat cushion portion 4c and seat body portion 3c of the third embodiment shown in Figures 5A and 5B are the same as the seat cushion portion 4a and seat body portion 3a of the first embodiment in terms of their other features and effects, except for the difference in the shape of the protruding portion and the shape of the opening described above, so a detailed explanation is omitted here.

[0060] <Fourth Embodiment> Figure 6A shows a perspective view from below of only the seat cushion portion 4d of the seat cushion structure 2 according to the fourth embodiment, and Figure 6B shows a perspective view from above of only the seat body portion 3d of the seat cushion structure 2 according to the fourth embodiment.

[0061] The seat cushion portion 4d and seat body portion 3d of the fourth embodiment shown in Figures 6A and 6B differ from the seat cushion portion 4a and seat body portion 3a of the first embodiment in the shape of the protruding portion and the shape of the opening.

[0062] As shown in Figure 6B, the seat body 3d has a support portion 30 with a flat surface, and three openings 31a, 31b, and 31c that open on the surface of the support portion 30 and extend in three different radial directions from a first base point a located near the center of the support portion 30. Therefore, in the fourth embodiment, the openings 31a to 31c of the seat body 3d are formed in a Y-shape that intersects at the first base point a, and are also formed in a bottomed groove shape. The openings 31a to 31c may also be formed in a slit shape that penetrates the surface and back surface of the seat body 3d (support portion 30) (not shown).

[0063] On the other hand, as shown in Figure 6A, the seat cushion portion 4d has a top plate portion 40 supported by a support portion 30 of the seat body portion 3d, and three convex portions 41a, 41b, and 41c that protrude from the back surface 400 of the top plate portion 40 in a direction away from the top plate portion 40 and are positioned on each of three imaginary upper displacement lines P that extend in three different radial directions from a second base point b located near the center of the top plate portion 40. Therefore, in the fourth embodiment, the convex portions 41a to 41c of the seat cushion portion 4d are formed in a Y shape that intersects at the second base point b.

[0064] In the seat body 3d and seat cushion 4d of the fourth embodiment, the number of openings 31a to 31c and protrusions 41a to 41c efficiently control (guide) the contraction direction of the seat cushion 4d to the longitudinal direction of the openings 31a to 31c of the seat body 3d and the longitudinal direction (radial direction) of the protrusions 41a to 41c that coincide with them, thereby reliably absorbing the deformation of the seat cushion 4d.

[0065] Furthermore, according to the seat body 3d and seat cushion 4d of the fourth embodiment, the protruding portions 41a to 41c are more strongly restrained than in the third embodiment so as not to rotate within the horizontal plane of the openings 31a to 31c. In particular, even if the seat cushion 4d is subjected to a force in the horizontal direction, it is prevented from sliding sideways and detaching from the seat body 3d.

[0066] Note that the seat cushion portion 4d and seat body portion 3d of the fourth embodiment shown in Figures 6A and 6B are the same as the seat cushion portion 4a and seat body portion 3a of the first embodiment in terms of their other features and effects, except for the difference in the shape of the protruding portion and the shape of the opening described above, so a detailed explanation is omitted here.

[0067] <Common to Embodiments 1-4> Figure 7 is a schematic vertical cross-sectional view in the width direction showing the fitting state between the opening 31 of the seat or backrest main body 3,6 and the protruding portion 41 of the seat or backrest cushion 4,7 as an example common to the first to fourth embodiments described above, in which (a) the opening 31 and the protruding portion 41 are of a constant width, (b) the opening 31 is of a constant width and the protruding portion 41 has a widened portion, (c) the opening 31 and the protruding portion 41 have a stepped widened portion, and (d) the opening 31 and the protruding portion 41 have a trapezoidal (tapered) widened portion.

[0068] In the embodiment shown in Figure 7(a), the opening 31 of the main body 3,6 is formed as a bottomed groove and has a constant width dimension in the depth direction of the opening 31. On the other hand, the protruding portion 41 of the cushion portion 4,7 that fits into the opening 31 has a width dimension that is approximately the same as the width dimension of the opening 31 and has a constant width dimension in the protruding direction of the protruding portion 41. However, since the protruding portion 41 can move inside the opening 31 by deforming, the width dimension of the protruding portion 41 may be made slightly wider than the width dimension of the opening 31, or approximately the same length, in order to prevent the cushion portion 4,7 from easily detaching from the main body 3,6. In addition, although the opening 31 is formed as a bottomed groove in this embodiment, it may also be formed as a slit that penetrates the front and back surfaces of the support portion 30 of the main body 3,6.

