JPH0440532Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention relates to a chair that swings according to the user's posture.

(Conventional technology) A conventional chair is shown in FIG.

1 is a leg portion having a caster 1a, 2 is a vertical movement mechanism, 3 is a seat supported from the upper end of the vertical movement mechanism 2 via a torsion bar 6, and 4 is supported so as to be able to swing rearward from the seat 3. lower back, 5
is an upper back part supported so as to be able to swing rearward from the lower back part 4. Reference numeral 6 denotes a torsion bar that is a swing axis and is provided to be located forward of the center of the leg portion 1.

When a person sits on the above-mentioned chair and swings his or her body, the torsion bar 6 constituting the swing axis of the seat part 3 is twisted in the direction of arrow A, and the lower back part 4 is twisted as shown in FIG. The upper back portion 5 swings in the direction of arrow B and in the direction of arrow C, respectively. By arranging the torsion bar 6 in front of the center of the leg 1 in this manner, it can be swung with a large stroke with a small external force, and the comfort of the person sitting can be increased. However, if the swing stroke is too large, problems arise. In particular, when a short person sits on the seat and swings the seat a lot, the tip of the seat 3 lifts upward, which may cause his or her feet to lift off the floor.

(Problem to be solved by the invention) When a person is sitting on the above-mentioned chair and rocking it,
I feel anxious when my feet lift off the floor.

Therefore, an object of the present invention is to provide a chair in which, for example, a short person can sit on the chair and his or her feet will not rise off the floor even if the seat is swung.

[Effects of the invention] (Means for solving the problem) The structure of the invention is such that the seat and the back are integrally supported in a swingable manner by a swing shaft located forward from the center of the legs. , the back part is divided into a lower back part and an upper back part, the upper back part through a first pivot point with respect to the lower back part, and a second pivot point with respect to the seat part. In the chair, the lower back portions are each rotatably supported rearward through the seat, and the seat portion is divided into a central seat portion and a front seat portion,
The front seat part is configured to be rotatable downward through a third rotation point with respect to the center seat part, the swing axis is disposed near the front side of the lower surface of the center seat part, and the first and the third rotation point are provided.

(Function) When a person sits on a chair and rocks his or her body, the central seat, lower back, and upper back swing. Therefore, when the seat tilts backward, the weight of the feet pushes the front seat near the back of the knees. And since this front seat part rotates downward, there is no need for the feet to float. Therefore, rocking can be performed without feeling anxious.

(Example) FIG. 1 is a perspective view of an embodiment of the present invention.

1 is a leg part having casters 1a, 2 is a vertical movement mechanism, 3a is a central seat part on which a person sits, 3b is a front seat part on which the back side of the person's knees is placed, 4 is a lower seat part, 5 is an upper back part, 7 is an armrest, and 8 is a mat covering the surfaces of the seat parts 3a, 3b and the back parts 4, 5.

FIG. 2 is a perspective view of the chair with the mat 8 removed.

The front seat portion 3a, the center seat portion 3a, the lower back portion 4, and the upper back portion 5 are all resin molded products.

9c is a torsion spring that elastically supports the front seat portion 3b from the center seat portion 3a; 9a is the upper back portion 5;
A coil spring 9b is provided between the central seat portion 3a and the lower back portion 4. 10 is the center line of the first rotation axis of the upper back part 5, 12 is the center line of the second rotation axis of the lower back part 4, and 11 is the center line of the third rotation axis of the front seat part 3b. This is the center line.

FIG. 3 is a sectional view taken along line DD in FIG. 2.

