JPH05111413A - Tilting controller for chair - Google Patents

Abstract

PURPOSE:To surely attain a fact that a comfortable sitting feeling is given irrespective of the weight of a person by adjusting automatically the spring constant of a spring means to the backward tilting of a back rest or a seat body, or both of them, in accordance with the weight of a person who sits down on a chair. CONSTITUTION:The controller is constituted so that the spring constant of a spring means 11 is increased in accordance with the weight of a person who sits down on a chair 1 by inserting a sliding piece 31 for moving by the amount corresponding to the weight of the person who sits down on the chair 1 between a tilting operating body 9 for which a back rest 5, etc., are attached and the spring means 11, the spring means 11 is positioned on the opposite side to the pivotally supporting pin 10 of the tilting operating body 9 by holding the sliding piece 31 therebetween and when the sliding piece 31 is separated from the pivotally supporting pin 10 of the tilting operating body 9, the spring constant of the spring means 11 is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair in which a backrest and / or a seat body or both can be tilted backwards against the elasticity of spring means. The present invention relates to a tilt control device capable of automatically adjusting the spring constant of a spring means according to the weight of a person sitting on a chair so that the spring constant is substantially constant regardless of the weight of the person.

[0002]

2. Description of the Related Art The applicant of the present application proposed a backrest tilt control device as shown in FIG. 27 in the above-mentioned utility model registration application (Japanese Patent Application No. 32-32296). That is, the invention of this prior application is such that the support mechanism 101 provided at the upper end of the leg 100 is
The tilting motion body 103 to which the backrest 102 is attached at the front end of the
And a cantilever-shaped leaf spring 104 that elastically supports the rearward tilting of the tilting movable body 103 so as to extend rearward. A slider 10 for applying a load from the tilt motion body 103 to the leaf spring 104 between the spring 10 and the spring 104.
5, the seat body 106 is supported by the tilting motion body 103 via the weight sensitive spring 107. Further, the tilting motion body 103 is provided with a parallel link mechanism 108 that is rotated in the front-rear direction by downward movement of the seat body 106, and the slider 105 is attached to the parallel link mechanism 108. The slider 105 is moved toward the proximal end portion of the leaf spring 104 according to the amount of lowering of the seat body 106, and the leaf spring 1
By increasing the spring constant of 04 in proportion to the weight of the person sitting on the chair, the tilting motion body 103 is tilted backward by the same angle regardless of the weight of the person sitting on the chair. It was

[0003]

However, in the prior invention, the spring constant of the leaf spring 104 is increased by moving the slider 105 toward the pivotal portion of the tilting motion body 103. Because it was, slider 10
The movement of 5 increases the load on the leaf spring 105, and the increase in the load acting on the leaf spring 105 offsets the increase in the spring constant of the leaf spring 105, resulting in an incomplete automatic control function. There was a problem to say.

That is, in the invention of this prior application, the slider 105
When the tilting moving body 103 approaches the pivot portion, the slider 10
Before and after the movement of 5, the distance S1 from the pivot portion of the tilting motion body 103 to the slider 105 and the tilting motion body 10 are moved.
The ratio (S1: S2) from the distance S2 from the pivot portion to the backrest 102 of 3 becomes small, and the load acting on the leaf spring 104 via the slider 103 moves the slider 105 by the principle of leverage. Since the load acting on the leaf spring 104 becomes larger when the tilting motion body 103 tilts backward without moving, the leaf spring 104 is largely deformed despite the increase in the spring constant. However, the automatic control function of allowing the backrest 102 to be tilted backward by a substantially constant angle is insufficient.

It is an object of the present invention to provide a tilt control device that solves this problem.

[0006]

To achieve this object, the present invention provides a support mechanism provided at the upper ends of legs with a tilting motion body attached to a backrest, a seat, or both, for rearward tilting. A slider is provided so as to be separated from the pivotal portion of the tilting motion body according to the magnitude of the downward load on the seat body, and elastically supports the rearward tilting of the tilting motion body via the slider. The spring means is formed so that the spring constant increases in response to the slider moving away from the pivoting portion of the tilting motion body.

[0007]

[Operation / Effect] With this configuration, the ratio of the distance from the pivotal portion of the tilting motion body to the slider and the distance from the pivotal portion of the tilting motion body to the point of action of the load on the tilting motion body , The load acting on the spring means via the slider becomes large before and after the slider moves away from the pivoting portion of the tilting body, and the tilting body moves backward while the slider does not move. Since the spring means becomes smaller than that of the spring means, not only is it difficult for the spring means to be deformed by the increase of the spring constant due to the movement of the slider, but it is also difficult for the spring means to be deformed by the decrease of the load acting on the spring means. The degree to which the means is less likely to be deformed can be accurately and automatically adjusted according to the weight of the person sitting on the chair.

