JPH06133828A - Supporting method of seated person on chair by back rest and chair using this supporting method - Google Patents

Abstract

PURPOSE:To allow a person to be seated for many hours by dividing a back rest into the upper half part and the lower half part of the back rest, and displacing the lower half part of the back rest to the front side of the seat surface, while inclining backward, when the back rest surface is inclined backward. CONSTITUTION:The back rest lower half part 7 attaches integrally the upper end 7a to the upper end part 6a of a supporting frame 6, and on the other hand, attaches the lower end 7b to the rear end of the seat surface 2 and forms them integrally. In this case, the front side of the back rest lower half part 7 becomes a circular arc-like side face shape whose curvature is small in the vicinity of a backward inclination terminal, although it is circular arc-like side face shape whose curvature is comparatively large before it is inclined backward. This face means a fact that, while the upper and the lower half parts 3, 7 of the back rest are inclining backward integrally, only the back rest lower half part 7 is displaced so as to advance in the forward direction. When the back rest is inclined backward, the upper half part 3 executes an operation for following such a posture variation as the upper half part of the body of a seated person is inclined backward, and on the other hand, the lower half part 7 can follow a posture variation of the lumber vertebra B and the upper part of the pelvis of the seated person, therefore, an excellent seated sensation is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair newly developed from the viewpoint of ergonomics.

[0002]

2. Description of the Related Art Up to now, many chairs have been proposed which have been developed from the viewpoint of ergonomics in pursuit of good sitting comfort. Most of the chairs that have been proposed to be comfortable to sit on are used to prevent the clothes such as shirts from being turned up or the knees from being lifted when the seated person leans forward or backward, or the backrest is seated. It was developed for the purpose of conforming to changes in the shape of the spine that accompany changes in the posture of the person. For example, when the seated person takes a forward leaning (tilting the body forward. The same applies below) or backward leaning (tilting the body backward. In order to maintain a constant relationship between the recession or the depression on the front side of the seat and the rearward tilt of the backrest, or the forward tilt of the backrest, the above-mentioned respective operations of the seat plate and the backrest are performed by using a link mechanism or the like. An example is one that associates.

In the conventional chair as described above, the upright posture in the sitting posture is a natural body, that is, the seated person is supposed to perform various works in the upright posture, such as office work and desk work. The seating surface is designed, and the operation of the backrest and the seating surface, for example, the manner of the depression operation and the backward tilting operation, or the center points of those operations are set.

However, in recent years, offices have rapidly become OA,
Or, with the introduction and installation of various OA equipment accompanying this, the proportion of VDT operation among the work performed while sitting in the office has dramatically increased. Many people have complained of a feeling of fatigue, which is thought to be caused by the uncomfortable sitting of the chair, in the VDT operation.

In order to investigate the cause as described above, the inventors of the present invention perform a VDT operation, or take a resting posture while sitting in a sitting posture because of tiredness of the work, or in the prior art. The upright posture at the time of sitting, which is said to be the basic posture of the occupant, is shown at multiple points on the body of the occupant M (subject) and the relationship between the backrest and the seat surface of the actual chair supporting the body. Take a picture using a line camera etc.,
In addition, we tried to analyze the locus of movement by capturing continuous changes in posture and performing image processing on this captured image. FIG. 1 is a skeleton diagram of a seated occupant M who is this test subject in a sitting upright posture. In FIG. 1, A is the pelvis, B is the lumbar vertebra consisting of the first to fifth lumbar vertebrae, and C is the first thoracic vertebra C ₁ to.
Thoracic consisting twelfth thoracic vertebra C _12, D is cervical composed of the first cervical vertebra D ₁ ~ seventh cervical vertebra D _7, E is Futoshimomokotsu, F is the ischial tuberosities point, f
Is the center of rotation, G is the center of rotation of the femur, H is the ear canal, J
Is the vertebral bone, K is the ankle, and L is the spine of each of the above vertebrae B to D.

