JPH0795913A - Chair with backrest - Google Patents

Abstract

PURPOSE:To provide a comfortable rocking condition by supporting uniformly the whole upper hair body on a backrest when a person leans on the backrest. CONSTITUTION:A backrest 4 is composed of a back support part 4a and waist support part 4b. The waist support part 4b is moved forward in the rearward inclination of the back support part 4a by the guide action of a guide body 34 mounted to a seat body 3 or seat carrier part 2 not to be inclined rearward. By providing a projection 14a in the waist support part 4b for example, the waist support part 4b is substantially moved forward within the range of rearward inclination of the back support part 4a to a fixed angle (theta2), and the forward movement of the waist support part 4b is restrained or stopped after the back support part 4a is inclined rearward to the fixed angle theta2. Since the waist support part 4b does not excessively project, a comfortable rocking condition can be provided over the whole range of the backrest on which a person leans.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair having a backrest that tilts backwards against the elasticity of a spring or the like.

2. Description of the Related Art In a chair having a backrest that can be tilted rearward, the applicant of the present application has filed a patent application (Japanese Patent Application No. 4-288).
No. 663) proposed a chair having a structure conceptually shown in FIG. That is, the chair according to this prior application has a back support portion 4a 'for supporting the backrest 4'and the back A of a person.
And a waist supporting portion 4b 'for supporting the waist B of a person, and when the back supporting portion 4a' tilts backward, the waist supporting portion 4b '.
Was configured to project forward.

According to the invention of the prior application, the upper half of the person's upper body is supported by the backrest 4 in a large area when the person leans against the backrest, so that the sitting comfort in the rocking state is improved. It has the advantage that it can. However, in this invention of the prior application, the waist support moves forward in proportion to the amount of rearward tilt of the back support, so even if the upper half of the person's upper body is properly supported at the beginning of the rearward tilt of the backrest. However, if the backrest is greatly tilted backward, there is a problem in that the waist of the person may be pressed too strongly by the waist support and a comfortable rocking state may not be obtained. An object of the present invention is to provide a chair that solves this problem.

To achieve this object, the present invention provides a backrest that tilts backward in an elastically supported state with a back support portion and a waist support portion, while a seat body or a seat is provided. In the chair, wherein the receiving portion is provided with a guide body for moving the waist supporting portion forward relative to the back supporting portion by rearward tilting of the back supporting portion, the guide body and the waist supporting portion are provided. When the back support part is tilted backward by a certain angle, the relative forward movement of the waist support part with respect to the back support part is suppressed or stopped. In the present invention, the term "waist" refers to a part of the upper half of the body of a person sitting on a chair, which is above the seat surface and below the back, and
It is a concept that also includes the buttocks.

With this structure, in the range in which the back support portion starts to tilt backward and then tilts backward to a certain angle, the waist support portion makes a large forward movement, so that the person's waist becomes the waist support portion. Can be properly supported. Then, after the back support portion is tilted backward to a certain angle, the forward movement of the waist support portion is suppressed or stopped, so that the waist support portion is prevented from being excessively pressed and the waist is lowered. The supporting portion retains a state of being supported with appropriate strength. In other words, when a person leans against the backrest, the waist and the back of the person can be kept in a natural state without burden from the beginning of the backrest until the time when the backrest is fully tilted. Therefore, according to the present invention, there is an effect that a comfortable rocking state can be obtained over the entire range in which the back support portion tilts backward. Also,
As in claim 2, when the waist support part is formed so as to enter from the front end of the back support part to the rear, the waist support part fits the waist of the person while the person sitting on the chair is standing upright. Therefore, there is an effect that a comfortable sitting comfort can be obtained both in a state where the upper half of the body is raised and a state where the backrest leans against the backrest. By the way, when the backrest tilts backward, the backrest and the seat body tend to separate from each other.
The waist separates from the waist support and becomes selfish. As a result, a person's back may slip from the backrest, and the person's shirt may be pulled upward. On the other hand, when the seat body is configured to move rearward in conjunction with the rearward tilting of the backrest, the relative slippage phenomenon between the person's back and the backrest can be prevented. Thus, there is an advantage that a person's shirt can be prevented from being uncomfortable when it is pulled upward.

