JP2009254514A - Resilient for chair and chair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the moving distance of a variable fulcrum member is restricted and the adjustable range of the resiliency of a leaf spring is narrowed in a device having the leaf spring supported to a fixed member in an overhung beam state and energizing a movable member at its free end side, and a variable fulcrum member served as a fulcrum when the leaf spring is resiliently deformed and being movable along the leaf spring when the leaf spring is in an initial position, adjusting the resiliency of the leaf spring by moving the variable fulcrum member and increasing/decreasing a distance to a contact point between the fulcrum of the leaf spring and the movable member, in the resilient interposed between the fixed member and the movable member and operating resiliency when the movable member is tilt by a load applied from a user. <P>SOLUTION: The resilient 10B for the chair is provided with a nonuniform cross-section part 14e for reducing the width and/or the thickness of a fixed end side 14b more than the width and/or the thickness of a free end side 14a within the moving range of the variable fulcrum member 15 of the leaf spring 14. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a chair elastic device for use in a chair having a fixed member and a movable member pivotally attached to the fixed member, and for imparting elasticity to the movement of the movable member, and the elastic device thereof It is related with the chair provided with.

The seat fixed to the top of the support leg is used as a fixed member, while the seat mounted on the seat so as to be tiltable is used as a movable member, and the seat is moved between the seat and the seat. A chair provided with a resilient device for imparting elasticity is described in Patent Document 1, for example.
Japanese Utility Model Publication 4-36675

  As shown in FIG. 12, the chair of Patent Document 1 includes a seat 2 fixed to the top of a support leg 1 and a seat 4 that is pivotally attached to a front end of the seat 2 by a swing shaft 3 so as to be tilted backward. (To be precise, the support bracket 4b integrally fixed to the bottom of the seat plate 4a), a backrest (not shown) attached to the rear end of the seat portion 4, and a chair that imparts elasticity to the seat portion 4. And the elastic device 100 for use.

  The chair elastic device 100 is fixed at one end to the front end of the pedestal 2 and is supported in a cantilever shape. Further, the chair elastic device 100 is a constant width band plate that urges the rear end of the seat portion 4 upward on the free end 101a side. The leaf spring 101 and a pillow that is movable along the leaf spring 101 in the state shown in FIG. 12 that is a fulcrum when the leaf spring 101 is elastically deformed and is in an initial position where the leaf spring 101 does not receive a load from the user. And the movable fulcrum member 102 is moved as shown by an arrow X in FIG. 12 to change the distance to the contact point between the fulcrum of the leaf spring 101 and the seat portion 4. The elasticity of the leaf spring 101 is adjusted.

  FIGS. 13 (a) to 13 (c) show the chair elastic device 100 as a schematic diagram. In the figure, δ = deflection, W = load from the user, L = distance from the fulcrum to the point of application of the load, b = width of the leaf spring, and h = thickness of the leaf spring. As shown in FIG. 13C, the deflection δ when the user receives a load W on the free end of the leaf spring 101 can be adjusted by moving the variable fulcrum member 102 as shown in FIG. The magnitude of the flexure δ decreases as the variable fulcrum member 102 approaches the position shown in FIG. 13B from the position shown in FIG. 13A, that is, the elasticity of the leaf spring 101 becomes stronger and the movement of the seat portion 4 becomes harder. Become.

Chair elastic device 100 of Patent Document 1, its size is limited to the range of size of the seat 4, inevitably FIG. 13 (a), the difference between the distance L ₁ and the distance L ₂ (b) Therefore, there is a problem that the adjustable range of the elasticity of the leaf spring 101 is very narrow. This means that the range of weights that can be handled is limited, which is a fatal problem for mass-produced products.
In addition, there is a chair that incorporates the chair elastic device in a chair that can swing back and move as a movable member, but the situation is the same even in that case.