Therefore, according to the present invention, the degree to which the spring means for the tilting motion body is less likely to be deformed can be automatically adjusted appropriately according to the weight of the person sitting on the chair. Has an effect that it is possible to surely achieve that a comfortable seating comfort can be achieved regardless of the difference in weight by making it possible to hold substantially constant.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. 1 to 16 show a first embodiment, and a chair denoted by reference numeral 1 in these figures is a support mechanism 3 provided on an upper end of a leg body 2 and a seat body 4 attached to the support mechanism 3. When,
A backrest 5 integrally connected to the seat body 4 is provided, and cushion materials 4a and 5a are stretched on the upper surface of the seat body 4 and the front surface of the backrest 5, respectively.

The seat body 4 is divided into front and rear parts, as shown in FIG.
As shown in, the abutting portion between the front seat body 4b and the rear portion 4c is formed in a zigzag shape in a plan view. The support mechanism 3 is
The leg 2 is provided with a fixed frame 6 having a substantially U-shaped cross section fixed to the upper end of the leg 2, and a box-shaped rotating frame 7 having an upward opening fitted into the fixed frame 6 from below. , The rotating frame 7
The rear end portions of the left and right side plates 7a, 7a are pivotally attached to the left and right side plates 6a, 6a of the fixed frame body 6 by a pair of left and right first pivot pins 8 extending horizontally. By contacting the rear end portion 7b 'of the bottom plate 7b of the rotating frame body 7 with the lower surface of the fixed frame body 7, only the forward tilting is possible.

Both left and right side plates 7a of the rotating frame body 7,
A side view L in which the backrest 5 is attached to a portion near the rear end of 7a.
The front end of the character-shaped tilting motion body 9 is pivotally attached by a pair of left and right second pivot pins 10, while the front plate 7c of the pivot frame 7 is attached.
As an example of spring means for the tilt motion body 9, a pair of left and right torsion coil springs 11 each having a cantilever-shaped load acting portion 11a extending rearward are provided on the inner surface of the. As shown in FIGS. 5 and 12, the second pivot pin 10 has:
The collar 12 is fitted.

The tilting moving body 9 is provided with a base body 13 formed of a metal plate or the like, and a support body 14 made of synthetic resin or the like fixed to the upper surface of the base body 13 with screws. The support body 1 is provided in the front and rear recesses 13a formed in
4. The left and right side plates 14b, 14b formed by fitting the downward projection 14a formed in 4 on the front and rear approximately midway portions of the support body 14,
The second pivot pin 10 pivotally attaches to the left and right side plates 7a, 7a of the pivot frame 7.

Further, on the left and right sides of the lower surface of the base body 13, horizontal portions 15a of a pair of left and right support rods 15 formed in a substantially L shape in side view are fixed, and the upper ends of the left and right support rods 15 are seen in a plan view. A bushing body with a brim, which is connected by a U-shaped connecting rod 16 and is formed on a cylindrical body 16a having upper and lower openings fixed to the left and right ends of the connecting rod 16 so as to be slightly bent and deformed by a hard synthetic resin or the like. 17 is inserted into the bush body 17,
Cylindrical portions 5b integrally formed on the left and right sides of the backrest 5 are fitted.

Further, the support 1 in the tilting motion body 9
4, a tubular portion 18 that is open upward and a first guide body 19 that has a key groove 19a extending in the vertical direction are integrally connected to each other in a portion approximately in the middle of the left and right of the rear end portion of the tubular portion 1.
8, the guide bush 20 is fitted and inserted into the guide bush 20. The guide bush 22 is inserted into the guide bush 22 so as to project downward from the rear support plate 21 made of synthetic resin or the like that supports the rear seat body 4c. Then, the coil spring 23 for applying a feeling of weight for lowering the seat body 4 according to the weight of the person sitting on the chair 1 is inserted.

Further, on the lower surface of the front end portion of the rear supporting plate 21, rack teeth are formed on the front surface of the first rack 2 having a vertically elongated shape.
4 is fixed by screwing, and the first rack 24 is vertically slidably fitted into the key groove 19a of the first guide body 19 of the support body 14. Furthermore, a pinion shaft 25 having a first pinion gear 25 a meshing with the first rack 24 is rotatably attached to the left and right side plates 14 b, 14 b of the support body 14 of the tilting motion body 9 via a shaft body 26. The first pinion gear 25a of the pinion shaft 25 is supported.
A second pinion gear 25b having a diameter larger than that of the first pinion gear 25 is formed on both left and right sides of the pinion gear. Is forming.

Further, the support 1 in the tilting motion body 9
A second guide body 28 having a U-shaped cross-section upward opening and having a guide groove 28a formed on the inner surface is fixed to two portions of the upper surface of 4 corresponding to the second pinion gear 25b. A second rack 30 having rack teeth formed on the upper surface thereof is mounted on both of the second guide bodies 28, 28 so as to be slidable in the front-rear direction, and the wing piece 3 protruding from the side surface of the both second racks 30.
0a is fitted into the guide groove 28a of the second guide body 28 so as to be slidable back and forth.

