JP7086543B2 - Posture holder - Google Patents

Description

The present invention relates to a posture holder.

Patent Document 1 discloses a posture holder that keeps the seated posture in a correct state. This posture holder includes a buttocks support portion that supports the buttocks of the seated person from below, and a lumbar support portion that rises from the trailing edge of the buttocks support portion. The lumbar support portion has a height capable of supporting the waist of the seated person and the lower end portion of the back, and has a substantially rectangular plate shape as a whole.

Japanese Unexamined Patent Publication No. 2014-12130

In the above posture holder, the front surface of the lumbar support (the surface where the waist and back touch) is generally flat, so the seated person can tilt the upper body to the left or right or twist the upper body to the left or right. Easy to do. However, since this posture holder cannot stabilize the upper body of the seated person in the correct posture, the seated person spends a long time with the upper body tilted to the left and right or the upper body twisted to the left and right. There is concern that it will end up.

The present invention has been completed based on the above circumstances, and an object of the present invention is to hold the upper body of the seated person in a correct posture.

The posture holder of the present invention is
With the seat
The backrest, which stands up from the rear end of the seat,
A first support portion that constitutes the backrest portion and abuts the central portion of the seater's back in the left-right direction, and a first support portion.
A pair that constitutes the backrest and is arranged on both the left and right sides of the first support portion by extending from the left and right side edges of the first support portion, and abuts the left and right side portions of the back of the seated person. Equipped with a second support part of
The lowermost end portion of the upper edge portion of the first support portion is arranged at a position lower than the uppermost end portion of the upper edge portion of the second support portion.
The first support portion supports the entire or part of the seated person's back from the upper part of the lumbar spine to the lower part of the thoracic spine.
The second support portion supports all or part of the corresponding portion of the back of the ribs on the back of the occupant from the lower part of the thoracic vertebra to the middle height of the thoracic vertebra.
The upper end portion of the first support portion is curved so as to warp diagonally upward and backward.

The seated person sits with a relatively low portion in the central part of the back against the first support portion and a relatively high portion in both the left and right sides of the back against the second support portion. Since the posture holder of the present invention supports the back of the occupant with three support portions, it suppresses the occupant's upper body from being tilted to the left or right or twisted to the left or right, and the occupant's upper body is correct. Can be held in posture.

Perspective view of the posture holder of the first embodiment Front view of posture holder Top view of posture holder A-A line cross-sectional view omitting the exterior sheet of FIG. BB line cross-sectional view omitting the exterior sheet of FIG. A cross-sectional view taken along the line CC in which the exterior sheet of FIG. 2 is omitted. DD line cross-sectional view omitting the exterior sheet of FIG. EE line cross-sectional view omitting the exterior sheet of FIG. FF line cross-sectional view omitting the exterior sheet of FIG. GG line cross-sectional view omitting the exterior sheet of FIG. HH line cross-sectional view omitting the exterior sheet of FIG. FIG. 2 is a cross-sectional view corresponding to line AA showing the usage state of the posture holder.

In the present invention, the upper end portion of the second support portion may be curved so as to warp diagonally backward toward the upper side.
According to this configuration, there is no possibility that the upper end edge of the second support portion will bite into the seated person's body when the upper body of the seated person is leaned deeply against the backrest portion.

In the present invention, the seat portion constituent plate portion constituting the seat portion and the backrest portion constituent plate portion constituting the backrest portion are elastically displaced relative to each other with the lower end portion of the backrest portion constituent plate portion as a substantially fulcrum. The backrest portion constituting plate portion is connected so as to be possible, and the backrest portion constituting plate portion protrudes diagonally forward from the first support plate portion constituting the first support portion and the left and right side edges of the first support plate portion to support the second support portion. It is composed of a second support plate portion constituting the portion, and the protrusion dimension from the first support plate portion in the lower end side region of the second support plate portion may be gradually reduced downward.
According to this configuration, when the seated person presses the upper body against the backrest, the backrest is elastically displaced backward with the lower end edge as a substantially fulcrum. Since the protrusion dimension from the first support plate portion in the lower end side region of the second support plate portion gradually decreases downward, the lower end side region of the backrest portion constituent plate portion is also elastically deformed. This makes it possible to prevent stress concentration on the lower end edge of the backrest portion constituent plate portion.