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.
A fixed frame body 7 fixed to the upper end of the leg body 1 and a movable seat receiving plate 8 arranged above the fixed frame body 7 are provided. The movable seat receiving plate 8 is formed slightly narrower than the seat body 3.
The fixed frame body 7 is formed in a box shape with an upward opening, and the front portion thereof is formed obliquely upward in a side view, and is fixed to the upper end of the front portion with the same width dimension as the movable seat receiving plate 8. The seat receiving plate 9 is fixed. Fixed to the lower surface of the movable seat support plate 8 are hanging pieces 8a extending along the left and right side surfaces of the fixed frame body 7, and the tip portions of these hanging pieces 8a are attached to the left and right side plate portions 7a of the fixed frame body 7. The first bearing portion 10 formed in FIG. 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 and can be tilted 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 is in a state in which a back support portion 4a supporting a person's back A and a narrow waist support portion 4b supporting a person's waist B are vertically connected, and the waist support portion 4b is a side surface. It is formed in a state of being curved in a convex shape facing backward. The back support portion 4a has an angle θ1 with respect to the horizontal plane set to about 100 degrees in a side view when no load is applied (see FIG. 12). Also, the backrest 4 is
As shown in FIGS. 4 to 5 and 12, an inner shell 14 made of a synthetic resin and an outer shell 15 made of a synthetic resin arranged at the rear of the inner shell 14 are fixed to each other by an appropriate means such as screwing to form a hollow shape. The back surfaces of the left and right side portions of the inner shell 14 are fixed to the upper end portion of the back support 16 formed in an L shape in a side view by an appropriate means such as screwing. The inner shell 14 is formed in a plate shape. A surrounding wall 15a is formed on the outer shell 15 except its lower end. In the outer shell 15 of the waist support portion 4a, a plurality of slits 17 extending between the left and right side edges of the outer shell 15 are formed at appropriate vertical intervals so as to allow the deformation. Therefore, the back support portion 4a of the backrest 4 hardly elastically deforms, but the waist support portion 4b of the backrest 4 can elastically deform toward a state of extending linearly in a side view. In this case, the groove 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. Further, as shown in FIG. 14, when the outer shell 15 is stretched and deformed to some extent, the slits 17 are closed at the back surface of the outer shell 15, and the waist support portion 4b is set so as not to be further deformed. ing. Then, on the back surface of the inner shell 14 in the waist support portion 4b, a mountain-shaped convex portion 14a protruding rearward in side view is formed. The convex portion 14a is formed by fixing an elastic body such as hard rubber by adhesion. At the front ends of the horizontal portions of the both back support rods 16,
A mounting plate 18 extending along the side surface of the fixed frame body 7 is fixed, and the upper and lower midway portions of the front portion of the mounting plate 18 are formed on the side plates 7a of the fixed frame body 7 slightly more than the first pivot 11. The second bearing portion 19 formed at the rear portion is pivotally attached by a second pivot 20 extending in the left-right direction.
In addition, the mounting plate 18 on the left and right back support rods 16
The first support shaft 21 mounted between the lower ends of the two and the second support shafts 22 mounted between the front ends of the left and right side plates 7a of the fixed frame 7 have two left and right springs, respectively. Receiving 2
A coil spring 24 is mounted as an example of an elastic body in which the backrest 4 is elastically supported between the pair of front and rear spring receivers 23. The back support 16
So that the mounting plate 18 and the movable seat receiving plate 8 can be tilted rearward 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 such that the first pivot shaft 11 fits therein. It is made larger than the protruding size of the first bearing portion 10. 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, of the lower surface of the seat body 3, the third pivot 25
An engaging member 26 having a pair of left and right side plates 26a is fixed to an upper portion of the engaging member 26, and engaging groove holes 27 with downward openings are formed on both left and right sides 26a of the engaging member 26.
It fits in 5. In addition, front and rear long guide grooves 28 extending slightly backward in a side view are formed in the upper part of the mounting plate 18 of the left and right back supports 16, and both guide grooves 28 are formed.
The end portion of the guide shaft 29 mounted between the left and right hanging pieces 8a of the movable seat receiving plate 8 is inserted in. 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 indicated by reference numeral 31. See FIGS. 3, 6, 11 and the like). . Therefore, when the back support body 16 tilts rearward, the seat body 3 tilts rearward due to the rearward tilting of the movable seat receiving plate 8, the pressing action of the third support shaft 25, and the guiding action of the guide groove hole 28. It slides rearward (however, the front portion 3a of the seat body 3 only slides rearward and does not tilt rearward). On the rear end surface of the fixed frame body 7, a guide body 35 made of a metal plate extending substantially obliquely upward toward the inside of the hollow portion of the waist support portion 4b of the backrest 4.