Further, the front ends of the left and right second racks 30, 30 are connected by a connecting pin 32, and a roller-shaped slider 31 is fitted on the connecting pin 32, and the slider 31 is connected to the second pivot. It is configured so that it can be brought into contact with the load acting portions 11a of the left and right torsion coil springs 11 at a portion in front of the landing pin 10. The slider 31 may be formed integrally with the connecting pin 32.

In this case, a stopper projection 29 with which a slider 31 abuts is formed on the upper surface of the support 14 of the tilting motion body 9 so as to regulate the retracted positions of the left and right second racks 30. In a state where the tilting motion body 9 does not rotate, the load acting portion 11a of the torsion coil spring 11 contacts the stopper projection 29, so that the load acting portion 11a of the torsion coil spring 11 and the slider 31 are connected. Between,
A gap having a slight interval dimension e is provided.

The left and right torsion coil springs 11 are fitted on a support shaft 33 penetrating the left and right side plates 7a of the rotary frame 7, and the left and right torsion coil springs 11 have coil portions made of hard rubber or the like. A buffer member 34 having a semicircular cross section, which is formed of a material that can be slightly elastically deformed, is arranged so that the flat surface 34a of the buffer member 34 is in contact with the support shaft 33 with the flat surface 34a positioned obliquely downward. By making the diameter of the coil portion 11 smaller, the rearward tilting of the tilting motion body 9 is elastically supported.

The left and right torsion coil springs 11 are also provided.
Is supported by a support piece 35 formed by cutting and raising the bottom plate 7b of the rotating frame body 7. Further, the front plate 7c of the rotating frame body 7 has a fixed end portion 1 of the torsion coil spring 11.
A bolt 36 adapted to adjust the initial elastic force of the torsion coil spring 11 is screwed into contact with 1b. Figure 6
Reference numeral 37 indicates a collar fitted to the support shaft 33 in order to prevent lateral displacement of the both torsion coil springs 11.

A front support plate 38 is fixed to a horizontal flange portion 7d formed at the front end of the rotating frame 7, and a front seat 4b is fixed to the front support plate 38. Further, an arm body 39 having a U-shaped cross section that extends obliquely upward toward the rear is fixed to the rear end portion of the fixed frame body 6, and the arm body 3
The left and right side plates 39a, 39a in FIG. 9 are each provided with an elongated slot 40 extending obliquely in a side view, while the connecting portion 41 between the rear seat body 4c and the backrest 5 is projected rearward in a side view. Is formed in a curved shape, and a pair of left and right brackets 42 extending substantially downward are integrally or separately formed at a connecting portion 41 between the rear seat body 4c and the backrest 5 and inserted into the left and right brackets 42, 42. By inserting the guide pin 43 into the left and right long holes 40, 40 of the arm body 39, the rear seat body 4c and the backrest 5 are tilted backward while descending.

Reference numeral 44 shown in FIGS. 6, 12 to 13 and 16 indicates the slider 3 in a state where the tilting motion body 9 is tilted backward.
1 is an example of a spring constant holding device that holds 1 in the forward position to keep the spring constant of the torsion coil spring 11 constant. In other words, with the person sitting on the chair 1 leaning against the backrest 5, lightly raise the upper body, etc.
When the downward load on the slider becomes small, the slider 31
2 is an example of a spring constant holding device for preventing the position of the variable and the spring constant of the torsion coil spring 11 from changing.

The spring constant holding device 44 includes a pair of left and right ratchet wheels 25c formed on the pinion shaft 25, and the ratchet wheel 2
The ratchet pawl 45 for 5c is formed, and the ratchet pawl 45 is formed in a substantially downward U-shape when viewed from the side, and its upper end is provided on the side plate 14b and the bracket plate that are erected on the support body 14 of the tilting motion body 9. 14c is pivotally attached to the left and right longitudinal pins 46, so that the ratchet pawl 45 is rotated so that the pawl portion 45a is engaged with and disengaged from the ratchet wheel 25c. The twisting spring 47 biases the claw portion 45a of the ratchet claw 45 in a direction away from the ratchet wheel 25c.

Then, the base body 13 and the support body 14 of the tilting motion body 9 are provided with a through hole 48, and a vertically long and vertically rotatable member 49 inserted into the through hole 48 is attached to a left and right longitudinal pin 50. Pivotally attached to the base body 13 and the rotating member 5
While the lower end of 0 contacts the upper surface of the bottom plate 6b of the fixed frame body 6, the ratchet pawl 45 is attached to the upper end of the rotating member 49.
A wide engaging portion 49a that fits in the downward recess 45b is formed, the upper surface of the engaging portion 49a is formed in an upward convex arc shape, and the jaw portion 49b near the rear end of the engaging portion 49a is formed into a circle. It is formed in an arc shape.