As described in claim 1, when the movable member is tilted by a load received from a user and interposed between the fixed member and a movable member that is pivotally attached to the fixed member. An elastic device for a chair that exerts elasticity in a direction to prevent
A leaf spring that fixes one end to the fixed member and is supported in a cantilever shape and urges the movable member on the free end side;
A variable fulcrum member that is movable along the leaf spring in a state in which the leaf spring is in an initial position where the leaf spring is elastically deformed and is not subjected to a load from a user;
In the elastic device for a chair, the elastic force of the leaf spring can be adjusted by moving the variable fulcrum member and increasing or decreasing the distance to the contact point between the fulcrum of the leaf spring and the movable member.
Provided is an elastic device for a chair provided with a variable cross section for making the fixed end side smaller than the free end side within at least the movement range of the variable fulcrum member of the leaf spring.

In addition, as described in claim 2, between the free end of the leaf spring and the variable fulcrum member, the contact pressure between the leaf spring and the variable fulcrum member is reduced or a clearance is formed between the two. Provided with elastic means for applying force in the direction
The elastic means applies a force to the leaf spring in an initial state that does not receive a load from the user so that the leaf spring can maintain a predetermined posture against the load received from the movable member itself, while being seated. The elastic device for a chair according to claim 1, which is elastically deformed together with a leaf spring when a load from a user is received via the leaf spring.

  According to a third aspect of the present invention, a bending prevention member is provided corresponding to a section of the variable fulcrum member from the fixed end of the leaf spring, and the bending prevention member causes the free end side of the leaf spring to bend. The elastic device for a chair according to claim 1 or 2, wherein deformation of the section that may occur is suppressed.

  According to a fourth aspect of the present invention, the chair elastic device according to any one of the first to third aspects is provided, and the fixed member is a pedestal integrated with a support leg, while the movable member is provided. Provides a chair that is a backrest that is swingably attached to the seat.

  According to a fifth aspect of the present invention, the chair elastic device according to any one of the first to third aspects is provided, wherein the fixed member is a pedestal integrated with a support leg, while the movable member Provides a chair which is a seat part swingably attached to the seat.

When the variable fulcrum member is moved from the free end side to the fixed end side at the variable cross section, the distance of the leaf spring is L ₁ → L ₂ → L _{3 as} shown in FIGS. At the same time, the width decreases from b ₁ → b ₂ → b ₃ , and both changes act synergistically, so that the deflection δ of the free end of the leaf spring increases dramatically. In this way, the adjustment range of the elasticity of the leaf springs is greatly expanded as compared with the conventional case, so that it can accommodate users with a wide range of weights.

  Further, as in claim 2, between the free end of the leaf spring and the variable fulcrum member, the contact pressure between the leaf spring and the variable fulcrum member is reduced or a force is applied in the direction in which the clearance is formed. Because the elastic means to be applied is provided and the force is applied so that the leaf spring can maintain a predetermined posture against the load received from the movable member itself against the leaf spring in the initial state that does not receive a load from the user The frictional resistance between the leaf spring and the variable fulcrum member can be zero or very small. Accordingly, the movable fulcrum member can be moved easily. On the other hand, when the leaf spring receives a load from the user, the elastic means is elastically deformed together with the leaf spring, so that the function of the leaf spring is not impaired. Further, since the bending of the leaf spring uses the variable fulcrum member as a fulcrum, a large frictional resistance acts on the variable fulcrum member due to the force applied at that time. Therefore, while the user is sitting on the seat and applying a load to the movable member, there is almost no problem that the movable fulcrum member moves and the elasticity of the movable member naturally changes during use.

  Further, as in claim 3, a bending prevention member is provided corresponding to the section of the variable fulcrum member from the fixed end of the leaf spring, and the bending prevention member can be caused by the bending of the free end side of the leaf spring. When the deformation of the section is suppressed, a change in the bending of the leaf spring due to the change of the position of the variable fulcrum member appears surely. Incidentally, in the elastic device as in Patent Document 1 without the bending prevention member, the section of the variable fulcrum member is bent in an arch shape from the fixed end of the leaf spring as the free end side of the leaf spring is bent. Even if it is changed, the change in the bending of the leaf spring is less likely to appear.

[Embodiment 1]
Embodiment 1 of the present invention will be described below with reference to FIGS. 1 (a) to 1 (c) are perspective views of the chair elastic device, and FIGS. 2 (a) to 2 (c) are perspective views showing leaf springs.

  Since the chair of Embodiment 1 is the same as that of FIG. 12 except for the chair elasticity device 10A, the description thereof is omitted.

