CHAIR SET AND OPTIONAL MEMBER

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Patent Application No. 2024-143116 filed on August 23, 2024 with the Japan Patent Office, the entire disclosure of which is incorporated herein by reference .

BACKGROUND

The present disclosure relates to a chair set and an optional member.

Japanese Unexamined Patent Application Publication No. 2024-55028 discloses a chair in which a container holding portion capable of holding a container, such as a plastic bottle, is attached to a support portion, which is fixed to a seat so as to be located in an area on the left and upper side of the seat. The container holding portion is rotationally moved between a first position, which is to the right of the support portion and overlaps with the seat in an up-down direction, and a second position, which is to the left of the support portion and does not overlap with the seat in the up-down direction, about a rotation axis, of the support portion, extending in a front-rear direction of the chair. The chair is stackable in the up-down direction when the container holding portion is in the second position.

SUMMARY

In the meantime, chairs formed to be stackable may have a wide variety of shapes depending on the environment in which they are used and/or the intended purpose. Moreover, in recent years, there has been a trend toward the desire to attach an optional member capable of holding a container, such as a plastic bottle, to the chairs of a wide variety of shapes. Therefore, there is a demand that the chairs can be stacked with the optional accessories attached thereto.

One aspect of the present disclosure is to provide a technology that enables the chairs to be stacked with the optional accessories attached thereto.

One aspect of the present disclosure is a chair set including a chair formed to be stackable and an optional member attached to the chair and capable of holding a given object. The optional member allows the given object to be put in and taken out of it along an axis extending in a substantially up-down direction of the chair. The optional member includes an upper portion, a lower portion, and a fixing portion. The upper portion includes at least portions arranged to face each other with the axis therebetween and forms an inlet/outlet through which the given object is put in and taken out. The lower portion is located below the upper portion. The lower portion is formed to cover at least one of a side surface or a bottom surface of the given object and also to be open at a front side and a rear side, in a front-rear direction of the chair, of a lower area below the upper portion. The fixing portion is formed to fix the upper portion and the lower portion to the chair. The chair is one of a first chair and a second chair. The optional member is one of a first optional member and a second optional member. In a stacked state in which the second chair is stacked on the first chair, the first optional member fixed to the first chair and the second optional member fixed to the second chair are stacked such that the upper portion of the second optional member partially overlaps above and with the first optional member and such that the lower portion of the second optional member overlaps with a front-side part of the first optional member.

In such a configuration, when the second chair is stacked on the first chair, the second optional member is also stacked on an upper-front side of the first optional member. This enables the chairs to be stacked with the respective optional accessories attached thereto.

In one aspect of the present disclosure, the chair may include a seat allowing a user of the chair to be seated thereon. A width of the upper portion in the substantially up-down direction may be smaller than a first chair pitch, in the substantially up-down direction, between the seat of the first chair and the seat of the second chair in the stacked state.

Such a configuration makes it possible to stack the chairs with the respective optional accessories attached thereto such that the height of the stack in the up-down direction is unchanged from that when the chairs alone with no optional accessories attached thereto are stacked. In other words, the multiple chairs can be stacked in the same manner in terms of the height in the up-down direction, regardless of the presence/absence of the optional accessories.

In one aspect of the present disclosure, the lower portion may include a bottom part and a side part. The bottom part extends in a left-right direction of the chair and is capable of supporting the bottom surface of the given object. The side part extends upward from at least one end, in the left-right direction, of the bottom part to be continuous with the upper portion.

Such a configuration allows the bottom surface and the side surface of the given object to be supported by the bottom part and the side part, thus making it possible to hold the given object more stable than in a configuration in which the lower portion includes only the bottom part or the side part.

In one aspect of the present disclosure, the side part may include an overlapping area that overlaps with a front-side part of the upper portion of the optional member stacked immediately below. A width, in the front-rear direction, of the side part in the overlapping area may be smaller than a second chair pitch, in the front-rear direction, between the seat of the first chair and the seat of the second chair in the stacked state.

Such a configuration makes it possible to stack the chairs with the respective optional accessories attached thereto such that the width of the stack in the front-rear direction is unchanged from that when the chairs alone with no optional accessories attached thereto are stacked. In other words, the multiple chairs can be stacked in the same manner in terms of the width in the front-rear direction, regardless of the presence/absence of the optional accessories.

In one aspect of the present disclosure, the bottom part may include a body and an extension. The extension is coplanar with the body and extends rearward from the body. The extension may be formed such that a width thereof, in the left-right direction, at at least its extending end is narrower than a width of the body in the left-right direction and such that the extension extends to a position where the extending end does not intersect with a plane connecting lower edges of front ends of the upper portions of the first optional member and the second optional member in the stacked state.

Such a configuration enables the bottom part to have a larger area for supporting the bottom surface of the given object while inhibiting the first optional member and the second optional member from affecting stacking of the first chair and the second chair.

In one aspect of the present disclosure, the chair may include a seat allowing a user of the chair to be seated thereon. The optional member may be arranged in an area on a front-lower side of the seat so as to overlap at least partially with the seat in the substantially up-down direction.

Such a configuration allows, in the stacked state, the first optional member attached to the first chair to be more likely to be located in an area below the seat of the second chair located above.

In one aspect of the present disclosure, the fixing portion may include a rotation axis extending in the substantially up-down direction. The optional member may be attached to the chair in a manner rotatable about the rotation axis so as to be moved between a storage position and a use position. The storage position may be a position in which, in the stacked state, the first optional member and the second optional member are stackable. The use position may be a position in which the optional member is capable of holding the given object and in which the optional member and the seat do not overlap with each other in the substantially up-down direction.