[0069] In this embodiment, in order to further prevent the cushion portions 4 and 7 from shifting or detaching from the main body portions 3 and 6, the openings 31 of the main body portions 3 and 6 may be provided with a narrow opening 310 formed adjacent to the surface of the support portion 30, having a width dimension approximately the same as the width dimension of the protruding portion 41 of the cushion portions 4 and 7 in the vertical cross section in the width direction of the opening 31 (a vertical cross section perpendicular to the longitudinal direction of the opening 31), and a wide opening 311 formed adjacent to the narrow opening 310, having a width dimension wider than the narrow opening 310 (Figures 7(c), (d)).

[0070] Furthermore, for the same purposes as described above, the protruding portion 41 of the cushion portion 4,7 may be provided with a neck portion 410 that has a width dimension approximately the same as the width dimension of the opening 31 on the surface of the support portion 30 of the main body portion 3,6 and is formed adjacent to the back surface 400 of the top plate portion 40 in the vertical cross section in the width direction of the protruding portion 41 (a vertical cross section perpendicular to the longitudinal direction of the protruding portion 41), and a widening portion 411 that has a width dimension wider than the width dimension of the neck portion 410 and is formed adjacent to the neck portion 410 (Figures 7(b), (c), (d)).

[0071] More specifically, in the embodiment shown in Figure 7(b), the opening 31 of the main body 3,6 is formed in the shape of a slit that penetrates the front and back surfaces of the support 30, and has a constant width dimension in the depth direction of the opening 31. On the other hand, the protruding portion 41 of the cushion portion 4,7 that fits into the opening 31 has a neck portion 410 that has a width dimension approximately the same length as the width dimension of the opening 31 and has a constant width dimension in the protruding direction of the protruding portion 41, and a widening portion 411 that has a width dimension wider than the width dimension of the neck portion 410 and is formed adjacent to the neck portion 410. As a result, in this embodiment, the protruding portion 41 is effectively prevented from coming out of the opening 31, and the cushion portion 4,7 is prevented from easily detaching from the main body 3,6.

[0072] In the embodiment shown in Figure 7(c), the opening 31 of the main body 3,6 is formed in the shape of a bottomed groove, and has a narrow opening 310 formed adjacent to the surface of the support 30 and having a constant width dimension that is approximately the same as the width dimension of the protruding portion 41 of the cushion portion 4,7 in the depth direction of the opening 31, and a wide opening 311 formed adjacent to the narrow opening 310 and having a width dimension that is wider than the width dimension of the narrow opening 310, forming a step. On the other hand, the protruding portion 41 of the cushion portion 4,7 that is fitted into the opening 31 has a neck portion 410 that has a width dimension that is approximately the same as the width dimension of the narrow opening 310 and has a constant width in the protruding direction of the protruding portion 41, and a widened portion 411 formed adjacent to the neck portion 410 and having a width dimension that is wider than the width dimension of the neck portion 410. As a result, in this embodiment, the protruding portion 41 is effectively prevented from coming out of the opening 31 and the cushion portion 4,7 from easily detaching from the main body 3,6. In this embodiment, the opening 31 is formed as a bottomed groove, but it may also be formed as a slit that penetrates the front and back surfaces of the support portion 30 of the main body portion 3, 6.

[0073] In the embodiment shown in Figure 7(d), the opening 31 of the main body 3,6 is formed in the shape of a bottomed groove, and is trapezoidal in shape so as to connect a narrow opening 310, which has a width dimension approximately the same as the width dimension of the protruding portion 41 of the cushion portion 4,7 and is formed adjacent to the surface of the support portion 30 of the main body 3,6, and a wide opening 311, which has a width dimension wider than the width dimension of the narrow opening 310 and is formed adjacent to the narrow opening 310, with a continuous tapered surface. On the other hand, the protruding portion 41 of the cushion portion 4,7 that fits into the opening 31 is trapezoidal in shape so as to connect a neck portion 410, which has a width dimension approximately the same as the width dimension of the narrow opening 310, and a widening portion 411, which has a width dimension wider than the width dimension of the neck portion 410 and is formed adjacent to the neck portion 410, with a continuous tapered surface. As a result, in this embodiment, the protruding portion 41 is effectively prevented from coming out of the opening 31 and the cushion portion 4,7 from easily detaching from the main body 3,6. In this embodiment, the opening 31 is formed as a bottomed groove, but it may also be formed as a slit that penetrates the front and back surfaces of the support portion 30 of the main body portion 3, 6.