[Elastic device for chairs]
As shown in FIGS. 1A to 1C, the chair elastic device 10 </ b> A according to the first embodiment includes a flat horizontal plate 11 and a vertical plate 12 projecting vertically at one end of the horizontal plate 11. The fixed member 13 having a substantially L shape in front view is fixed at one end in the middle of the height of the vertical plate 12 of the fixed member 13 and is supported in a cantilever shape, and is movable on the free end 14a side. A leaf spring 14 for urging the seat 4 in the direction away from the lateral plate 11 and an initial position where the leaf spring 14 becomes a fulcrum when the leaf spring 14 is elastically deformed and the leaf spring 14 does not receive a load from the user. 1 (a) to 1 (c), a fulcrum fulcrum member 15 that slides on the horizontal plate 11 and is movable along the leaf spring 14, and a bend formed on the upper part of the fulcrum fulcrum member 15. And a stop member 16.

[Plate spring]
The plate spring 14 has a uniform thickness. As shown in FIG. 2A, the fixed end 14b side has a small width portion 14c with a small width, the free end 14a side has a large width portion 14d with a small width, and a smaller width. A tapered cross section 14e is formed between the portion 14c and the large portion 14d, and has a substantially battledore shape as a whole.

[Variable fulcrum member and anti-bending member]
The variable fulcrum member 15 and the anti-bending member 16 have an integral structure, and the leaf spring 14 is passed through a horizontally long through hole 17 formed at the boundary portion between them. The through hole 17 has substantially the same width as the large portion 14 d of the leaf spring 14. Further, the through hole 17 is formed to have a vertical width slightly larger than the plate thickness of the plate spring 14 so that an appropriate clearance can be formed on both the upper and lower surfaces of the plate spring 14. Accordingly, the leaf spring 14 and the through hole 17 are not in contact with each other in the state shown in FIG. 1 where the leaf spring 14 is not subjected to a load from the user. The movement of the member 15 is smooth. The movement of the variable fulcrum member 15 is performed, for example, by engaging a rotatable operation lever 18 with the variable fulcrum member 15 as in Embodiment 2 described later, or a rack gear is mounted on the upper surface of the variable fulcrum member 15. The pinion gear formed and meshed with the rack gear is rotated by a handle.

[how to use]
Next, the usage method of the chair of Embodiment 1 is demonstrated. In addition, the position of the fluctuation | variation fulcrum member 15 of the elastic device 10A for chairs shall be in the position of Fig.1 (a).

  First, when the user sits on the seat 4 of the chair, the seat 4 tilts backward about the swing shaft 3. Then, the rear side of the seat part 4 presses the free end 14a side of the leaf spring 14 of the elastic device 10A for the chair and elastically deforms it. At this time, the leaf spring 14 bends with the end on the free end 14 a side of the through hole 17 of the variable fulcrum member 15 as a fulcrum. On the other hand, due to the reaction of the bending on the free end 14a side of the leaf spring 14, a stress of a component that deforms the same portion into an arch shape acts between the fixed end 14b of the leaf spring 14 and the fulcrum. In the first embodiment, since the anti-bending member 16 provided immediately above the variable fulcrum member 15 suppresses the arch-shaped deformation of the plate spring 14, the plate spring 14 hardly deforms between the variable fulcrum member 15 and the fixed end 14b. Therefore, since the substantially fixed end of the leaf spring 14 can be considered as the end of the through hole 17 of the variable fulcrum member 15, the strength of the leaf spring 14 is maximum in the state of FIG. A resiliency of 4 is suitable for heavy weight users.

Next, when a user having a lighter weight than the user sits on the seat portion 4, the variable fulcrum member 15 is shown in a state where the user does not sit on the seat portion 4, that is, in an initial state where no load is applied to the leaf spring 14. Slide to position 1 (b). Then the distance from the free end 14a side of the end of the fluctuation fulcrum member 15 (the fulcrum) to the point of application of the load is increased from L ₁ to L _2, whereas the width of the end of the leaf spring 14 of the change fulcrum member 15 b ₁ reduced to b ₂ from an increase in the L ₂ from L ₁ of the distance, since a decrease in the b ₂ is interact synergistically from b ₁ of width, dramatically leaf spring 14 works susceptibility of And a soft elasticity suitable for light weight users.