In the present invention, the first support surface of the first support portion facing the back and the second support surface of the second support portion facing the back are connected via a pair of left and right connecting surfaces. In a plan view, the curvature of the first support surface and the curvature of the second support surface may be smaller than the curvature of the connecting surface.
According to this configuration, since the back does not hit the connecting surface having a large curvature, the upper body of the seated person can be stably supported at three points of the first support surface and the pair of left and right second support surfaces. ..

<Example 1>
Hereinafter, Example 1 embodying the present invention will be described with reference to FIGS. 1 to 12. In the following description, the front-back direction is defined as the left side in FIGS. 4 to 6 and 12 and the lower side in FIGS. 3 and 7 to 10 as the front direction. As for the vertical direction, the directions appearing in FIGS. 1, 2, 4 to 6, 11 and 12 are defined as upward and downward as they are. Regarding the left-right direction, the directions appearing in FIGS. 2, 3, 7 to 11 are defined as left and right as they are.

The posture holder 10 of the first embodiment is structurally and functionally composed of a seat portion 11 that supports the buttocks 51 of the seated person 50 from below, and a backrest portion 16 that supports the back 52 of the seated person 50 from behind. It is configured and has a symmetrical shape. The seat portion 11 and the backrest portion 16 are integrated. In the first embodiment, the "back 52 of the seated person 50" is defined as the back and waist of the seated person 50 (the back side and the side surface side of the trunk of the upper body).

The plan view shape of the seat portion 11 will be described. As shown in FIG. 3, in the front-rear direction, the rear end side support region 12R extending from the rear end of the seat portion 11 to approximately two-thirds forward forms a substantially trapezoid that gradually widens toward the front. In the rear end side support region 12R, the width dimension (dimension in the left-right direction) of the seat portion 11 becomes maximum. The outer peripheral edge of the front end side support region 12F in front of the rear end side support region 12R of the seat portion 11 is composed of a pair of symmetrical front side curved edge portions 13 and a leading edge scooping portion 14. The front curved edge portion 13 is connected to the left and right side edges of the rear end side support region 12R, and constitutes the front edge portion of the seat portion 11. The leading edge cutting portion 14 has an obtuse-angled concave shape at the central portion in the left-right direction of the seat portion 11, and connects the left and right front curved edge portions 13.

The front view shape of the seat portion 11 will be described. As shown in FIGS. 2 and 11, the seat portion 11 is composed of a pair of symmetrical support portions 15 curved so that the upper surface side is recessed. Since the seat portion 11 has a high center portion in the left-right direction and both left and right ends, the buttock portion 51 of the seated person 50 and the base portion of the thigh can be stably supported.

As shown in FIGS. 1 and 4, the backrest portion 16 is in a form of rising upward from the rear end portion of the seat portion 11. The backrest portion 16 is composed of a first support portion 17 that constitutes the central portion in the left-right direction of the backrest portion 16 and a pair of symmetrical second support portions 18 that form the left and right side edges of the backrest portion 16. Has been done. The left and right second support portions 18 are in a form of cantilever extending diagonally forward from the left and right side edges of the first support portion 17. The extending direction of the left and right second support portions 18 is such that the distance between the left and right second support portions 18 in the left-right direction gradually widens toward the front in a plan view.

The front surface of the backrest portion 16 is a support surface 19 that contacts or faces the back 52 of the seated person 50. The front view shape of the support surface 19 (backrest portion 16) will be described. As shown in FIGS. .. The outer peripheral edge of the upper end side support region 21 above the lower end side support region 20 of the backrest portion 16 is composed of a pair of symmetrical upper curved edge portions 22 and an upper edge scooping portion 23. The upper curved edge portion 22 is connected to the left and right side edges of the lower end side support region 20 and constitutes the upper edge portion of the backrest portion 16. The upper hollow portion has an obtuse-angled concave shape at the central portion in the left-right direction of the backrest portion 16 and connects the left and right upper curved edge portions 22.

