JPH07155238A - Chair swing device - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the feeling of backward tilting and standing up in a chair. [Structure] To a fixed frame body 4 on the seat body side, a rocking body 8 attached to the base side of a backrest support rod 7 is connected via a horizontal support shaft 5 so as to be able to tilt backward and swing, and , The first fixed to the fixed frame body 4
A cylindrical body 13, a second cylindrical body 14 fixed to the rocking body 8, and a third cylindrical body 15 arranged between the two cylindrical bodies are rotatably fitted to the support shaft 5 to form a fixed frame body. 4 and rocker 8 are provided with support springs 9 and 10 for respectively engaging the ends with each other to urge the backrest support rod 7 in the upright direction, while the backward tilted contact coil spring 11 is provided.
Is attached over the outer circumferences of both the second tubular body 14 and the third tubular body 15, and the restored close contact coil spring 12 is placed over the outer circumferences of both the first tubular body 13 and the third tubular body 15. So that they are in close contact with each other. Restoring close contact coil spring 12 when tilted backward
Slides on the outer peripheries of the first cylindrical body 13 and the third cylindrical body 15. When the standing direction is restored, the backward tilted close contact coil spring 11 slides on the outer circumferences of the second cylinder body 14 and the third cylinder body 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a swinging device capable of tilting a backrest of a chair backward.

[0002]

2. Description of the Related Art Conventionally, a chair having a backrest tilted is known because a person sitting on a seat of a chair for office work or the like is in a comfortable posture. As disclosed in Japanese Examined Patent Publication No. 48-13629, the lower end horizontal portion of the support rod of the backrest is rotatably connected to the rear end of the support frame attached to the leg through a horizontal support shaft. One end of the coil spring in which the coil portion is loosely fitted on the shaft is locked to the support frame side, and the other end of the coil spring is locked to the horizontal portion to resist the external force in the backward tilting direction to the backrest. It is proposed that the support rod is configured to be biased in the standing direction.

[0003]

However, the relationship between the load and the displacement of the coil spring is substantially linear, and the load-displacement amount curve is within the elastic limit.
The values are substantially the same when a load is applied (when the load sequentially increases from 0) and when unloading (when the load sequentially decreases from a predetermined load). Therefore, especially when the backrest tilted state is restored to the standing direction, the coil spring in which a large torsional force is accumulated pushes the backrest support rod strongly in the standing direction (front of the chair). Has a problem that the feeling (feeling) when moving from a comfortable posture to a working state is poor.

Therefore, one of the applicants of the present invention firstly mentioned that
In JP-A-141232, there has been proposed a gas spring, which is connected to a support rod of a backrest and a support frame, instead of the coil spring in the above-mentioned prior art. According to this gas spring, a so-called hysteresis loop is drawn on the load-displacement amount curve Ko as shown in FIG.
The resistance is different when the piston rod extends and when it contracts,
In general, there is a characteristic that the resistance force is weaker at the time of contraction corresponding to the erecting of the support rod of the backrest than at the time of extension corresponding to the rearward tilt of the backrest. However, as can be seen from FIG.
In the vicinity of the end of extension, when the backrest approaches the backward tilted state of a predetermined angle and when it starts to restore in the standing direction, the curve passes through the curved portion K1. He could not solve the problem that he had a bad feeling when shifting from the comfortable posture to the working state.

The present invention aims to solve this problem.

[0006]

In order to achieve the above object, the present invention is directed to a rearward tilting of a rocking body which is attached to a base of a backrest supporting rod via a horizontal support shaft with respect to a fixed frame of a seat. In a chair that is swingably connected, a first cylinder fixed to the fixed frame body, a second cylinder fixed to the rocking body, the first cylinder and the second cylinder are attached to the support shaft. A third tubular body disposed between the tubular body and the third tubular body is rotatably fitted to the support shaft, and ends thereof are respectively locked to the fixed frame body and the rocking body to erect the backrest support rod. A biasing means for biasing the coil in the direction is provided, while the backward tilted coil spring is brought into close contact with the outer circumferences of both the second cylindrical body and the third cylindrical body, and the restoring contacted coil spring is The present invention is characterized in that each of the first cylinder and the third cylinder is fitted over the outer circumferences of both cylinders so as to be in close contact therewith.

