JP2022070286A - Chair - Google Patents

Abstract

To provide a chair having such a superior design freedom that the chair can has configuration in which a backrest and a seat are in conjunction with each other and furthermore has configuration in which a support base portion and the seat is hard to separate excessively.SOLUTION: A chair is provided, comprising: a support base portion 2; a seat 5 arranged on the support base portion 2; a backrest 4 supported rotationally operatively between a normal posture (A) and a backward tilted posture being backward tilted more than the normal posture (A) with respect to the support base portion 2; and a link mechanism 6 comprising a front link member 61 capable of rotatably supporting a front portion of the seat 5 through a seat support shaft J2, and capable of being in conjunction with the rotational motion of the backrest 4. The rear of the seat 5 is supported by the support base portion 2 in such a manner that the rear of the seat 5 is slidably movable in a front-rear direction with respect to the support base portion 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a chair preferably used in an office or the like.

Conventionally, a chair having a backrest that is rotatably supported between a normal posture and a backward leaning posture tilted backward from the normal posture with respect to a support base attached to the upper end of the leg has been known. ing.

Some chairs of this type are configured so that the seat is linked to the rotational movement of the backrest. For example, the backrest of the chair of Patent Document 1 is provided with a protrusion for supporting the rear part of the seat (corresponding to the seat support rod 6d) extending in the vertical direction in the vicinity of the support base. Then, the upper end portion of the protruding portion extending in the vertical direction is rotatably connected to the rear portion of the seat arranged on the support base portion, and the seat can be rotatably supported.

However, in this type of chair, since the backrest is provided with a protrusion extending in the vertical direction, the support base and the seat tend to have a structure in which the support base and the seat are largely separated in the vertical direction.

If the support base and the seat are largely separated from each other, for example, it becomes difficult to design the space between the support base and the seat so as to give a feeling of compactness and slimness. Further, if the support base and the seat are largely separated from each other, it is difficult to make the leg columns supporting the support base look long and to make them look good.

In other words, in the conventional chair, the support base and the seat are easily separated from each other, which limits the degree of freedom in design that can form a suitable appearance.

Japanese Unexamined Patent Publication No. 2019-126379

The present invention has been made by paying attention to the above circumstances, and at least, the freedom of design is such that the support base and the seat can be configured not to be excessively separated from each other while having a configuration in which the backrest and the seat can be interlocked with each other. It is to provide excellent chairs.

That is, the present invention has the following configuration.

The invention according to claim 1 rotates between a support base, a seat arranged on the support base, and a normal posture with respect to the support base and a backward leaning posture tilted backward from the normal posture. It is provided with a backrest that is operably supported and a link mechanism that includes a front link member that can rotatably support the front portion of the seat via a seat support shaft and that can be interlocked with the rotational movement of the backrest. The chair is a chair in which the rear portion of the seat is supported so as to be slidable in the front-rear direction with respect to the support base.

The invention according to claim 2 is the chair according to claim 1, wherein the rear portion of the seat is configured to be vertically detachable from the support base portion.

The invention according to claim 3 is provided so that the link mechanism can operate integrally with the front link member rotatably supported by the support base via a support shaft and the backrest. The rear link member and the rear end portion are rotatably connected to the rear link member via the rear connecting shaft, and the front end portion is rotatably connected to the front link member via the front connecting shaft. The chair according to claim 1 or 2, which is provided with a connected intermediate link member.

In the invention according to claim 4, the front link member can support the seat support shaft in front of the support shaft, and supports the front connecting shaft below the support shaft. The chair according to claim 3, which is obtained.

In the invention according to claim 5, the backrest is rotatably supported with respect to the support base via a spindle, and is urged in the direction of the normal posture by a reaction force spring. The front end portion of the reaction force spring is supported by the front spring receiving portion disposed on the support base portion, and the rear end portion of the reaction force spring operates integrally with the backrest. The chair according to claim 1, 2, 3, 4 or 5, which is supported by a spring receiving portion after being provided below the spindle.

The invention according to claim 6 is configured such that the seat can take a forward leaning posture tilted forward from the normal posture by rotating about the seat support shaft, and the support base portion. The chair according to claim 1, 2, 3, 4 or 5, wherein a movement restricting portion that can engage with the seat in the forward leaning posture is provided.