10a is a first rotation axis (first rotation point) provided between the upper back part 5 and the lower back part 4, and 12a is provided between the central seat part 3a and the lower back part 4. The second rotation axis (second rotation point) 11a is a third rotation axis (third rotation point) provided between the front seat portion 3b and the center seat portion 3a. Reference numeral 6 denotes a torsion bar which is a swinging shaft located near the third rotational axis 11a located in front of the center of the leg portion 1 and rearward from this third rotational axis 11a, and 5a denotes an upper back portion. 5b is a concave portion provided in the convex portion 5a to accommodate the coil spring 9a; 4a is a convex portion provided at the upper end of the lower back 4; 4b is a convex portion A recessed portion 4c is provided in the lower back portion 4 for accommodating the coil spring 9a.
4d is a concave portion for accommodating the coil spring 9b provided in the convex portion 4c, 3b is a convex portion provided at the rear end of the central seat portion 3a, and 3c is this convex portion. A recessed portion provided in the portion 3b for accommodating the coil spring 9b; 7 is a flexible resin armrest connected to the first rotation shaft 10a and the third rotation shaft 11a; 12a; is the central seat part 3a
This is a second pivot shaft provided between the lower back part 4 and the lower back part 4. 14 is a reinforcing metal fitting which reinforces the back surface of the central seat portion 3a and whose tips are fixed to both ends of the torsion bar 6; 2a is an arm fixed to the center of the torsion bar 6 from the upper end of the vertical movement mechanism 2; and 13 is a thin-walled reinforcing metal fitting. It is a resin cover that has a certain hinge portion 13a and an opening portion 13b, and covers the back surfaces of the seat portions 3a, 3b and the back portions 4, 5. The coil spring 9a is in the recess 5
The coil spring 9b is provided between the recess 4b and the coil spring 9b.
is provided between the recess 4d and the recess 3c.
Further, reference numeral 11b denotes a stopper which is a displacement stopping member protruding from the center of the third rotating shaft 11a to the front side, and the rotating shaft 11a is fixed to the central seat portion 3a.

Note that 13c in the figure is a pin that is attached to a hole 5c provided on the back side of the upper back portion 5.

Next, the operation will be explained.

A person sits on the central seat part 3a and leans his back against the back parts 4 and 5. When you shake your body, the torsion bar 6 of the central seat 3a is twisted and A
swing in the direction. Further, in the lower back part 4, the coil spring 9b is compressed, and the range 16 of the gap between the end face 3d, which is the displacement stopper on the rear side of the central seat part 3a, and the end face 4f, which is the lower displacement stopper of the lower back part 4, is 16. Then, the lower back part 4 swings in the direction b. In addition, in the upper back part 5, the coil spring 9a is compressed, and the gap range 15 between the end face 4e, which is the upper displacement stopper member of the lower back part 4, and the end face 5d, which is the lower displacement stopper member of the upper back part 5, is
The upper back portion 5 swings in the direction of arrow C. and,
The front seat portion 3b has a stopper 11.
It oscillates in a range 17 corresponding to b. On the other hand, the relative positions of the first rotation axis 10a and the third rotation axis 11a are as follows:
When the central seat portion 3a swings in the direction of arrow A or when the upper back portion 5 swings in the direction of arrow C, the shape of the armrest does not change. Further, even if the lower back portion swings in the direction of arrow B, the armrest deforms only slightly, and since the armrest is made of a flexible material, the design of the armrest becomes easy.

When a person sits on the above-mentioned chair and swings, the torsion bar 6 is placed forward of the center of the leg 1, so that the chair can be rocked greatly with a small external force, increasing the comfort of the seater. I can do it.
At this time, since the weight of the foot is applied to the front seat part 3b, a load resisting the torsion spring 9c is applied to the front seat part 3b.
b, the front seat portion 3b rotates downward. Therefore, even if a short person sits on the seat and rocks the seat, his or her feet will not come off the floor, so he or she can swing without feeling anxious.

Moreover, since the seat parts 3a, 3b and the back parts 4, 5 are resin molded products, the seat parts 3a, 3b and the back parts 4, 5 can be easily manufactured.

Furthermore, since the back sides of the seat parts 3a, 3b or the back parts 4, 5 are covered with a resin cover 13, the seat part 3
The appearance of the back sides of a, 3b and back parts 4, 5 becomes beautiful.