[0007]

[Embodiments] Next, embodiments embodying the present invention will be described. FIG. 1 is a side view cross-sectional view of a chair with a backrest standing upright. A cylindrical mounting portion 3 provided on a bottom plate 1b of a support frame 1 having a substantially rectangular plan view is provided with casters (not shown) at its lower end. The leg column or the upper end of the gas spring 2 is attached,
The support frame 1 is supported so as to be able to move up and down.

At the rear end of the support frame 1, there is a fixed frame 4 having a rearward U-shape in plan view, a horizontal support shaft 5, and a back support rod 7.
An oscillating body 8 fixed to the base of each of the members with bolts, a pair of support springs 9 and 10 as urging means for urging the back support rod 7 in the upright direction, and a rearward tilted contact coil described in detail later. A rocking device 6 including a spring 11 and a recovery contact coil spring 12 is mounted, and a backrest support rod 7 to which a backrest 17 is attached can be tilted rearward.

Next, the rocking device 6 will be described with reference to FIGS. Left and right side pieces 4a, 4b of the fixed frame body 4 fixed to the rear end of the support frame body 1 with bolts or the like.
And the left and right side pieces 8a of the swinging body 8 having a U-shape facing forward in plan view,
A cylindrical support shaft 5 penetrating four pieces with 8b is sandwiched between a first cylinder body 13 and a second cylinder body 14 having the same outer diameter on the outer periphery thereof, and both cylinder bodies 13, 14. Third cylindrical body 15 positioned as
And are rotatably fitted. The first cylindrical body 13 is fixed to the left side piece 4b of the fixed frame body 4 by welding or the like so as to rotate integrally, and is loosely rotatably fitted to the left side piece 8b of the rocking body 8 relatively. . The second tubular body 14 is fixed to the right side piece 8a of the swing body 8 so as to rotate integrally by welding or the like, and is loosely rotatably fitted relative to the right side piece 4a of the fixed frame body 4. . The third tubular body 15 includes the left and right side pieces 8 of the rocking body 8.
Located between b and 8a, the first cylinder 13 and the second cylinder 14 are immovable in the axial direction, and the support shaft 5 has snap rings 16 and 16 fitted on both ends thereof. It cannot be pulled out.

A pair of support springs 9 as biasing means for biasing the backrest support rod 7 to which the backrest 17 is attached in the standing direction.
Reference numeral 10 denotes a coil spring, the coil portion of which is the first cylindrical body 13
And the second cylindrical body 14 are loosely fitted to the support springs 9 and 10 respectively.
Of the other end 9a and 10a of the
b and 10b are locked to the side of the rocking body 8 (in the embodiment, a locking rod 18 attached to the rocking body 8) (see FIG. 4). The coil portion of the backward tilted close contact coil spring 11 is disposed so as to be fitted over the outer circumferences of the second cylinder body 14 and the third cylinder body 15, and the inner peripheral surface of the coil portion is the both cylinders. It is wound so as to be in close contact with the outer peripheral surfaces of the bodies 14 and 15. Further, the backward tilted contact coil spring 11 forms a coil portion so as to be left-handed (counterclockwise) when observing a chair as shown in FIG. On the other hand, the coil portion of the restoration close contact coil spring 12 is fitted over the outer circumferences of both the first cylinder body 13 and the third cylinder body 15, and the inner peripheral surface of the coil portion has the inner wall surface of both cylinders. Body 13,
It is wound so as to be in close contact with the outer peripheral surface of 15. The restoration contact coil spring 12 forms a coil portion so as to be right-handed (clockwise) when observing a chair as shown in FIG. Reference numeral 19 is a flange portion provided in the left-right center portion of the third cylindrical body 15 to prevent interference such that the contact coil springs 11 and 12 contact each other, and reference numeral 20 is a cushion material. It is a built-in seat.