The upper curved edge portion 22 is formed only on the outer peripheral edge of the second support portion 18. The upper edge cutting portion 23 constitutes the entire area of the upper edge portion of the first support portion 17 and a part of the upper edge portion of the second support portion 18. The height dimension of the upper edge portion of the backrest portion 16 is maximum at the upper end of the upper curved edge portion 22 and minimum at the lowermost end of the upper edge cutting portion 23 (center in the left-right direction of the backrest portion 16). In other words, the lowermost end portion 17L at the upper edge portion of the first support portion 17 is arranged at a position lower than the uppermost end portion 18U at the upper edge portion of the second support portion 18. The lowermost end portion 17L in the upper edge portion of the first support portion 17 is located at a position higher than the lower end (height at which the backrest portion 16 has the maximum width) of the upper curved edge portion 22 (upper end side support region 21). The lower end of the upper curved edge portion 22 is the height at which the backrest portion 16 has the maximum width.

As shown in FIG. 2, the width dimension of the backrest portion 16 is maximum at the upper end of the lower end side support region 20 (the lower end of the upper curved edge portion 22). The maximum width dimension of the backrest portion 16 is set to be slightly smaller than the maximum width dimension of the seat portion 11. The width dimension of the backrest portion 16 is the minimum at the lower end portion 16L (that is, the rear end portion of the seat portion 11) of the backrest portion 16 (lower end side support region 20). The distance (width dimension) between the upper ends of the left and right upper curved edge portions 22 is smaller than the maximum width dimension of the backrest portion 16. The height dimension of the backrest portion 16 is set to be larger than the front-rear dimension of the seat portion 11.

As shown in FIGS. 2 and 3, the support surface 19 is composed of a first support surface 24 constituting the first support portion 17 and a pair of symmetrical second support surfaces 28 constituting the second support portion 18. Has been done. The first support surface 24 is arranged at the center of the support surface 19 in the left-right direction, and forms a vertically long substantially rectangular shape as a whole. As shown in FIG. 4, the upper end portion of the first support surface 24 is a first upper curved surface 25 that bulges diagonally upward and forward and curves diagonally upward and backward.

As shown in FIG. 4, the lower end portion 24L of the first support surface 24 is smoothly connected to the rear end portion of the seat portion 11 curved so as to have an upward slope toward the rear. The region of the first support surface 24 below the first upper curved surface 25 is a substantially planar first receiving surface 27. The first receiving surface 27 is oriented substantially in the vertical direction while the posture holder 10 is being used. The vertical dimension of the first receiving surface 27 is approximately ½ of the total height dimension of the first support surface 24.

The pair of left and right second support surfaces 28 are arranged on both the left and right sides of the first support surface 24 of the support surfaces 19. The second support surface 28 has a shape extending diagonally forward from the left and right side edges of the first support surface 24. The leading edge portion of the second support surface 28 has a shape curved so as to bulge toward the front. That is, the dimension in the front-rear direction of the second support surface 28 (the dimension extending from the side edge portion of the first support surface 24) becomes larger toward the upper side in the upper end side support region 21 of the second support surface 28. In the lower end side support area 20 of the second support surface 28, the size becomes smaller toward the lower side.

The region of the second support surface 28 that is close to the first support surface 24 in the left-right direction is the second receiving surface 29. The second receiving surface 29 has a substantially flat shape substantially parallel to the extending direction of the second support portion 18. The peripheral edge portion of the second support surface 28 that surrounds the second receiving surface 29 from above, front, and below is bulging diagonally forward and inward and curved so as to warp diagonally backward.

The upper end of the second support surface 28 is a second upper curved surface 30 that bulges diagonally upward and forward and curves diagonally upward and backward. Both the left and right second upper curved surfaces 30 are smoothly connected to the left and right side portions of the first upper curved surface 25. The lower end of the second support surface 28 is a second lower curved surface 31 that is curved so as to bulge diagonally downward and forward.