According to the seventh aspect of the present invention, the rear portion of the seat is provided with a sliding contact portion capable of sliding contact with the support base portion in accordance with the rotational operation of the backrest, and the sliding contact portion is provided with the support base portion. The chair according to claim 1, 2, 3, 4, 5 or 6, which is provided with a receiving portion through which the portions can be slidably contacted.

The invention according to claim 8 is the chair according to claim 7, which is provided with a lateral displacement suppressing means capable of suppressing the sliding contact portion from shifting in the left-right direction with respect to the receiving portion.

The invention according to claim 9 is provided with an upright wall in which the lateral displacement suppressing means is erected on the receiving portion and can engage with the sliding contact portion when the sliding contact portion shifts in the left-right direction. The chair according to claim 8.

The invention according to claim 10 is configured such that the seat can be tilted backward in conjunction with the backward tilting motion of the backrest. Claims 1, 2, 3, 4, 5, 6, 7, 8 Or the chair according to 9.

The invention according to claim 11 includes a guide groove provided in either one of the support base portion and the rear portion of the seat, and a guided member provided in the other and guided by the guide groove. The chair according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

The invention according to claim 12 is configured such that the seat can take a forward leaning posture tilted forward from the normal posture by rotating about the seat support shaft, and the guide groove. However, the seat extends in the front-rear direction and extends in the vertical direction with the first guide groove component with which the guided member is engaged when the seat operates between the normal posture and the backward tilted posture. 11. The chair according to claim 11, further comprising a second guide groove component with which the guided member is engaged when the seat operates between the normal posture and the forward leaning posture.

As described above, according to the present invention, there is provided a chair having at least a structure in which the backrest and the seat can be interlocked, and a chair having an excellent degree of freedom in design capable of having a structure in which the support base and the seat are not excessively separated. It will be something that can be done.

A side view (normal posture) of a schematic main part showing an embodiment of the present invention. The central sectional view corresponding to FIG. 1 in the same embodiment. A side view (backward leaning posture) of a schematic main part showing the same embodiment. The central sectional view corresponding to FIG. 3 in the same embodiment. A side view of a schematic main part showing the same embodiment (forward leaning posture of the seat). FIG. 5 is a central sectional view corresponding to FIG. 5 in the same embodiment. An exploded perspective view of the same embodiment. An exploded perspective view of the same embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 8. It should be noted that the drawings show only the main parts for explaining the present invention, and some configurations (particularly, the seat 5 and the like) are particularly schematically simplified.

This embodiment applies the present invention to an office swivel chair (hereinafter, simply referred to as "chair") preferably used in an office or home.

The chair has a leg 1, a support base 2 attached to the upper end of the leg 1, a seat 5 arranged on the support base 2, and a normal posture (A) and the normal posture (A) with respect to the support base 2. The backrest 4 rotatably supported between the backward tilted posture (B) tilted backward from A) and the front link capable of rotatably supporting the front portion of the seat 5 via the seat support shaft J2. It includes a member 61 and includes a link mechanism 6 that can be interlocked with the rotational movement of the backrest 4. In this chair, the rear portion of the seat 5 is supported so as to be slidable in the front-rear direction with respect to the support base portion 2.

This chair is configured so that the seat 5 can tilt backward in conjunction with the backward tilting motion of the backrest 4. In other words, the chair is provided with a synchro locking mechanism that interlocks the rotational movement of the seat 5 with the rotational movement of the backrest 4.

The leg 1 can support the support base 2 and the members supported by the support base 2 (backrest 4, seat 5, etc.) so as to be able to turn horizontally. The leg 1 has, for example, a plurality of leg blades (not shown) arranged radially with casters (not shown) at the tip, and is erected at the base end of the leg blades and expands and contracts in the vertical direction inside. It is provided with a leg strut 11 provided with a possible gas spring.

The support base 2 is supported by the legs 1 and is configured to be able to rotate. The support base 2 is formed with a fitting hole 22a that connects the left and right side walls 21 arranged in pairs on the left and right and the lower part of the rear portion of the left and right side walls 21 and to which the upper end of the leg support 11 can be fitted. The receiving portion 24 to which the leg connecting portion 22 is connected, the front connecting portion 23 connecting the front portions of the left and right side walls 21, and the sliding contact portion 52 attached to the leg connecting portion 22 and provided at the rear portion of the seat 5 can be slidably contacted. It is equipped with.