Such a configuration enables the optional member to be moved to the storage position to allow the chair with the optional member attached thereto to be stackable and also enables the optional member to be moved to the use position to improve the ease of taking the given object in and out.

One aspect of the present disclosure is an optional member attachable to a chair formed to be stackable. The optional member is capable of holding a given object and allows the given object to be put in and taken out of it along an axis extending in a substantially up-down direction of the chair. The optional member includes an upper portion, a lower portion, and a fixing portion. The upper portion includes at least portions arranged to face each other with the axis therebetween and forms an inlet/outlet through which the given object is put in and taken out. The lower portion is located below the upper portion. The lower portion is formed to cover at least one of a side surface or a bottom surface of the given object and also to be open at a front side and a rear side, in a front-rear direction of the chair, of a lower area below the upper portion. The fixing portion is formed to fix the upper portion and the lower portion to the chair. The optional member is one of a first optional member and a second optional member. The first optional member and the second optional member stacked on the first optional member are stacked such that the upper portion of the second optional member partially overlaps above and with the first optional member and such that the lower portion of the second optional member overlaps with a front-side part of the first optional member. A ratio of a dimension of the upper portion in the substantially up-down direction to a dimension of the optional member in the substantially up-down direction is 1/3 or less.

In such a configuration, the second optional member can be stacked on an upper-front side of the first optional member. Thus, when the respective optional accessories are attached to the corresponding chairs, the chairs can be stacked with the respective optional accessories attached thereto.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments of the present disclosure will be described hereinafter with reference to, as examples, the accompanying drawings, in which:

FIG. 1 is a front view showing a chair set;

FIG. 2 is a plan view showing the chair set;

FIG. 3 is a left side view showing multiple chairs in a stacked state;

FIG. 4A is an enlarged perspective view of an optional member in a storage position, as viewed from the left front side;

FIG. 4B is an enlarged perspective view of the optional member in a use position, as viewed from the left front side;

FIG. 5 is an enlarged perspective view of the optional member in the storage position, as viewed from the right rear side;

FIG. 6 is an enlarged perspective view of the optional member in the use position, as viewed from the right rear side;

FIG. 7A is a front view of the optional member;

FIG. 7B is a plan view of the optional member;

FIG. 7C is a bottom view of the optional member;

FIG. 7D is a right side view of the optional member;

FIG. 7E is a left side view of the optional member;

FIG. 7F is a rear view of the optional member;

FIG. 8 is a perspective view showing multiple chair sets in a stacked state;

FIG. 9 is a left side view showing multiple optional accessories in a stacked state;

FIG. 10A is a side view showing the multiple chair sets stacked on a chair cart and a loading height thereof;

FIG. 10B is a view showing a loading space in which the chair sets are stacked on the chair cart;

FIG. 11 is an enlarged perspective view of an optional member of a first modified example, in a storage position, fixed to the chair, as viewed from the right rear side;

FIG. 12 is an enlarged perspective view of the optional member of the first modified example, in a use position, fixed to the chair, as viewed from the right rear side;

FIG. 13 is a perspective view showing multiple chair sets with the optional accessories of the first modified example in a stacked state;

FIG. 14 is a perspective view showing a chair set of a second modified example;

FIG. 15 is a perspective view showing multiple chair sets shown in FIG. 14 in a stacked state;

FIG. 16 is a perspective view showing a chair set of a third modified example;

FIG. 17 is a perspective view showing multiple chair sets shown in FIG. 16 in a stacked state;

FIG. 18 is a perspective view showing a chair set of a fourth modified example;

FIG. 19 is a perspective view showing multiple chair sets shown in FIG. 18 in a stacked state;

FIG. 20 is a perspective view showing a chair set of a fifth modified example; and

FIG. 21 is a perspective view showing multiple chair sets shown in FIG. 20 in a stacked state.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[1. Configuration]

[1-1. Overall Configuration]

A chair set 1 shown in FIGS. 1 and 2 comprises a chair 2 and an optional member 3. FIGS. 1 and 2 show two chair sets 1 arranged alongside. In the present embodiment, the chair set 1 further comprises an optional-accessory attaching member 4. The optional member 3 is formed to be attachable to the chair 2 via the optional-accessory attaching member 4. In the present embodiment, the optional-accessory attaching member 4 is formed to be detachably attached to the chair 2, details of which will be described below. In the descriptions hereafter, an up-down direction, a front-rear direction, and a left-right direction are represented based on a user who is seated on the chair 2 in a normal manner.

[1-2. Chair]

As shown in FIGS. 1 and 2, the chair 2 comprises a right leg body 10, a left leg body 20, a coupling rod 30, a seat 40, and a backrest 50.

The right leg body 10 and the left leg body 20 are support bodies that are formed by bending and welding a tubular metal pipe and that support the seat 40 and the backrest 50.

The right leg body 10 is arranged on the lower right side of the seat 40 and comprises a right front leg 11, a right rear leg 12, and a right bottom rail 13. The right front leg 11 is located on the front side of the right leg body 10 and extends in the up-down direction. The right rear leg 12 is located on the rear side of the right leg body 10 and extends in the up-down direction. The right bottom rail 13 is located on the lower side of the right leg body 10 to couple a lower end of the right front leg 11 and a lower end of the right rear leg 12 to each other. The right bottom rail 13 is to be positioned along a floor surface on which the chair 2 is placed.

