JPH11169256A - Rocking mechanism for chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide rocking mechanism for a chair provided with structure allowing the change of a seated position according to the figure of a person seated in the chair and using a plurality of springs to make the rocking mechanism act corresponding to the change of the seated position, with a different purpose from the form of using a plurality of springs in conventional rocking mechanism. SOLUTION: A seat face and a seat back of a chair are supported by lever members 5 and 6 journalled to a base member 2 provided at the upper part of a support 1 of the chair, so as to be springly oscillated through a spring 4. The backward sinking action of the seat face and the backward inclining action of the seat back are therefore synchronized. In this case, two force points 7 and 8 are set behind the rocking center of the lever members 5 and 6, in front and rear positions in a lengthwise direction. The front force point 7 is related to the spring 4, and the rear force point 8 is related to an auxiliary spring 10 provided at the base member 2 below this force point 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing mechanism in which a seat and a backrest are interlocked with each other, which is useful mainly for an office swivel chair.

[0002]

2. Description of the Related Art Various types of chair swinging mechanisms have been proposed and many of them have been put to practical use. Some of these swinging mechanisms include two or as a cushioning member for buffering the sinking of the seat surface and the backward tilt of the backrest, that is, the swinging motion of the seating surface and the backrest, and improving the sitting comfort. Some use two or more types of springs or springs.

[0003] In a conventional swing mechanism of a chair using a plurality of springs, one main spring supports most of the rocking operation of the backrest and the seating surface, and the other spring acts as a sub-spring to form a main spring. Most are incorporated to reduce the movement of operating knobs and handles to adjust the strength of the spring action.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to change the seating position according to the body shape of a person sitting on a chair, with a different purpose from the above-mentioned conventional swing mechanism in which a plurality of springs are used. It is an object of the present invention to provide a swing mechanism of a chair using a plurality of springs, which has a structure that allows the swing mechanism and operates the swing mechanism in response to a change in the seating position.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a swing mechanism according to the present invention has a structure in which a seat surface and a backrest of a chair are attached to a base member provided above a support column of the chair. A chair member formed so as to synchronize the sinking operation behind the seat surface and the backward tilting operation of the backrest by being supported by a lever member pivotally supported so as to resiliently swing with the interposition of In the mechanism, two force points are set back and forth in the longitudinal direction behind the swing center of the lever member, and the forward force point is related to the spring, and the rear force point is a base below this force point. The present invention is characterized in that it is associated with an auxiliary spring provided on a member.

In addition to or in addition to the above-described configuration, the swing mechanism of the present invention couples and integrates a lower end of a back support member disposed behind the lever member with the lever member. One of the features of the configuration is that the backrest support member is formed in a structure that expands and contracts in the length direction thereof.

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side cross-sectional view of a main part of an example of the mechanism of the present invention, FIG. 2 is a cross-sectional view of the left half of FIG.
1 is a cross-sectional view of the right half as viewed from the direction of the arrow AA in FIG. 1, FIG. 4 is a side view as viewed from the direction of the arrow B in FIG. 1, FIG. FIG. 7 is a side view of a main part with a partial cross section, FIG.
1 is a side view of an example of a chair incorporating the mechanism of the present invention.

In FIGS. 1 to 5 and 7, reference numeral 1 denotes a leg support in an office swivel chair, which is not shown, but is provided at the lower end of the support 1 with a so-called star-shaped or disk-shaped chair, for example. Feet are provided. 2 is at the upper end of this leg support 1,
A rotatable or non-rotatable base member having a generally shallow bottom box shape. 2a is a joint between the base member 2 and the upper end of the column 1, 2b is a bottom wall of the base member, and 2c is a front wall. ,
2d is a rear wall, 2e is a left side wall and a right side wall.
Here, as an example, it is formed so that the upper end of the column 1 can be fitted to a bearing-like member formed on the bottom wall 2b near the rear wall 2d.

Reference numeral 3 denotes the support column 1 of the base member 2.
Is a horizontal axis erected between the left and right side walls 2e in a horizontal posture in front of the
A torsion spring 4 is fitted on the outer circumference of the vehicle, having a core rod 3a for connecting a back support member 15 described later. 5,
Reference numeral 6 denotes left and right lever members having front ends connected to the shaft 3 outside the left and right side walls 2e of the base member 2 in the example shown in the figure. It is provided in a posture inclined upward.