Therefore, when the tilting motion body 9 tilts backward, the rotating member 49 rotates in the direction of arrow A shown in FIG. 12 to rotate the ratchet pawl 45 against the torsion spring 46, whereby the ratchet. The claw portion 45a of the claw 45 meshes with the ratchet wheel 25c, whereby the pinion shaft 25 is held irreversibly, and the position of the slider 31 is held unchanged. And
When a person raises the upper body from the backrest 5 and the tilting motion body 9 returns to the original posture, the ratchet pawl 45 and the rotating member 49 return to the original posture by the spring force of the torsion spring 47 and rotate, and the ratchet pawl 45. The engagement between the ratchet wheel 25c and the ratchet wheel 25c is released.

In this case, the downward recess 4 of the ratchet 45
5b and the engaging portion 49a of the rotating member 49 have the shapes as shown in the drawing, the ratchet pawl 45 is attached to the ratchet wheel 25.
The claw wheel 25c is in the direction of arrow B (second
Rack 30 can be rotated in the direction of advancing)
Therefore, the rearward tilting of the tilting motion body 9 is allowed while maintaining the state where the ratchet claw 45 is in contact with the ratchet wheel 25c.

A stopper body 55 having an L-shape in a side view is formed on the lower surface of the rear end portion of the base body 13 of the tilting motion body 9, and a horizontal portion 55a at the lower end thereof is brought into contact with the lower rear surface of the fixed frame body 7. By doing so, the forward tilt angle of the tilt motion body 7 is regulated. The stopper body 55 has a cutout hole 55b which is fitted into the leg 2 when the tilting motion body 9 is tilted backward so that the tilting motion body 9 can be tilted backward.

By the way, in the case where the rotating frame body 7 is constructed so as to be able to tilt forward as in the embodiment, when the tilting motion body 9 tilts rearward due to a person leaning against the backrest 5, the tilting motion body 9 is tilted.
Is tilted rearward about the second pivot pin 10, but the rotating frame body 7 can be tilted forward about the first pivot pin 8, and the tilting motion body 9 is tilted rearward. Then, since there is no means for elastically supporting the forward tilting of the rotating frame body 7, when the person leans against the backrest 5, the entire body is rocked back and forth without changing the angle between the upper body and the lower body. Then, while the tilting angle of the tilting motion body 9 with respect to the turning frame body 7 is kept unchanged, the turning frame body 7 and the tilting motion body 9 tilt forward about the first pivot pin 8, There is a possibility that a state in which the elastic force of the torsion coil spring 11 does not act on the seat body 4 and the backrest 5 occurs.

Regarding this point, FIG. 7, FIG. 10 to FIG.
As indicated by reference numeral 56, a pair of left and right tilt guide means 56 provided between the tilting motion body 9 and the fixed frame body 5 copes with the problem. That is, the front-rear tilt guide means 56 includes a pair of left and right first bracket plates 58 respectively arranged at a pair of left and right first punched holes 57 formed in the bottom plate 7b of the rotating frame 7, and the tilting motion. Support 14 in moving body 9
To the left and right first bracket plates 58, 58, the projection 59 is provided so as to project downward between the left and right first bracket plates 58, 58, and the left and right first bracket plates 58, 58 are fixed to the fixed frame body 6. The 1 bracket plate 58, 58 is provided with a guide hole 61 into which the guide pin 60 fixed to the protrusion 59 is fitted.

At this time, the guide hole 61 is formed as a long hole having a substantially longitudinal length so that the tilting motion body 9 is allowed to rotate about the second pivot pin 10. In the state where the motion body 9 is tilted rearward, the rotary frame body 7 is configured so as not to be tilted forward, and the rear end of the guide hole 61 is further provided with an inclined portion 61a extending obliquely rearward in a side view. The tilting motion body 9 and the rotating frame body 7 are formed into the first
The pin 8 is configured to be tiltable forward.

At the lower part of the support mechanism 3, means for elastically supporting the forward tilting of the rotary frame 7 by the torsion coil spring 11, in other words, the torsion coil spring 11,
A pair of left and right link bodies 62 formed in a sideways V-shape in a side view are provided as means for using the spring means for the rearward tilting of the seat body 4 and the backrest 5 and the forward tilting of the seat body 4.

That is, the left and right link bodies 62 are arranged at right and left positions at the positions of the second punched holes 63 formed in the bottom plate 7b of the rotating frame body 7. The rear end is pivotally attached to the second bracket plate 64 protruding from the fixed frame body 6 in a substantially forward direction by the pins 65 extending in the left and right directions, while the lower ends of the front portions of both link bodies 62 are connected to the rotating frame body 7. The pair of left and right downwardly facing pieces 66, 66 formed by cutting and raising the bottom plate 7b of the link body 62 are pivotally attached by the left and right longitudinal pins 67 with the collar 67a. Of the lower surface of the base body 13 in contact with a portion in front of the second pin 10.