The left and right side walls 21 are made of metal and have a plate shape extending in the front-rear direction. The left and right side walls 21 are arranged substantially in parallel with a certain interval. Between the left and right side walls 21, a link mechanism 6 for connecting the backrest 4 and the front portion of the seat 5 and a reaction force spring 3 for urging the backrest 4 in the normal posture (A) direction are arranged. There is.

The left and right side walls 21 are provided with a spindle holding hole 21a that can rotatably hold the spindle J1 extending in the left-right direction provided at the base end portion c of the backrest 4. The spindle holding hole 21a is provided in the upper part of the rear portion of the left and right side walls 21.

The left and right side walls 21 are provided with a support shaft holding hole 21b capable of holding the support shaft S pierced by the front link member 61 before the main shaft holding hole 21a. The support shaft holding holes 21b are provided at substantially the same height as the main shaft holding holes 21a on the left and right side walls 21. The support shaft S extends in the left-right direction and is erected between the left and right side walls 21.

The upper end edge of the front portion of the left and right side walls 21 forms a portion where the lower surface of the seat 5 can come into contact with the seat 5 when the seat 5 is in the forward leaning posture (H). That is, the upper end edge of the front portion of the left and right side walls 21 is a movement restricting portion 21c capable of positioning the forward leaning posture (H) of the seat 5. In other words, the support base portion 2 is provided with a movement restricting portion 21c that can engage with the seat 5 in the forward leaning posture (H).

The leg connecting portion 22 is made of metal having a rectangular block shape as a whole. A fitting hole 22a is formed in the central portion of the leg connecting portion 22 in the left-right direction so as to penetrate in the vertical direction into which the upper end portion of the leg support 11 is internally fitted. The leg connecting portion 22 is provided with an extension piece 22b that has a substantially horizontal plate shape and extends rearward. A receiving portion 24 that can be slidably engaged with the rear portion of the seat 5 is attached to the extension piece 22b.

The front connecting portion 23 is made of a metal mainly composed of a bottom wall 23a and a front wall 23b extending upward from the front end portion of the bottom wall 23a. On the bottom wall 23a of the front connecting portion 23, a front spring receiving portion 23c that can support the front end portion of the reaction force spring 3 is disposed.

The front spring receiving portion 23c supports the front spring holding member 32 constituting the reaction force spring 3. The front spring receiving portion 23c rotates the reaction force adjusting lever L to move the position of the spring receiving block 23d connected to the front spring holding member 32 in the front-rear direction to generate the reaction force of the reaction force spring 3. It is a known configuration that can be adjusted.

The receiving portion 24 can support the rear portion of the seat 5. The receiving portion 24 can support the rear portion of the seat 5 so as to be slidable in the front-rear direction in accordance with the locking operation of the backrest 4 and the seat 5. The receiving portion 24 is a portion where the sliding contact portion 52 provided at the rear portion of the seat 5 can be slidably contacted when the seat 5 is interlocked with the rotational movement (tilting movement in the front-rear direction) of the backrest 4. The receiving portion 24 is provided between the left and right back support arms 41 constituting the backrest 4 supported by the support base 2.

The receiving portion 24 has a horizontally long block shape and has a receiving portion main body 24a whose upper surface is a receiving surface m1 on which the sliding contact surface m2 of the sliding contact portion 52 can be slid into contact, and the receiving portion main body 24a is supported by the leg connecting portion 22. It is provided with the main body support portion 24b of the above.

A nut n1 is embedded in the receiving portion main body 24a. The receiving portion main body 24a is attached to the main body supporting portion 24b using a screw v1 that can be screwed to the nut n1.

In this embodiment, the left and right upright walls e1 constituting the lateral slip suppressing means E are integrally erected on the left and right side portions of the receiving portion main body 24a. The left and right upright walls e1 are portions that can engage with the side portion e2 of the sliding contact portion 52 formed on the seat 5 when the seat 5 shifts in the left-right direction from the desired position. That is, the left and right upright walls e1 can exert a function of suppressing the sliding contact portion 52 from shifting in the left-right direction with respect to the receiving portion 24.

In other words, the chair is provided with lateral displacement suppressing means E that can suppress the sliding contact portion 52 of the seat 5 from shifting in the left-right direction with respect to the receiving portion 24 of the support base 2. In this embodiment, the lateral displacement suppressing means E is erected on the side portion e2 of the sliding contact portion 52 projecting from the seat 5 and the receiving portion 24 of the support base portion 2, and the sliding contact portion 52 is displaced in the left-right direction. In this case, it is mainly composed of an upright wall e1 that can engage with the side portion e2 of the sliding contact portion 52.