2 to 4, the office swivel chair CH with a backrest (the backrest BR can be tilted backward and the seat surface SE is shown).
A support line of a seat surface and a backrest in a retractable structure), angles BRθ and SEθ between a backrest BR and a seat surface SE, an outline of a seated person M and respective angles Lθ of the spine and pelvis of the person. , Aθ in the upright posture (FIG. 2), at the time of VDT work (FIG. 3), and at rest (FIG. 4) with the body of the backrest BR resting (FIG. 4).

As can be seen from FIGS. 2 to 4, it is clear that the occupant M is working in a slightly tilted posture, that is, in a posture in which his / her body is leaned against the backrest BR during VDT work. This is because the VDT work is mainly a work on the keyboard near the desk.
It is considered that this is because the line of sight is restricted because the operation is performed while looking at the board and the screen, and therefore it is easier to lean back a little to perform such work.

However, as can be seen from FIGS. 3 and 4, the occupant M sits on the backrest BR and leans back B.
When R and the body are tilted backward, the rear side of the buttocks of the occupant M and the waist portion continuing to the butt are in a state of being floated (away from) the seat surface SE of the chair and the backrest BR and not supported.

The inventors of the present invention, in order to know the postures of the spine L and the pelvis A in the backward tilted state as described above, the X-ray photographs of the seated person M in the forward tilted posture, the upright posture, and the backward leaned posture. When the image was taken and the image was processed, the posture of the skeletal system of the seated person M as shown in the schematic views of FIGS. 5 to 7 was obtained. That is, in the backward tilted posture shown in FIGS.
It was revealed that the rear side of the pelvis A and the pelvis A are not supported by the seating surface SE of the chair or the backrest BR.

In a chair which is said to have been developed from a conventional ergonomic standpoint, the upper half of the spine L of the seated person M, specifically, the backrest point, between the upright sitting posture and the backward tilt. An attempt was made to support the upper vertebra L along with a change in the posture thereof, and it is generally considered that this is sufficient, but for the pelvis A, a change in the sitting posture occurs. Since it rotates about the ischial joint F, it is formed by the idea that the seat surface SE should be supported so that the center of rotation (the ischial joint F) does not move. However, according to the tests and investigations conducted by the inventors of the present invention, it is clear that the pelvis A changes its posture according to the change of the sitting posture, but its behavior is the same as in the conventional viewpoint. It turned out that it was not a simple rotational movement about F.

The behavior of the pelvis A due to the change in the sitting posture known to the inventors is as shown in FIGS. 8 to 9, and when viewed from the upright posture in FIG. 9, in the forward leaning posture in FIG. F is slidingly displaced forward, and its inclination angle is slightly changed.
In the rearwardly tilted posture, when viewed from the upright posture of FIG.
Is that the pelvis A itself is further tilted and rotated while being displaced forward. The spine L above the pelvis A that behaves in this manner and supported by the pelvis A, the back muscles, the abdominal muscles, and the like is shown in FIGS. I knew that the posture would be as shown in. 8 to 10, a,
b and c are fixed temporary reference points set on the seating surface, and the above facts are clarified by observing the relative positional relationship between these reference points a to c and the ischial tuberosity point F in each of FIGS. 8 to 10. You can figure it out.

Further, by analyzing FIGS. 8 to 10,
I learned the following. That is, it is empirically known that, in a desk work or the like, a seated posture of leaning forward (FIG. 8) or leaning backward (FIG. 10) is easier than an upright posture. This is the lumbar vertebrae B _{5 to} B ₃ in FIGS. 8 and 10.
Considering the above, each lumbar vertebra B _{5 to} B ₃ in the upright posture of FIG.
The gap between them is more uneven than in the forward and backward tilted postures shown in FIGS. 8 and 10, and the lumbar inclination in this uneven gap makes the upright posture painful or not easy. This is a point that is considered to be one of the factors. Even in the forward tilted posture of FIG. 8, the gaps between the lumbar vertebrae B _{5 to} B ₃ are non-uniform and pressure is applied to the ventral side. Further, in the rearward tilted state shown in FIG. 9, it appears as a substantially uniform gap as a whole. However, the fourth
There is a non-uniform gap between the fifth lumbar vertebrae B ₄ and B ₅ .