The left leg body 20 is arranged on the lower left side of the seat 40 and comprises a left front leg 21, a left rear leg 22, and a left bottom rail 23. The left front leg 21 is located on the front side of the left leg body 20 and extends in the up-down direction. The left rear leg 22 is located on the rear side of the left leg body 20 and extends in the up-down direction. The left bottom rail 23 is located on the lower side of the left leg body 20 to couple a lower end of the left front leg 21 and a lower end of the left rear leg 22 to each other. The left bottom rail 23 is to be positioned along the floor surface on which the chair 2 is placed.

The coupling rod 30 is a tubular metal pipe extending in the left-right direction from the right front leg 11 or the left front leg 21 of the chair 2 and couples the right front leg 11 and the left front leg 21 to each other.

The seat 40 is substantially rectangular and is formed to allow the user to be seated thereon.

The backrest 50 is substantially rectangular and is capable of supporting the back of the seated user.

As shown in FIG. 3, the chair 2 described above is formed to be stackable. “To stack” means to place one upon another neatly. In particular, “to stack” as used herein means to stack multiple chairs 2 so that the total volume of a space occupied by them is smaller than that occupied by the multiple chairs 2 not stacked. Specifically, as shown in FIGS. 1 and 2, the right leg body 10 and the left leg body 20 of the chair 2 are outwardly more spaced from each other as they extend downward, and the right leg body 10 and the left leg body 20 are formed such that the distance therebetween in the left-right direction is greater on the side where the right rear leg 12 and the left rear leg 22 are located than on the side where the right front leg 11 and the left front leg 21 are located. This makes it possible to stack the chairs 2 of the same shape.

In other words, “to stack” as used herein means to stack the multiple chairs 2 of the same shape with a pitch smaller than the height and the width of the chair 2. Specifically, another chair 2 is stacked on the chair 2 such that the seat 40 and the backrest 50 of such another chair 2 are stacked, respectively, above the seat 40 of the chair 2 and in front of the backrest 50 of the chair 2. Hereinafter, a state in which another chair 2 is stacked on the chair 2 is referred to as a stacked state. For convenience of description, the stacked chairs 2 are hereinafter also referred to individually, with the same reference numeral, as a first chair 2, a second chair 2, …, in order from below.

[1-3. Optional Accessory]

As shown in FIGS. 1, 2, 4A, and 4B, in the present embodiment, the optional member 3 is attached to the right front leg 11 and the coupling rod 30 of the chair 2 via the optional-accessory attaching member 4. The optional member 3 is attached to the chair 2 in a manner rotatable about a rotation axis B, of a fixing portion 33 to be described below, extending in a substantially up-down direction. The substantially up-down direction includes a vertical direction and a direction slightly inclined relative to the vertical direction. The substantially up-down direction is also a direction in which a given object 5 is put in and taken out of the optional member 3, as will be described below. Specifically, the optional member 3 rotates relative to the optional-accessory attaching member 4 attached to the chair 2 so as to be moved between a storage position shown by a solid line in FIG. 4A and a use position shown by an imaginary line (two-dot chain line) in FIG. 4A and also shown in FIG. 4B.

The storage position is a position in which, in the stacked state, the optional member 3 fixed to the first chair 2 and the optional member 3 fixed to the second chair 2 are stackable. For convenience of description, the stacked optional accessories 3 are hereinafter also referred to individually, with the same reference numeral, as a first optional member 3, a second optional member 3, …, in order from below.

The optional member 3 is capable of holding the given object 5 shown in FIG. 4B. In the present embodiment, the optional member 3 is a cup holder for holding a beverage container, such as a cup and a plastic bottle, which are examples of the given object 5. The use position described above is a position in which the optional member 3 can hold the given object 5.

In the present embodiment, the optional member 3 in the storage position is located in an area on the front-lower side of the seat 40 of the chair 2 so as to partially overlap with the seat 40 in the substantially up-down direction. The optional member 3 in the use position is located in an area frontward of the right front leg 11 of the chair 2 so as not to overlap with the seat 40 of the chair 2 in the substantially up-down direction and so as not to interfere with the chair 2 of another chair set 1 arranged adjacent to the subject chair 2.

As shown in FIGS. 5 and 6, the optional member 3 has an axis A extending in the substantially up-down direction. The optional member 3 shown in FIG. 5 is in the storage position, and the optional member 3 shown in FIG. 6 is in the use position. The optional member 3 is formed to allow the given object 5 to be put in and taken out of it along the axis A. As shown in FIGS. 4A to 7F, the optional member 3 comprises an upper portion 31, a lower portion 32, and the fixing portion 33. The optional member 3 shown in FIGS. 7A to 7F is in the storage position.

The upper portion 31 has a shape like a ring formed of a plate circumferentially extending about the axis A. The upper portion 31 is substantially cylindrical as an example, and its sectional shape perpendicular to the axis A is substantially circular. In the present embodiment, the axis A is a center axis passing through the center of the upper portion 31. The upper portion 31 is open in the substantially up-down direction to form an inlet/outlet for taking the given object 5 in and out.

The lower portion 32 is located below the upper portion 31. The lower portion 32 is formed to partially cover a side surface and a bottom surface of the given object 5, and is formed to be open at the front side and the rear side of a lower area S below the upper portion 31 shown in FIGS. 7D and 7E when the optional member 3 is in the storage position. For example, the optional member 3 has a shape as if the front side and the rear side of the lower area S have been cut out, and there exist spaces, where no member is present, on the front side and the rear side of the lower area S. In the present embodiment, the lower portion 32 comprises a bottom part 321 and two side parts 322.