As shown in FIGS. The connecting surface 32 is recessed in an arc shape. The pair of connecting surfaces 32 are symmetrical and elongated in the vertical direction. In a plan view, the curvature of the first support surface 24 (first receiving surface 27) and the curvature of the second support surface 28 (second receiving surface 29) are small values close to zero, whereas the curvature of the connecting surface 32 The curvature is large. In front of the backrest portion 16, a substantially trapezoidal holding space 33 opened forward is formed by being partitioned by a first support surface 24, both left and right second support surfaces 28, and both left and right connecting surfaces 32. Has been done.

The first receiving surface 27 of the first support portion 17 is a region of the first support surface 24 where the central portion of the back 52 of the seated person 50 in the left-right direction can hit when seated. The second receiving surface 29 of the second support portion 18 is a region of the second support surface 28 where the left and right sides of the back 52 of the seated person 50 can hit when seated. The uppermost position of the first receiving surface 27 is set to a position lower than the uppermost position of the second receiving surface 29. The first receiving surface 27 is positioned so as to be sandwiched between the pair of second receiving surfaces 29 in the left-right direction. Therefore, the posture holder 10 can support the back 52 of the seated person 50 at three points by one first receiving surface 27 and a pair of left and right second receiving surfaces 29. The receiving surfaces 27 and 29 at these three locations have a height difference, and are in a positional relationship with a space between the left and right sides and a space between the front and back sides.

As shown in FIG. 12, the posture holder 10 is composed of an outer shell member 34, a cushion material 39, and an exterior sheet 40 in terms of component composition. The outer shell member 34 is a single member made of a hard synthetic resin and having a constant thickness over the entire region. The outer shell member 34 is formed into a curved shape so that the side view shape is substantially L-shaped. The outer shell member 34 includes a seat portion constituent plate portion 35 constituting the seat portion 11 and a backrest portion constituent plate portion 36 constituting the backrest portion 16. The seat portion constituent plate portion 35 has substantially the same shape as the shape of the seat portion 11 described above, and is composed of a plurality of curved plate portions curved so as to have different curvatures. The backrest portion constituent plate portion 36 is in a form of rising upward from the rear end portion of the seat portion constituent plate portion 35, and includes the first support plate portion 37 constituting the first support portion 17 and the second support portion 18. It is composed of a pair of symmetrical second support plate portions 38.

The shape of the first support plate portion 37 is substantially the same as that of the first support portion 17 and the first support surface 24 described above. The height region of the first support plate portion 37 corresponding to the first receiving surface 27 has a curved shape so that the side view shape as a whole bulges forward, and the posture holder 10 is placed on a horizontal plane. The direction is slightly tilted forward from the vertical direction. Further, the region of the first support plate portion 37 corresponding to the first upper curved surface 25 is curved so as to warp diagonally upward and backward. The region of the first support plate portion 37 corresponding to the first lower curved portion 26 has a shape curved so as to have a downward slope and to bulge diagonally downward and rearward.

The pair of second support plate portions 38 extend diagonally forward from the substantially linear left and right side edges of the first support plate portion 37 and cantilevered so that the distance between the left and right sides of the first support plate portion 37 widens toward the front. Is. The shape of the second support plate portion 38 is substantially the same as the shape of the second support portion 18 and the second support surface 28 described above. The region of the second support plate portion 38 corresponding to the second receiving surface 29 has a substantially flat plate shape, and the peripheral edge portion of the second support plate portion 38 has a shape curved so as to warp diagonally backward.

As shown in FIG. 4, the lower end portion 36L of the backrest portion constituent plate portion 36 is connected to the rear end portion of the seat portion constituent plate portion 35, but constitutes the lower end portion 36L of the backrest portion constituent plate portion 36. Only the first support plate portion 37 is used. That is, the first support plate portion 37 is directly connected to the seat portion constituent plate portion 35, but the second support plate portion 38 is directly connected to the seat portion constituent plate portion 35. Instead, it is connected to the seat component plate portion 35 via the first support plate portion 37.