However, since the VDT work is performed in a comfortable posture, for example, even if the seated posture is slightly tilted backward, even if the user sits for a long time, for example, for about one hour, he / she may feel sickness, pain, and pressure. The subjects reported that they perceived discomfort, and if they were forced to maintain their posture, they also suffered from muscle fatigue due to tension in the abdominal muscles and the like. In the conventional chair, as described with reference to FIGS. 2 to 4, the weight of the seated person when tilted backward is intensively supported in the vicinity of a part of the backrest BR and the ischium joint F of the seat surface SE. It is considered that the load is concentrated on the supported part because the part of the hip from the rear side of the buttocks is not supported.

[0014]

SUMMARY OF THE INVENTION Accordingly, the problem to be solved by the present invention is to support not only when standing upright or leaning forward, but especially when the posture of the seated person is slightly tilted backward or backward. It is an object of the present invention to provide a method for supporting a seated person by a backrest that can stably hold a region from the rear surface of the buttocks to the waist of the seated person, and a chair that employs this supporting method.

[0015]

The structure of the supporting method according to the present invention made for the purpose of solving the above-mentioned problems is as follows.
When a seated person is supported by the backrest in a chair formed so that the backrest surface is tilted backward by the seated person's rearward tilt, the backside of the seated person performs different operations above and below the vicinity of the waist. While supporting from the rear by the backrest surface formed in the above, the support above the waist of the seated person is supported by the upper backrest that tilts backward in proportion to the backward tilt of the seated person, while from the vicinity of the waist of the seated person. As for the lower support, a part of the seated person from the lumbar vertebra to the pelvis is abutted against the seated back part of the seated person, and is supported by the lower backrest surface which is tilted rearward and is displaced forward of the seat surface. It is a feature.

Further, the chair adopting the above-mentioned supporting method has a seating surface and a backrest, and in a chair formed so that the backrest tilts backward when a person sits down, the backrest is the waist of the seated person. In the vicinity, the upper and lower backrests, which operate differently above and below, are formed.
The lower backrest is formed by a lower support member that abuts against the lumbar vertebrae or pelvis of a seated person from the rear,
Further, the supporting member is linked and supported by the upper backrest or an upper backrest supporting member that moves in unison with the rearward tilt of the upper backrest so that the lower backrest tilts backward when the upper backrest tilts backward. However, it is characterized in that it is arranged so as to advance to the front side of the seat surface.

[0017]

Embodiments of the present invention will now be described with reference to the drawings. In view of the conventional state of the art as described above, the present invention takes various postures such as forward leaning, upright leaning, or rearward leaning on a chair, the upper part of the pelvis in each posture, and By supporting the lumbar region, which is the lower half of the spine connected to it, in accordance with each of the above postures, even in the same posture, perceive uncomfortable feeling such as oppressive feeling for at least one hour. It proposes a chair that is comfortable to sit from a new perspective. Specifically, in a chair having a backrest that can be tilted backward, the lumbar spine B of the occupant M
Alternatively, the lumbar vertebra B and the upper part of the pelvis A form a support portion that abuts and supports them. Hereinafter, the example will be described.

First, FIG. 11 shows the concept of the supporting method of the present invention. In FIG. 11, the backrest BR of the chair is, for example, the upper half of the backrest BR ₁ supporting above the third to fourth lumbar vertebrae or the vicinity thereof and below the third lumbar vertebra or the fourth lumbar vertebrae or the vicinity thereof. there are, the upper half of the pelvis a, specifically formed divided into a backrest lower half BR ₂ abutting on to the vicinity of the rotor f pelvic a, backrest upper half BR ₁ is of the seated person In the upright posture, the upper part of the pelvis or immediately after the fourth lumbar vertebra is formed so as to perform a tilting motion with the center P ₁ and the lower backrest half BR ₂ is slightly forward of the ischium contact F in the upright posture. has center P ₂ in the vicinity immediately below the seat surface SE there is displaced toward the front of the seat surface in the rear slope in the center P _2, preferably the lower half B
The lower half of the backrest is supported so that the lower half of R ₂ is displaced further forward. P ₃ is the sinking fulcrum of the seating surface SE, and PO is the post of this chair. here,
The upper and lower divisions of the backrest BR need only be divided into the upper half portion BR ₁ and the lower half portion BR ₂ in the operation surface or the functional surface, and need not be divided into the upper portion and the lower portion in appearance.