Furthermore, since the hinge 13a of the cover 13 is provided near the rotation shafts 10a, 11a, and 12a and is thin, the cover 13 can be easily bent.

Even if the coil springs 9a, 9b and torsion spring 9c, which are swingably supported members, are significantly deformed, the stress can be kept low, resulting in a long service life.
The upper back part 5, the lower back part 4, and the front seat part 3b each have the swingable ranges 15, 16,
Since the structure has a stopper function (displacement stopping member) that prevents the springs from swinging beyond 17 degrees, the springs 9a, 9b, and 9c are safe and will not be damaged even if an excessive force is applied inadvertently.

Finally, a large number (3) of rotation axes 10a, 11a,
By providing the seat portion 3 and the back portions 4 and 5 with the seat portion 12a, natural rocking can be performed, further increasing the comfort of the person sitting on the seat.

[Effects of the invention] As detailed above, according to the invention, the swing axis is positioned in front of the center of the leg, and the swing stroke is designed to be large with a small external force. However, since the front seat part that rotates by gravity is provided, and the swing axis is located near the front side of the lower surface of the central seat part, it does not interfere with the rotation range of the front seat part. Therefore, even if a short person, for example, sits on the seat and swings, his or her feet will not come off the floor, so he or she can do so without feeling anxious.

Since the armrest is connected between the first pivot point and the third pivot point, the design of the armrest is facilitated and the presence of the armrest increases the comfort of the sitter.

Next, a biasing member for biasing each of the upper and lower backs, between the lower back and the central seat, and between the central seat and the front seat, and a displacement stop member are provided. In this case, the biasing member allows for smooth rocking, and the displacement stopping member prevents damage to the biasing member even if excessive force is applied inadvertently.
Rocking can be done safely.

Further, when the armrest is made of a flexible material, even if an excessive force is applied, the armrest itself can be bent to prevent damage to the armrest.

Furthermore, if the seat or the back is molded from resin, the seat or the back can be easily manufactured.

Furthermore, if the back side of the seat or back is made of resin and covered with a cover that has a thin hinge, the cover can be easily bent at the hinge, and the seat or back can be easily bent. The appearance of the back side becomes beautiful.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a perspective view of essential parts, FIG. 3 is a sectional view taken along line DD in FIG. 2, and FIG. 4 is a perspective view of a conventional example. DESCRIPTION OF SYMBOLS 1... Leg part, 3a... Central seat part, 3b... Front seat part, 3d, 4e, 4f, 5d... End face (displacement stop member), 4... Lower back part, 5... Upper back part, 6
...Towsion bar (swing axis), 7...Armrest, 8
...Torsion spring (biasing member), 9a, 9b...Coil spring (biasing member), 10a...First rotation axis (first rotation point), 11a...Third rotation axis (3rd
(rotation point), 11b... stopper (displacement stop member), 12b... second rotation axis (second rotation point),
13...Cover.

Claims (1)

[Claims for Utility Model Registration] (1) The seat and back are supported so as to be able to swing integrally by a swing shaft located forward from the center of the legs, and the back is supported by a swing shaft located forward from the center of the legs, and the back is connected to the lower back and the upper back. the upper back via a first pivot point relative to the lower back and the lower back via a second pivot point relative to the seat; In a chair that is rotatably supported backwards,
The seat portion is divided into a central seat portion and a front seat portion, the front seat portion is configured to be rotatable downward through a third pivot point with respect to the central seat portion, and The chair is characterized by comprising an armrest arranged near the lower front side of the central seat portion and connected to the first rotation point and the third rotation point. (2) Between the upper and lower back parts, between the lower back part and the central seat part, and between the central seat part and the front seat part,
The chair according to claim 1, further comprising a biasing member for biasing each member and a displacement stop member. (3) The chair according to claim 1, wherein the armrest is made of a flexible material. (4) Claim 1, further comprising a resin cover having a thin hinge portion on the back surface of the seat portion or the back portion.
The chair mentioned.