  Of course, in the case of a user with a lighter weight, the variable fulcrum member 15 may be slid from the position shown in FIG. 1B to the position shown in FIG. In addition, in the state of FIG.1 (c), the strength of the leaf | plate spring 14 is the minimum, and the elasticity of the seat part 4 is suitable for the user with a light weight.

  As described above, the position of the variable fulcrum member 15 has been described in three stages of FIGS. 1A, 1B, and 1C. However, the variable cross-section portion 14e of the first embodiment is tapered and the variable fulcrum member 15 has a tapered shape. Therefore, the change in the elasticity of the seat portion 4 can be realized regardless of the position at which the variable fulcrum member 15 is stopped.

  In the first embodiment, an example in which the leaf spring 14 is formed into a feather plate shape is shown. However, as shown in FIG. 2B, a triangle in plan view from the end of the variable cross section 14e toward the free end 14a is shown. It may be formed in a generally rhombic shape in plan view, and one of the corners forming an acute angle may be the fixed end 14b. The leaf spring 14 of FIG. 2B having such a shape is more flexible than the leaf spring 14 having the same width on the free end 14e side as shown in FIG. be able to.

[Embodiment 2]
3 to 9 show Embodiment 2 of the present invention. 3 is a perspective view of a main part of the chair with the seat omitted, FIG. 4 is an exploded perspective view of FIG. 3, FIG. 5 is a longitudinal sectional view of the main part, FIG. 6 is a transverse plan view of the main part, FIG. FIGS. 9A and 9B are perspective views of the leaf springs, FIGS. 8A and 8B are longitudinal sectional views and cross-sectional plan views of the main part showing the state where the elasticity is maximized, and FIGS. ) Are a longitudinal sectional view and a transverse plan view of the main part showing a state in which the elasticity is minimized.

[Chair]
The chair according to the second embodiment is attached to a base 2 fixed to the top of the support leg 1, a seat plate 4 a fixed to the upper surface of the base 2, and a swinging shaft 5 attached to the rear end of the base 2. A backrest 6 and a chair elasticity device 10B that imparts elasticity to the backrest 6.

[Pedestal (fixing member)]
The pedestal 2 constitutes a fixing member in the second embodiment, and stands on a rectangular bottom plate 2a, an inverted concave spring mounting member 2b fixed to the upper surface of the bottom plate 2a, and both sides of the bottom plate 2a. The raised side plates 2c and 2c, seat plate mounting pieces 2d and 2d with the upper edges of the side plates 2c and 2c bent outward, and elastic stoppers 2e protruding from the bottom plate 2a.

[Backrest (movable member)]
The backrest 6 constitutes a movable member in the second embodiment, and the support shaft 5 is passed through the distal ends of two left and right backrest pipes 6a and 6a that are substantially L-shaped in a side view. Both ends are rotatably inserted into the side plates 2c, 2c of the seat 2 so that the whole can be swung around the support shaft 5. A lower horizontal rod 6b and an upper horizontal rod 6c are fixed between the left and right backrest pipes 6a, 6a in parallel with the support shaft 5.

[Elastic device for chairs]
The chair elastic device 10B is supported in the form of a cantilever with one end fixed to the inner surface of the ceiling plate 2f of the spring mounting member 2b of the seat 2 and at the free end 14a side. A leaf spring 14 for urging the backrest 6 and a fulcrum when the leaf spring 14 is elastically deformed, and the leaf spring 14 is in an initial state where it does not receive a load from the user. Operation for a fulcrum fulcrum member 15 that can slide and move along the leaf spring 14 and a fulcrum fulcrum member 15 that is pivotally mounted on the bottom plate 2a while passing through one side plate 2c of the seat 2. The lever 18 and the elastic means 19 for providing an appropriate clearance between the leaf spring 14 and the variable fulcrum member 15 are schematically configured.