The upper and lower split operation type backrests BR ₁ and BR ₂ conceptually shown in FIG. 11 have side surfaces as shown in FIGS. 12 and 13, for example. Here, the backrest upper half B
R ₁ supports a part of the spine L including the eighth thoracic vertebra C ₈ to the first lumbar spine B ₁ , and the lower back half BR ₂ includes the lumbar vertebra B including the fourth lumbar spine B ₄ and the posterior surface of the pelvis A. It is formed as a support. These supports are used for the posture change of the occupant M, especially for the back half BR of the backrest even when the back leans.
₂ is required to support the lumbar spine B below the fourth lumbar spine B ₄ and the posterior surface of the pelvis A while abutting on the body of the occupant M. In this respect, in a chair having a structure in which the seat surface SE is submerged, the chair is supported in a state of being moved in synchronism with the subduction of the seat surface SE.

FIG. 14 is a side view showing one of the concrete examples for realizing the above-mentioned supporting mode. In this figure, 1 is a base frame of a chair which is rotatably attached to and supported by a pole-like support (not shown), and 2 is an upper surface side of the base frame 1, for example, a front end. Although not shown, a cushion member is usually attached to the upper surface of a seat frame or a seat shell, which is a seat surface that is vertically swingable (sinkable) about the horizontal shaft 2a.

Reference numeral 3 denotes an upper half of the backrest arranged above the rear end of the seat surface 2, and the length up to the lower end of the backrest is approximately a backrest point B.
It is formed up to the vicinity of P. An upper end 4a of the backrest upper half 3 is integrally connected to the left and right sides of the lower end of the backrest 3, and a lower end 4b is pivotally attached to the frame 1 by a shaft 4c so that the shaft 4c is centered. And a supporting frame of the backrest upper half 3 which supports the backrest upper half 3 so as to be capable of swinging back and forth.

Here, it is assumed that a spring for restoring and holding the posture of the support frame 4 at a fixed position is interposed in the shaft 4c portion as an example although not shown.
The upper half 3 of the backrest is formed of a metal plate, a metal pipe, a synthetic resin plate, a synthetic resin pipe, or the like, and a cushion material (not shown) is mounted on the front side as in the case of the seat surface 2. It is something.

Reference numeral 5 is a guide member having vertical guide grooves 5a provided on the lower left and right sides of the upper half 3 of the backrest.
Reference numeral 6 denotes a support frame for the lower half portion 7 of the backrest, in which the upper end 6a is supported and guided by the guide groove 5a of the guide member 5, while the lower end side 6b is axially attached 6c to the rear end of the base frame 1. is there.
The support frame 6 is provided with a guide member 5 when the upper end portion 7a of the lower back half portion 7 is not tilted backward.
Its length is adjusted so that it can be positioned at the lower end of the guide groove 5a.

The lower half 7 of the backrest has its upper end 7a integrally attached to the upper end 6a of the support frame 6, while the lower end 7b is attached.
Is integrally attached to the rear end of the seat surface 2 and is formed of a relatively flexible and extensible member as a whole.

Since the upper half 3 of the backrest is integral with the supporting frame 4, for example, when tilted rearward, the upper half 3 of the backrest pivots and tilts rearward about the axis 4c. When the upper half 3 of the backrest and its supporting frame 4 are tilted backward about the axis 4c, the upper end 6a of the supporting frame 6 of the lower half 7 of the backrest is supported and guided by the guide groove 5a of the guide member 5. Axis 6c for being
Although it will be tilted backward about the axis, the shaft 4c and the shaft 6c,
The positions are deviated from each other, and the frame
Since the frame 4 and the frame 6 have different lengths, the upper end of the support frame 6 of the lower back half 7 is the guide member 5.
It will be tilted backward while moving upward in the guide groove 5a.