The main body support portion 24b is made of metal and is rigidly connected to the leg connection portion 22. The main body support portion 24b is connected to the left and right upright walls k1 attached to the extension piece 22b of the leg connection portion 22 and the upper end edges of the left and right upright walls k1 forming a horizontal plate extending in the left-right direction. It is provided with a horizontal wall k2 and a front wall k3 extending downward from the front end edge of the horizontal wall k2 and connected to the front end edge of the upright wall k1. The receiving portion main body 24a is mounted on the horizontal wall k2 and is fixed by the screw v1.

The backrest 4 is rotatably supported with respect to the support base 2 via the spindle J1 and is urged in the normal posture (A) direction by the reaction force spring 3. The backrest 4 can take a backward leaning posture (B) by receiving a load from a user or the like and leaning backward against the urging force of the reaction force spring 3.

The backrest 4 includes a backrest main body (not shown) and a back frame 4a capable of supporting the backrest main body.

The backrest body (not shown) has a backrest surface that can come into contact with the back of the user. The backrest main body is supported by the support base 2 via the back frame 4a.

The back frame 4a includes left and right back support arms 41 arranged in pairs on the left and right, and a connecting plate 42 connecting the upper portions of the left and right back support arms 41.

The left and right back support arms 41 are rotatably supported with respect to the support base 2 via the main shaft J1. A spindle J1 extending in the left-right direction is rigidly connected to the base end portions c of the left and right back support arms 41 by welding.

The left and right back support arms 41 extend substantially horizontally in the front-rear direction in the normal posture (A), and have a horizontal arm portion 41a having a base end portion c for holding the main axis J1 at the front end portion, and a rear of the horizontal arm portion 41a. A rear arm portion 41b extending diagonally rearward and upward from the end portion to which the connecting plate 42 is connected, and a rear link member extending diagonally forward and downwardly from the front end portion of the horizontal arm portion 41a via a shaft-shaped connecting member r. It is provided with a front arm portion 41c connected to 62.

The lower end edge of the horizontal arm portion 41a is provided with a contact portion t capable of contacting the shock absorber 22c arranged on the leg connection portion 22 in the support base portion 2 in the backward tilted posture (B). The main shaft J1 attached to the base end portion c of the horizontal arm portion 41a projects outward, and the protruding portion is held by the main shaft holding hole 21a provided in the support base portion 2.

Between the left and right horizontal arm portions 41a in the normal posture (A), the receiving surface m1 of the receiving portion 24 provided on the support base 2 and the sliding contact surface m2 of the sliding contact portion 52 provided on the seat 5 are provided. It is designed to be located.

The front arm portion 41c plays a role of supporting the rear link member 62 constituting the link mechanism 6 so as to be able to rotate integrally with the back frame 4a.

More specifically, the upper end portion of the rear link member 62 arranged in pairs on the left and right is rigidly connected to the portion of the spindle J1 located between the left and right back support arms 41. Further, between the vertical intermediate portion of the left rear link member 62 and the lower portion of the left front arm portion 41c, and between the vertical intermediate portion of the right rear link member 62 and the lower portion of the right front arm portion 41c. The spaces are connected by a shaft-shaped connecting member r extending in the left-right direction.

A rear connecting shaft J4 that extends in the left-right direction and also serves as a rear spring receiving portion is supported at the lower end portions of the left and right rear link members 62.

The reaction force spring 3 capable of urging the backrest 4 in the normal posture (A) direction includes a spring main body 31 composed of a coil spring, a front spring holding member 32 mounted on the front portion of the spring main body 31, and a spring. It is provided with a spring holding member 33 after being mounted on the rear portion of the main body 31.

The front spring holding member 32, which is the front end portion of the reaction force spring 3, is supported by the front spring receiving portion 23c arranged on the support base portion 2. The rear spring holding member 33, which is the rear end portion of the reaction force spring 3, operates integrally with the backrest 4 and is supported by the rear connecting shaft J4, which is the rear spring receiving portion provided below the main shaft J1. ing. That is, the urging force of the reaction force spring 3 is transmitted to the backrest 4 via the rear connecting shaft J4, the rear link member 62, the main shaft J, and the connecting member r.

