JP3249163U - chair - Google Patents

Abstract

To provide a new chair that allows a user to sit in a stable seating position, reduces strain on the lower back, and allows the user to sit in a stable posture, preventing the loss of posture.
[Solution] The chair 1 has a seat 3 and legs 4, 5, and when the seat 3 is in a reclined state where it can be sat on, has a seat surface 3C that slopes downward from the rear part 3A to the front part 3B, and has a determining part 40 that determines the seating position of a user 10 on the seat surface when the seat 3 is in the reclined state. The height L4 of the seat surface is set longer than the shin length L3 of the seated user.
[Selected figure] Figure 3

Description

The present invention relates to a chair, and more particularly to a chair having a restricting portion that restricts the sitting position on an inclined seat.

Technical Background

The present applicant has proposed a chair, as disclosed in Patent Document 1 listed below, in which the seat surface on which the user sits is inclined downward from the rear end of the seat to the front end of the seat, and the angle of this inclination is set within a specified range, thereby allowing the user to sit in a stable posture with less strain on the lower back and preventing posture loss.

Utility model registration number 3245175

In the configuration of Patent Document 1, the seat is set longer than the shin length of the user seated on the seat, thereby keeping the inclination angle of the seat within a predetermined range. However, if the user's seating position deviates from the allowable range, even if the user sits on the seat at an angle set according to the user's physique, the knee angle may deviate from the expected angle, and sufficient effect may not be obtained.
The purpose of this invention is to provide a new chair that allows the user to sit in a stable seating position, reduces strain on the lower back, and allows the user to sit in a stable posture, thereby preventing the loss of posture.

In order to achieve the above-mentioned objective, the chair of the present invention has a seat and legs, and when the seat is in a reclined state in which it can be sat on, has a seat surface that slopes downward from the rear of the seat to the front of the seat, and has a determining part that determines the user's sitting position on the seat surface when the seat is in the reclined state.
The chair according to the present invention is characterized in that the height of the seat is set to be longer than the shin length of a seated user.
In the chair according to the present invention, the defining portion is disposed toward the rear end of the seat portion.
In the chair according to the present invention, the determining portion is provided so as to be movable in the inclination direction of the seat surface.
In the chair of the present invention, the determining portion is movable between a determined position where it can come into contact with at least one of the buttocks or lower back of a user seated on the seat, and a released position where it does not come into contact with the buttocks or lower back of the seated user.

According to the present invention, since the seat surface slopes downward from the rear of the seat to the front of the seat when the seat is reclined, the seating position of the user is determined by a determining portion, allowing the user to sit in a stable position. This allows the user to sit in a stable position with less strain on the lower back, and prevents the user from losing their posture.

FIG. 1 is a side view illustrating the configuration of a chair according to one embodiment of the present invention. FIG. 2 is a front view illustrating the configuration of a chair according to one embodiment of the present invention. FIG. 3 is a side view showing a state in which a user is seated on the chair according to the embodiment. FIG. 4 is a cross-sectional view illustrating the configuration of the seat of the chair according to the embodiment. FIG. 5 is a cross-sectional view illustrating another configuration of the seat of the chair according to the embodiment. FIG. 6 is a side view showing another embodiment of a determining portion for determining a seating position. 7(a) and 7(b) are enlarged views showing one embodiment of the seat height adjustment portion. 8(a) and 8(b) are enlarged views showing the manner in which the seat height adjustment portion is used.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
Fig. 1 is a side view of the chair according to the present invention, Fig. 2 is a front view of the chair according to an embodiment of the present invention, Fig. 3 is a side view of the chair according to the embodiment with a user seated. Fig. 4 is a cross-sectional view of the seat of the chair according to the embodiment, Fig. 5 is a cross-sectional view of another configuration of the seat of the chair according to the embodiment. Fig. 6 is a side view of another form of the determining portion for determining the seating position, Figs. 7(a) and 7(b) are enlarged views of one embodiment of the adjusting portion, and Figs. 8(a) and 8(b) are enlarged views of the seat height adjusting portion in use.