Here, the upper end 6a of the support frame 6 moves upward in the guide groove 5a of the guide member 5, and the upper end 7a of the lower backrest half 7 is the upper end 6a of the frame 6. On the other hand, since the lower end 7b is integral with the rear end of the seat surface 2, the lower backrest half 7 is deformed in such a manner that it is pulled toward the upper end thereof. That is, the front side of the lower backrest half 7 has an arcuate side surface shape with a relatively large curvature (that is, a small radius) before it tilts backward, but has a small curvature near the end of the tilt backward (that is, It has an arcuate side surface shape (having a large radius).

This means that the upper and lower back half 3,7
Means that, while leaning backward together, only the lower half 7 of the backrest is displaced so as to advance to the front side of the seat surface 2. Thus, in the chair of the present invention, when the backrest is tilted backward,
The upper half 3 of the occupant's lumbar spine B and the upper part of the pelvis A of the seated occupant of the occupant, while the upper half of the occupant moves to follow the posture change in which the upper half of the occupant leans backward. Since it is possible to follow changes in posture, it is possible to obtain an excellent sitting comfort that cannot be obtained with conventional products. In this embodiment, it is optional whether the upper half 3 and the lower half 7 of the backrest are externally divided, or externally covered with an integral covering material. In the present invention,
This is because it suffices if the upper half 3 and the lower half 7 of the backrest can perform different operations when tilted rearward.

As a supporting structure of the backrest which can obtain the above effects, there is also one shown in FIG. In this example, the upper half 3 of the backrest is supported by the supporting frame 4 and tilts backward, which is similar to that of the previous embodiment, but there is a difference in the support structure of the lower half 7 of the backrest. Therefore, this point will be described.

In FIG. 15, the upper end of the lower half 7 of the backrest
7a is fixed to the upper end of the support frame 4 of the upper half 3 of the backrest, while the lower end 7b of the lower half 7 is arranged at the rear end of the seat 2 along the seat 2. It is supported by a guide member 5'having a horizontally long guide groove 5a '. The lower end 7b of the lower half 7 is attached to the tip 41a of the lever 41 which is integrally formed with the support frame 4 of the upper half 3 from the shaft 4c. The lower end 7b and the lower end 7b are connected via a connecting link 61.

With the above structure, when the upper half 3 of the backrest is integrally tilted with the supporting frame 4 about the shaft 4c,
As shown in FIG. 15, a lever portion 41 integrated with the support frame 4 is provided.
Rotates angularly in the counterclockwise direction and extends the lower end side of the connecting link 61 forward, so that the lower end 7b of the lower backrest half 7 is pulled forward in the guide groove 5a 'of the guide member 5'. Become.
This means that the lower half 7 of the backrest is displaced forward while the upper end 7a of the lower half 7 is inclined rearward integrally with the upper half 3 of the backrest, and the lower half 7b is displaced forward. It shows that the vehicle tilts backward with displacement to move forward. Also in the embodiment of FIG. 15, for the same purpose as that of the embodiment of FIG. 14, it is arbitrary whether the upper half 3 and the lower half 7 of the backrest are externally integrated or divided. .

In each of the above embodiments, the seat surface 2
Although the subduction structure of No. 1 is not mentioned, whether or not the seating surface 2 can be submerged in the present invention is also arbitrary. Also in the chair adopting the structure in which the seat surface 2 can be depressed, the operation modes of the upper half 3 and the lower half 7 of the backrest of the above embodiment are substantially the same as those of the above embodiment.