In the middle of the left and right lever members 5 and 6, the front and rear lever members 5 and 6 are located two
The connecting rods 7 and 8 are provided so as to be bridged between the left and right lever members 5 and 6. These two connecting rods 7, 8
It becomes a member that acts as a point of force in the lever members 5 and 6. Here, the two connecting rods 7, 8 are connected to lever members 5, 6, respectively.
It is positioned at the same height when viewed from the ground, regardless of the upward slope.

The torsion spring 4 has its starting end 4a supported by a spring receiver 9a screwed on a screw rod provided on the bottom wall 2b of the base member 2, and the spring receiver 9a is rotated by rotation of the screw rod 9b.
Is arranged so as to be pulled downward by a spring force adjusting mechanism 9 formed to raise and lower
The rear end 4b of the spring 4 is disposed so as to be pressed from above by the connecting rod 7. Reference numeral 9c denotes an operation knob provided on the lower surface of the bottom wall 2b of the base member 2 at the lower end of the screw rod 9b.

On the other hand, a coil spring 10 whose upper surface is in contact with the lower surface of the rear connecting rod 8 among the connecting rods 7 and 8 provided on the lever members 5 and 6 is provided below the base member 2.
Is provided in a standing posture on the upper surface of the bottom wall 2b.

In the lever members 5 and 6, the connecting rod 7
And a connecting rod 8 supporting the rear end 4b of the torsion spring 4.
Is the point of force in the lever members 5 and 6. Hereinafter, the symbols (7) and (8) are used for the two points of force.

Reference numeral 11 denotes a support member at the front of the seat surface for supporting the front portion of the seat surface (Sf in FIG. 7) provided on the upper portion of the front wall 2c of the base member 2 via the connecting member 12. On connecting member 12,
The lower end connects the upper end of the front wall 2c and the lower surface of the support member 11 via horizontal shafts (or pins) 12a and 12b.

Reference numeral 13 denotes a support member at the rear end of the seat surface, which is supported on the members 5, 6 via a horizontal shaft 14 at the rear ends of the lever members 5, 6; 13
Shaft 14 on the downward bracket 13a formed on the lower surface of the
Are connected to the lever members 5, 6.

A member forming the seat surface Sf is mounted on the upper surfaces of the support members 11 and 13 before and after the seat surface, for example, via a seat frame Fs, so that a load is applied to the seat surface Sf by the occupant. This load is resiliently supported by the two springs 4 and 10 via the lever members 5 and 6.

On the other hand, in the mechanism in which the seat surface Sf of the chair and the backrest Sb swing synchronously,
Usually, it is connected to a back support member. Also in the present invention, the back support member 15 is provided with the lever members 5 and 6.
In the illustrated example, the following association structure is employed.

As shown in FIG. 7 and FIGS. 2 to 6, the backrest support member 15 is connected to the left and right sides of the shaft 3 fixed to the lever members 5 and 6, and is integrated with the shaft 3. The left and right lower end horizontal portions 15a and the outer portions of the horizontal portions 15a
The left and right vertical portions 15b which are bent and raised by 90 degrees, the cylindrical cover portion 15c extrapolated to the left and right vertical portions 15b, and the vertical portion 15b
Retraction adjustment mechanism 1 provided in association with the cover part 15c
6, and about 30 to 60 degrees with respect to the seating surface Sf,
Here, it is formed in a posture inclined backward about 45 degrees,
A backrest Sb is provided at the rear end (the upper end in FIG. 7).
The connection between the horizontal portion 15a of the support member 15 and the shaft 3 is formed by press fitting or serration connection or spline connection in FIG. 2, but in FIG. The joint shaft 3b is externally fitted, and a horizontal portion 15a is connected to an end of the joint shaft 3b. 3c is the binding key. In the present invention, the left and right horizontal portions of the shaft 3 and the support member 15
The form of connection with 15a is not limited to the above example, and any other structure may be used as long as both 3 and 15a are combined and integrated. Alternatively, the lower end of the backrest support member 15 may be directly connected to the lever members 5 and 6.
Thus, the backward tilt of the backrest Sb and the sinking of the bottom surface Sf are synchronized.

As shown in FIG. 7, the backrest support member 15 has a backrest Sb above the cylindrical cover portion 15c. The backrest Sb moves the tubular cover portion 15c above the vertical portion 15b. It is formed so that it can be moved forward and backward and positioned by the forward and backward adjusting mechanism 16 to adjust the front and rear relative to the seat surface Sf and the vertical position.