The outer shell member 34 maintains the overall shape of the posture holder 10, and has rigidity (shape retention) capable of stably holding the posture of the seated person 50. However, when it receives a static load due to the weight of the seated person 50 or a dynamic load caused by a change in the seated posture of the seated person 50, it can be elastically deformed to the extent that it does not affect the seated posture. It has become. Specifically, the second support plate portion 38 is elastically displaced relative to the first support plate portion 37 so as to expand in the left-right direction with the left and right side edges of the first support plate portion 37 as substantially fulcrums. It has become possible.

Further, when the above-mentioned static load or dynamic load is received, the backrest portion constituent plate portion 36 (backrest portion 16) has a backrest portion constituent plate with respect to the seat portion configuration plate portion 35 (seat portion 11). With the lower end portion 36L of the portion 36 (rear end portion of the seat portion constituent plate portion 35) as a substantially fulcrum, the relative displacement can be elastically performed so as to incline the posture in the front-rear direction. At this time, the amount of elastic deformation (stress generated in the backrest component plate portion 36) of the backrest portion constituent plate portion 36 is maximum at the lower end portion 36L which is a substantially fulcrum of the elastic displacement, but the first support plate portion 37 At least the lower end side support region 20 is also elastically deformed. Elastic deformation of the lower end side support region 20 of the first support plate portion 37 is preferable as a means for avoiding stress concentration at the lower end portion 36L of the backrest portion constituent plate portion 36.

However, the second support plate portion 38 protruding from the left and right side edges of the first support plate portion 37 functions as a reinforcing rib that resists elastic deformation of the first support plate portion 37. Therefore, as shown in FIGS. 8 to 10, the protrusion dimension from the first support plate portion 37 in the lower end side region of the second support plate portion 38 is set so as to gradually decrease downward. As a result, when the backrest portion constituent plate portion 36 is elastically displaced in the front-rear direction with respect to the seat portion constituent plate portion 35, the lower end side region of the first support plate portion 37 is also elastically curved and deformed. There is. In the first embodiment, the lower end side region of the second support plate portion 38 is defined as a region extending at least about 1/3 of the height from the lower end portion 38L of the second support plate portion 38.

The cushion material 39 is attached so as to be laminated on the surface of the outer shell member 34 facing the seater 50 (the upper surface of the portion constituting the seat portion 11 and the front surface of the portion constituting the backrest portion 16). There is. The cushion material 39 is made of, for example, urethane foam or the like, and is a member for avoiding discomfort caused by the buttocks 51 and the back 52 of the seated person 50 hitting the hard outer shell member 34. The thickness of the portion of the cushion material 39 corresponding to the first receiving surface 27 is not a constant dimension in the vertical direction, but the thickness dimension is changed so as to gradually become thicker downward. As a result, when the posture holder 10 is placed on a horizontal surface, the first receiving surface 27 of the first support surface 24 is oriented so as to stand up substantially vertically.

The exterior sheet 40 is made of cloth and faces the outer surface of the outer shell member 34 (the lower surface of the portion constituting the seat portion 11 and the rear surface of the portion constituting the backrest portion 16) and the cushion material 39 facing the seater 50. It covers the entire surface (the upper surface of the portion constituting the seat portion 11 and the front surface of the portion constituting the backrest portion 16). When the outer shell member 34 is elastically deformed, the cushion material 39 and the exterior sheet 40 are flexibly deformed following the elastic deformation.

The posture holder 10 can be used in a state of being directly placed on a floor surface (not shown) or in a state of being placed on a chair 53. FIG. 12 shows a state in which the chair is used. When the seated person 50 sits on the posture holder 10, the buttocks 51 are supported from below by the seat 11, the trunk of the upper body is housed in the holding space 33, and the back 52 is supported from behind by the backrest 16. At this time, the portion of the central portion of the back 52 in the left-right direction corresponding to the lower part of the thoracic spine abuts on the first support surface 24, and the left and right bilateral portions of the back 52 abut on the left and right second support surfaces 28.