The bottom part 321 has a plate-like shape and is located below the upper portion 31, spaced apart from the upper portion 31. The bottom part 321 extends in a direction perpendicular to the axis A so as to partially overlap with an area of the opening of the upper portion 31 as viewed from above. Specifically, the bottom part 321 extends in the left-right direction when the optional member 3 is in the storage position, and does not overlap with an area on the front side and on the rear side of the opening of the upper portion 31 as viewed from above. The bottom part 321 supports the bottom surface of the given object 5.

The bottom part 321 comprises a body 323 and an extension 324. The body 323 extends in the left-right direction when the optional member 3 is in the storage position and has a shape of a substantially rectangle with long sides extending in the left-right direction and short sides extending in the front-rear direction as viewed from above. The extension 324 is coplanar with the body 323 and projects rearward from the body 323. The extension 324 is formed such that the width of its extending end in the left-right direction is narrower than the width of the body 323 in the left-right direction. In the present embodiment, the extension 324 projects such that the width thereof in the left-right direction gradually becomes narrower toward the rear side from a rear end of the body 323 to have a substantially trapezoidal shape.

Each side part 322 has a plate-like shape and extends upward from a corresponding one of the ends, in the left-right direction, of the body 323 of the bottom part 321 to be continuous with the upper portion 31. That is, each side part 322 couples the upper portion 31 and the bottom part 321 to each other. The two side parts 322 face each other with the axis A therebetween and are located alongside in the left-right direction when the optional member 3 is in the storage position.

As shown in FIGS. 7A and 7F, the lower portion 32 is formed in a substantially U-shape as viewed in the front-rear direction. As shown in FIGS. 7D and 7E, the upper portion 31 and the lower portion 32 are arranged to have a substantially T-shape as viewed in the left-right direction. This results in a configuration in which the right side, the left side, and the lower side of the lower area S below the upper portion 31 are partially covered by the lower portion 32 and in which the front side and the rear side thereof are open.

The fixing portion 33 is a portion for fixing the upper portion 31 and the lower portion 32 to the chair 2. In the present embodiment, the fixing portion 33 extends, from a part of the side part 322 and a part of the upper portion 31 above it, which are located on the right side when the optional member 3 is in the storage position, in a direction substantially perpendicular to an outer surface of the side part 322, and an extending end of the fixing portion 33 is fixed to the optional-accessory attaching member 4. By attaching the optional-accessory attaching member 4 to the chair 2, the upper portion 31 and the lower portion 32 are fixed to the chair 2 via the fixing portion 33.

In the present embodiment, the fixing portion 33 has the rotation axis B, as described above. The fixing portion 33 contains, for example, a through-hole passing through the fixing portion 33 in the substantially up-down direction, and the optional-accessory attaching member 4 contains an insertion hole. The fixing portion 33 is fixed by means of a shaft pin or the like inserted from below into the through-hole and the insertion hole. The shaft pin penetrates through the fixing portion 33 in the substantially up-down direction to be inserted into the optional-accessory attaching member 4, thus functioning as the rotation axis B. This allows the fixing portion 33 to be fixed to the optional-accessory attaching member 4 in a manner rotatable about the rotation axis B.

[1-4. Optional-accessory Attaching Member]

The optional-accessory attaching member 4 is a member for attaching the optional member 3 to the chair 2. As shown in FIGS. 5 to 7F, the optional-accessory attaching member 4 comprises a first holding portion 41, a second holding portion 42, a coupling portion 43, and a lock portion 44.

The first holding portion 41 and the second holding portion 42 are portions for holding the chair 2.

In the present embodiment, the first holding portion 41 can hold the right front leg 11 of the chair 2. The first holding portion 41 has a plate-like shape extending in the substantially up-down direction and has a cross section, perpendicular to the substantially up-down direction, of a substantially U-shape. In other words, the first holding portion 41 covers a part of an outer circumferential surface of the right front leg 11 and has a shape opened rearward so as to allow the right front leg 11 to pass through the opening. Specifically, the first holding portion 41 holds the right front leg 11 so as to face the outer circumferential surface of the right front leg 11 from the front side, the left side, and the right side. The distance between an inner surface of a left-side wall and an inner surface of a right-side wall, which form the first holding portion 41, is substantially the same in length as an outer diameter of the right front leg 11 or slightly larger than the outer diameter of the right front leg 11. That is, the first holding portion 41 is formed such that the right front leg 11 fits snugly thereinside or such that the right front leg 11 is inserted with play thereinside.

In the present embodiment, the second holding portion 42 can hold the coupling rod 30 of the chair 2. The second holding portion 42 is located upward and leftward of the first holding portion 41. The second holding portion 42 has a plate-like shape extending in the left-right direction and has a cross section, perpendicular to the left-right direction, of a substantially U-shape. In other words, the second holding portion 42 covers a part of an outer circumferential surface of the coupling rod 30 and has a shape opened downward so as to allow the coupling rod 30 to pass through the opening. Specifically, the second holding portion 42 holds the coupling rod 30 so as to face the outer circumferential surface of the coupling rod 30 from the front side, the upper side, and the rear side. That is, the second holding portion 42 is formed to be hooked onto the coupling rod 30. The distance between an inner surface of a front-side wall and an inner surface of a rear-side wall, which form the second holding portion 42, is substantially the same in length as an outer diameter of the coupling rod 30 or slightly larger than the outer diameter of the coupling rod 30. That is, the second holding portion 42 is formed such that the coupling rod 30 fits snugly thereinside or such that the coupling rod 30 is inserted with play thereinside.