However, when the tilting motion body 9 tilts backward, the posture of the rotary frame body 7 does not change, so that the tilting motion body 9 is separated from the link body 62, and the tilting motion body 9 is free to move. Can tilt backwards. On the other hand, the seat body 4 and the rotating frame body 9
If the link body 62 does not exist, the tilting motion body 9 and the turning frame body 7 integrally tilt forward, and the tilting movement of the turning frame body 7 is elastically supported. There is no such thing.

However, the link body 62 has the first pivot pin 8
Since it is provided in a portion between the coil portion and the coil portion of the torsion coil spring 11, as shown conceptually in FIG.
When the rotating frame body 9 tilts forward by a certain angle θ, the descending amount h2 of the link body 62 becomes smaller than the descending amount h1 of the torsion coil spring 11, so that the torsion coil spring 11 moves downward against its elasticity. Due to the elastic deformation of the torsion coil spring 11, the rotating frame body 7 and the tilting motion body 9 are formed.
The forward tilting of is elastically supported.

In this case, when the person sitting on the chair 1 leans forward, the force acting on the front portion of the seat body 4 acts on the tilting motion body 9 when leaning against the backrest 5. Since the force is smaller than the force, when the torsion coil spring 11 simply supports the forward tilting of the rotating frame body 7, the torsion coil spring 11 is too hard, and it becomes difficult to tilt the seat body 4 forward. ..

However, in the configuration of the embodiment, the tilting motion body 9 is also tilted forward, and the torsion coil spring 11 is elastically deformed, so that the person sitting on the chair 1 only tilts his body forward. Even if there is, the seat body 4 and the tilting motion body 9 can be surely tilted forward, and therefore, with one torsion coil spring 11, both the back tilting of the backrest 5 and the front tilting of the seating body 4 can be performed. It can be properly supported.

As described above, the tilting motion body 9 is
Since the forward tilt angle is restricted to a certain range θ by the stopper body 55, after the forward tilt of the tilting motion body 9 is stopped, only the rotating frame body 7, in other words, only the front seat body 4b is twisted. The coil spring 11 is tilted forward against the elastic force of the coil spring 11.
In the above configuration, when a person sits on the chair 1, the rear seat body 4c descends against the elasticity of the coil spring 23, and in conjunction with the descending movement of the rear seat body 4c, via the first rack 24. Since the pinion shaft 25 rotates, the alternate long and short dash line in FIG. 8 and FIG.
As shown by the solid line in FIG. 4, the left and right second racks 30 advance, the supporting span L1 of the left and right torsion coil springs 11 shortens, and the spring constant of the left and right torsion coil springs 11 increases.

At this time, since the spring constant of the coil spring 23 is constant, the descending amount of the rear seat body 4c is proportional to the weight of the person sitting on the chair 1.
The amount of movement of 0, 30 also increases in proportion to the weight of the person sitting on the chair 1, and as a result, the left and right torsion coil springs 11, 11
The spring constant of increases in proportion to the weight of the person sitting on the chair 1.

When the person sitting on the chair 1 leans against the backrest 5, the tilting motion body 9 tilts rearward about the left and right second pivot pins 10 as shown by the solid line in FIG. The backrest 5 and the rear seat body 4c tilt rearward, and the rear tilting of the tilting motion body 9 is elastically supported by the left and right torsion coil springs 11 and 11 via the slider 31. In this case, as shown in FIGS. 8 and 14, the torsion coil spring 1
1 is located in front of the second pivot pin 10, which is the pivot portion of the tilting motion body 9, and the slider 31 is the second pivot attachment 10.
The distance (L2: L3) between the distance L2 from the second pivot pin 10 to the slider 31 and the distance L3 from the second pivot pin 10 to the backrest 5 becomes smaller by separating from the second pivot pin 10 and the torsion coil spring. The load acting on 11 is smaller than that when the tilting motion body 9 tilts backward without the slider 31 moving forward.

Thus, in addition to the spring constant of the torsion coil spring 11 increasing in accordance with the weight of the person sitting on the chair 1, the load acting on the torsion coil spring 11 is increased before the slider 31 moves forward. The torsion coil spring 11 is less likely to be deformed according to the weight of the person sitting on the chair 1, and as a result, the tilting motion body 9 is tilted rearward regardless of the weight of the person sitting on the chair 1. To torsion coil spring 1
The amount of deformation of No. 1 can be maintained substantially constant, and a comfortable sitting comfort can be provided regardless of whether the weight is light or light.

In the embodiment, since the backrest 5 itself can be slightly bent and deformed, when a person sitting on the chair 1 leans against the backrest 5, the backrest 5 as a whole leans backward and comes into close contact with the back of the person. Will be transformed like
The backrest 5 is pulled downward by the guide action of the elongated hole 40 of the arm body 39, so that the backrest 5
Tilts rearward at an angle smaller than the rearward tilting angle of the tilting motion body 9.