According to this structure, when the seated person leans against the backrest 17 and leans the backrest support rod 7 rearward in the X direction in FIG. 4 to take a comfortable posture, the support springs 9 and 10 are twisted. The oscillating body 8 is subjected to elastic deformation as shown in FIG.
Rotate counterclockwise. At this time, the second cylindrical body 14 also rotates counterclockwise at the same time. Since the coil portion of the backward-inclined contact coil spring 11 is left-handed (counterclockwise winding), the coil portion extends over both the second cylinder body 14 and the third cylinder body 15 and closely contacts the outer peripheral surface thereof from the beginning. If this is done, the coil portion will be deformed so as to be contracted in diameter, so that the third tubular body 1 rotatable with the second tubular body 14 via the backward tilted coil spring 11
5 and 5 will rotate in the counterclockwise direction integrally.

On the other hand, the first stationary state mounted on the fixed frame body 4
Since the restoration contact coil spring 12 that is in close contact with the cylindrical body 13 and the third cylindrical body 15 and is in close contact with each other is right-handed (clockwise winding), the third cylindrical body 15 that tries to rotate in the counterclockwise direction is rotated. The coil portion closely adhered to the outer periphery loosens on the side where the diameter increases, and the inner peripheral surface of the coil portion of the restoration contact coil spring 12 rubs against the outer peripheral surfaces of the first cylinder body 13 and the third cylinder body 15, respectively. While slidingly rotating (slidingly rotating) while receiving the frictional resistance due to this sliding, the backrest support rod 7 and thus the rocking body 8 tilt backwards against the spring force of the support springs 9 and 10. In other words, when the oscillating body 8 is tilted backward, in addition to the urging spring force of the support springs 9 and 10 in the upright direction, the inner peripheral surface of the coil portion of the restoration contact coil spring 12, the first tubular body 13 and the third tubular body. A sliding frictional resistance force with the outer peripheral surface of the body 15 acts, and a curve C1 having a steeper inclination than the load-backward inclination (displacement) curve by the usual support springs 9 and 10 is formed (see FIG. 5).

Contrary to the above, when the backrest 20 is returned from the rearwardly tilted state to the upright state, the swinging body 8 is rotated in the Y direction, and the first cylinder body 13 in the stationary state is moved relative to the first cylinder body 13. The two cylinders 14 rotate clockwise as shown in FIG. At this time, the stationary first cylinder 13 and the third cylinder 1 attached to the fixed frame 4 are attached.
Since the restoration contact coil spring 12 that is in close contact with and straddling 5 is right-handed (clockwise), the third tubular body 15 is held non-rotatably. On the other hand, since the coil portion of the backward tilted close contact coil spring 11 is left-handed (counterclockwise winding), the coil portion extends over both the second cylinder body 14 and the third cylinder body 15 and closely contacts the outer peripheral surface thereof. Even if it is made, the coil portion loosens on the side where the diameter of the coil portion increases, and the inner circumferential surface of the coil portion of the rearwardly inclined contact coil spring 11 is rubbed against the outer circumferential surfaces of the second tubular body 14 and the third tubular body 15, respectively. Since the sliding rotation (sliding rotation) is performed, the friction resistance acts by the sliding against the spring force of the support springs 9 and 10 that urge the backrest support rod 7 and thus the rocking body 8 in the upright direction. Will be done. Therefore, sliding friction between the inner peripheral surface of the coil portion of the rearwardly inclined contact coil spring 11 and the outer peripheral surfaces of the second cylindrical body 14 and the third cylindrical body 15 against the biasing spring force of the support springs 9 and 10 in the standing direction. The resistance force acts in the opposite direction, and the curve C2 has a gentler inclination than the load-backward inclination (displacement) curve of the normal support springs 9 and 10 (see FIG. 5).