Is fixed, and between the left and right side plates 35a formed by bending at the tip of the guide body 35, a pressing roller 35 that comes into contact with the back surface of the inner shell 14 in the waist support portion 4b 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 that abuts the back surface of the guide body 35 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 portion is steep and the upper portion is slightly slanted. The pressing roller 35 of the guide body 35 and the convex portion 14a of the inner shell 14 are provided in a state where no load acts on the backrest 4.
The pressing roller 35b is located at the lower end of the convex portion 14a, and the backrest 4 has a certain angle θ2 (about 11
When tilted backward to 0 degree), the pressing roller 35b moves to the convex portion 14a.
When the backrest 4 is tilted backward to the angle θ3 (about 120 degrees in the embodiment) of the backward tilt limit (see FIG. 14), the pressing roller 35b is set to be positioned at the upper end of the convex portion 14a. is doing. In the above configuration, since the waist support portion 4b of the backrest 4 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 to the user's waist so that work can be performed for a long time without feeling fatigue.
On the other hand, if a person sitting in a chair leans back on the backrest 4,
As shown in FIGS. 13 and 14, the backrest 4 tilts backward against the elasticity of the coil spring 24. Since the guide body 35 is held by the support roller 25 and the regulation roller 37, the waist support portion 4b of the backrest 4 is deformed so as to extend linearly in a side view, and the back support portion is formed. It moves forward relative to 4a. In this case, since the convex portion 14a is formed on the back surface of the inner shell 14 in the waist supporting portion 4b, the waist supporting portion 4b quickly moves forward until the pressing roller 35 of the guide body 34 reaches the apex of the convex portion 14a. To go. And the pressing roller 3
When 5b passes the apex of the convex portion 14a, since the slope of the upper portion of the convex portion 14a is substantially upward in a side view, the forward movement of the waist support portion 4b is suppressed, so that the position of the waist support portion 4b is almost constant. The back support portion 4a tilts backward without changing. On the other hand, as described above, the rear portion 4a of the seat body 3 is rotated by the movable seat receiving plate 8, the pressing action by the third support shaft 25, and the guide action by the guide groove hole 28, so that the backrest 4 is supported.
In conjunction with the rearward tilting, the rearward tilting slides backward, and the front portion 3a of the seat body 3 slides rearwardly by the rearward tilting. By the way, when the backrest 4 is simply tilted backward, the backrest 4 moves away from the seat body 3, so that the person's waist B moves away from the backrest 4, and the weight of the upper body of the person is almost Since it is supported by the back support portion 4a, it is not possible to increase the support area of the upper half of the body of the person and maintain a comfortable rocking state. On the other hand, as in the present invention, when the backrest 4 is composed of the back support portion 4a and the waist support portion 4b and the waist support portion 4b is moved forward by tilting the back support portion 4a backward, Since B is supported by the waist support portion 4b,
The entire upper body of the person can be supported by the entire backrest 4. In this case, when the forward movement of the waist supporting portion 4b is merely interlocked with the backward tilting of the back supporting portion 4a, the waist supporting portion 4b
Moves too far and presses the person's waist B too much. However, as in the invention of the present application, the convex portion 14 is formed on the inner shell 14.
When a is provided, as shown in FIG. 13, after the back support 4a is tilted backward to an angle θ2 (about 110 degrees in the embodiment), the waist support 4b hardly moves forward and the back support 4a and Since the posture of the waist support portion 4b does not change much, the waist support portion 4b is prevented from excessively advancing and pressing the person's waist B, and as a result, the entire range in which the backrest 4 tilts backward. In, it is possible to secure a comfortable locking state. In this way, a comfortable and comfortable state can be obtained by supporting the person's waist B with the waist supporting portion 4b, but this is considered to be physiologically rationable as follows. That is, first, as shown in FIG. 20, a human spinal cord D is composed of a large number of intervertebral discs d, and the abdominal muscles and back muscles support the spinal cord. In this case, when the intervertebral discs D are parallel to each other, the load on the abdominal and back muscles is the smallest. On the other hand, when a person leans against the backrest 4, the waist B