FIG. 17 shows a spring constant holding device for preventing the return rotation of the pinion shaft 25 and keeping the spring constant of the torsion coil spring 11 constant when the tilting motion body 9 is tilted backward. It is a second embodiment showing the embodiment of. In this embodiment, the ratchet pawl 45 is formed in an L-shape in a side view, and the connecting portion of the vertical portion 45c and the horizontal portion 45d is pivoted to the left and right side plates 6a, 6a of the fixed frame body 6 by a pin 46. The vertical portion 45c, and the vertical portion 45c is extended upward from the hole 48 formed in the base body 13 and the support body 14 of the tilting motion body 9 to form the claw portion 45a at the upper end of the vertical portion 45c, while The tip of a leaf spring 68 fixed to the lower surface of the base 13 of the tilt motion body 9 is fixed to the upper surface of the portion 45d, and the horizontal portion 45d of the ratchet pawl 45 is compressed with a spring force weaker than that of the leaf spring 68. It is supported by a spring 69.

In this embodiment, when the tilting motion body 9 tilts rearward, the ratchet pawl 45 causes the ratchet wheel 2 via the leaf spring 68.
By rotating the ratchet wheel 25c in the direction of arrow B while being biased to rotate in the direction in which it meshes with 5c, and the ratchet wheel 45c is in contact with the ratchet wheel 45c, the ratchet wheel 25c rotates in the direction of arrow B.
When the descending movement of the rear seat body 4c is permitted and the rotation of the ratchet wheel 25c is stopped, the claw portion 45a of the ratchet claw 45 is locked by the ratchet wheel 25c.
The pinion shaft 25 is held in a non-reversible manner by meshing with c.

The third embodiment shown in FIGS. 18 to 19 shows another example of the spring constant holding device adapted to prevent the return rotation of the pinion shaft 25 in conjunction with the downward movement of the seat body 4. It is a thing. That is, in this embodiment, the side plate 24b and the bracket plate 1 that are provided on the supporting body 14 of the tilting motion body 9 are projected.
4c, ratchet pawl 4 that extends rearward in a side view
5, the guide pin 70 extending in the left-right direction is inserted into the ratchet pawl 45, and the ratchet pawl 45
Guide projections 45e inclined in a direction intersecting the longitudinal direction of the ratchet pawl 45 are provided on both left and right side surfaces of the side wall 14b of the support body 14 and the bracket plate 14c.
The ratchet pawl 45 is provided with a long hole 71 into which the guide pin 70 is fitted and a guide piece 72 with which the guide protrusion 45e abuts.
It is formed so as to extend in an inclined shape along the same direction as the guide protrusion 45f.

Further, the side plate 14b of the support 14 is
On the bracket plate 14c and on the rear side of the ratchet pawl 45, a front and rear midway portion of a lever 73 extending in the front-rear direction is pivotally attached by a pin 74, and a front end portion 74a of the lever 74 is attached to the ratchet pawl. It is formed in a bifurcated shape in a plan view so as to be fitted on the guide pin 45. The guide pin 70 is inserted into the bifurcated front end portion 74a, and a through hole 75 for the guide pin 70 is formed along the longitudinal direction of the ratchet pawl 45. A compression spring 76 is inserted between the rear end portion of the lever 73 and the rear support plate 21 facing the rear seat body 4c while forming the elongated hole.

The pivot pin 74 of the lever 73 is also used.
A tension spring 77 is inserted between a portion in front of the ratchet claw 45 and the supporting body 14 of the tilting motion body 9 to move the ratchet pawl 45.
Is provided in a direction away from the ratchet wheel 25c, and a plate spring 78 is provided on the upper surface of the support body 14 of the tilting motion body 9 so that the lower end of the ratchet pawl 45 contacts when the ratchet pawl 45 retracts. ing.

In this embodiment, when the seat body 4 descends, the lever 73 rotates in the direction of arrow C via the compression spring 76, the ratchet pawl 45 advances toward the ratchet wheel 25c, and the ratchet pawl 45 moves. The claw portion 45a abuts on the ratchet wheel 25c, and in that state, the ratchet pawl 45 moves in small steps toward and away from the ratchet wheel 25c, so that the pinion shaft 25 moves in the direction of arrow B.
When the ratchet 45 rotates in the direction and stops rotating, the ratchet 45 meshes with the ratchet wheel 25c, and the pinion 25 is held irreversibly.

Then, a person raises his / her waist from the chair 1 and sits down on the seat 4.
When the lever is raised, the lever 73 is returned to the original posture by the tension spring 76, so that the ratchet pawl 45 also moves toward the ratchet wheel 25c.
To the non-meshing state. A fourth embodiment shown in FIG. 20 is a spring constant holding device for holding the pinion shaft 25 irreversibly from the rotated state of the pinion shaft 25 by the downward movement of the seat body 4 as in the third embodiment. Another example is shown.