The coupling portion 43 is a portion that couples the first holding portion 41 and the second holding portion 42 to each other. In the present embodiment, the first holding portion 41 and the second holding portion 42 are fixed, for example, to a rear surface of the coupling portion 43 with a bolt or the like. The coupling portion 43 has a thickness in the front-rear direction and is formed to allow insertion thereinto, in the substantially up-down direction, of the shaft pin or the like functioning as the rotation axis B of the fixing portion 33 of the optional member 3. That is, the coupling portion 43 of the optional-accessory attaching member 4 is also a portion that fixes the fixing portion 33 in a manner rotatable about the rotation axis B. Arranged on the right side of the coupling portion 43 is the first holding portion 41, on the upper side is the second holding portion 42, and on the lower left side is the fixing portion 33. In the present embodiment, the coupling portion 43 has a shape as if its lower left part has been cut out in a substantially rectangular shape, and the fixing portion 33 is located in the cut-out part.

In the present embodiment, the lock portion 44 is configured to lock a position of the first holding portion 41 relative to the right front leg 11, a position of the second holding portion 42 relative to the coupling rod 30, and a position of the optional member 3 that is in the use position. The lock portion 44 comprises a first part 443 extending from a first end part 441 to a second end part 442 and a second part 444 extending frontward from the first end part 441, thus having a substantially L-shape. A substantially center part of the first part 443 is fixed, with a shaft pin 445, to the rear surface of the coupling portion 43 such that the lock portion 44 is located between the first holding portion 41 and the fixing portion 33 of the optional member 3 as viewed from the rear side. As shown in FIGS. 5 and 6, the shaft pin 445 functions as a rotation axis extending in the front-rear direction. The lock portion 44 is rotatable about the shaft pin 445 so as to be moved between an unlock position shown in FIG. 5 and a lock position shown in FIG. 6.

The unlock position is a position of the lock portion 44 at the time when the optional member 3 is in the storage position. In the unlock position, the first part 443 extends in the up-down direction and the second part 444 is located below the coupling portion 43 with a clearance from it. The lock position is a position of the lock portion 44 at the time when the optional member 3 is in the use position. In the lock position, the first part 443 extends in the left-right direction, and the second part 444 is located on the left side of the coupling portion 43 with the fixing portion 33 of the optional member 3 held between the second part 444 and the coupling portion 43.

When in the lock position, the lock portion 44 can close, with the second end part 442 of the first part 443, the opening of the first holding portion 41 on the rear side and can fix, with the second part 444, the position of the optional member 3 that is in the use position. Specifically, when the lock portion 44 is in the lock position, the right front leg 11 and the coupling rod 30 can be held firmly in the front-rear direction by the lock portion 44, the first holding portion 41, and the second holding portion 42. This makes it possible to fix a position of the optional-accessory attaching member 4 relative to the chair 2. Also, when the lock portion 44 is in the lock position, the fixing portion 33 of the optional member 3 in the use position can be held firmly in the left-right direction by the second part 444 and a part of the coupling portion 43. This makes it possible to fix a position of the optional member 3 relative to the optional-accessory attaching member 4 (i.e., to the chair 2).

[2. Steps for Attaching Optional-accessory Attaching Member to Chair]

Next, a description will be given of the steps for attaching the optional-accessory attaching member 4 with the optional member 3 fixed thereto to the chair 2 with reference to FIGS. 4A to 6.

First, the second holding portion 42 is positioned on the rear side of the coupling rod 30, and the coupling rod 30 is caused to pass through an open part of the second holding portion 42 such that an inner surface of an upper-side wall of the second holding portion 42 and the coupling rod 30 come in contact with each other, to thereby attach the second holding portion 42 to the coupling rod 30. At this time, the optional member 3 is in the storage position, the lock portion 44 is in the unlock position, and the first holding portion 41 is located substantially in front of the right front leg 11.

Next, the optional-accessory attaching member 4 is rotated downward about the coupling rod 30, and the right front leg 11 is caused to pass through an open part of the first holding portion 41 such that an inner surface of a front-side wall of the first holding portion 41 comes in contact with the right front leg 11, to thereby attach the first holding portion 41 to the right front leg 11. This allows the optional-accessory attaching member 4 with the optional member 3 fixed thereto to be attached to the chair 2 in a state shown in FIGS. 4A and 5.

Subsequently, as shown in FIG. 4A, the optional member 3 is moved from the storage position to the use position. Then, as shown in FIG. 6, the lock portion 44 is moved from the unlock position to the lock position. This causes the second end part 442 of the lock portion 44 to come in contact with the right front leg 11 from the rear side. At this time, the front-side wall of the first holding portion 41 and a front-side wall of the second holding portion 42 are respectively in contact with the right front leg 11 and the coupling rod 30 from the front side. Thus, the right front leg 11 and the coupling rod 30 are held firmly by the first holding portion 41, the second holding portion 42, and the lock portion 44, thus restricting the optional-accessory attaching member 4 from moving relative to the right front leg 11 and the coupling rod 30 in the front-rear direction, in the up-down direction, and in the left-right direction.

Also, the second part 444 of the lock portion 44 comes in contact with the fixing portion 33 of the optional member 3 from the left side. This causes the fixing portion 33 of the optional member 3 to be held firmly in the left-right direction by the second part 444 and a part of the coupling portion 43, thus restricting the optional member 3 from moving in a rotational direction about the rotation axis B. In this way, the optional member 3 in the use position is fixed to the chair 2 via the optional-accessory attaching member 4.

When the optional-accessory attaching member 4 with the optional member 3 fixed thereto is to be detached from the chair 2, the above-described steps are to be carried out in reverse. Specifically, the lock portion 44 is moved from the lock position to the unlock position. Next, the optional member 3 is moved from the use position to the storage position. Subsequently, the optional-accessory attaching member 4 is rotated upward about the coupling rod 30 to detach the first holding portion 41 from the right front leg 11. Lastly, the second holding portion 42 is moved rearward to detach the second holding portion 42 from the coupling rod 30. In this way, detachment of the optional-accessory attaching member 4 from the chair 2 is completed.