As can be understood from FIG. 5, however, a gradual difference occurs between the load-backward tilt angle (displacement) curve C1 at the time of backward tilting and the curve C2 at the time of standing motion, and the backward tilting coil spring 1 is shown.
1 and the restoring contact coil spring 12 and the outer peripheral surface of each of the cylinders cause a frictional resistance action to draw a so-called hysteresis curve, and when the backrest 20 is tilted backward, a solid spring is used immediately after the start of backward tilting. Gives the same feeling as supported. In addition, when the backrest returns to the standing state, it is possible to give a feeling that the person stands up with a soft feeling without strongly pushing the back of the person. The number of windings of the coil portion of the backward tilted close contact coil spring 11 and the restored close contact coil spring 12, the diameter of the wire of each spring, the material, etc. are changed appropriately
It goes without saying that the feelings at the time of tilting backward and at the time of standing up can be arbitrarily changed by setting.

In the embodiment shown in FIG. 6, the back support rod 7 is provided.
Urging force adjusting means 30 for changing and setting the load-backward tilt angle displacement curve (spring elastic coefficient) of the coil spring-shaped support springs 9 and 10 as urging means for urging the spring in the upright direction.
The female screw block 32 is erected downward on the guide plate 31 fixed to the rear portion of the support frame 1, and the sliding block 34 is relatively attached to the tip of the adjusting bolt 33 screwed to the female screw block 32. Rotatably mounted, adjusting bolt 3
The slide block 34 is moved along the guide plate 31 by the forward / backward movement of 3
Is configured to be movable back and forth. A horizontally-long support bar 35 that abuts and slides on the upper surfaces of the ends 9a, 10a of the support springs 9, 10 is fixed to the sliding block 34, and the upper surface of the support bar 35 corresponds to the left and right side plates of the support frame 1. It is configured to be in sliding contact with the guide surface 36. As a result, when the support rod 35 is brought closer to the side closer to the coil block of the support springs 9 and 10, the spring elastic coefficient becomes larger (harder), and the spring elasticity coefficient becomes smaller (softer) when separated. . The biasing means is replaced with a coil-shaped support spring 9 or 10 fitted on the outer periphery of the support shaft 5, and a compression coil spring is provided between the support frame 1 and the rocking member 8 or the back support rod 7. It may be mounted.

As a modification, the mounting relationship of the first cylinder 13 and the second cylinder 14 with respect to the fixed frame body 4 and the rocking body 8 with respect to the left and right center of the support shaft 5 in FIG. Then, the backward tilted contact coil spring 11 and the restored contact coil spring 1
The winding direction of the second coil portion may be reversed. 7 and 8 show a locking means 40 for arbitrarily fixing the tilting angle of the rocking body 8 and thus the backrest support rod 7.
In the first embodiment, the middle part of the brake plate 41 fixed so as to rotate integrally with the oscillating body 8 or the back support rod 7 is rotated to the support shaft 5 (or the first cylindrical body 13 or the like). A brake block 43, which is freely pivotally supported and is rotated by an operating lever 42, is pivotally supported on a shaft 44 on the outer surface of the support frame 1. In the groove 45 of the brake block 43, a brake pad 46 is urged by a spring 47 so as to face the circular arc peripheral surface of the brake plate 41.

In the state shown by the solid line in FIG. 8, the tip end side of the operation lever 42 is rotated downward to rotate the brake block 43 so that the brake pad 46 is separated from the arcuate circumferential surface of the brake plate 41, and then, optionally. After the back support rod 7 is tilted backward by the angle (see the chain double-dashed line in FIG. 8), the operation lever 42 is rotated upward again, and the brake pad 46 is pressed against the circular arc circumferential surface of the brake plate 41. The posture of the backrest support rod 7 can be maintained at the predetermined angle.

In the second embodiment of the locking means 40 shown in FIG. 9, a cam plate 48 is used instead of the brake block 43, and the cam plate 48 is fixed to the operating lever 42. It is locked by the wedge effect between the plate 48 and the circumferential surface of the brake plate 41. Locking means 4 shown in FIG.
In the third embodiment of No. 0, it is set so that the side surface of the brake plate 41 is inserted into the concave groove 50 of the support block 49 provided on the outer side surface of the support frame 1, and the base end is screwed to the side surface of the support block 49. By fixing the brake pad 51 to the base end of the combined operation lever 42 and pressing the brake pad 51 against the side surface of the brake plate 41 by the rotation of the operation lever 42, the backrest support rod 7 can be moved at any angle. The posture can be maintained.