The forward / backward adjusting mechanism 16 for this purpose has a structure shown in FIG. 6 as an example. That is, 16a is a locking recess recessed at equal pitch intervals on the longitudinally outer surface of the vertical portion 15b of the back support member 15, and 16b is a cylindrical cover portion 15c.
Having a locking claw portion 16f disposed and supported by a shaft 16d and a pressing spring 16e in a case 16c housed in a base 16i provided at a portion corresponding to the row of the concave portions 16a outside the above. When the case 16c is pressed to release the claw 16f of the locking lever 16b from the recess 16a against the repelling force of the spring 16e, the cylindrical cover 15c is moved in the longitudinal direction of the vertical portion 15b. The claw portion 16f is fitted and held in another concave portion 16a by the repulsive force of the spring 16e, and can be freely retracted or advanced with respect to the vertical portion.
The relative position between 15b and the cylindrical cover 15c can be changed and fixed. In FIG. 6, 16g is a support shaft of the case 16c, and 16h is a locking lever 16b protruding from the inner surface of the case 16c.
Push projection.

Normally, in a chair with a backrest for an office, a seated person sits with his / her back in contact with the backrest and leans against the backrest. The front-back relative position with respect to Sf, and the vertical relative position can be changed, and when the position is changed, the position of the seated person sitting on the seating surface Sf, that is, the seating point, the front-back and front-back and up-down of the backrest Sb It moves back and forth on the seating surface Sf as the position changes. Here, the change of the position of the backrest Sb is necessary in order to obtain a good sitting position on the seating surface Sf and a good support position by the backrest, mainly according to the difference in the physique of the seated person. When a person sits on the chair in which the seating position and the supporting position of the back are selected in this way, whether the seating point is forward or rearward on the seating surface Sf, and the back support of the backrest Sb Depending on factors such as whether the point is near or far from the axis 3 and the magnitude of the weight of the occupant, the magnitude of the rotational moment generated in the lever members 5 and 6 varies, The swing mechanism of the present invention can cope with a wide variation in the rotational moment generated in the lever members 5 and 6 by displacing the backrest Sb by changing the weight and the physique of the seated person. Will be described.

Generally, it is necessary to position the backrest more rearward and upward as viewed from the seating surface, for a person with a large physique, and a large body has a large weight. on the other hand,
Positioning the backrest more forward and downward when viewed from the seat is a person with a small build and therefore not too much weight.

The fact that the position of the backrest Sb is closer to the rear end of the seat surface Sf both in the front-rear direction and the up-down direction means that the length of the backrest support member 15 about the shaft 3 is short, Although the seating point is also substantially at the intermediate portion on the seating surface Sf, the fact that the backrest Sb is separated from the rear end of the seating surface Sf both in the front-rear direction and the vertical direction means that the length of the backrest supporting member 15 as viewed from the axis 3 is large and , The seating point is also closer to the rear of the seating surface Sf.

On the other hand, before and after the two power points (7) and (8) set by the connecting rods 7 and 8 on the lever members 5 and 6, the load is applied to the lever members 5 and 6 so that the center of the support shaft 3 is maintained. When making a clockwise angular rotation, at the same rotation angle, the rear power point
Since the vertical displacement of (8) is greater than the vertical displacement of the forward power point (7), the angular velocity for displacing the rear power point (8) is the angular velocity of the forward power point (7). Faster than. This is because the connecting rods 7 and 8 serving as the power points (7) and (8) have different positions on the rotation radius of the shaft 3 serving as the center of rotation, and the lever member whose rear end is inclined upward. 5,
This is because the emphasis points (7) and (8) were set to be horizontal (as viewed from the ground) in 6. The above two points of emphasis (7), (8)
The amount of displacement in the up and down direction is different, that is, the angular velocity of the power point (8) is larger than the angular velocity of the power point (7), the initial stage of the sinking of the seating surface Sf, or the initial stage of the backward tilt of the backrest Sb. This means that the rear force point (8) strongly receives the repulsion force of the coil spring 10 and the ratio of receiving the repulsion force of the torsion spring 4 is low.