[Plate spring]
In the leaf spring 14 of the second embodiment, as shown in FIG. 7 (a), the fixed end 14b side is a bifurcated portion 14g having a constant outer width and a split port 14f provided therein, while the free end 14a side is provided. Further, the tapered triangular portion 14h is formed, and the section from the tip of the bifurcated portion 14g to the starting point of the triangular portion 14h is formed as a variable cross-sectional portion 14e formed by a triangular notch 14i cut out in a tapered shape.
The plate spring 14 has a shape in which the fixed end 14b side is aligned with the inside of the ceiling plate 2f of the spring mounting member 2b. Therefore, it is fixed to the seat 2 as a fixing member via the spring mounting member 2b. Further, in the state of being attached to the spring mounting member 2b, the leaf spring 14 is covered with the ceiling plate 2f of the spring mounting member 2b at the bifurcated portion 14g and the deformed section 14e.
Further, the end portion of the leaf spring 14 on the free end 14a side is in contact with the lower lateral flange 6b of the backrest 6 and, on the other hand, comes into contact with the elastic stopper 2e of the seat 2 when elastically deformed. .

[Variable fulcrum member]
As shown in FIG. 4, the variable fulcrum member 15 has a horizontally long rectangular parallelepiped shape and a pillow member 15a that fits in the transverse shape inside the spring mounting member 2b, and a connecting piece 15b that protrudes behind the pillow member 15a. The guide member 15c protrudes from the upper surface of the pillow member 15a and the connecting piece 15b, and an L-shaped spring base 15d fixed to the front of the pillow member 15a.

The connecting piece 15b of the variable fulcrum member 15 has a long hole 15e penetrating in the vertical direction at its rear end, and a connecting pin 18a planted upward at the end of the operating lever 18 is loosely fitted in the long hole 15e. Has been.
On the other hand, the guide portion 15c of the variable fulcrum member 15 has a height substantially equivalent to the plate thickness of the leaf spring 14, and substantially coincides with the slit 14f of the leaf spring 14 and the triangular notch 14i of the variable cross section 14e. The movement of the variable fulcrum member 15 is restricted to a linear motion by being snugly fitted with a slidable fit in the split opening 14f of the leaf spring 14. Accordingly, when the operating lever 18 protruding to the side of the seat 2 is rotated as shown in FIG. 6, the force is transmitted to the connecting piece 15b through the connecting pin 18a and the long hole 15e, and the fluctuation caused by the force is transmitted. The fulcrum member 15 is guided by the guide portion 15c and moves in the linear direction.

  As described above, the bifurcated portion 14g is formed in the leaf spring 14, and the guide portion 15c protruding from the upper surface of the variable fulcrum member 15 is fitted into the bifurcated portion 14g, and the movement of the variable fulcrum member 15 is thus performed. Is configured to straightly regulate the bifurcated portion 14g necessary for forming the deformed section 14e in the leaf spring 14, the connecting piece 15b required for connecting the variable fulcrum member 15 and the operating lever 18. Can be used effectively, and only the guide portion 15c is added to them.

[Elastic means]
The elastic means 19 has a coil spring 19a fixed to the tip of a spring pedestal 15d fixed to the front surface of the pillow member 15a, and a contact 19b having a spherical top at the top of the coil spring 19a. A force in the direction of lifting the leaf spring 14 is applied to the free end 14a side of the leaf spring 14, so that the leaf spring 14 in the initial position that does not receive a load from the user is backrest 6 It can be supported so as not to bend by its own load. Accordingly, an appropriate clearance can be provided and maintained between the leaf spring 14 and the variable fulcrum member 15, so there is no fear that the variable fulcrum member 15 is rubbed against the leaf spring 14 and hardly moves. Further, even when there is no clearance between the leaf spring 14 and the variable fulcrum member 15, the contact pressure between the two can be reduced by the elastic means 19, so that the frictional resistance acting on the variable fulcrum member 15 can be reduced. It is.

[Bending prevention member]
As described above, the section from the fixed end 14b of the leaf spring 14 to the deformed section 14e is covered with the ceiling plate 2f of the spring mounting member 2b. Therefore, even if the leaf spring 14 is bent on the free end 14a side with the pillow member 15a of the variable fulcrum member 15 as a fulcrum, the portion covered with the spring mounting member 2b cannot hit the ceiling plate 2f and bend. Therefore, the spring mounting member 2b of the second embodiment also functions as a bend preventing member that suppresses deformation of the section that may occur due to the bending of the leaf spring 14 on the free end 14a side.