Next, the seat 5 will be described. In the figure, the seat 5 is shown schematically for convenience of explanation.

The seat 5 is a slide that is projected from the lower surface side of the rear portion of the seat body 51 and has a seating surface on the upper surface, and can be slidably contacted with the receiving portion 24 of the support base 2 as the backrest 4 rotates. Left and right shaft support portions that can rotatably support both ends of the seat support shaft J2 provided in pairs on the lower surface side of the front portion of the seat body 51 and the contact portion 52 and supported by the front link member 61. It is equipped with 53.

The seat body 51 is provided with a seating surface having a size that allows the seated person to sit.

The sliding contact portion 52 has a rectangular block shape that protrudes downward from the central portion in the left-right direction of the rear portion of the seat body 51. On the lower surface of the sliding contact portion 52, a sliding contact surface m2 capable of sliding contact with the receiving surface m1 of the receiving portion main body 24a facing upward is provided. The left and right side portions e2 of the sliding contact portion 52 constitute the lateral slip controlling means E.

The left and right shaft support portions 53 have bearing holes 53a capable of rotatably supporting both ends of the seat support shaft J2.

In this embodiment, the rear portion of the seat 5 is supported so as to be slidable in the front-rear direction with respect to the support base portion 2. That is, the rear portion of the seat 5 can slide in the front-rear direction with respect to the support base portion 2 in conjunction with the tilting motion in the front-rear direction of the backrest 4.

Further, in this embodiment, the rear portion of the seat 5 is configured to be vertically accessible and detachable from the support base portion 2. That is, the seat 5 is configured to be able to take a forward leaning posture (H) tilted forward from the normal posture (F) by rotating around the seat support shaft J2. When the seat 5 takes the forward leaning posture (H), the sliding contact portion 52 of the seat 5 is separated from the receiving portion 24 of the support base portion 2.

The link mechanism 6 is arranged between the left and right side walls 21 of the support base 2. The link mechanism 6 is connected to the left and right paired front link members 61 rotatably supported by the support base 2 via the support shaft S, and the backrest 4 via the spindle J1 and the connecting member r. A pair of left and right rear link members 62 provided so as to be able to rotate integrally with the backrest 4, and a rear end portion that can rotate with respect to the lower end portion of the rear link member 62 via a rear connecting shaft J4. The front end is rotatably connected to the lower end of the front link member 61 via the front connecting shaft J3, and the left and right paired intermediate link members 63 are provided.

In the normal posture (A), the left and right front link members 61 are formed in front of the support shaft support hole h2 capable of supporting the support shaft S and at substantially the same height position as the support shaft support hole h2. It has a seat support shaft support hole h1 that can support the shaft J2 and a front connecting shaft support hole h3 that is below the support shaft support hole h2 and is formed at substantially the same front-rear position and can support the front connecting shaft J3. Is.

The front link member 61 has a shape similar to a triangle in a side view, and the support shaft support hole h2, the seat support shaft support hole h1, and the front connecting shaft support hole h3 are located at the three corners. ing. In other words, the left and right front link members 61 support the seat support shaft J2 extending in the left-right direction in front of the support shaft S, and support the front connecting shaft J3 below the support shaft S. are doing.

The left and right rear link members 62 extend in the vertical direction. A rear connecting shaft J4 that also serves as a rear spring receiving portion is supported at the lower end portion of the rear link member 62. A rear spring holding member 33 is connected to a portion of the rear connecting shaft J4 located between the left and right rear link members 62. The lower rear end edge of the rear link member 62 is in contact with the shock absorber 22d provided on the front surface of the leg connecting portion 22 of the support base portion 2 in the normal posture (F).

The intermediate link member 63 extends in the front-rear direction. The intermediate link member 63 is interposed between the rear link member 62 and the front link member 61.

Hereinafter, the operation of the chair shown in the present embodiment will be described with reference to FIGS. 1 to 6.

As shown in FIGS. 1 and 2, when the seated person is not leaning on the backrest 4, the backrest 4 is in the normal posture (A). That is, the backrest 4 can take a normal posture (A) by receiving the urging force of the reaction force spring 3 arranged in the support base portion 2.

More specifically, the urging force of the reaction force spring 3 is transmitted to the backrest 4 via the rear connecting shaft J4 that also serves as the rear spring receiving portion, the rear link member 62, the main shaft J1, and the connecting member r. The backrest body is urged to move forward.

