JPH0795912A - Chair with backrest - Google Patents

Abstract

PURPOSE:To prevent a phenomenon that a shirt a person is wears is pulled upward when the person, seating on a chair, lens on a backrest. CONSTITUTION:A seat body 3 interlocked with a backrest 4 inclined rearward is moved rearward while being inclined rearward. When a person leans on the backrest 4, a vertical length dimension L on the surface of the person's skin from the neck to the hip tends to be shorten by the tendency of elongating his body. A change in the length dimension L of the surface of the person's skin from the neck to the hip is offset by the rearward movement of the seat body 3. As a result, the person's shirt is not pulled upward so that the person can be prevented from uncomfortable feeling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair having a backrest which can be tilted rearward.

[0002]

2. Description of the Related Art In a chair having a backrest that tilts backwards against the elasticity of a spring or the like, if the backrest is merely configured to tilt backwards, when the backrest tilts backwards, the backrest and the seat body are tilted. The distance between and will increase. For this reason, when a person leans against a backrest, the shirt worn by the person may be pulled upward, which causes a discomfort to the person.

As a means for coping with this problem, the applicant of the present application has proposed a chair having a structure as shown in principle in FIG. 20 in the previous patent application (Japanese Patent Application No. 4-288663). That is, the chair according to this earlier application has a backrest 4 ',
The back support portion 4a 'that supports the back A of the person and the waist support portion 4b' that supports the waist B of the person are separately configured.
When the a'is tilted rearward, the waist support portion 4b 'is configured to project forward.

[0004]

According to the invention of the prior application, the lower end of the shirt worn by the person is pressed against the body by the waist support portion 4b 'when the person leans his / her upper body backward. , I could prevent the shirt from climbing up, but the effect was still insufficient. A first object of the present invention is to surely prevent the phenomenon that the shirt is pulled upward, and a second object is to obtain a comfortable and comfortable state in which the shirt is leaned against the backrest. .

[0005]

Means for Solving the Problems The present inventor has studied the shape of a person sitting on a chair when he or she leans or leans backward, and as a result, as a means for achieving the first object. As described in claim 1, "a seat,
A backrest that tilts rearward while being elastically supported, and moves the backrest and the seat rearward while interlocking with the rearward tilting of the backrest while the seatback tilts backward or without tilting backward. So that they are related ".

Further, as a main structure for achieving the second object, as described in claim 2, on the premise of the structure of claim 1, "a back support portion which hardly elastically deforms the backrest, Consists of elastically deformable waist support,
The back support portion in the backrest is attached to a seat body or a back support body extending from the seat receiving portion so as to tilt backward in a state of being elastically supported, and the back support portion and the waist support portion in the backrest are attached to the back support portion. It is related so that the waist support portion relatively projects forward when tilted backward. "

In the present invention, the term "waist" refers to a portion above the seat surface and below the back, and is therefore a concept including the buttocks.

[0008]

When the person sitting on the chair raises his body to work, the side shape of the body is as shown in FIG.
Straighten your spine as shown by the solid line in (a),
As shown by the solid line in FIG. 6B, the user leans forward. Then, when the upper half of the body is tilted backward, the human body is in a stretched state as shown by the alternate long and short dash line in FIGS.

In this case, in both cases (a) and (b), the curvature of the bending of the body when the body is raised is
The vertical length L of the skin from the neck to the buttocks gradually decreases in proportion to the size of the back tilt angle because it is smaller than the curvature of the body when leaning against the backrest and extending the body. It is a thing. Then, as in the above-mentioned prior application, in a state where the waist support portion is simply applied to a person's waist, it is not possible to effectively deal with the change in the vertical length dimension L of the surface of the skin, and the back A and the waist B Since the phenomenon of relative slippage occurs between the skin and the shirt, the phenomenon of pulling the shirt cannot be prevented.

On the other hand, according to the structure of claim 1 of the present application, the seat body moves rearward because the vertical length dimension L of the skin surface from the person's neck to the buttocks is reduced by leaning on the backrest. By doing so, in other words, the buttocks move backward so as to cancel the decrease in the vertical length dimension L of the skin surface, and as a result, when the backrest leans against a person, It is possible to reliably prevent the shirt from being pulled and causing discomfort to a person.

In this case, if the seat body is configured to move backward while tilting backward, the seat body and the backrest wrap the human body, so that a more comfortable and comfortable state can be obtained. . On the other hand, according to the configuration of claim 2, since the waist of the person is supported by the waist support portion in a state in which the person sitting on the chair leans the upper body backward, the upper body can be supported in a large area. It is possible to prevent the upper half of the body from feeling pressure and to obtain a more comfortable and comfortable state.

