JP3388846B2 - Chair with backrest - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair provided with a backrest that can be tilted rearward. [0002] When the [prior art] human hip in a state of leaning against the backrest (buttocks) is supported, it is comfortable to be able to reduce the burden on the spinal vertebrae. Therefore, US Pat. No. 4,687,733 discloses a back support and a waist support made of an elastically deformable material as means for supporting a waist in a state where a person leans on the back. And the back support part in the backrest is attached to the L-shaped back support rod pivotally attached to the leg so as to be tiltable rearward, while the waist support part is formed in an L shape in side view. It describes a configuration in which the front end of the horizontal portion of the control member is attached to the upper end of the formed control member, and the front end of the horizontal portion is pivotally supported by a pin in a longitudinal long hole formed in a portion near the front end of the back support. That is, in this prior art, when the backrest is deformed so as to be in close contact with the upper body of the person, the control member adjusts the amount of forward projection of the waist support portion. [0005] However, this prior art merely deforms the backrest by a backrest load (body pressure of the upper body of the person) and does not forcibly push the waist support portion. There is a problem in that the function of supporting the waist support is low, and there is a limit in improving comfort. Another problem is that the structure is complicated because a control member is required. [0006] The present invention is, though it is easy single structure, it is an object of the present invention to provide a chair to be able to properly support the waist of the person. [0007] In order to achieve this object, a chair according to the present invention comprises a seat body and a backrest which is separated from the seat body. Part and a waist support part that can be bent and deformed so as to protrude forward in a side view are formed in a vertically connected form, and the lower end of the waist support part is locked to the rear end of the seat, or A downwardly extending portion is provided on the support portion, and this is locked to the seat receiving portion. The back support portion is positioned around a portion in front of a location where the waist support portion is locked to the seat or the seat receiving portion. the Rukoto attached to the back support rod for tilting, the back support portion is to the rear tilt
Then, set so that the distance between the back support and the seat is narrow
I have. Further, the waist support is bent and deformed in a side view.
Structure with a substrate made of a material that does not shrink and deform
Then, the upper end of the substrate is integrally connected to the back support.
On the other hand, the lower end of the substrate is locked to the rear end of the seat or the seat receiving part.
Further, the substrate is tilted backward by the back support.
Adds a bending habit to bend forward and flex in side view
ing. Name your, the "hip" is a concept that includes the buttocks in the present invention. In this configuration, the back support portion is
When tilted back, the board of the waist support is
Pressing to compress from above and below while tilting backward
This vertical pressing action and the bending tendency of the substrate
Accordingly, the waist support portion bends and deforms so as to protrude forward relative to the back support portion, and as a result, the waist support portion supports the waist of the person. Thus, according to the present invention, the waist support is
With a simple structure that only locks the lower end of the board to be fixed to the seat or the seat receiving portion, it is possible to accurately support the waist of the person, so a chair with significantly improved comfort in the rocking state is inexpensive. It has the effect that it can be manufactured. Next, an embodiment of the present invention will be described with reference to the drawings. 1 to 12 show a first embodiment of the present invention. In these figures, reference numeral 1 denotes a chair leg, and reference numeral 2 denotes a chair leg.
Denotes a seat receiving portion provided at the upper end of the leg 1, reference numeral 3 denotes a seat attached to the seat receiving portion 2, and reference numeral 4 denotes a backrest.
The backrest 4 is attached to the seat receiving portion 2 by a back support rod 5 formed in a substantially L shape in a side view. The seat receiving portion 2 has a fixed frame 6 fixed to the leg 1. The fixed frame 6 is formed so as to open upward and to have a front portion extending obliquely upward when viewed from the side, and a support plate 7 having a pair of left and right side plates 7 a at the upper end of the front of the fixed frame 6. Is pivoted on the first support shaft 8,
The seat 3 is attached to the support plate 7. The seat 3 is composed of a seat plate 3 'and a cushion 3 "stretched on the upper surface thereof. The back support rod 5 includes a pair of left and right side plates 5a. Is formed so as to extend obliquely downward at the front portion of the side plate 5a.
Is pivotally attached to the fixed frame 6 by the second support shaft 9. The front ends of the left and right side plates 5a of the back support rod 5 project forward from the fixed frame 6, and the shaft 10 is mounted between the left and right side plates 5a. A left and right longitudinal shaft 12 is attached via a bracket 11, and a spring 14 is inserted between the shaft 12 and a shaft 10 provided at the tip of the back support rod 5 via a spring receiver 13. The left and right side plates 5a of the back support rod 5
A long hole 15 obliquely downward from the front to the rear is formed in the middle of the front and rear of the third support shaft 16 mounted on a portion of the support plate 7 near the rear end of the left and right side plates 7a. The rod 5 is inserted into the long hole 15 . At this time, as clearly shown in FIGS. 5 and 6, the posture in which the elongated hole 16 extends is changed to the third support shaft 16.