The chair 1 according to the embodiment has a frame 2 and a seat 3. The frame 2 includes a first frame 21 and a second frame 22. The first frame 21 and the second frame 22 are each formed by bending a pipe material into a substantially U-shape in side view. The first frame 21 and the second frame 22 have mutually opposing portions formed parallel to each other, and are configured as legs 4 and 5. In other words, the chair 1 includes the legs 4 and 5 at both ends of the first frame 21 and the second frame 22 formed by bending a pipe material.

In this embodiment, the legs 4, 4 form the front legs, and the legs 5, 5 form the rear legs. The length L1 of the legs 4, 4 is shorter than the length L2 of the legs 5, 5. Therefore, the intermediate portions 6, 6 of the first frame 21 and the second frame 22 located between the legs 4, 4 and the legs 5, 5 are formed so as to slope downward from the legs 5, 5 (rear legs) toward the legs 4, 4 (front legs).
As shown in Fig. 3, a third frame 23 is fixed to the intermediate regions 6, 6 so as to straddle both of them. That is, the independent first frame 21 and second frame 22 are connected to each other and integrated by the third frame 23 at the intermediate regions 6, 6. In this embodiment, the third frame 23 is made of a pipe material, and both ends thereof are fixed to the first frame 21 and the second frame 22 by welding, respectively. The third frame 23 may be fixed to the first frame 21 and the second frame 22 by fastening members such as bolts and nuts or adhesives instead of welding. The third frame 23 may be made of a plate-shaped member instead of a pipe material.

The seat 3 is rotatably supported at its rear end 3A by the first frame 21 and the second frame 22. In this embodiment, the seat 3 is rotatably supported at its rear end 3A by the third frame 23. The seat 3 is in an upright state shown by the two-dot chain line in Fig. 1 and in a reclined state shown by the solid line. It is preferable that at least one of the first frame 21 or the second frame 22, or the third frame 23, is provided with a stopper that comes into contact with the seat 3 in the upright state, regulates movement in the upright direction, and maintains the seat 3 in the upright state.
In the chair 1, the seat 3 is in a reclined state and abuts against at least one of the intermediate portion 6 and the third frame 23 to be held in the reclined state, allowing the user 10 to sit on it. The seat 3 may be rotated manually by the user, or may be rotated automatically from the reclined state to the standing state by using a spring to give it a rotational tendency in the standing state, and the user may manually operate the seat in the reclining direction when sitting down. In this case, it is preferable to have a holding part that temporarily holds the seat 3 in the reclined state.

The seat 3 has a seat surface 3C that is inclined downward from the rear end 3A of the seat to the front end 3B of the seat in the reclined state. This inclined seat surface 3C is a flat seat surface on which the buttocks of the user 10 seated on the chair 1 are placed when the user sits down. In this embodiment, the seat surface 3C is rectangular in plan view. The plan view shape of the seat surface 3C may be any of a rectangular, square, circular, and elliptical shape. The plan area of the seat surface 3C is set to a size that takes into consideration the length of the back of the thighs of the seated user 10 and the size of the buttocks when sitting. Specifically, as shown in FIG. 2, the total length L of the seat surface 3C in the inclination direction D is set to an arbitrary value in the range of 30 cm to 50 cm. This is because the total length L, which is the depth, is set to a sufficient length so that the buttocks do not protrude from the rear end 3A of the seat, considering that the chair can also be used by tall users with long legs. This improves the comfort of sitting.
In this embodiment, the seat portion 3 has been described as being rotatable between the first frame 21 and the second frame 22, but it may also be fixed in a reclined state between the first frame 21 and the second frame 22.

As shown in Fig. 4, the seat 3 is formed by covering the entire exterior of a plate-shaped core material 31 with a skin material 32. A relatively thin urethane mat having a thickness of, for example, 10 to 20 mm is used for the core material 31. The skin material 32 is preferably one having an anti-slip function. As a skin material having an anti-slip function, for example, a sheet material such as "Suberanne" (registered trademark) or "Zenzensuberanne" (registered trademark) manufactured by Syncol Material Co., Ltd. can be used. The skin material 32 may also have stain resistance, flame retardancy, water repellency, etc.