Further, according to the third aspect of the present invention, since the deformation of the waist support portion is guided by the guide body, it is possible to prevent the waist support portion from excessively projecting and pressing the person's waist strongly. , You can get a more comfortable and comfortable state.

[0013]

Embodiments of the present invention will now be described with reference to the drawings. 1 to 14 show the first embodiment, and in these drawings, reference numeral 1 indicates a leg of a chair, reference numeral 2 indicates a seat receiving portion,
Reference numeral 3 indicates a seat body supported by the seat receiving portion 2, and reference numeral 4
Indicate the backrest respectively. Cushion bodies 5 and 6 are stretched on the upper surface of the seat body 2 and the front surface of the backrest 4, respectively.

The seat receiving portion 2 is, as shown in FIGS. 3 to 4 and 11, a fixed frame body 7 fixed to the upper end of the leg body 1.
And a movable seat receiving plate 8 arranged above it. The movable seat receiving plate 8 is formed slightly narrower than the seat body 3. The fixed frame body 7 is formed in the shape of a box with an upward opening, the front portion thereof is formed obliquely upward, and the fixed seat receiving plate having the same width dimension as the movable seat receiving plate 8 is formed at the upper end of the front portion. 9 is stuck.

On the lower surface of the movable seat support plate 8, fixed hanging pieces 8a extending along both left and right side surfaces of the fixed frame body 7,
The tip ends of the two hanging pieces 8a are pivotally attached to a first bearing portion 10 formed on the left and right side plates 7a of the fixed frame body 7 by a first pivot 11 extending in the left-right direction. Sliders 13 are fitted on the left and right side edges of the movable seat receiving plate 8 and the left and right side edges of the fixed seat receiving plate 9, respectively, and the seat body 3 is fixed to these sliders 13. Therefore, the seat body 3 is movable in the front-rear direction, tiltable rearward, and
The seat body 3 can be bent at a connecting portion between the front portion 3a and the rear portion 3b.

The backrest 4 has a back support portion 4a for supporting a person's back A and a narrow waist support portion 4b for supporting a person's waist B, which are vertically connected to each other.
b is formed in a state of being curved in a backward convex shape in a side view. As shown in FIGS. 4 to 5, the backrest 4 includes an inner shell 14 made of synthetic resin and an outer shell 15 made of synthetic resin arranged behind the inner shell 14.
The inner shell 14 is formed in a hollow shape by being fixed by an appropriate means such as screwing, and the back surfaces of the left and right sides of the inner shell 14 are screwed to the upper end portion of the back support 16 formed in an L shape in a side view. It is fixed by appropriate means.

The inner shell 14 is formed in a plate shape, and an enclosing wall 15a is formed on the outer shell 15 except its lower end. Waist support 4a
The outer shell 15 has slits 17 extending between the left and right side edges of the outer shell 15 at appropriate vertical intervals. Therefore, of the backrest 4, the back support portion 4a
Is hardly elastically deformed, but the waist support portion 4b of the backrest 4 can be elastically deformed toward a state of extending linearly in a side view.

In this case, the slit width of each slit 17 in the outer shell 15 is formed so as to become wider toward the side edge of the surrounding wall 15a, so that the outer shell 15 is easily elastically deformed. , Again,
As shown in FIG. 4, when the waist support portion 4b extends linearly in a side view, the slits 17 are closed at the back surface of the outer shell 15 so that the waist support portion 4b is not further deformed. is doing.

A mounting plate 18 extending along the side surface of the fixed frame 7 is provided at the front end of the horizontal portion of the both back support rods 16.
Is fixed, and the upper and lower intermediate portions of the front portion of the mounting plate 18 are formed in the side plate 7a of the fixed frame body 7 at a portion slightly rearward of the first pivot 11.
It is pivotally attached to the bearing portion 19 by a second pivot 20 extending in the left-right direction.

A first support shaft 21 mounted between the lower ends of the mounting plates 18 of the left and right back support rods 16 is also provided.
And the second support shafts 22 mounted between the front end portions of the left and right side plates 7a of the fixed frame 7 are fitted with two left and right spring bearings 23, respectively. A coil spring 24 is mounted between the two 23 as an example of an elastic body that elastically supports the backrest 4.