In this embodiment, between the side plate 14b of the support body 14 and the bracket plate 14c of the tilting motion body 9,
By arranging the ratchet claws 45 extending rearward in a side view,
The ratchet pawl 45 is provided with a pin 7 at the upper end so that the pawl portion 45a at the lower end can be disengaged from the ratchet wheel 25c.
9, a torsion spring 80 fitted to the pin 79 urges the pawl wheel 25c away from the pawl portion 45a, and the ratchet pawl 45 extends backward. 81 is fixed, and the rear end of the leaf spring 81 is brought into contact with the lower surface of the seat body 4.

Reference numerals 82 and 83 are stopper pieces for restricting the rotation range of the ratchet pawl 45. Also in this embodiment, the ratchet pawl 45 is moved by the downward movement of the seat body 4.
The claw portion 45a comes into contact with the ratchet wheel 25c, and the ratchet wheel 25c rotates in the direction of arrow B in this state, whereby the seat body 4
Is allowed to descend, and when the rotation of the ratchet wheel 25c is stopped,
The claw portion 45a of the ratchet claw 45 meshes with the ratchet wheel 25c, and the pinion shaft 25 is held in a non-reversible manner.

The fifth embodiment shown in FIG. 22 is a modification of the first embodiment, and a leaf spring 84 formed in an L-shape in side view is used as spring means for supporting the rearward tilting of the tilting motion body 9. It was used. The leaf spring 84 is fixed to the inner surface of the front plate 7c of the rotating frame 7 with bolts 85.
In the sixth embodiment conceptually shown in FIG. 23, the support mechanism 3 is formed only by the fixed frame body 6, and the intermediate portion along the front-back direction of the tilting motion body 9 is fixed to the fixed frame body 6 by the pin 10 '. And the backrest 5 is attached to the tilting motion body 9, while the seat body 4 is attached to the fixed frame body 6 via the weight-sensing applied coil spring 23 so as to be movable down, and at the same time. The pinion shaft 25 and the second rack 30 having the same configuration as the embodiment are provided,
Further, a torsion coil spring 11 is provided at the front end of the fixed frame body 6, and between the portion of the tilting motion body 9 in front of the pivot pin 10 ′ and the load acting portion 11 a of the torsion coil spring 11, A slider 31 that moves forward in two racks 30 is inserted.

In the seventh embodiment conceptually shown in FIG. 24, the tilting motion body 9 is attached to the fixed frame body 6 as in the sixth embodiment.
The pinion shaft 25 and the second rack 3 having the same structure as described above are pivotally attached by a pin 10 'along the longitudinal direction thereof.
0 and further, when the seat body 4 is provided on the fixed frame body 6 so as to be movable downward, the spring means is provided at a portion of the fixed frame body 6 which is located in front of the pivotally connecting portion pin 10 '. As an example, an operating rod 86 extending along the front-rear direction, and a compression spring 8 inserted between the front end portion of the operating rod 86 and the fixed frame body 6.
7, the operating rod 86 is pivotally attached to the supporting portion 6c of the fixed frame body 6 by means of a longitudinally extending pin 88 at its front and rear intermediate portions so as to rotate in a balance type, and the front end of the tilting motion body 9 is provided. A slider 31 adapted to be moved forward by the second rack 30 is inserted between the portion and a portion near the rear end of the operating rod 86.

In the embodiment shown in FIG. 24, when a person sits on the chair 1, the slider 31 moves forward through the pinion shaft 25 and the second rack 30 to move the pivot pin 86 of the operating rod 86 to the compression spring 87. And the distance L4 between the pivot pin 87 of the operating rod 86 and the slider 31 (L3: L4) become smaller, the compression spring 87 is less likely to be deformed, and the compression spring 87 and the operating rod 87. While the spring constant of the spring means composed of 86 increases, the slider 31 separates from the pivot pin 10 'of the tilting motion body 9 due to the sitting of a person, and therefore, the same effect as each of the above embodiments is obtained. Play.

In the eighth embodiment conceptually shown in FIG. 25, the front end of the seat 4 and the front end of the tilting motion body 9 to which the backrest 5 is attached are rearwardly pinned to the front end of the fixed frame 6. A first leaf spring 89 for weighting is provided which is pivotally mounted so as to be tiltable and elastically supports the seat body 4. Further, the fixed frame body 6 is provided with a first rack 22 projecting downward from the seat body 4. A pinion shaft 25 that is driven to rotate and a second rack 30 that moves the slider 31 backward by tilting the seat body 4 rearward, and the rear of the fixed frame body 6 behind the pinion shaft 25. As a spring means for the tilting motion body 9, a second leaf spring 90 extending in the forward direction is fixed to the portion of the above position, and the slider 31 is interposed between the second leaf spring 90 and the tilting motion body 9. is there.