At this time, the contact portion with the second support surface 28 is at a position higher than the contact portion with the first support surface 24 and at a position ahead of the contact portion with the first support surface 24. .. That is, the back 52 can support a plurality of parts having different positions in the three-dimensional direction. Further, when the seated person 50 is an adult having an average body shape, the contact position with the second support surface 28 is on the back side of the ribs and at a height lower than that of the scapula.

The posture holder 10 of the first embodiment has a seat portion 11 that supports the buttocks 51 of the seated person 50 from below, and a form in which the upper body of the seated person 50 is raised from the rear end portion of the seated portion 11 from the back 52 side. It is equipped with a supporting backrest portion 16. The backrest portion 16 is arranged on both the left and right sides of the first support portion 17 and the left and right sides of the first support portion 17 so as to abut the central portion of the back 52 of the seated person 50 in the left-right direction. It is configured to include a pair of second support portions 18 for abutting the portions.

The first support portion 17 supports a relatively low portion in the central portion of the back 52 of the seated person 50 from the rear, and the pair of left and right second support portions 18 are higher than the first support portion 17 of the left and right side portions of the back 52. Support the part so that it is sandwiched from diagonally behind. Therefore, the seated person 50 sits in a state where the relatively low portion in the central portion of the back 52 is applied to the first support portion 17, and the relatively high portions in the left and right sides of the back 52 are applied to the second support portion 18. .. The seated person 50 is spaced from the left and right by the three support portions 17 and 18, and the back 52 can be supported at three points having different heights. It is suppressed to become. Therefore, the posture holder 10 of the first embodiment can hold the upper body of the seated person 50 in the correct posture.

Further, the first support portion 17 supports a relatively low portion of the back 52 of the seated person 50 (the whole or a part of the range extending from the upper part of the lumbar spine to the lower part of the thoracic spine), and the second support portion 18 is a comparison of the back 52. When the seated person 50 deposits his / her weight on the backrest 16 because it supports a high target part (all or a part of the back of the ribs corresponding to the lower part of the thoracic vertebrae to the middle height of the thoracic vertebrae). The back 52 is supported at a plurality of places having different heights. As a result, the upper body of the seated person 50 is maintained in the correct posture so that the spine draws an appropriate curve in lateral view. Here, the correct posture is a posture in which the thoracic spine is curved so as to bulge posteriorly, the lumbar spine is curved so as to bulge forward, and the posture is curved so as to bulge backward from the sacrum to the coccyx.

Further, when the height of the upper end of the first support portion 17 is aligned with the height of the upper end of the second support portion 18, the thoracic vertebrae portion of the back 52 that is curved so as to bulge backward is the first support portion 17. It hits the upper end of the spine, and it may be difficult for the spine to draw an appropriate curve. As a countermeasure, the posture holder 10 of the first embodiment forms an upper edge cutting portion 23 on the upper end edge of the backrest portion 16, and sets the height of the upper end of the first support portion 17 to the upper end of the second support portion 18. Although it is made lower, when the upper edge cutting portion 23 is formed, the space is located immediately above the first support portion 17 (that is, between the upper ends of both the left and right second support portions 18), so that the first support portion 17 is formed. The back 52 cannot be supported in the immediate vicinity above the support portion 17. Therefore, there is a concern that the portion of the upper body of the seated person 50 above the first support portion 17 (a relatively low portion of the back 52) may warp backward, but the upper body of the seated person 50 is the first. Since the seated person 50 is supported by the second support portion 18 on both the left and right sides above the first support portion 17, the seated person 50 can sit in a relaxed state with a moderately open chest.

Further, in the seated state, the second support portion 18 is elastically displaced diagonally backward due to the pressing pressure from the upper body of the seated person 50, so that the elastic restoring force of the second support portion 18 (second support plate portion 38) causes the second support portion 18 to be elastically displaced backward. Pressure is strongly felt on both the left and right sides of the back 52 rather than the central part. Therefore, it is possible to prevent the upper body of the seated person 50 from being tilted to the left or right or twisted to the left or right.