[3. Stacking of Chair Sets]

Next, stacking of the chair sets 1 will be described with reference to FIGS. 3, 8 and 9.

As shown in FIG. 8, the chair set 1 described above is formed to be stackable when the optional member 3 attached to the chair 2 via the optional-accessory attaching member 4 is in the storage position. That is, the chair 2 is stackable while the optional member 3 remains to be attached to the chair 2 via the optional-accessory attaching member 4. FIG. 9 shows a state in which the first to third optional accessories 3 are stacked, as an example, in the stacked state, although illustration of the stacked chairs 2 is omitted. The first to third optional accessories 3 are stackable also in a state in which they are detached from the chairs 2. Shown in FIG. 3 is a state in which the first to third chairs 2 alone are stacked.

In the stacked state in which the second chair 2 is stacked on the first chair 2, the first optional member 3 fixed to the first chair 2 and the second optional member 3 fixed to the second chair 2 are stacked in a state to be described here. When the first optional member 3 and the second optional member 3 in the storage position are in the stacked state, the upper portion 31 of the second optional member 3 partially overlaps above and with the first optional member 3, and the lower portion 32 of the second optional member 3 overlaps with a front-side part of the first optional member 3. In the present embodiment, the first optional member 3 and the second optional member 3 further overlap, in the stacked state, such that part of the upper portion 31 of the first optional member 3 frontward of the side parts 322 enters a space between the two side parts 322 of the second optional member 3. The third chair 2 and the third optional member 3, and the chair 2 and the optional member 3 to be further stacked are respectively stacked in a similar manner.

In the present embodiment, in the stacked state, as shown in FIG. 3, a first chair pitch WA1 and a first optional-accessory pitch WA2 have substantially the same value. Also, in the stacked state, a second chair pitch WB1 and a second optional-accessory pitch WB2 have substantially the same value.

The first chair pitch WA1 is a pitch (regular distance to be repeated) between the chairs 2 alone in the stacked state; specifically, the first chair pitch WA1 is a distance in the substantially up-down direction between the seat 40 of the first chair 2 and the seat 40 of the second chair 2 in the stacked state. As shown in FIG. 3, the first chair pitch WA1 is a distance in the substantially up-down direction between, for example, upper surfaces of the seats 40 of the respective chairs 2 in the stacked state. The second chair pitch WB1 is a pitch between the chairs 2 alone in the stacked state; specifically, the second chair pitch WB1 is a distance in the front-rear direction between the seat 40 of the first chair 2 and the seat 40 of the second chair 2 in the stacked state. As shown in FIG. 3, the second chair pitch WB1 is a distance in the front-rear direction between, for example, front ends of the seats 40 of the respective chairs 2 in the stacked state.

The first optional-accessory pitch WA2 is a distance in the substantially up-down direction between the bottom part 321 of the first optional member 3 and the bottom part 321 of the second optional member 3 in the stacked state. As shown in FIG. 9, the first optional-accessory pitch WA2 is a distance in the substantially up-down direction between, for example, lower surfaces of the bottom parts 321 of the respective optional accessories 3 in the stacked state. The second optional-accessory pitch WB2 is a distance in the front-rear direction between the bottom part 321 of the first optional member 3 and the bottom part 321 of the second optional member 3 in the stacked state. As shown in FIG. 9, the second optional-accessory pitch WB2 is a distance in the front-rear direction between, for example, front ends of the bottom parts 321 of the respective optional accessories 3 in the stacked state.

The above-described configuration makes it possible to stack the chairs 2 with the respective optional accessories 3 attached thereto such that the height in the up-down direction and the width in the front-rear direction of the stack are unchanged from those when the chairs 2 alone with no optional accessories 3 attached thereto are stacked.

In the present embodiment, in order for the chair sets 1 to be in the stacked state described above, the optional member 3 is formed so as to meet the conditions to be described here.

As shown in FIG. 9, the upper portion 31 of the optional member 3 is formed such that a width WA3 in the substantially up-down direction is smaller than the first chair pitch WA1. The side part 322 of the optional member 3 is formed such that a width WB3 in the front-rear direction in an overlapping area is smaller than the second chair pitch WB1. The overlapping area refers to an area, of the side part 322, that overlaps with a front-side part of the upper portion 31 of the optional member 3 stacked immediately below.

The extension 324 of the bottom part 321 of the optional member 3 is formed so as to extend to a position where its extending end does not intersect, in the stacked state, with a plane P1 connecting lower edges of front ends of the respective upper portions 31 of the first optional member 3 and the second optional member 3.

The ratio of the dimension of the upper portion 31 in the substantially up-down direction to the dimension of the optional member 3 in the substantially up-down direction is preferably 1/3 or less.

As shown in FIG. 10A, the chair sets 1 can be stacked and stored on a chair cart 6, which is used to store the stacked chairs 2 in the stacked state. As described above, when the optional accessories 3 are in the storage position, the chair sets 1 can be stacked such that the height in the up-down direction and the width in the front-rear direction of the stack are unchanged from those when the chairs 2 alone with no optional accessories 3 attached thereto are stacked. This enables the chair sets 1 to be stacked and stored on the chair cart 6 with the loading space and loading height that are the same as the loading space shown in FIG. 10B and the loading height in the case where the stacked chairs 2 alone are stacked on the chair cart 6.