Also in this embodiment, when the slider 31 moves rearward, the spring constant of the second leaf spring 90 increases and the slider 31 separates from the pivoting portion of the tilting motion body 9, so that each of the above-described embodiments is performed. Similar to the example, the rearward tilt angle of the tilting motion body 9 can be kept substantially constant regardless of the weight of the person sitting on the chair 1. In the ninth embodiment conceptually shown in FIG. 26, the front end of the tilting motion body 9 is pivotally attached to the front end portion of the fixed frame body 6, and the seat body 4 is attached to the tilting motion body 9 for applying the feeling of weight. A pinion shaft 25 that rotates by the descending motion of the seat body 4 and a slider 31 that moves rearward by the rotation of the pinion shaft 25 are provided while being mounted via a coil spring 23 so as to move downward. Is inserted between the forward-moving leaf spring 90 provided at the rear end of the fixed frame body 6 and the tilting motion body 9.

In this embodiment, the seat body 4 and the backrest 5 are integrally tilted rearward against the elasticity of the leaf spring 90. In the embodiment of FIG. 26, the spring force of the leaf spring 90 is
The leaf spring 89 is not deformed only by a person sitting on the chair 1, and is set to a size such that the leaf spring 89 is deformed only when the person leans against the backrest 5 and a large moment acts on the tilting motion body 9.

In each of the above embodiments, the backrest and the seat are elastically supported by the spring means according to the present invention, or only the back tilting of the backrest is elastically supported by the spring means according to the present invention. Although it is supported, only the rearward tilting of the seat body may be supported by the spring means according to the present invention, and the backrest may be supported by another spring means. Further, the means for moving the slider when seated is not limited to the mechanism composed of the rack and the pinion as in the embodiment, and other mechanism such as a link mechanism may be used. Further, the spring means may be a rod-shaped spring. It goes without saying that other spring bodies such as a body may be adopted. Even when a spring body such as a leaf spring is fixed to the second link body and a support body for the spring body is fixedly provided to the support mechanism and the spring body is moved, the same effect as the present application can be obtained. it can.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a chair according to a first embodiment.

FIG. 2 is a sectional view taken along line II-II of FIG. 5 in an assembled state.

FIG. 3 is a schematic perspective view showing attachment of a tilting motion body.

FIG. 4 is an exploded perspective view showing an outline of a weight sensitive mechanism.

FIG. 5 is a schematic perspective view showing attachment of a seat body and a backrest.

6 is a plan sectional view taken along line VI-VI of FIG.

FIG. 7 is a bottom view taken along the line VII-VII in FIG. 1.

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

9 is a sectional view taken along line IX-IX of FIG.

10 is a cross-sectional view taken along line XX of FIG.

11 is a sectional view taken along line XI-XI of FIG.

12 is a sectional view taken along line XII-XII of FIGS. 6 and 10. FIG.

13 is a sectional view taken along line XIII-XIII in FIG.

FIG. 14 is a diagram showing a rearward tilted state of a tilting motion body.

FIG. 15 is a conceptual diagram showing an operating state when leaning forward.

FIG. 16 is a diagram showing an operating state of a spring constant holding device.

FIG. 17 is a cross-sectional view of essential parts showing a second embodiment.

FIG. 18 is a cross-sectional view of essential parts showing a third embodiment.

FIG. 19 is a view taken along line XIX-XIX in FIG. 18.

FIG. 20 is a cross-sectional view of essential parts showing a fourth embodiment.

21 is a view taken along line XXI-XXI of FIG. 20. FIG.

FIG. 22 is a sectional view showing a fifth embodiment.

FIG. 23 is a conceptual diagram showing a sixth embodiment.

FIG. 24 is a conceptual diagram showing a seventh embodiment.

FIG. 25 is a conceptual diagram showing an eighth embodiment.

FIG. 26 is a conceptual diagram showing a ninth embodiment.

FIG. 27 is a conceptual diagram showing prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chair 2 Leg body 3 Support mechanism 4 Seat body 5 Backrest 6 Fixed frame body 7 Rotating frame body 9 Tilting motion body 10 Second pivot pin 11 Torsion coil spring as an example of spring means 21 Coil spring for weight sense application 22 First rack 25 Pinion shaft 25a First pinion gear 25b Second pinion gear 30 Second rack 32 Slider 44 Spring constant holding device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Iwabuchi 1-4-18 Imafukuhigashi, Joto-ku, Osaka City Ito Ki Kobo Co., Ltd.

Claims (1)

[Claims] 1. A tilting motion body to which a backrest or a seat or both are attached is pivotally attached to a support mechanism provided at the upper end of a leg body so as to be tiltable rearward, and the tilting body is tilted in accordance with the magnitude of a downward load on the seat body. A slider is provided so as to be separated from the pivot portion of the moving body, and spring means for elastically supporting the rearward tilting of the tilting moving body via the slider is provided. A tilting control device for a chair, characterized in that a spring constant is formed so as to increase in response to the receding movement from the landing portion.