In a posture inclined forward from the rotation locus O1. Therefore, when the back support rod 5 is tilted backward, the long hole 1
The third support shaft 16 moves downward by the guide operation of 5, and the seat body 3 also leans backward with the movement. In this case, as shown in FIG. 6, the third support shaft 16 is
Can rotate only along the trajectory shown by the arrow,
6 moves along the rotation trajectory O3 by the dimension L2 of the radius difference between the rotation trajectory O1 at one end of the elongated hole 15 and the rotation trajectory O2 at the other end, and the amount of movement of the third pivot 16 L2 is smaller than the movement amount L1 of the entire long hole 16. Therefore, the rearward inclination angle θ2 of the seat 3 is smaller than the rearward inclination angle θ1 of the back support rod 5. The spring force of the spring 14 is set to such a value that a person does not contract when the person sits on the seat 3 alone. The backrest 4 comprises a back support 4a for supporting a person's back and a waist support 4b for supporting the waist.
The whole is formed by stretching a cushion 18 on a substrate 17 made of synthetic resin. As shown in FIGS. 10 and 11, the upper edge 17a and the left and right edges 1 of the substrate 17 in the back support 4a are provided.
7b is bent forward. On the other hand, as shown in FIG. 9, the substrate 17 of the waist support 4b is formed in a flat plate shape. Therefore, the back support 4a is hardly deformed, and only the waist support 4b can be bent and deformed. On the other hand, a pair of left and right brackets 20 project rearward from the rear of the seat body 3, and the lower end of the substrate 17 is locked between the left and right brackets 20 by pins 21. In this case, the pin 21 is inserted through a cylindrical portion 17c formed integrally with the lower end of the substrate 17, and the axis of the pin 21 is displaced rearward by a distance e slightly smaller than the lower end 17d of the substrate 17. ing. Incidentally, the cylindrical portion 17c may be formed separately from the substrate 17, and this may be fixed to the substrate 17 by appropriate means such as rivets or screws. In the above configuration, when a person leans against the backrest 4, the back support 4a tilts rearward about the second support shaft 9 against the elasticity of the spring 14, as shown in FIG. The backrest 4 is tilted backward together with the back support rod 5, and the seat body 3 is slightly tilted backward about the first pivot 8. In this case, the lower end of the back support 4b is
While moving along the arc O4 about the support shaft 9, the virtual locus where the lower end of the back support 4a rotates about the pin 21 with respect to the lower end of the waist support 4b is indicated by reference numeral O5. Become. That is, while the vertical length of the waist support 4b in the no-load state is L3, the vertical length of the waist support 4b when the back support 4a is inclined backward is L4. And smaller. For this reason, the waist support 4b is subjected to the action of being compressed and contracted in the vertical direction, and is bent and deformed into a forwardly protruding state. As a result, the waist support 4b supports the human waist. When the axis of the pin 21 for locking the waist support 4b is eccentric to the rear of the lower end 17d of the board 17 as in the embodiment, the waist support 4b is surely projected forward. Can be deformed. In the above embodiment, the lower end of the waist support 4b is locked by the pin 21, but the means for locking the waist support 4b is as shown in FIG. 13 as a second embodiment. It may be received only by the gutter-shaped support member 22 which is mounted between the right and left brackets 20 for definitive on the seat body 3. FIG. 14 shows a third embodiment. In this embodiment, the waist support portion 4b is formed in a convex shape facing backward in a side view in a no-load state, and the lower end of the substrate 17 is attached to the bracket It is fixed with. In this case, by forming the lower end portion 17d of the substrate 17 to the forward convex, by placing a bending tendency to the substrate 17, even when formed into forward generally concave waist support portion 4b, the straight line when viewed from the side It can be bent and deformed so as to extend in the shape of a circle. FIG. 15 shows a fourth embodiment. In this embodiment, a bracket 2 projecting rearward from a seat body 3 is provided.
0, the lower end of the waist support portion 4b is locked by the pin 21 so that the pin insertion hole 24 of the bracket 20 is inserted into the horizontal portion 24a.
And an inclined portion 24b extending obliquely downward from the front end thereof . By the way, the pressing force acting on the pin 21 due to the deformation of the waist support portion 4b acts almost vertically downward when the back support portion 4a is initially tilted backward.
