JPH0910065A - Seat back for chair - Google Patents

Abstract

PURPOSE: To improve feeling for use through pertinent flexible deformation and also comfortable touch feeling while maintaining rigidity as a seat back. CONSTITUTION: In a structure having a synthetic resin shell 5 and a mounting section 7 formed approximately at the breadthwise center of the shell 5 for coupling to the upper end of the seat back support level of a chair, the shell 5 has the first rib 51 formed at such a position as reinforcing the section 7, the second rib 52 formed along the periphery of a seat back, the third rib 53 formed at such a position as intermittently jointing the first and second ribs 51 and 52, respectively as integral part thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair backrest that is preferably used in offices and the like.

[0002]

2. Description of the Related Art Some chair backs have a structure in which they are attached to the upper end of a back support rod projecting from the rear of the chair toward the upper rear. In such a backrest, a resin shell a as shown in FIG.
In addition, a mounting portion b attached to the upper end of the back support rod of the chair is set, and a vertical rib c and a horizontal rib d originating from the mounting portion b, and the mounting portion b and the like from the outer edge of the shell a. It is customary to integrally provide a large number of slanted ribs e extending at substantially equal intervals. And the load on the backrest,
The vertical ribs c, the horizontal ribs d, and the diagonal ribs e are concentrated on the mounting portion b, and the mounting portion b is supported by the back support rod of the chair.

[0003]

However, with the shell a having such a structure, the rigidity necessary for the backrest is sufficiently secured, but the shell a is less likely to bend. That is, since the horizontal ribs d are provided over the entire width direction and the vertical ribs c are provided over the entire height direction, the diagonal ribs e are evenly distributed over the entire backrest a. There is no region that causes the shell a to bend, and when the backrest is leaned against the back, the user feels a rugged and hard feeling as a whole, and a comfortable feeling tends to be impaired. In addition, in this way, the ribs c, d, and e are closely packed so that the ribs c, d, and e are relatively narrow and arranged close to each other. When sitting, standing, moving, or the like, when the hand is placed on the upper end of the backrest of the chair, the ribs c, d, and e are difficult to fit into the hand, are hard to hold, and have a poor hand feeling.

An object of the present invention is to provide a backrest of a chair which can suitably solve such problems.

[0005]

In order to achieve the above object, the present invention employs the following configuration.

That is, the backrest of the chair according to the present invention is provided with a resin shell, and the mounting portion set approximately in the center in the width direction of the shell is attached to the upper end portion of the back support rod of the chair. The first rib formed at a position to reinforce the attachment portion, the second rib formed along the outer edge of the backrest, and the first rib and the second rib intermittently. It is characterized in that it integrally has a third rib formed at a position connected to.

As a concrete embodiment, the first rib and the second rib have a substantially annular shape, the third rib has a substantially linear shape, and the third rib extends from the mounting portion to the outer edge. One of them is formed at a position that extends radially.

[0008]

If the shell having such a rib structure is the main constituent element, the load applied to the center of the backrest will be concentrated directly on the mounting portion via the first ribs and will be applied to the periphery of the mounting portion of the backrest and the outer edge. The load applied is once supported by the third rib, the second rib, etc., and then concentrates on the mounting part via the first rib, and as a result, the load applied to the entire backrest is applied to the back of the chair at this mounting part. It is supported on the upper end of the pole. Therefore, sufficient rigidity can be secured over the entire backrest. Moreover, since there is no rib in the region surrounded by the first rib, the second rib, and the third rib, elastic deformation of the resin is caused when a load is applied to this region. For this reason, if the number of the third ribs is limited to the necessary minimum and the area is expanded to a relatively wide range, the flexure when leaning against the backrest is suitably induced and an appropriate cushioning property is exhibited. can do. Moreover, since such a rib structure requires a smaller total number of ribs than the conventional rib structure, the rib interval can be wide and each rib can be made wide as necessary. Therefore, when the backrest is placed on the hand, the ribs easily fit in the hand, and the user does not feel discomfort.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

In the chair shown in FIG. 1, a seat 3 is rotatably supported on a column 2 which is erected from the leg blades 1, and a back support rod 4 is provided so as to project rearward and upward from a rear portion of the seat 3. At the same time, the backrest 6 having the shell 5 as a main constituent element is attached to the upper end portion of the back support rod 4. As the other components except the shell 5, those widely known in this field can be used, and the description thereof will be omitted.

The shell 5 is made of, for example, a hard rigid resin integrally molded with a resin, and has a semicircular plate shape as shown in FIGS. It has a shape that is smoothly depressed and the back side bulges correspondingly. Then, at the time of molding, the first rib 51 and the second rib 5 having a U-shaped cross section on the back surface side of the shell 5.
The second and third ribs 53 are provided so as to project.