In the reclined state, the seat 3 is held so that the seat surface 3C is at an arbitrary inclination angle θ within a predetermined inclination angle range. In this embodiment, the inclination angle θ is set to 20 degrees as an example. The inventor conducted an experiment on the inclination angle of the seat surface and the sitting comfort. In the experiment, a total of 200 male and female subjects were asked to sit on chairs with different seat angles and to give their impressions of the sitting comfort. In this embodiment, the knee angle refers to the angle formed by the shin and thigh when the user 10 sits on the chair and bends the knee with the entire sole of the foot in contact with the installation surface of the chair 1. If the knee angle becomes acute when sitting, the knee will be higher than the seating position where the buttocks contact the seat surface, and the pelvis 12 will be tilted backward (sacrum sitting), making it difficult to stand up and making it easy to hunch over, which is undesirable, the inventor had found.

Therefore, in this experiment, we decided to find the optimal angle within the range where the knee angle is an obtuse angle. A knee angle of 180° means that the user 10 is standing upright. The inclination angle θ of the seat surface 3C was changed so that the angle became shallower from this angle, such as 170°, 160°, etc. Note that the vertical state of the seat surface 3C was set to 90°, and the seat surface angle was tilted from the vertical state toward the horizontal.
According to this experiment, when the seat inclination angle was 45° (equivalent to a knee angle of 135°), many people said that it felt more like standing than sitting. When the seat inclination angle was reduced, people said that the seat was comfortable at an inclination angle of about 20° (knee angle of about 110°). Further sitting experiments were then conducted with the inclination angle increased or decreased in 1° increments from 20°, and more people said that the seat was comfortable within a range of +-5° from 20°. In other words, the seat 3 is more comfortable to sit on by setting the seat surface 3C to a specified inclination angle range (15° to 25°).

According to this embodiment, when the seat 3 is in the reclined state, the seat surface 3C slopes downward from the rear end 3A to the front end 3B, and no mechanism is required to tilt the seat 3. Therefore, with a simple structure, the user 10 who is seated can sit on the seat surface 3C in a forward-leaning state with the pelvis in an upright position, and the body is supported by both legs and the lower back. This reduces the burden on the lower back, allows the user to sit in a stable position, and prevents the user from losing their posture.
In addition, sitting in a forward-leaning position on the seat surface 3C allows the user 10 to sit in a correct posture, which suppresses lumbar kyphosis of the user 10 and is expected to have the effect of correcting a rounded back, or hunched shoulders.

According to this embodiment, since the seat 3 is foldable, it is sufficient to fold the seat 3 when sitting down, and space can be secured when not in use. This means that when chairs 3 are lined up in a row, a path for movement to an adjacent chair 1 can be secured, which leads to improved usability.
Although the chair 1 according to the present embodiment has been described as a standalone chair, it can also be applied to a bench-like chair installed in an environment where many people sit at the same time, such as a lecture hall, a theater, etc. For example, by applying the chair to a bench-like chair with a common frame extending in the longitudinal direction and multiple reclining seat sections, it is possible to reduce the burden on the lower backs of many people, allow them to sit in a stable posture, and prevent many people from losing their posture.
The chair 1 according to this embodiment has been described as having no backrest, but of course, the same effects as those of the embodiment can be obtained even if the chair is applied to a chair with a backrest.

As shown in FIG. 3, the height L4 of the front end 3B of the seat is set based on the length L3 of the shin 11 (the length of the tibia 11) of the seated user 10. In this embodiment, the height L4 of the front end 3B of the seat is the length from the front upper end 3C1 of the seat surface 3C at the front end 3B of the seat to the tip surfaces 4a, 4a of the legs 4, 4 (front leg parts). The height L4 of the front end 3B of the seat is set longer than the length L3 of the shin of the seated user 10. The length L3 of the shin of the seated user 10 refers to the length (height) from the installation surface 20 to the tip 11a of the tibia 11 (or the upper part of the knee) when the entire sole of the seated user 10 is in contact with the installation surface 20 on which the chair 1 is placed. The inclination angle θ of the seat surface 3C is based on the premise that the height L4 is greater than the length L3.
By setting the height L4 to be greater than the length L3 in this manner, when the user 10 sits on the seat surface 3C, the user can sit with the knees at an obtuse angle and in a forward leaning position.