When the back inclination angle of the back support portion 4a is large, the back support portion 4a acts from obliquely rearward. Therefore, in the configuration shown in FIG. 15, while the back support portion 4a is tilted backward to a certain angle, the pin 21 is stopped at the rear end of the pin insertion hole 24, and the waist support portion 4b is large forward. When the back support 4a protrudes and tilts to the rear to some extent, the pin 21 slides forward in the pin insertion hole 24, and therefore, the waist support 4b can be prevented from excessively protruding. FIGS. 16 and 17 show a fifth embodiment. In this embodiment, the board 17 in the waist support 4b is used.
Is extended downward, and the lower end of the downward extension portion 17e of the substrate is locked by pins 21 between the left and right side plates 6a of the fixed frame 6. FIG. 18 shows a sixth embodiment. This sixth embodiment has the same structure as that of the fifth embodiment, and is provided with pin insertion holes formed in the left and right side plates 6a of the fixed frame 6. The hole 24 is formed as a long hole extending in the front-rear direction. According to this embodiment, as in the case of the fourth embodiment (FIG. 15), when the back support portion 4a is tilted backward to some extent, the pin 21 slides forward through the pin insertion hole 24 and moves.
b is prevented from protruding excessively forward. In each of the above embodiments, the seat body is configured to tilt backward with the backrest. However, it is needless to say that the seat body may not be tiltable backward.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a first embodiment. FIG. 2 is a rear view of FIG. FIG. 3 is an enlarged view of a main part of FIG. 1; FIG. 4 is a plan view as viewed from IV-IV in FIG. 1; FIG. 5 is a sectional view taken along line VV of FIG. 4; FIG. 6 is a diagram illustrating a relationship between a back support rod and a seat body in a backward inclination angle. FIG. 7 is a sectional view taken along line VII-VII of FIG. 3; 8 is a plan sectional view taken along line VIII-VIII in FIG. 3; FIG. 9 is a sectional view taken along line IX-IX of FIG. 3; FIG. 10 is a sectional view taken along line XX of FIG. 2; 11A is a cross-sectional plan view taken along the line XIA-XIA in FIG. 1,
(B) is a plane sectional view taken along the line XIB-XIB of FIG. 1. FIG. 12 is a diagram showing an operation. FIG. 13 is a sectional view of a main part showing a second embodiment. FIG. 14 is a sectional view of a main part showing a third embodiment. FIG. 15 is a right side view showing the fourth embodiment. FIG. 16 is a right side view showing the fifth embodiment. 17 is a sectional view taken along the line XVII-XVII in FIG. 16; FIG. 18 is a right side view of the sixth embodiment. DESCRIPTION OF SYMBOLS 1 leg 2 seat receiving portion 3 seat 4 backrest 4a back support 4b waist support 5 back support rod 6 fixed frame 7 support plate 17 backrest board 17e downward extension of backrest board 20 bracket 21 pin

Continuing from the front page (72) Inventor Kazuki Oki 1-4-1-12 Imafuku-Higashi, Joto-ku, Osaka-shi Inside Ito-Kikulebio Co., Ltd. (72) Inventor Masaaki Miki 1-4-12 Imagifuku-Higashi, Joto-ku, Osaka-shi (72) Inventor Masaru Nakasako 28-24, Kamiueno-cho, Muko-shi, Kyoto, Japan (56) References JP-A-2-52606 (JP, A) JP-A-4- 58905 (JP, A) JP-A-1-170412 (JP, A) JP-A-62-257518 (JP, A) JP-A-3-30050 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) A47C 3/026 A47C 7/44

Claims (1)

(57) [Claim 1] A seat body and a backrest separated therefrom are provided, and the backrest is configured to protrude forward in a side view when the backrest is hardly elastically deformed. The lower back of the waist support is locked to the rear end of the seat body, or a lower extension is provided in the lower back of the waist support. To the seat receiving portion, and the back support portion is attached to a back support rod that is tilted rearward about a portion in front of a location where the waist support portion is locked to the seat or the seat receiving portion. > by with Rukoto, back support when the back support portion is a rear tilt
The chair is set so that the space between the
Therefore, the waist support portion is bent and deformed in a side view, but is not contracted and deformed.
A structure with a substrate made of
While the end is integrally connected to the back support, the lower end of the board is
The rear end of the seat body or a seat receiving portion,
Has a forward convex shape in side view due to the back tilt of the back support.
A chair with a backrest that has a bending habit to bend and deform .