The first rib 51 is a substantially semicircular arc-shaped rib 51a located at the center of the backrest 6, and this arc-shaped rib 51.
a linear rib 51b that connects the lower ends of a to each other, and a linear rib 51c that has one end in the gathering portion of the arc-shaped rib portion 51a and the linear rib 52a and the other end that hangs down toward the lower edge of the backrest 6. It is a continuous installation. The linear rib 51c also serves as a mounting portion 7 for mounting the shell 5 on the upper end of the back support rod 4.
The common fasteners (not shown) are fixed to the holes 7a provided in the back support rod 4 and the holes 4a provided at the corresponding positions of the upper ends of the back support rods 4 to fix the shell 5 to the upper end of the back support rod 4. I am trying.

The second rib 52 is formed along the outer edge of the backrest 5, and has an annular shape in which an upper edge rib 52a, left and right side edge ribs 52b and a lower edge rib 52c are continuously formed in a circular shape. Is.

The third ribs 53 are formed at positions where the first ribs 51 and the second ribs 52 are intermittently connected. Specifically, a right radial rib 53a inclined upward to the right is provided at the position where the right healthy bone of the user leaning on the backrest 6 is attached, and a right radial rib 53a is inclined downward to the position where the left healthy bone is attached. A left radial rib 53b is provided, and the base ends of the ribs 53a and 53b are connected to the first rib 51.
In addition, the tips are integrally connected to the second ribs 52, respectively.

If the shell 5 having such a rib structure is the main constituent element, the load applied to the center of the backrest 6 will be concentrated on the mounting portion 7 directly via the first ribs 51,
The outer edge of the backrest 6 and the load applied between the outer edge and the center are once supported by the second ribs 52 and the third ribs 53, and then concentrated on the mounting portion 7 via the first ribs 51. As a result, all the load applied to the backrest 6 is supported on the upper end of the back support rod 4 of the chair at this mounting portion 7. For this reason,
The backrest 6 can be made sufficiently rigid as a whole. Moreover, since no rib exists in the region S surrounded by the first rib 51, the second rib 52, and the third rib 53, when a load acts on this region S,
Elastic deformation of the resin is caused. Therefore, the third rib 53
By reducing the number of the parts as much as possible within a range that does not impair the rigidity, and securing the region S over a relatively wide range, the upper half part bends backward when the backrest 6 leans and the left and right An appropriate cushioning property can be exhibited by suitably inducing a backward bending operation of both side edge portions. That is,
The shell 5 of this embodiment provided with such a rib structure can achieve both functions as a backup member in terms of ensuring rigidity and improving usability. Moreover, such a rib structure requires a smaller total number of ribs as compared with the conventional rib structure, the rib interval can be wide, and each rib can be wide as required. Therefore, when the backrest 6 is put on the hand, the ribs 52 and 53 are particularly easy to fit in the hand, and the inconvenience that the user feels uncomfortable can be eliminated at the same time.

The specific shape of the rib and the position of the mounting portion are not limited to those in the above-described embodiment, but various modifications can be made without departing from the spirit of the present invention. For example, the third rib may be provided only at one location or at three or more locations within a range that does not impair the function of the present invention. However, if it is provided in two places on the left and right as described above, it is possible to support the position where the healthy bone is just attached, and at the same time suitably allow the upper half part of the shell and the left and right side parts to bend backward. Therefore, it is preferable.

[0017]

EFFECT OF THE INVENTION The chair back according to the present invention is mainly composed of the shell having the rib structure as described above, so that it is temporarily attached to the mounting portion via the first rib, the second rib and the third rib. Not only can the collected load be reliably supported on the upper end of the back support rod to ensure proper rigidity as a backrest, but the flexure of the shell can be allowed by making the area surrounded by each rib sufficiently wide. However, there is an excellent effect that it can be made flexible and have a good feeling in use. Such effects are
The ribs can be easily and properly exhibited by adopting a structure in which the ribs are formed in a substantially annular shape and adopting a structure in which the third ribs are linear, or by adopting a structure in which the third ribs are extended in the radial direction. Become. In addition, since the structure is not such that a large number of narrow ribs are densely assembled, it is possible to keep the chair comfortable to handle, easy to hold, and comfortable.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention together with a chair.

FIG. 2 is a perspective view showing a shell of a backrest used in the embodiment.

FIG. 3 is a rear view of the same.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 3;

FIG. 5 is a diagram corresponding to FIG. 3 showing a conventional example.

[Explanation of symbols]

 4 ... Back support rod 51 ... 1st rib 52 ... 2nd rib 53 ... 3rd rib 5 ... Shell 7 ... Attachment part

Claims (3)

[Claims] 1. A backrest having a structure comprising a resin shell, wherein a mounting portion set at a substantially central portion in the width direction of the shell is mounted on an upper end portion of a back support rod of a chair, the shell comprising: A first rib formed at a position that reinforces the attachment portion, a second rib formed along the outer edge of the backrest, and a position that intermittently connects the first rib and the second rib. A backrest of a chair, characterized in that the backrest of the chair has an integral third rib. 2. The first rib and the second rib have a substantially annular shape,
The chair back according to claim 1, wherein the third rib has a substantially linear shape. 3. The backrest of a chair according to claim 2, wherein the third rib is formed at a position radially extending from the attachment portion toward the outer edge.