[0019]

As described above, the swinging device for a chair of the present invention is attached to the fixed frame body on the seat body side on the backrest support rod base side via a horizontal support shaft. In a chair in which an oscillating body is connected so as to be able to tilt and oscillate backward, a first cylinder body fixed to the fixed frame body, a second cylinder body fixed to the oscillating body, and a first cylinder are provided on the support shaft. A third tubular body disposed between the tubular body and the second tubular body is rotatably fitted to the support shaft, and ends thereof are respectively locked to the fixed frame body and the rocking body so that the spine is supported. A biasing means for biasing the support rod in the upright direction is provided, while a backward tilted contact coil spring is placed in close contact with the outer circumferences of both the second cylinder and the third cylinder to make a recovery close contact. Coil springs are fitted over the outer circumferences of both the first and third cylinders so as to be in close contact with each other. In addition to the urging force in the standing direction by the urging means, a sliding friction resistance force acts when the inner peripheral surface of the coil portion of the restoring contact coil spring slides on the outer peripheral surfaces of the first and third cylindrical bodies. A curve having a steeper inclination than a load-backward inclination (displacement) curve by a normal biasing means, and the backrest support rod is supported by a hard biasing means.

On the other hand, when the backrest support rod is restored to the upright direction, the inner circumferential surface of the coil portion of the backward tilted coil spring is the second tubular body against the biasing force in the upright direction by the biasing means such as the support spring. Also, since the sliding frictional resistance force when sliding on the outer peripheral surface of the third tubular body acts in the opposite direction, and the curve becomes gentler than the load-backward tilt angle (displacement) curve by the usual biasing means.
When returning from an easy posture to a standing posture, do not push the person's back strongly forward with the backrest.

Therefore, according to the present invention, it is possible to improve the feeling at the time of the rocking operation such as the rearward tilting of the backrest and to easily set the feeling to a desired one. Play.

[Brief description of drawings]

FIG. 1 is a side view of a chair in a back-standing state.

FIG. 2 is a plan view taken along the line II-II of FIG.

FIG. 3 is an enlarged plan view of a main part of the rocking device.

FIG. 4 is a partially cutaway side sectional view taken along the line IV-IV of FIG.

FIG. 5 is a diagram of a load-backward tilt angle displacement curve by the swing device of the present invention.

FIG. 6 is a side sectional view of biasing force adjusting means.

FIG. 7 is a plan sectional view showing a first embodiment of a locking means for holding the rearward tilt angle arbitrarily.

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

FIG. 9 is a perspective view showing a second embodiment of locking means.

FIG. 10 is a plan sectional view showing a third embodiment of a locking means.

FIG. 11 is a diagram showing a load-expansion / contraction displacement curve by a gas spring.

[Explanation of reference numerals] 1 support frame 4 fixed frame 5 support shaft 7 back support rod 8 rocking body 9, 10 support spring 11 rear tilted contact spring 12 restoration contact spring 13 first cylinder 14 second cylinder 15 15th 3 cylinders 20 seats

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Koichi Kato 3-23-5 Ojidai, Sakura City, Chiba Prefecture (72) Inventor Fumihisa Miyasaka 3179 Kitazonobencho, Ichikawa City, Chiba Prefecture

Claims (1)

[Claims] 1. A chair comprising a fixed frame body on the seat body side and a rocking body attached to the back support bar base side through a horizontal support shaft so as to be capable of tilting and tilting backward. Includes a first cylindrical body fixed to the fixed frame body, a second cylindrical body fixed to the rocking body, and a third cylindrical body arranged between the first cylindrical body and the second cylindrical body. While being rotatably fitted to each of the support shafts and provided with biasing means for biasing the back support rod in the upright direction by locking the ends of the fixed frame body and the rocking body respectively, The tilted close contact coil spring is closely contacted across the outer circumferences of both the second cylinder and the third cylinder, and the restoration close contact coil spring is adhered to the outer circumferences of both the first cylinder and the third cylinder. A swinging device for a chair, characterized in that each is fitted so as to straddle and closely contact each other.