[how to use]
Next, the usage method of the chair of Embodiment 2 is demonstrated. In addition, the position of the fluctuation | variation fulcrum member 15 of the elastic device 10B for chairs shall be in the free end 14a side most shown in FIG.

  In the chair according to the second embodiment, when the user sits on the seat 4 and leans on the backrest 6 and puts his / her weight on the chair, the backrest 6 tilts around the support shaft 5. Then, as shown in an imaginary line in FIG. 5, the lower horizontal heel 6b of the backrest pipe 6a presses the free end 14a side of the leaf spring 14 of the chair elastic device 10B to elastically deform it. At this time, the leaf spring 14 bends with the upper corner portion of the pillow member 15a of the variable fulcrum member 15 as a fulcrum. On the other hand, due to the reaction of the bending on the free end 14a side of the leaf spring 14, a stress of a component that deforms the same portion into an arch shape acts between the fixed end 14b of the leaf spring 14 and the fulcrum. In Mode 2, since the ceiling plate 2f of the spring mounting member 2b suppresses the arch-shaped deformation of the leaf spring 14, the leaf spring 14 hardly deforms between the variable fulcrum member 15 and the fixed end 14b. Therefore, since the substantially fixed end of the leaf spring 14 can be considered as the end of the variable fulcrum member 15, the strength of the leaf spring 14 is maximum in the state of FIG. 8, and the elasticity of the backrest 6 is heavy. Suitable for users or users who want to increase the movement of the backrest 6.

  Next, when a user having a lighter weight than the above-mentioned user is used, or when the user desires to change the elasticity of the backrest 6 softly, sit in a posture not to lean on the backrest 6, In the initial state in which the user's load is not applied to the spring 14, the operation lever 18 is rotated, and the variable fulcrum member 15 is slid to the position shown in FIG. Then, the distance from the end (fulcrum) on the free end 14a side of the variable fulcrum member 15 to the point of application of the load increases, while the width of the leaf spring 14 in contact with the end (fulcrum) of the variable fulcrum member 15 decreases. Since the increase in distance and the decrease in width act synergistically, the strength of the leaf spring 14 changes dramatically, and a soft elasticity is obtained.

  As described in the first embodiment, the variable cross section 14e of the leaf spring 14 is tapered and its width continuously changes in accordance with the position of the variable fulcrum member 15. Adjustments can be made steplessly.

  Further, in the second embodiment, the free end 14a side of the leaf spring 14 is the triangular portion 14h. However, as shown in FIG.

[Embodiment 3]
FIGS. 10A to 10C show the chair elastic device 10C according to the third embodiment, which is an example in which the variable cross section 14e is stepped to change the thickness of the leaf spring 14 step by step. . The inner surface of the ceiling plate 2f (anti-bending member 16) of the spring mounting member 2b has a reverse stepped shape with respect to the deformed section 14e, and therefore the deformed section 14e of the leaf spring 14 and the ceiling plate 2f are in close contact with each other.
Since the chair elastic device 10C can change the thickness of the leaf spring 14 stepwise by moving the variable fulcrum member 15, the elasticity of the leaf spring 14 changes dramatically as in the first and second embodiments. Can be made.
As shown in FIG. 11, the thickness of the leaf spring 14 can be continuously changed by making the variable cross section 14e into a tapered shape that becomes thinner from the free end 14a side to the fixed end 14b side.

  As mentioned above, although this invention was demonstrated about Embodiment 1-3, this invention is not limited to the said embodiment of course. For example, the elasticity of the seat 4 is adjusted as in the first embodiment with the chair elasticity devices 10B and 10C of the second and third embodiments, and the backrest 6 is elastic with the chair elasticity device 10A of the first embodiment. It can also be adjusted.

In the first to third embodiments, either the width or the thickness of the leaf spring 14 is changed. However, as in the embodiment 1 + embodiment 3 or the embodiment 2 + embodiment 3, the leaf spring 14 is changed. The width and thickness of the film may be changed together.
In the first to third embodiments, the leaf spring 14 is symmetric with respect to the center line in the longitudinal direction. For example, as shown in FIG. You may make it the form which did. By doing so, it is easy to make a space for installing other parts (for example, a height adjusting device of the support leg 1) in the seat 2.