In order that the mounting plate 18 of the back support 16 and the movable seat receiving plate 8 can be tilted backward without interfering with each other, the projecting dimension of the second bearing portion 19 into which the second shaft pivot shaft 20 is fitted is set as follows. It is made larger than the projecting dimension of the first bearing portion 10 into which the first pivot 11 is fitted. The upper portions of the mounting plates 18 of the left and right back support members 16 project above the fixed frame member 7, and the third support shaft 25 is mounted between the front portions of the upper ends of the left and right mounting plates 18. On the other hand, an engaging member 26 having a pair of left and right side plates 26a is fixed to a portion of the lower surface of the seat body 3 above the third pivot 25, and a downward opening formed on both left and right sides 26a of the engaging member 26. The engaging groove hole 27 of is fitted into the third support shaft 25.

Further, a guide groove 28 is formed in the upper part of the mounting plate 18 of the left and right back supports 16 and extends longitudinally to the rear so as to be slightly inclined rearward, and the movable seat receiving plate 8 is provided in both guide grooves 28. The end of the guide shaft 29 mounted between the left and right hanging pieces 8a is inserted. Relief holes 30 for allowing the rotation of the third support shaft 25 are formed in the left and right hanging pieces 8a of the movable seat receiving plate 8. In addition, the front end portion of the movable seat receiving plate 8 is notched to allow the rearward movement of the engaging member 26 (this notch is designated by reference numeral 3).
It shows with 1. (See FIGS. 3, 6 and 11).

Therefore, when the back support member 16 tilts backward, the seat member 3 is tilted rearward by the movable seat receiving plate 8, the pressing action of the third support shaft 25, and the guide action of the guide groove 28.
It slides rearward while tilting rearward (however, the front portion 3a of the seat body 3 only slides rearward and does not tilt rearward). A guide body 35 made of a metal plate is attached to the rear end surface of the fixed frame body 7 and extends substantially obliquely upward toward the hollow portion of the waist support portion 4b of the backrest 4, and is bent at the tip of the guide body 35. Between the formed left and right side plates 34a, a pressing roller 35b that comes into contact with the lower rear surface of the inner shell 14 is rotatably attached. Further, a bracket 36 fitted to the guide body 35 is fixed to the inner surface of the lower end portion of the inner shell 14, and a regulation roller 37 abutting against the back surface of the guide body 34 between the tips of the left and right side plates of the bracket 36. Is rotatably attached.

The upwardly extending portion of the guide member 35 is bent so that the lower part is steep and the upper part is slightly slanted. In the above configuration, a person has a backrest 4
Even if the vertical length of the skin surface from the person's neck to the buttocks is shortened by leaning back against the person's neck, the change in the skin surface length is offset by the seat body 3 moving backward. It is possible to reliably prevent discomfort caused by the shirt moving upward.

It should be noted that the backrest point (the point at which the upper half of the body first hits the backrest (JIS standard) and the point P in FIGS. 1 and 14 in the embodiment) and the sitting position standard point (the center point of the load on the seat, In the embodiment, point H in FIGS. 1 and 14 is assumed).
Since the distance between and is smaller than the dimension L2 (see FIG. 1) when the backrest 4 is not tilted backward (see FIG. 1), the dimension L3 (see FIG. 14) is when the backrest 4 is fully tilted backward. Yes, in the embodiment, the difference between L2 and L3 is set to about 4 mm.

As in the embodiment, the waist support 4 of the backrest 4
When b is formed in a convex shape facing backward in a side view, when a person sitting on a chair raises his / her upper body, as shown in FIG.
The waist support portion 4b fits the person's waist B, and fatigue is not felt for a long time. On the other hand, a person sitting in a chair has a backrest 4
When leaning back, the backrest 4 tilts backwards against the elasticity of the coil spring 24, as shown in FIGS. 13 and 14. In that case, since the guide body 34 is in a state of being held by the support roller 25 and the regulation roller 37, the backrest 4
The waist support portion 4b extends and deforms toward a state of linearly extending with the back support portion 4a.

Further, as described above, the rear portion 4a of the seat body 3 is supported by the rotating action of the movable seat receiving plate 8, the pressing action by the third support shaft 25, and the guiding action of the guide groove hole 28. In conjunction with the rearward tilting of the seat 4, the seating body 3 slides backward while tilting backward, and the front part 3a of the seat body 3 slides rearward by the rearward tilting of the backrest 4. By the way, when a person leans against the backrest 4, the load of the upper half of the body of the person acts on the backrest 4 as a moment, so that the backrest 4
The pressing force of the upper body of the person against becomes smaller as going downward. Therefore, when the backrest 4 is simply tilted backward, the weight of the upper body of the person is almost supported by the back support portion 4a, and as a result, the supporting area of the upper body of the person should be increased. It is impossible to maintain a comfortable and comfortable state.