In this embodiment, the seat surface 3C has an anti-slip function, which is preferable because it can prevent the seated user 10 from slipping on the seat surface 3C and allows the user 10 to sit in a forward-leaning position more reliably.

As shown in Fig. 5, in this embodiment, the front end surface 3d of the seat 3 is formed to be a vertical plane when the seat surface 3C is inclined. Normally, when a user 10 sits on the chair 1, the backs of the thighs come into contact with the seat surface 3C, but if the contact area extends close to the backs of the knees, the reaction force from the seat surface 3C to the hamstrings tends to be strong. If excessive pressure is applied to the hamstrings from the seat surface 3C in this way, it is expected to become a resistance when the hamstrings expand and contract, and to be an obstacle when sitting in a forward leaning position.
For this reason, the inventors have made the front end surface 3d of the seat portion 3 a vertical plane when the seat surface 3C is inclined, thereby narrowing the contact area between the seat surface 3C and the back of the thighs compared to when the end surface is perpendicular to the inclined seat surface 3C, thereby enabling the seated user 10 to more reliably sit with the pelvis tilted forward.

As a method for narrowing the contact area between the backs of the thighs of the user 10 and the seat surface 3C, the seat may be shaped so that the front upper end 3C1 of the seat 3 is located closer to the rear end 3A of the seat 3 than the front lower end 3C2 of the seat 3, as shown in Fig. 5. In the embodiment shown in Fig. 5, the end surface 3d is inclined so that the front upper end 3C1 is located closer to the rear end 3A of the seat than the imaginary vertical line X passing through the front lower end 3C2.
Even with this configuration, the contact area between the seat surface 3C and the back of the thighs is narrower than when the end surface is perpendicular to the inclined seat surface 3C, so the seated user 10 can more reliably sit with his/her pelvis tilted forward.

In this embodiment, the height L4 of the seat 3 is set to be longer than the length L1 of the legs 4, 4, so that the seat surface 3C of the seat 3 in the reclined state has an arbitrary inclination angle θ within a predetermined inclination angle range. However, as long as the seat surface 3C of the seat 3 in the reclined state is located within a predetermined inclination angle range, the seat height L4 and the length L1 of the legs 4, 4 may be the same height, or the seat height L4 may be lower than the length L1 of the legs 4, 4.

As shown in Figs. 1 and 2, the chair 1 according to this embodiment has a regulating portion 40 that regulates the seating position of the user 10 on the seat surface 3C when the seat 3 is in a reclined state. The regulating portion 40 is disposed near the rear end 3A of the seat 3. In this embodiment, the regulating portion 40 includes a plate-shaped member 41 and a support member 42. The regulating portion 40 is supported by the support member 42 so that the plate-shaped member 41 can be reclined at a prescribed position shown by a solid line and at a released position shown by a virtual line. The support member 42 is a pair of arms, and one end 42a of each of the support members 42 is rotatably supported by a shaft 43 at the intermediate portions 6, 6. The plate-shaped member 41 has ends 41b, 41c located in the width direction W intersecting with the total length L of the inclination direction D of the seat surface 3C, which are attached to the other end 42b that is the free end of the support member 42. Reference numeral 44 denotes a holding portion that holds the plate-shaped member 41 at a prescribed position.
The specified position is a position where at least one of the buttocks or waist of the user 10 seated on the seat surface 3C can come into contact with the support surface 41a of the plate-like member 41. The release position is a position that is approximately parallel to the seat surface 3C and where the waist of the seated user 10 does not come into contact with the support surface 41a of the plate-like member 41. The specified position of the plate-like member 41 is a position where the knee angle is within a set range when a user 10 with a physique assumed for the chair 1 sits on the seat surface 3c.