[0032]

As described above, according to the present invention, in a chair having a backrest that can be tilted backward, the backrest is divided into an upper half and a lower half of the backrest, and the lower half of the backrest is the lumbar portion of the seated person. It is arranged as a lumbar support member applied to, and when the backrest surface tilts backward, the lower half of the backrest, that is, the support member near the lumbar spine, is displaced forward of the seat surface while tilting backward. Since the lumbar vertebrae of the seated person, which are neglected in the conventional chair, in the forward leaning, upright leaning, and backward leaning postures, particularly the third and fourth lumbar vertebrae and the upper part of the pelvis, are actively supported in each posture. , Regardless of the posture, the body pressure of the occupant is distributed over the entire support surface of the chair, allowing a long-time sitting.

Further, since the lumbar vertebra and the pelvis can be supported in each of the postures as described above, particularly in a backward tilted posture suitable for VDT operation and the like, it is almost difficult with the conventional chair. Seating that continues for a long time becomes possible without perceiving any discomfort such as pressure or tension in the abdominal muscles, which is a special effect not obtained with conventional chairs.

[Brief description of drawings]

FIG. 1 is a schematic view showing a skeleton of a human body viewed from a side when seated.

FIG. 2 is a perspective view showing a relationship between a seat surface and a backrest in an upright position of a conventional chair, and a spine and a pelvis of a seated person.

FIG. 3 is a slant view showing a relationship between a seat surface and a backrest and a seated person's spine and pelvis when tilting backward in a conventional chair.

FIG. 4 is a perspective view showing a relationship between a seat surface, a backrest, a spine of a seated person, and a pelvis of a conventional chair at the time of reclining and resting.

FIG. 5 is a model diagram showing the relationship between the spine and the pelvis in a forward leaning posture when seated.

FIG. 6 is a model diagram showing the relationship between the spine and the pelvis in an upright posture when seated.

FIG. 7 is a model diagram showing the relationship between the spine and the pelvis in a backward tilted posture when seated.

FIG. 8 is a side view showing a state of the pelvis and the lumbar spine in a forward leaning posture when seated.

FIG. 9 is a side view showing a state of the pelvis and the lumbar spine in an upright posture when seated.

FIG. 10 is a side view showing a state of the pelvis and the lumbar spine in a backward tilted posture when seated.

FIG. 11 is a model diagram for explaining the operation of the pelvis and spine when the posture is changed during sitting.

FIG. 12 is a side view showing an example of the external configuration of the chair of the present invention.

13 is a side view of the chair of FIG. 12 with the backrest tilted backward.

FIG. 14 is a side view showing an example of the basic structure of the chair of the present invention.

FIG. 15 is a side view showing another example of the chair of the present invention.

[Explanation of symbols]

 1 Base frame of chair 2 Seating surface 3 Upper half of backrest 4 Support frame of upper half 3 of backrest 5 Guiding member 6 Support frame of lower half of backrest 7 Lower half of backrest

Claims (2)

[Claims] 1. When a seated person is supported by the backrest in a chair formed so that the backrest surface is tilted backward by tilting the seated person backward, the backside of the seated person is separated from above and below the vicinity of the waist. Is supported from the rear by a backrest surface formed so as to operate, and the upper part of the seated person above the lumbar region is supported by the upper backrest surface which tilts backward in proportion to the backward tilting of the seated person, while The lower part of the back of the seated person is the lower backrest surface, which contacts the part from the lumbar vertebra of the seated person to the vicinity of the pelvis with respect to the backward tilt of the seated person and displaces to the anterior side of the seat surface while tilted backward. A method of supporting a occupant's back in a chair, characterized in that the chair is supported by. 2. A chair having a seat surface and a backrest, wherein the backrest is tilted backward when a person sits down, the backrest being raised near the waist of the seated person,
The lower backrest is formed by an upper backrest and a lower backrest that operate differently below, and the lower backrest is formed by a lower support member that is applied by abutting the lumbar vertebra or pelvis of a seated person from the rear, and By supporting the member by interlockingly connecting the upper backrest or the upper backrest supporting member that moves together with the rearward tilt of the upper backrest, when the upper backrest tilts backward, the lower backrest tilts backward and the seating surface. A chair characterized by advancing and displacing forward.