On the other hand, as in the present invention, when the backrest 4 is tilted backward, the waist support portion 4b is seen from the side and the back support portion 4a is seen.
If it is configured to extend and deform in a straight line with
Since b protrudes forward relative to the back support portion 4a, the waist portion B of the person is forcibly pressed by the waist support portion 4b, and as a result, the upper half of the person's upper body is entirely supported by the backrest 4. It can be supported in a substantially even state, and a comfortable and comfortable state can be secured.

As described above, a comfortable and comfortable state can be obtained by supporting the person's waist B with the waist supporting portion 4b, but it is considered that this can be physiologically reasoned as follows. To be That is, first, as shown in FIG. 22, the human spinal cord D is composed of a large number of intervertebral discs d,
The abdominal and back muscles support the spinal cord. In this case, the intervertebral disc D
Are parallel to each other, the burden on the abdominal and back muscles is the smallest.

On the other hand, when a person leans against the backrest 4 and the pelvis E leans backward without supporting the waist B, the spinal cord D bends forward in side view as shown in FIG. 22 (a). As a result, the burden on the abdominal muscles supporting the spinal cord D and the back muscles increases, and fatigue is felt in a short time. On the other hand, when the pelvis E is supported by the lumbar support 4b as in the present invention, the posterior tilting of the pelvis E is prevented or suppressed, so that the spinal cord D also has its intervertebral discs d parallel to each other. Will be retained.

As described above, since the intervertebral disc d is held in parallel with the backrest 4 leaning against the backrest 4, the load on the abdominal muscles and the back muscles is reduced, and as a result, fatigue is felt even in the same posture for a long time. It is thought that a comfortable sitting comfort can be obtained without giving the. Therefore, it is particularly useful when, for example, the backrest 4 leans lightly to work.

By the way, as a means for supporting the waist B of a person, as shown by the alternate long and short dash line in FIG. 23, if the waist support portion 4b 'is largely projected without sliding the seat body 3'backward, It is considered that the supporting force of the waist B by the supporting portion 4b 'can be increased. However, if the waist support portion 4b 'is excessively protruded, the waist B is excessively compressed, and the posture of the waist B and the posture of the back A become unnatural, which rather makes the person feel uncomfortable. Will be done.

In this respect, when the seat body 3 is slid rearward in association with the rearward tilting of the backrest 4 as in the present invention, FIG.
As shown in FIG. 3 and FIG. 14, under the state where the postures of the back support portion 4a and the waist support portion 4b are maintained in an appropriate relationship so as not to press the person's waist portion B excessively with the waist support portion 4b, Since it is possible to prevent the seat body 3 and the backrest 4 from being separated from each other, it is possible to prevent the phenomenon that the shirt is pulled while ensuring a comfortable sitting comfort.

Also, as shown in FIG. 23, the backrest 4 '
Is composed of an inner shell 14 'and an outer shell 15', and the inner shell 14 'in the waist support portion 4b is
If only the back support rod 34 'is supported, the inner shell 14' uses the upper end of the back support rod 34 'as a fulcrum,
Since it rotates so as to project forward, the inner shell 1
In order to allow the rotation of 4 ', it is necessary to increase the distance between the inner shell 14' and the outer shell 15 'in the waist support portion 4b', and then the outer shell 15 'in the waist support portion 4b becomes large. There is a problem that the appearance is deteriorated due to the state of bulging backward.

On the other hand, when the waist support portion 4b is deformed along the guide body 35 as in the present invention, the outer shell 15 of the waist support portion 4b does not have to be largely projected rearward, so Although the guide body 34 is inserted inside the support portion 4b to make it compact, it is possible to prevent the appearance from being deteriorated. As in the embodiment, when the seat body 3 is configured to be bent in a side view and the front portion 3a of the seat body 3 is configured to slide only rearward, a person leans against the backrest 4. Thus, it is possible to prevent the thigh portion from being pushed up at the front portion of the seat body 3.

In the above embodiment, the regulating roller 37 is provided on the back surface of the inner shell 14 of the backrest 4, but as shown in FIG. 15 as the second embodiment, the front surface of the lower end portion of the outer shell 15 is provided. Regulation roller 37
May be provided. Further, for example, as shown as a third embodiment in FIG. 16, the guide body 34 may be configured to tilt backwards against the spring 38 (in this case, the spring 38).
Is stronger than the spring force of the coil spring 24 with respect to the backrest 4 so that the guide body 35 is tilted backward at a lesser angle than the backrest 4).