By providing the chair 1 with such a regulating portion 40, the user 10 can sit in a desired position by contacting the buttocks or lower back with the seat surface 3C that slopes downward from the rear seat portion 3A to the front seat portion 3B. This allows the user 10 to sit in a stable seating position, reduces strain on the lower back, allows the user to sit in a stable posture, and prevents the user from losing his/her posture, making it possible to provide a new chair 1.

In the above embodiment, the defining portion 40 is tiltable at a fixed position in the inclination direction D of the seat surface 3C, but it may be provided so as to be movable in the inclination direction D. In this case, for example, as shown in Fig. 5, a pair of sliders 50, 50 may be attached to the intermediate portions 6, 6, and one end 42a, 42a of each of the pair of support members 42, 42 may be fixed to the sliders 50, 50. Note that the sliders 50, 50 preferably have a locking portion that can be fixed at the same position in the width direction W.
Alternatively, a plurality of attachment portions for the support members 42 , 42 may be formed in the intermediate portions 6 , 6 toward the inclined direction D, so that the support members 42 can move in accordance with the physique of the user 10 .

In this way, by making the defining portion 40 movable in the inclination direction D of the seat surface 3c, the position of the defining portion 40 can be adjusted, so that the seating position can be finely adjusted and the user 10 can be seated in a more stable seating position. Therefore, it is possible to provide a new chair 1 that reduces strain on the lower back, allows the user to sit in a stable posture, and prevents the user from losing his/her posture.

As shown in Fig. 1, the chair 1 according to this embodiment is provided with an adjustment unit 30 for adjusting the height L4 of the front upper end 3C1 of the seat surface 3C, which is the height of the seat surface 3C when the seat 3 is in a reclined state. In the chair 1 according to this device, the adjustment unit 30 adjusts the length L1 of the legs 4, 4 and the length L2 of the legs 5, 5 individually. Specifically, the adjustment unit 30 is configured such that parts of the legs 4, 5 are detachable. That is, the adjustment unit 30 is configured as a split leg that is detachable from each of the pipe-shaped legs 4, 5. In this embodiment, the chair 1 is provided with a plurality of adjustment units 30. The adjustment unit 30 is attached to the tip surfaces 4a, 4a of the legs 4, 4 (front legs) and the tip surfaces 5a, 5a of the legs 5, 5 (rear legs), which respectively constitute the leg ends, thereby extending the lengths L1, L2 of each leg, and is detached from the tip surfaces 4a, 4a and tip surfaces 5a, 5a of each leg, thereby shortening the lengths L1, L2 of each leg.

In this embodiment, as shown in Figures 7(a) and 7(b), the adjustment unit 30 includes a divided main body 31 having an outer diameter equal to the outer diameter of the leg, and a protrusion 32 extending outward from one end face 31a of the divided main body 31. A threaded portion 33 is formed on the outer periphery of the protrusion 32. A threaded portion 34 that screws into the threaded portion 33 of the protrusion 32 is formed on the tip faces 4a, 4a and tip faces 5a, 5a of the leg to which the divided main body 31 (adjustment unit 30) is attached, and on the other end face 31b of the divided main body 31 that constitutes the tip face when attached to each leg.
That is, the adjustment part 30 can be tightened to the ends of the legs 4, 5 to extend the length of the legs 4, 5 and make the seat 3C higher, and can be loosened and removed from the ends of the legs 4, 5 to shorten the length of the legs 4, 5 and make the seat 3C lower. Therefore, the seat height can be adjusted according to the shin length L3 which changes according to the physique of the user 10, so there is no need to prepare chairs 1 for each physique of the user 10, and installation and storage can be space-saving.

The length of the legs 4, 5 that can be increased or decreased by one adjustment unit 30, i.e., the height L4 of the seat surface, is, for example, 3 centimeters. The length that can be increased or decreased by one adjustment unit 30 is not limited to 3 centimeters, and may be adjustable within an arbitrary range of 2 to 5 centimeters. If the height L4 to be adjusted by the adjustment unit 30 cannot be adjusted by one adjustment unit, it can be dealt with by connecting multiple adjustment units 30 in a daisy chain and attaching them to the legs 4, 5, as shown in, for example, FIG. 8(a) and FIG. 8(b). In addition, when connecting multiple adjustment units 30, the adjustment range can be expanded by combining adjustment units 30 with different adjustment ranges to adjust the height L4 of the seat surface. Note that the divided main body 31 does not have to have the same outer diameter as the outer diameter of the legs, and may have a large diameter, or may have a shape with a partially small diameter portion.