[4. Effects]

The above-detailed embodiment produces the following effects:

(4a) In the present embodiment, in the stacked state, the first optional member 3 and the second optional member 3 in the storage position are stacked such that the upper portion 31 of the second optional member 3 partially overlaps above and with the first optional member 3 and such that the lower portion 32 of the second optional member 3 overlaps with the front-side part of the first optional member 3. Thus, when the second chair 2 is stacked on the first chair 2, the second optional member 3 is also stacked on an upper-front side of the first optional member 3. This enables the chairs 2 to be stacked with the respective optional accessories 3 attached thereto. As a result, it is not necessary to detach the optional accessories 3 when stacking and storing the chairs 2, thus enabling reduction in the time and effort required to detach the optional accessories 3.

(4b) In the present embodiment, since the lower portion 32 comprises the bottom part 321 and the side parts 322, the bottom surface and the side surface of the given object 5 are respectively supported by the bottom part 321 and the side parts 322. This makes it possible to hold the given object 5 more stable than in a configuration in which the lower portion comprises only the bottom part or the side parts.

(4c) In the present embodiment, the optional member 3 is formed such that the width WA3 of the upper portion 31 in the substantially up-down direction is smaller than the first chair pitch WA1 and such that the width WB3 of the side part 322 in the front-rear direction in the overlapping area is smaller than the second chair pitch WB1. Thus, the chairs 2 with the respective optional accessories 3 attached thereto can be stacked such that the height in the up-down direction and the width in the front-rear direction of the stack are unchanged from those when the chairs 2 alone with no optional accessories 3 attached thereto are stacked. That is, during stacking, the chairs 2 can be inhibited from being affected by the respective optional accessories 3.

(4d) In the present embodiment, the bottom part 321 of the optional member 3 comprises the body 323 and the extension 324, and the extension 324 is formed to extend to the position where its extending end does not intersect with the plane P1. This enables the bottom part 321 to have a larger area for supporting the bottom surface of the given object 5 while inhibiting the first optional member 3 and the second optional member 3 from affecting stacking of the first chair 2 and the second chair 2.

(4e) In the present embodiment, the optional member 3 in the storage position is located in an area on the front-lower side of the seat 40 of the chair 2 so as to partially overlap with the seat 40 in the substantially up-down direction. This allows, in the stacked state, the first optional member 3 attached to the first chair 2 to be more likely to be located in an area below the seat 40 of the second chair 2 located above. In other words, in the stacked state, the optional member 3 is less likely to jut out to an area outside the chair 2. This enables inhibition of an increase in the loading dimension when the chair sets 1 are stacked and stored on the chair cart 6.

(4f) In the present embodiment, the optional member 3 is formed to be rotatable, relative to the optional-accessory attaching member 4 attached to the chair 2, about the rotation axis B of the fixing portion 33 so as to be moved between the storage position and the use position. The optional member 3 in the use position is located in the area frontward of the right front leg 11 of the chair 2 so as not to overlap with the seat 40 of the chair 2 in the substantially up-down direction. This enables the optional member 3 to be moved to the storage position to allow the chair 2 with the optional member 3 attached thereto to be stackable and also enables the optional member 3 to be moved to the use position to improve the ease of taking the given object 5 in and out.

[5. Other Embodiments]

Although the embodiment of the present disclosure has been described so far, the present disclosure can take various forms without being limited to the above-described embodiment.

(5a) In the above-described embodiment, the upper portion 31 of the optional member 3 is substantially cylindrical (i.e., annular), and its sectional shape perpendicular to the axis A is substantially circular. However, the shape of the upper portion is not limited thereto. For example, the upper portion may be tubular with its sectional shape perpendicular to the axis A being substantially elliptical or substantially polygonal.

Alternatively, instead of being annular, for example, the upper portion may be formed to include portions located to face each other with the axis A therebetween so as to partially cover the side surface of the given object 5 circumferentially. Specifically, the upper portion may have a shape with a part partially opened circumferentially, such as a substantially C-shape, or may have a shape in which two arc-shaped members are arranged to face each other.

(5b) In the above-described embodiment, the optional member 3 is a cup holder for holding a beverage container, such as a cup and a plastic bottle, which are examples of the given object 5. However, for example, the optional member may be a small-item container that can hold therein a small item or the like used around the chair, which is one example of the given object.

(5c) In the above-described embodiment, the lower portion 32 comprises the bottom part 321 and the two side parts 322, and is formed in a substantially U-shape as viewed in the front-rear direction. However, the form of the lower portion is not limited thereto. For example, the lower portion may comprise the bottom part and a single side part, thus being formed in a substantially L-shape as viewed in the front-rear direction. In this case, the side part extends upward from one of the ends, in the left-right direction, of the bottom part to be continuous with the upper portion.

Alternatively, for example, the lower portion may comprise the side part alone that extends downward from the upper portion, that is, may be formed to include no bottom part. Alternatively, for example, the lower portion may comprise the bottom part alone, that is, may be formed to include no side part. In the case where the lower portion comprises the bottom part alone, the upper portion and the lower portion may be coupled to each other by the fixing portion.

(5d) In the above-described embodiment, the upper portion 31, the bottom part 321 and the side parts 322 of the optional member 3 are each formed of a plate-like member. However, for example, the upper portion, the bottom part, and the side parts may each be formed of a rod-like or wire-like member.