When the pelvis E tilts backward without supporting the spinal cord E, the spinal cord D tends to curve forward in side view as shown in FIG. ), The burden on the abdominal muscles and the back muscles that support the spinal cord D 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. In this way, by holding the intervertebral disc d parallel while leaning against the backrest 4, the burden on the abdominal muscles and the back muscles is reduced, and as a result, fatigue is not given even in the same posture for a long time. , You can get a comfortable sitting comfort. Further, in the present application, since the pelvis E is not excessively pressed, a comfortable rocking state can be maintained in the entire range in which the backrest 4 tilts backward. In addition, when the backrest 4 tilts backward, the human body tends to stretch, so that the seat body 3 is fixed to the seat receiving portion 2, or the seatbody 3 moves forward in conjunction with the back tilting of the backrest 4. In the case of such a structure, a shirt worn by a person may be pulled upward. On the other hand, as in the embodiment, when the seat body 3 is tilted backward and slides backward while interlocking with the rearward tilting of the backrest 4, it is possible to prevent a person's shirt from being pulled upward. That is, when a person sitting in a 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 any of (a) and (b), since the curvature of the bending of the body when the body is raised is smaller than the curvature of the body when the body is leaned against the backrest and extended. The vertical length dimension L of the skin from the neck to the buttocks decreases in proportion to the size of the back tilt angle of the backrest. Therefore, in a chair in which the backrest 4 is simply tilted backward, when a person leans against the backrest 4, the shirt may be pulled upward, and the waist support portion 4b is simply projected forward. Since the change in the vertical dimension L of the surface of the person's skin cannot be dealt with by itself, the phenomenon in which the shirt is pulled upward can hardly be suppressed. On the other hand, when the seat body 3 is configured to move backward in conjunction with the back tilting of the backrest 4 as in the embodiment, the vertical length dimension L of the skin surface from the neck to the buttocks of the person is reduced. , The seat body 3 can be offset by moving the seat body 3 rearward, and as a result, it is possible to reliably prevent the person's shirt from being pulled when the person leans against the backrest 4 and makes the person feel uncomfortable. Of. Furthermore, when the seat body 3 is configured to move backward while tilting backward, as in the embodiment, the seat body 3 and the backrest 4 wrap the body of the person, so that a more comfortable and comfortable state is achieved. Can be obtained. It should be noted that the backrest point (the point at which the upper half of the body first hits the backrest (JIS standard) in the embodiment, points P in FIGS. 1 and 14) and the sitting standard point (the center point of the load on the seat, in the embodiment, H in FIGS. 1 and 14
The distance between the backrest 4 and the backrest 4 is larger than the distance L2 (see FIG. 1) when the backrest 4 is not tilted backward (see FIG. 1). 14), the difference between L2 and L3 is set to about 4 mm in the embodiment. As in the embodiment, when the waist support 4b is formed in a state of being curved rearwardly in a convex shape, the waist support 4b fits to the waist B of the person with the upper body raised, so that work can be performed without tiredness for a long time. can do. 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 slid only rearward as in the embodiment, a person leans against the backrest 4. In this state, there is an advantage that the thigh portion can be prevented from being pushed up by the front portion of the seat body 3. The above example
In the case where the regulation roller 37 is provided on the back surface of the inner shell 14 in the backrest 4, the regulation roller 37 is
As shown as a second embodiment in FIG. 15, it may be provided on the front surface of the lower end portion of the outer shell 15. In both of the above-mentioned embodiments, the convex portion 14a is formed of an elastic body such as rubber, but as a means for forming the convex portion 14a, FIG.
As shown in the third embodiment, a metal plate or a hard synthetic resin plate is formed into a curved shape, which is fixed with screws or rivets (FIG. (A)), or is integrated into a hollow state. Molded ((b) in the figure) or, as shown in (c) in the figure,
Various other structures such as solid-integral molding ((c) in the figure) can be adopted. Further, the guide body 35 is not limited to being formed in a plate shape and inserted into the waist support portion 4b, and various other modes can be adopted. For example, FIG. 17 shows a fourth embodiment. So that the waist support 4
On both left and right sides of b, groove-shaped guide bodies 39 that open toward the waist support portion 4b are provided, while guide projections 41 that fit into the guide grooves 39a of the guide body 39 are provided on the back surface of the waist support portion 4b. Alternatively, the bracket 40 may be used for attachment. Furthermore, the back support portion 4a and the waist support portion 4b of the backrest 4 do not have to be integrally molded of synthetic resin,
It may be configured separately or connected. Further, the side surface shape of the waist supporting portion 4b does not need to be curved in a forward concave shape as in the embodiment, and as shown as a fifth embodiment in FIG. The support portion 4a and the waist support portion 4b may be bent. 1A is a side view before the backrest 4 is tilted backwards, FIG. 1B is a side view in which the backrest 4 is tilted backward halfway, and FIG. 1C is a side view when the backrest 4 is tilted backwards. It is a side view of the cut state.