In the above embodiment, the adjustment unit 30 for adjusting the height L4 of the front upper end 3C1 of the seat 3C, which is the height of the seat 3C, is exemplified by adjusting the length of the legs 4, 5, but the height L4 may also be adjusted by adjusting the thickness of the seat 3. That is, in this case, the adjustment unit is the seat 3 having a different thickness.
One example of adjusting the thickness of the seat 3 is to change the thickness of the plate-shaped core material 31. The thickness of the core material 31 is directly related to the comfort of sitting. For this reason, it is necessary to ensure a minimum thickness that does not sacrifice comfort, and it is preferable to ensure a minimum thickness of 10 millimeters.
Also, although this depends on the material of the core material 31, if the thickness of the seat portion 3 is increased, the seat surface 3c will sink more when the user 10 sits down, thereby eliminating the purpose of making the seat thicker. Therefore, when adjusting the height L4 by changing the thickness of the core material 31, it is preferable to use a core material 31 made of a material that sinks less (has high resilience).

The physical differences of the users 10 include differences in weight as well as the length of the shins 11. Since differences in weight result in differences in the amount of sinking of the seat surface 3c when seated, the thickness of the core material 31 may not be changed, and the seat height L4 may be adjusted, for example, by interposing a spacer between the seat surface 3 and the intermediate portion 6 or the third frame 23. In this case, the spacer functions as an adjustment unit. It is preferable to prepare spacers of different thicknesses, since this allows the height L4 of the seat portion 3 to be easily adjusted according to the physical build of the user 10.

In the above embodiment, the height L4 can be adjusted by attaching/detaching the same length-adjustable adjustment unit 30 to/from the legs 4, 5. This is because the seat angle is set within a predetermined range by changing the lengths of the legs (front legs) 4, 4 and the legs (rear legs) 5, 5 in advance.
However, the length of the legs (front legs) 4, 4 and the length of the legs (rear legs) 5, 5 may be set to be the same, and adjustment units 30 with different adjustment lengths may be attached to the legs (front legs) 4, 4 and the legs (rear legs) 5, 5, respectively, to adjust the angle of the seat surface 3. For example, by attaching an adjustment unit 30 with a longer adjustment length to the adjustment unit 30 attached to the legs (rear legs) 5, 5 than the adjustment unit 30 attached to the legs (front legs) 4, 4, it is possible to make the seat surface 3C slope downward from the rear end 3A of the seat portion to the front end 3B of the seat portion. By changing the length of the legs 4, 4 and the length of the legs 5, 5, by changing the adjustment units 30 with different adjustment lengths or the number of adjustment units 30 attached, the angle of the seat surface can be adjusted and set within a predetermined range.

1 Chair 3 Seat 3A Rear seat 3B Front seat 3C Seat surface 4, 5 Leg 10 User 11 Shin (tibia)
40 Adjustment part D Tilt direction θ Predetermined tilt angle L3 Length of user's shin L4 Height of seat

Claims (5)

A seat and legs are provided.
The seat has a seat surface that slopes downward from the rear of the seat to the front of the seat when the seat is in a reclined state in which the seat can be sat on,
A chair having a determining portion that determines the seating position of a user on the seat surface when the seat portion is in a reclined state. 2. The chair according to claim 1, wherein the height of the seat surface is set to be longer than the length of the shins of a seated user. The chair according to claim 2 , wherein the defining portion is disposed toward a rear end of the seat portion. The chair according to claim 3 , wherein the positioning portion is provided so as to be movable in a tilting direction of the seat surface. The chair according to claim 3, wherein the determining portion is movable between a determined position where it can come into contact with at least one of the buttocks or lower back of a user seated on the seat surface, and a released position where it does not come into contact with the buttocks or lower back of the seated user.

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