When the backrest 4 receives a load from a seated person or the like and tilts backward from this state, the reaction force spring 3 is pressed forward by the rear connecting shaft J4 that also serves as the rear spring receiving portion, as shown in FIGS. 3 and 4. It will be compressed with the previous spring receiving portion 23c. At the same time, the link mechanism 6 that can be interlocked with the backrest 4 is adapted to rotate the front link member 61 so that the seat support shaft J2 can move upward and backward.

More specifically, when the backrest 4 tilts backward around the main shaft J1, the lower end portion of the rear link member 62 which is arranged below the main shaft J1 and operates integrally with the backrest 4 moves forward. Then, the intermediate link member 63 connected to the lower end of the rear link member 62 via the rear connecting shaft J4 moves forward. Further, the front link member 61 connected to the front end of the intermediate link member 63 via the front connecting shaft J3 rotates around the support shaft S, so that the seat support shaft J2 supported by the front link member 61 is moved upward and backward. Will be pushed up to.

The seat 5 pivotally supported by the seat support shaft J2 gradually shifts to the backward leaning posture (G) so that the front side is positioned above the rear side as the seat support shaft J2 moves upward and backward. To go. Along with this transition of the seat 5, the sliding contact portion 52 provided on the rear portion of the seat 5 and placed on the receiving portion 24 of the support base 2 moves backward, and the receiving surface of the receiving portion 24 The sliding contact surface m2 of the sliding contact portion 52 is in sliding contact with m1.

Through the above operation, the backrest 4 changes its posture from the normal posture (A) to the backward leaning posture (B), and the seat 5 interlocks to change the posture from the normal posture (F) to the backward leaning posture (G). Posture. When the load for tilting the backrest 4 backward is released, the backrest 4 returns to the normal posture (A) through the reverse movement described above due to the elastic urging force of the reaction force spring 3. ..

The seat 5 of the chair in this embodiment is pivotally connected to only one seat support shaft J2 supported by the front link member 61 of the link mechanism 6, and the rear portion of the seat 5 is simply a support base. It is placed on top of 2. Therefore, as shown in FIGS. 5 and 6, when the seated person applies a load only to the front end portion of the seat 5, the rear portion of the seat 5 is flipped upward and the seat 5 shifts to the forward leaning posture (H). It is designed to be able to be made to.

Specifically, when the seated person loads downward with respect to the portion of the seat 5 located in front of the seat support shaft J2, the seat 5 rotates forward around the seat support shaft J2. Along with this, the sliding contact portion 52 provided at the rear portion of the seat 5 is supported from the state of being placed on the receiving portion 24 of the support base 2 (the state of being in contact with the receiving surface m1 of the receiving portion 24). The transition is made to a state away from the receiving surface m1 of the receiving portion 24 in the base portion 2.

When the seat 5 tilts forward within a certain range, the lower surface of the seat 5 in front of the seat support shaft J2 abuts on the movement restricting portion 21c of the support base 2, and the seat 5 tilts forward with the seat 5 set to a predetermined forward tilt degree. It is positioned in the posture (H). If the seated person releases the downward pressure on the portion of the seat 5 located in front of the seat support shaft J2, the seat 5 returns from the forward leaning posture (H) to the normal posture (F) due to its own weight. It has become like.

As described above, the chair according to the present embodiment has a support base 2, a seat 5 arranged on the support base 2, and a normal posture (A) and a normal posture (A) with respect to the support base 2. The backrest 4 rotatably supported between the backward tilted posture (B) and the front link member 61 capable of rotatably supporting the front portion of the seat 5 via the seat support shaft J2. It is provided with a link mechanism 6 which can be interlocked with the rotational operation of the backrest 4 including the above. The rear portion of the seat 5 is supported so as to be slidably movable in the front-rear direction with respect to the support base portion 2.

Therefore, it is possible to provide a chair having an excellent degree of freedom in design, which has a structure in which the backrest 4 and the seat 5 can be interlocked with each other, and the support base 2 and the seat 5 can be easily separated from each other. Become.

That is, the rear portion of the seat 5 is supported so as to be slidably movable in the front-rear direction with respect to the support base portion 2. Therefore, the seat 5 can be interlocked with the rotational movement of the backrest 4 without forming an upwardly extending protrusion that pivotally supports the rear portion of the seat 5 on the backrest 4, so that the support base 2 can be linked. It is possible to flexibly design a configuration in which the seat 5 and the seat 5 are difficult to be separated excessively.