On the other hand, the sink angles of the lever members 5 and 6 are
When tilting backward to the desired locking angle, this angle is almost the same regardless of the size of the occupant's physique,
Even at the same locking angle, the rotational moment applied to the shaft 3 via the lever members 5 and 6 is larger in the case of a occupant having a large physique and a large weight than a occupant having a small physique and a small weight. The lever members 5, 6
(The clockwise rotation about the axis 3) becomes larger than the above-described example of the initial sink. In this case, the front force point (7) of the lever members 5, 6 is supported by the repulsive force of the torsion spring 4, and the rear force point (8) is supported by the repulsive force of the coil spring 10, and the two springs 4, 10 cooperate. Thus, the rotational moment generated in the lever members 5, 6 is supported. In this case, since the torsion spring 4 exhibits a flexible repulsion characteristic to a load, a wide range of load adjustment is performed by the spring force adjusting mechanism 9 provided for the torsion spring 4 and in the entire rocking (subsidence) range. The two springs 4 and 10 cooperate to perform a repulsive action.

[0026]

As described above, the swing mechanism of the present invention is a chair swing mechanism in which the sinking operation of the seat surface and the backward tilting operation of the backrest are buffered by the lever member interposing the repulsive force of the spring. In the above, two force points are set on the lever member so that their angular velocities during the rotational movement are different, and springs having different characteristics are arranged so as to act on the respective force points in a corresponding manner. Even if the load applied by the occupant added to the seating point of the seat surface or the support point of the backrest changes by changing the position, the respective springs perform a buffering action corresponding to the load applied via the lever member. You can experience a uniform and good sitting comfort according to your body weight and body shape.

In the swing mechanism of the present invention, the position of the backrest facing the seat surface can be changed in the front-rear and up-down directions in accordance with the physique of the occupant. Accordingly, it is possible to obtain a good fit to each of the seat surface and the backrest and to sit down, and the load applied to the swing mechanism by changing the seating position is also the same as the two force points set on the lever member. Due to the repulsive action of the springs provided corresponding to the respective power points, it is possible to favorably support while irrespective of the magnitude of the load.

Therefore, the swing mechanism of the present invention has various body shapes,
In a swivel chair for office use by a person with a weight, it exhibits extremely excellent performance as a swing mechanism for performing a synchro tilt operation of a sinking operation of a seat surface and a backward tilting operation of a backrest.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a main part of an example of the mechanism of the present invention.

FIG. 2 is a cross-sectional view of the left half of FIG.

FIG. 3 is a cross-sectional view of the right half of FIG.

FIG. 4 is a side view of FIG.

FIG. 1 is a plan view of the right half as viewed from arrow C.

FIG. 6 is a side view of a main part in which a part of the backrest support member is sectioned.

FIG. 7 is a side view of an example of a chair incorporating the mechanism of the present invention.

[Explanation of symbols]

 Reference Signs List 1 support 2 base member 3 horizontal axis 4 torsion spring 5, 6 left and right lever members 7, 8 connecting rod (point of force) 9 spring force adjusting mechanism 10 coil spring 11 support member at front of seat 12 contact member 13 support at rear of seat Member 14 Axis 15 Back support member 16 Retraction adjustment member Sf Seat surface Sb Backrest

Claims (3)

[Claims] 1. A seat member and a backrest of a chair are supported by a lever member pivotally supported so as to resiliently swing with a spring interposed between a base member provided on an upper portion of a column of the chair, In a swing mechanism of a chair formed so as to synchronize the sinking operation behind the seat surface and the backward tilting operation of the backrest, there are two rearward and rearward movements in the length direction behind the swing center of the lever member. A swing mechanism for a chair, wherein a power point is set, a front power point is associated with the spring, and a rear power point is associated with an auxiliary spring provided on a base member below the power point. 2. A chair having a seat surface and a backrest supported by a lever member pivotally supported so as to resiliently swing with a spring interposed between a base member provided on an upper portion of a column of the chair, In a swing mechanism of a chair formed so as to synchronize the sinking operation behind the seat surface and the backward tilting operation of the backrest, the lower side of the support member of the backrest, the lever member supporting the rear half side of the seating surface, The backrest is formed so as to move integrally with the lever member, and the support member of the backrest is formed in a telescopic structure so that the height and the front-rear position of the backrest provided on the support member can be displaceably supported, and at the same time, the backrest is supported. The chair swinging mechanism is characterized in that the seating position of the seat can be changed back and forth depending on the position of the chair. 3. The chair swing mechanism according to claim 1, wherein a lower end of the backrest support member is coupled to a shaft that supports rotation of the lever member so as to move together with the lever member.