When the backrest 4 is composed of the inner shell 14 and the outer shell 15, the slits 17 of the outer shell 15 in the waist supporting portion 4b are formed so that the groove widths are the same throughout as shown in FIG. Alternatively, as shown in FIG. 17 as a fourth embodiment, the gap may be formed so as to widen toward the rear.

In each of the above embodiments, the guide body 35 is inserted into the hollow portion of the backrest 4, but the guide body 34 is used.
The guide means for the waist support portion 4b can adopt various other modes. For example, as shown as a fifth embodiment in FIG. 18, groove-shaped guide bodies are formed on both left and right sides of the waist support portion 4b. While providing 39, the waist support portion 4b may be provided with a guide protrusion 40 that fits in the guide groove 39a of the guide body 39.

Furthermore, it is not necessary to integrally form the back support portion 4a and the waist support portion 4b in the backrest 4,
It may be configured separately or connected. Further, the side surface shape of the waist support portion 4b does not need to be curved in a forward concave shape as in the embodiment, and as shown as a sixth embodiment in FIG. The support portion 4a and the waist support portion 4b may be bent.

[Brief description of drawings]

FIG. 1 is a right side view of a main part of a chair.

FIG. 2 is a rear view of the backrest.

FIG. 3 is an exploded perspective view of a main part.

FIG. 4 is an exploded perspective view of a backrest.

FIG. 5 is an enlarged side view of a main part.

6 is a plan view taken along line VI-VI of FIG.

7 is a sectional view taken along line VII-VII in FIG.

8 is a sectional view taken along line VIII-VIII of FIG.

9 is a sectional view taken along line IX-IX of FIG.

FIG. 10 is a sectional view taken along line XX of FIGS. 6 and 9.

FIG. 11 is a partial perspective view of a seat receiving portion.

FIG. 12 is a right side view of the rear portion of the chair.

FIG. 13 is a diagram showing a state in which the backrest is being tilted backward.

FIG. 14 is a diagram showing a state in which the backrest is fully tilted backward.

FIG. 15 is a diagram showing a second embodiment.

FIG. 16 is a schematic view showing a third embodiment.

FIG. 17 is a partial side view showing the fourth embodiment.

FIG. 18 is a partial perspective view showing a fifth embodiment.

FIG. 19 is a schematic view showing a sixth embodiment.

FIG. 20 is a conceptual diagram showing prior art.

FIG. 21 is a diagram for explaining the action, and is a diagram showing changes in the shape of the body.

FIG. 22 is a view showing the action, showing the relationship between the pelvis and the spinal cord.

FIG. 23 is a conceptual diagram showing a comparison with the present invention.

[Explanation of reference numerals] 1 leg 2 seat receiving portion 3 seat body 4 backrest 4a back supporting portion 4b waist supporting portion 7 fixed frame body 8 movable seat receiving plate 9 fixed seat receiving plate 13 slider 14 inner shell 15 outer shell 17 slit 24 Coil spring 26 Engaging member 28 Guide groove hole 35 Guide body 35b Pressing roller 37 Restricting roller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaru Nakasako 28-24 Mitomichi, Kamenoeno-cho, Muko-shi, Kyoto Prefecture

Claims (4)

[Claims] 1. A seat body, and a backrest that tilts rearward in a state of being elastically supported, and the seatback and the seat body are tilted backward while the seatbody is tilted backward in association with the back tilting of the backrest. A chair with a backrest, which is related to move backward without leaning backward. 2. The "backrest" according to claim 1, wherein the backrest is composed of a back support portion that hardly elastically deforms and an elastically deformable waist support portion, and the back support portion of the backrest is elastically supported. Attached to the seat support or the back support extending from the seat receiving part so as to tilt backward in the state of
A chair with a backrest, characterized in that the back support portion and the waist support portion in the backrest are related so that the waist support portion relatively projects forward when the back support portion is tilted backward. 3. The "backrest" according to claim 1, wherein the backrest is composed of a back support portion that hardly elastically deforms and a waist support portion that is elastically deformable, and the back support portion of the backrest is elastically supported. Attached to a back support that extends from the seat body or seat receiving portion so as to tilt rearward in the closed state, while supporting the waist support portion on the seat body or seat receiving portion in conjunction with the back tilting of the back support portion of the backrest. A chair with a backrest provided with a guide body which is elastically deformed so as to extend substantially linearly with the section. 4. The "claim 2" or "claim 3" according to claim 3, wherein the backrest is formed in a hollow shape by an inner shell located on the front side of the chair and an outer shell located on the rear side of the chair. A chair with a backrest, wherein the guide body is arranged in a hollow portion of a waist support portion.