  Moreover, although the elastic means 19 of Embodiment 2 was provided in the spring base 15d integral with the fluctuation | variation fulcrum member 15, and it was set as the structure which moves with the fluctuation | variation fulcrum member 15, for example, it is fixedly provided in the baseplate 2a of the pedestal 2 You may do it. Further, the type of spring of the elastic means 19 is not limited to the coil spring.

  Moreover, although the cross-section part 14e of Embodiment 1, 2 was comprised by the linear taper, you may comprise an outline with an arc-shaped curve, or you may make it a jagged outline.

(A)-(c) is a perspective view of the elastic device for chairs. (A)-(c) is a perspective view which shows a leaf | plate spring. It is a perspective view of the chair principal part which abbreviate | omitted the seat part. FIG. 4 is an exploded perspective view of FIG. 3. It is a longitudinal cross-sectional view of the principal part. It is a cross-sectional top view of the principal part. (A), (b) is a perspective view of a leaf | plate spring. (A), (b) is the longitudinal cross-sectional view and transverse plane figure of the principal part which show the state which maximized the elasticity. (A), (b) is the longitudinal cross-sectional view and transverse plane figure of the principal part which show the state which minimized the elasticity. (A)-(c) is a longitudinal cross-sectional view of the elastic device for chairs. (A)-(c) is a longitudinal cross-sectional view of the elastic device for chairs. It is a longitudinal cross-sectional view of the principal part which shows the conventional chair. (A)-(c) is a perspective view which shows the elastic device for chairs simply.

Explanation of symbols

1 ... support leg 2 ... base (fixing member)
2b ... Spring mounting member (bending stop member)
4 ... Seat (movable member)
6 ... Backrest (movable member)
DESCRIPTION OF SYMBOLS 10A, 10B, 10C ... Elastic device for chairs 13 ... Fixed member 14 ... Leaf spring 14a ... Free end 14b ... Fixed end 14e ... Deflection section 15 ... Fluctuating fulcrum member 16 ... Anti-bending member 19 ... Elastic means

Claims (5)

A chair that is interposed between a fixed member and a movable member that is pivotally attached to the fixed member and that exerts elasticity in a direction that prevents the tilt when the movable member is tilted by a load received from a user. A resilient device,
A leaf spring that fixes one end to the fixed member and is supported in a cantilever shape and urges the movable member on the free end side;
A variable fulcrum member that is movable along the leaf spring in a state in which the leaf spring is in an initial position where the leaf spring is elastically deformed and is not subjected to a load from a user;
In the elastic device for a chair, the elastic force of the leaf spring can be adjusted by moving the variable fulcrum member and increasing or decreasing the distance to the contact point between the fulcrum of the leaf spring and the movable member.
An elastic device for a chair, characterized in that a variable cross section for making the width and / or thickness smaller on the fixed end side than on the free end side is provided at least within the movement range of the variable fulcrum member of the leaf spring. An elastic means for reducing a contact pressure between the leaf spring and the variable fulcrum member between a free end of the plate spring and the variable fulcrum member, or applying a force in a direction in which a clearance is formed between them; Provided,
The elastic means applies a force to the leaf spring in an initial state that does not receive a load from the user so that the leaf spring can maintain a predetermined posture against the load received from the movable member itself, while being seated. 2. The elastic device for a chair according to claim 1, wherein when the load from a user is received through the leaf spring, the elastic device is elastically deformed together with the leaf spring.   A bend preventing member is provided corresponding to the section of the variable fulcrum member from the fixed end of the leaf spring, and the bend preventing member suppresses deformation of the section that may be caused by bending of the free end side of the leaf spring. The elastic device for a chair according to claim 1 or 2, wherein   4. The chair elastic device according to any one of claims 1 to 3, wherein the fixed member is a pedestal integrated with a support leg, while the movable member is swingably attached to the pedestal. A chair characterized by being a backrest.   4. The chair elastic device according to any one of claims 1 to 3, wherein the fixed member is a pedestal integrated with a support leg, while the movable member is swingably attached to the pedestal. A chair characterized by being a seated portion.

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