Further, since the second upper curved surface 30 which is curved so as to warp diagonally backward toward the upper side is formed at the upper end portion of the second support portion 18, the upper body of the seated person 50 is used as the backrest portion 16. The upper end edge of the second support portion 18 does not bite into the body of the seated person 50 when leaning deeply, and the seated person 50 can sit deeply on the seated portion 11. Further, by sitting deeply, the left and right side portions of the back 52 are firmly pressed against the second support portion 18, so that the upper body can be reliably prevented from being twisted to the left and right. Further, since the upper end portion of the second support portion 18 does not bite into the body of the seated person 50, the upper part of the back 52 can be appropriately bent backward, so that the seated person 50 can be held in the correct posture. can.

Further, the posture holder 10 is provided with an outer shell member 34 for maintaining its shape. The outer shell member 34 includes a seat portion constituent plate portion 35 constituting the seat portion 11 and a backrest portion constituent plate portion 36 constituting the backrest portion 16. The backrest component plate portion 36 is connected to the seat portion configuration plate portion 35 so as to be elastically relative to the seat portion configuration plate portion 35 with the lower end portion 36L of the backrest portion configuration plate portion 36 as a substantially fulcrum. Therefore, when the seated person 50 strongly presses the upper body against the backrest portion 16, the backrest portion 16 is elastically displaced rearward with respect to the seat portion 11 with the lower end portion 36L as a substantially fulcrum.

At this time, if stress is concentrated on the lower end portion 36L of the backrest portion constituent plate portion 36 which is the fulcrum of the relative elastic displacement, there is a concern that the stress concentration will be repeated and the deterioration will progress and the durability will decrease. .. As a means for avoiding stress concentration on the lower end portion 36L of the backrest portion constituent plate portion 36, not only the lower end portion 36L of the backrest portion constituent plate portion 36 but also at least the lower end side of the backrest portion constituent plate portion 36. It is preferable to elastically deform the region together.

However, the backrest portion constituent plate portion 36 constitutes the second support portion 18 so as to project diagonally forward from the left and right side edges of the first support plate portion 37 constituting the first support portion 17 and the left and right side edges of the first support plate portion 37. Since it is composed of a pair of left and right second support plate portions 38, it is not easily deformed. Therefore, the protruding dimension from the first support plate portion 37 in the lower end side region of the second support plate portion 38 is gradually reduced downward. As a result, not only the lower end portion 36L of the backrest portion constituent plate portion 36 but also the lower end side region is elastically deformed, so that it is possible to prevent stress from concentrating on the lower end portion 36L of the backrest portion constituent plate portion 36. Since the upper end side region of the backrest portion constituent plate portion 36 has higher bending rigidity and less elastic deformation than the lower end side region, the upper body of the seated person 50 can be stably held.

Further, the first support surface 24 of the first support portion 17 facing the back 52 and the second support surface 28 of the second support portion 18 facing the back 52 are interposed via a pair of left and right connecting surfaces 32. In a plan view, the curvature of the first support surface 24 and the curvature of the second support surface 28 are set to be smaller than the curvature of the connecting surface 32. According to this configuration, since the back 52 does not hit the connecting surface 32 having a large curvature, the upper body of the seated person 50 is stabilized at three points of the first support surface 24 and the pair of left and right second support surfaces 28. Can be supported.