[0074] <Backrest cushion structure> The cushion structure of the present invention and the bathroom chair equipped therewith can also be configured as a backrest cushion structure 5 and a bathroom chair 1 equipped therewith, as described above. In this case, the backrest cushion structure 5 used in the bathroom chair 1 of this embodiment consists of a backrest body 6 and a backrest cushion 7 that is detachably attached to the surface of the backrest body 6, as shown in Figures 1 and 2.

[0075] In addition, the back cushion structure 5 of this embodiment has the same configuration as the seat cushion structure 2 of the first to fourth embodiments described above, including the opening 31 formed in the back cushion body 6, the protrusion 41 formed in the back cushion 7 that engages with the opening 31, and the materials of the back cushion body 6 and the back cushion 7. Therefore, a detailed explanation is omitted here.

[0076] In the backrest cushion structure 5 of this embodiment, similar to the seat cushion structure 2 of the first to fourth embodiments, the fitting (engagement) of the radially extending protrusions 41 with the opening 31 controls (guides) the contraction direction of the backrest cushion 7 to the longitudinal direction of the opening 31 of the backrest body 6 and the longitudinal direction (radial direction) of the protrusions 41 that coincide with it, thereby reliably absorbing the deformation of the backrest cushion 7. Furthermore, since the protrusions 41 are strongly restrained to prevent rotation, especially within the horizontal plane of the opening 31, the backrest cushion 7 is prevented from sliding sideways and detaching from the backrest body 6 even when subjected to horizontal force. [Explanation of symbols]

[0077] 1...bathroom chair 2. Seat cushion structure 3,3a,3b,3c,3d... Seat body part 30...Support part 31,31a,31b,31c,31d...opening 310...Narrow opening 311... Wide opening 4, 4a, 4b, 4c, 4d... Seat cushion section 40····Top panel 400...Back side 41,41a,41b,41c,41d... Convex part 410... Neck section 411... Widening section 5. Backrest cushion structure 6. Backrest main body 7. Backrest cushion section 8. Armrest 9... Legs 90····Front leg frame 900... Front leg movable part 901... Resin cap with roller 91...Rear leg frame 910... Rear leg movable part 911... Resin cap a·····First starting point b....Second base point P·····Displacement line

Claims

1. The main body that forms the base of the seat or backrest of the chair, A cushion structure comprising a cushion portion that can be detachably attached to the main body, The main body is, A flat support section, The surface of the support portion has two or more openings that are open and extend radially from a first base point located near the center of the support portion, The aforementioned cushion part is The top plate portion is supported by the aforementioned support portion, The back surface of the top plate portion has two or more protruding ridges that project in a direction away from the top plate portion and are arranged on two or more displacement lines that extend radially from a second base point located near the center of the top plate portion, and The aforementioned protruding portion is arranged to align with and fit into the opening of the main body portion to which the cushion portion is attached. The width dimension of the protruding portion is approximately the same as the width dimension of the opening on the surface of the support portion. The cushion structure is characterized in that the longitudinal dimension of the protruding portion is approximately the same length as the longitudinal dimension of the opening on the surface of the support portion, or shorter than the longitudinal dimension of the opening on the surface of the support portion.

2. The cushion structure is characterized in that the convex portion extends radially from a second base point located near the center of the top plate portion.

3. The cushion structure according to claim 2, characterized in that the opening has at least two or more openings that intersect at the first base point.

4. The cushion structure according to claim 3, characterized in that the aforementioned protruding portion has at least two or more protruding portions that intersect at the second base point.

5. The cushion structure according to claim 2, characterized in that the opening is formed in the shape of a slit that penetrates the front and back surfaces of the support portion.

6. The cushion structure according to claim 2, characterized in that the opening is formed in the shape of a bottomed groove.

7. The cushion structure according to claim 1, characterized in that the cushion portion is formed from EVA resin.

8. The cushion structure according to claim 5 or 6, characterized in that the opening has a narrow opening formed adjacent to the surface of the support portion and having a width dimension approximately the same as the width dimension of the protruding portion in a vertical cross section perpendicular to the longitudinal direction of the opening, and a wide opening formed adjacent to the narrow opening and having a width dimension wider than the width dimension of the narrow opening.

9. The cushion structure according to claim 5 or 6, characterized in that the protruding portion has a width dimension in a longitudinal cross section perpendicular to the longitudinal direction of the protruding portion that is approximately the same length as the width dimension of the opening on the surface of the support portion and is formed adjacent to the back surface of the top plate portion, and has a widening portion that has a width dimension wider than the width dimension of the neck portion and is formed adjacent to the neck portion.

10. A bathroom chair characterized by comprising a cushion structure according to any one of claims 1 to 7.

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