[Brief description of drawings]

FIG. 1 is a right side view of a main part of a chair according to a first embodiment.

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 view showing a state in which the backrest is being inclined backward (outer shell is omitted).

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 perspective view of an essential part of the third embodiment.

FIG. 17 is a perspective view of a main part of the fourth embodiment.

FIG. 18 is a schematic side view of the fifth embodiment.

FIG. 19 is a conceptual diagram showing prior art.

FIG. 20 is a conceptual diagram showing the relationship between a human pelvis and the spinal cord.

FIG. 21 is a side view when a person leans backward.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Leg body 2 Seat receiving part 3 Seat body 4 Backrest 4a Back supporting part 4b Waist supporting part 7 Fixed frame body 8 Movable seat receiving plate 9 Fixed seat receiving plate 13 Slider 14 Inner shell 14a Convex part 15 Outer shell 24 Coil spring 26 Engagement Mating member 28 Guide groove hole 35 Guide body 35b Pressing roller 37 Regulation roller

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

Claims (3)

[Claims] 1. A backrest that tilts rearward while being elastically supported is composed of a back support portion and a waist support portion, and a waist is provided on a seat body or a seat receiving portion by tilting the back support portion backward. In a chair provided with a guide body for moving the support portion forward relative to the back support portion, the guide body and the waist support portion are moved relative to the back support portion when the back support portion tilts backward by a certain angle. A chair with a backrest, characterized in that the relative forward movement of the support part is related to be suppressed or stopped. 2. A chair with a backrest according to claim 1, wherein the waist support portion of the backrest is formed so as to be located rearward of the front end of the back support portion in a side view. 3. In "Claim 1" or "Claim 2",
A chair with a backrest, characterized in that the seat body and the backrest are interlocked so that the seat body moves rearward in conjunction with back tilting of the backrest.