Further, since the rear portion of the seat 5 is supported so as to be slidable and movable in the front-rear direction with respect to the support base portion 2, the front portion of the seat 5 is pulled forward in accordance with the conventional locking mechanism configuration. At the same time, since the phenomenon that the rear of the seat 5 is pulled backward (so-called crotch tearing phenomenon) does not occur, the seat 5 can be configured without setting the strength excessively.

The rear portion of the seat 5 is configured to be vertically accessible and detachable from the support base portion 2.

Therefore, it is easy to design a configuration that allows the seat 5 to take a forward leaning posture (H).

A front link member 61 rotatably supported by the support base 2 via a support shaft S, and a rear link member 62 provided so that the link mechanism 6 can operate integrally with the backrest 4. An intermediate link whose rear end is rotatably connected to the rear link member 62 via the rear connecting shaft J4 and whose front end is rotatably connected to the front link member 61 via the front connecting shaft J3. It is provided with a member 63.

Therefore, the tilting motion of the backrest 4 is suitably transmitted to the front link member 61 holding the seat support shaft J2, and the rear portion of the seat 5 can slide in the front-rear direction with respect to the support base 2. Can be suitably realized.

The front link member 61 can support the seat support shaft J2 in front of the support shaft S, and can support the front connecting shaft J3 below the support shaft S.

Therefore, the seat support shaft J2 can move in a suitable direction with the backward tilting motion of the backrest 4.

The backrest 4 is rotatably supported with respect to the support base 2 via the spindle J1 and is urged in the normal posture (A) direction by the reaction force spring 3. The front end portion of the reaction force spring 3 is supported by the front spring receiving portion 23c disposed on the support base portion 2, and the rear end portion of the reaction force spring 3 is integrally with the backrest 4. It operates and is supported by a rear connecting shaft J4 which is a spring receiving portion after being provided below the spindle J1.

Therefore, the backrest 4 can appropriately take the normal posture (A) by the urging force of the reaction force spring 3.

Moreover, the load of the seated person applied to the seat 5 when the backrest 4 is tilted backward is mainly transmitted directly from the rear portion of the seat 5 to the support base portion 2. Therefore, the load of the seated person received by the backrest 4 when the backward leaning posture (B) is taken is greatly reduced as compared with the conventional example.

As a result, the load applied to the back frame 4a is reduced, so that the strength required for the back frame 4a can be set relatively small, which contributes to the reduction of manufacturing cost.

The seat 5 is configured to be able to take a forward leaning posture (H) leaning forward from the normal posture (F) by rotating around the seat support shaft J2, and leans forward on the support base 2. A movement restricting portion 21c that can engage with the seat 5 in the posture (H) is provided.

Therefore, the seat 5 can take a forward leaning posture (H) without adopting a complicated configuration. Further, since the movement restricting portion 21c is provided on the support base portion 2, the seat 5 can be appropriately positioned in the forward leaning posture (H).

A sliding contact portion 52 that can be slidably contacted with the support base portion 2 is provided at the rear portion of the seat 5 as the backrest 4 rotates, and a receiving portion 24 that can be slidably contacted with the support base portion 2 is provided. Is provided.

Therefore, it is possible to preferably realize a configuration in which the rear portion of the seat 5 and the support base portion 2 can slide and move in the front-rear direction as the backrest 4 rotates.

A lateral displacement suppressing means E that can suppress the sliding contact portion 52 from shifting in the left-right direction with respect to the receiving portion 24 is provided.

For this reason, the seat 5 is appropriately suppressed from shifting in the left-right direction, and the seat 5 is preferably moved back and forth in conjunction with the rotational movement of the backrest 4.

The lateral displacement suppressing means E is provided with an upright wall e1 that is erected on the receiving portion 24 and can engage with the sliding contact portion 52 when the sliding contact portion 52 shifts in the left-right direction.

For this reason, the relatively simple structure makes it possible to realize a function in which the seat 5 is displaced in the left-right direction and is difficult to move.

The present invention is not limited to the embodiment described in detail above.

As for the specific configuration of the support base, the seat, and the backrest constituting the chair, an appropriate form can be adopted without departing from the spirit of the present invention.

For example, even if a guide groove is provided in either the support base portion or the rear portion of the seat, and a guided member (for example, a shaft-shaped member or the like) guided by the guide groove is provided in the other. good.