<Other Examples>
The present invention is not limited to the examples described in the above description and drawings, and for example, the following examples are also included in the technical scope of the present invention.
(1) The posture holder of the above embodiment has a seat portion and a backrest portion integrally formed, but the posture holder is configured by assembling a seat portion and a backrest portion of a separate member. It may be one.
(2) In the above embodiment, the upper end portion of the second support portion is curved so as to warp diagonally backward toward the upward direction, but the upper end portion of the second support portion is not curved. May be good.
(3) The backrest portion constituent plate portion of the above embodiment is formed by integrally forming the first support plate portion and the second support plate portion, but the backrest portion constituent plate portion is a separate member. 1 The support plate portion and the second support plate portion may be assembled and configured.
(4) In the above embodiment, the protrusion dimension from the first support plate portion in the lower end side region of the second support plate portion gradually decreases downward, but in the lower end side region of the second support plate portion. The protruding dimension from the first support plate portion may be substantially constant in the vertical direction.
(5) In the above embodiment, the seat portion and the backrest portion are elastically displaced relative to each other, but the seat portion and the backrest portion may not be displaced relative to each other.
(6) In the above embodiment, the first support surface and the second support surface are connected to each other via a connecting surface having a large curvature, and the back of the seated person is supported at three places with a space between the left and right sides. Not limited to this, the curvature of the connecting surface may be made smaller than that of the first embodiment, and the back may be supported in a region continuous in the left-right direction from the second support surface on the left side to the second support surface on the right side. Even in this case, it is possible to prevent the upper body of the seated person from being tilted to the left or right or twisted to the left or right.
(7) In the above embodiment, an upper edge scooping portion is formed on the upper edge portion of the first support portion so that a space is provided in the upper vicinity of the first support portion (between the upper ends of both the left and right second support portions). However, the height of the upper end of the first support portion and the height of the upper end of the second support portion may be made substantially the same without forming the upper edge cutting portion. Even if the upper edge of the backrest has a constant height over a wide area, the degree of backward tilting of the region corresponding to the upper end of the first support portion of the upper edge of the backrest is determined. By making it deeper than the upper end portion of the second support portion, it is possible to prevent the central portion of the back in the left-right direction from strongly hitting the upper edge portion of the backrest portion when the back is bent backward.

10 ... Posture holder 11 ... Seat 16 ... Backrest 17 ... First support 18 ... Second support 17L ... Bottom end of the upper edge of the first support 18U ... Upper edge of the second support 24 ... 1st support surface 28 ... 2nd support surface 32 ... Connecting surface 35 ... Seat configuration plate 36 ... Backrest configuration plate 36L ... Lower end of backrest configuration plate 37 ... 1st Support plate 38 ... Second support plate 50 ... Seated person 51 ... Buttocks 52 ... Back

Claims (4)

With the seat
The backrest, which stands up from the rear end of the seat,
A first support portion that constitutes the backrest portion and abuts the central portion of the seater's back in the left-right direction, and a first support portion.
A pair that constitutes the backrest and is arranged on both the left and right sides of the first support portion by extending from the left and right side edges of the first support portion, and abuts the left and right side portions of the back of the seated person. Equipped with a second support part of
The lowermost end portion of the upper edge portion of the first support portion is arranged at a position lower than the uppermost end portion of the upper edge portion of the second support portion.
The first support portion supports the entire or part of the seated person's back from the upper part of the lumbar spine to the lower part of the thoracic spine.
The second support portion supports all or part of the corresponding portion of the back of the ribs on the back of the occupant from the lower part of the thoracic vertebra to the middle height of the thoracic vertebra.
A posture holder characterized in that the upper end portion of the first support portion is curved so as to warp diagonally upward and backward. The posture holder according to claim 1, wherein the upper end portion of the second support portion is curved so as to warp diagonally backward toward the upper side. The seat portion constituent plate portion constituting the seat portion and the backrest portion constituent plate portion constituting the backrest portion can be elastically displaced relative to each other with the lower end portion of the backrest portion constituent plate portion as a substantially fulcrum. In a row,
The backrest portion constituting plate portion includes a first supporting plate portion constituting the first supporting portion and a second supporting portion constituting the second supporting portion so as to project diagonally forward from the left and right both left and right edges of the first supporting plate portion. It consists of a support plate and
The posture holder according to claim 1 or 2, wherein the protrusion dimension from the first support plate portion in the lower end side region of the second support plate portion gradually decreases downward. The first support surface of the first support portion facing the back and the second support surface of the second support portion facing the back are connected via a pair of left and right connecting surfaces.
The posture holder according to any one of claims 1 to 3, wherein the curvature of the first support surface and the curvature of the second support surface are smaller than the curvature of the connecting surface in a plan view.

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