The guide groove includes, for example, a first guide groove component portion that extends in the front-rear direction and in which the guided member is engaged when the seat operates between the normal posture and the backward tilted posture, and extends in the vertical direction. It can be mentioned that the seat has a substantially L-shape including a second guide groove component to which the guided member is engaged when the seat operates between the normal posture and the forward leaning posture.

In such a case, the seat can be set to take a forward leaning posture only when the backrest is in a normal posture. In other words, by providing a configuration in which the guided member is guided to a substantially L-shaped guide groove between the support base and the seat, it is not prepared when the backrest is in a backward leaning posture. It is possible to prevent the seat from taking a forward leaning posture.

The link mechanism can be interlocked with the rotational movement of the backrest, and various configurations can be applied as long as it includes a front link member capable of rotatably supporting the front portion of the seat via the seat support shaft. Is something that can be done.

The lateral displacement suppressing means may be any as long as it can suppress the sliding contact portion of the seat from shifting in the left-right direction with respect to the receiving portion of the support base, and an appropriate configuration can be applied to the configuration.

In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

1 ... Leg 2 ... Support base 4 ... Backrest 5 ... Seat 6 ... Link mechanism 24 ... Receiving part 52 ... Sliding part

Claims (12)

A support base, a seat arranged on the support base, and a backrest rotatably supported between a normal posture and a backward tilted posture tilted backward from the normal posture with respect to the support base. A chair comprising a front link member capable of rotatably supporting the front portion of the seat via a seat support shaft and a link mechanism capable of interlocking with the rotational movement of the backrest.
A chair in which the rear portion of the seat is supported so as to be slidable in the front-rear direction with respect to the support base. The chair according to claim 1, wherein the rear portion of the seat is configured to be vertically accessible and detachable from the support base portion. The link mechanism is rotatably supported by the support base via a support shaft, the front link member, the rear link member provided so as to be able to operate integrally with the backrest, and the rear end. The portion is rotatably connected to the rear link member via the rear connecting shaft, and the front end portion is provided with an intermediate link member rotatably connected to the front link member via the front connecting shaft. The chair according to claim 1 or 2. The third aspect of claim 3, wherein the front link member can support the seat support shaft in front of the support shaft and can support the front connecting shaft below the support shaft. Chair. The backrest is rotatably supported with respect to the support base via a spindle, and is urged in the direction of the normal posture by a reaction force spring.
The front end portion of the reaction force spring is supported by the front spring receiving portion disposed on the support base portion.
Claims 1, 2, 3, 4 or the rear end portion of the reaction force spring operates integrally with the backrest and is supported by a spring receiving portion after being provided below the main shaft. The chair described in 5. The seat is configured to be able to take a forward leaning posture that is tilted forward from the normal posture by rotating around the seat support shaft.
The chair according to claim 1, 2, 3, 4 or 5, wherein the support base is provided with a movement restricting portion that can engage with the seat in the forward leaning posture. A sliding contact portion that can be slidably contacted with the support base portion is provided at the rear portion of the seat.
The chair according to claim 1, 2, 3, 4, 5 or 6, wherein the support base is provided with a receiving portion through which the sliding contact portion can be slidably contacted. The chair according to claim 7, wherein the chair is provided with a lateral displacement suppressing means capable of suppressing the sliding contact portion from shifting in the left-right direction with respect to the receiving portion. The chair according to claim 8, wherein the lateral displacement suppressing means is provided with an upright wall that is erected on the receiving portion and can engage with the sliding contact portion when the sliding contact portion is displaced in the left-right direction. The chair according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, which is configured so that the seat can be tilted backward in conjunction with the backward tilting motion of the backrest. Claims 1, 2, 3, 4 provided with a guide groove provided in either one of the support base portion and the rear portion of the seat, and a guided member provided in the other and guided by the guide groove. 5, 6, 7, 8, 9 or 10 The chair. The seat is configured to be able to take a forward leaning posture that is tilted forward from the normal posture by rotating around the seat support shaft.
The guide groove extends in the front-rear direction, and extends in the vertical direction with the first guide groove component with which the guided member is engaged when the seat operates between the normal posture and the backward tilted posture. The chair according to claim 11, further comprising a second guide groove component with which the guided member is engaged when the seat operates between the normal posture and the forward leaning posture.

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