(5e) In the above-described embodiment, the upper portion 31 of the optional member 3 is formed such that the width WA3 in the substantially up-down direction is smaller than the first chair pitch WA1 so that the first chair pitch WA1 and the first optional-accessory pitch WA2 have substantially the same value in the stacked state. Also, the side part 322 of the optional member 3 is formed such that the width WB3 in the front-rear direction in the overlapping area is smaller than the second chair pitch WB1 so that the second chair pitch WB1 and the second optional-accessory pitch WB2 have substantially the same value in the stacked state. However, the first optional-accessory pitch WA2 and the second optional-accessory pitch WB2 relative to the first chair pitch WA1 and the second chair pitch WB1 in the stacked state, respectively, are not limited thereto.

For example, the upper portion of the optional member may be formed such that the width WA3 in the substantially up-down direction is substantially the same as or slightly larger than the first chair pitch WA1 so that only the first optional-accessory pitch WA2 is slightly larger than the first chair pitch WA1 in the stacked state. In this case, the height of the stack in the up-down direction is likely to be larger than that when the chairs 2 alone are stacked; however, the chairs 2 can be stacked with the respective optional accessories attached thereto.

Alternatively, for example, the side part of the optional member may be formed such that the width WB3 in the front-rear direction in the overlapping area is substantially the same as or slightly larger than the second chair pitch WB1 so that only the second optional-accessory pitch WB2 is slightly larger than the second chair pitch WB1 in the stacked state. In this case, the width of the stack in the front-rear direction is likely to be larger than that when the chairs 2 alone are stacked; however, the chairs 2 can be stacked with the respective optional accessories attached thereto.

Alternatively, for example, in the stacked state, the first optional-accessory pitch WA2 may be slightly larger than the first chair pitch WA1, and also the second optional-accessory pitch WB2 may be slightly larger than the second chair pitch WB1. In other words, in the stacked state, the upper portion of the optional member may be formed such that the width WA3 in the substantially up-down direction is substantially the same as or slightly larger than the first chair pitch WA1, and also the side part of the optional member may be formed such that the width WB3 in the front-rear direction in the overlapping area is substantially the same as or slightly larger than the second chair pitch WB1. In this case too, the chairs 2 can be stacked with the respective optional accessories attached thereto.

(5f) In the above-described embodiment, the bottom part 321 comprises the body 323 and the extension 324, and the extension 324 has a substantially trapezoidal shape. However, the shape of the extension is not limited thereto. For example, as another shape of the extension in which the width of its extending end in the left-right direction is smaller than the width of the body in the left-right direction, the extension may have a substantially triangular shape, a substantially semicircular shape, a rectangular shape with the width in the left-right direction entirely smaller than the width of the body in the left-right direction, or the like. Alternatively, for example, the bottom part may be formed to include the body alone, that is, may be formed to include no extension.

(5g) In the above-described embodiment, the optional member 3 in the storage position is located in the area on the front-lower side of the seat 40 of the chair 2 so as to partially overlap with the seat 40 in the substantially up-down direction. However, the location of the optional member in the storage position is not limited thereto. For example, the optional member in the storage position may be located in a position where the entirety thereof does not overlap with the seat 40 in the substantially up-down direction, or may be located so as to entirely overlap with the seat 40 of the chair 2 in the substantially up-down direction.

(5h) In the above-described embodiment, the optional member 3 is attachable to and detachable from the chair 2 via the optional-accessory attaching member 4 of a detachable type. However, for example, as shown in FIGS. 11 and 12, the optional member 3 of a first modified example may be fixed to the chair 2 via an optional-accessory attaching member 4a of a fixed type. The optional-accessory attaching member 4a may comprise the first holding portion 41, the second holding portion 42, the coupling portion 43, a lock portion 44a, and a rear wall portion 45. Since the first holding portion 41, the second holding portion 42, and the coupling portion 43 are formed similarly to those of the optional-accessory attaching member 4 of the above-described embodiment, the same reference numerals are used and the description is omitted.

The lock portion 44a is configured to lock a position of the optional member 3 that is in the use position. The lock portion 44a comprises a first part 443a extending from a first end part 441a to a second end part 442a and a second part 444a extending frontward from the first end part 441a, thus having a substantially L-shape. A part of the first part 443a near the second end part 442a is fixed, with a shaft pin 445a, to the rear surface of the coupling portion 43 such that the lock portion 44a is located between the first holding portion 41 and the fixing portion 33 of the optional member 3 as viewed from the rear side. The shaft pin 445a functions as a rotation axis extending in the front-rear direction. The lock portion 44a is rotatable about the shaft pin 445a so as to be moved between an unlock position shown in FIG. 11 and a lock position shown in FIG. 12. Similarly to the lock portion 44 of the above-described embodiment, when in the lock position, the lock portion 44a can fix, with the second part 444a, the position of the optional member 3 that is in the use position.

The rear wall portion 45 is a plate-shaped member that closes an opening behind the first holding portion 41 and that covers an area of the rear surface of the coupling portion 43 above the second end part 442a of the lock portion 44. Similarly to the optional-accessory attaching member 4 of the above-described embodiment, the rear wall portion 45 is fixed to the rear surface of the coupling portion 43 with a bolt or the like after the second holding portion 42 is attached to the coupling rod 30 and then the first holding portion 41 is attached to the right front leg 11. This enables the right front leg 11 and the coupling rod 30 to be held firmly in the front-rear direction by the rear wall portion 45, the first holding portion 41, and the second holding portion 42, thus fixing a position of the optional-accessory attaching member 4a relative to the chair 2. Thus, the optional member 3 of the first modified example is fixed to the chair 2 via the optional-accessory attaching member 4a so as to be unable to be detached easily.

In the case where the optional member 3 is fixed to the chair 2 via the optional-accessory attaching member 4a of a fixed type as described above, theft of the optional member 3 can be inhibited. Moreover, as shown in FIG. 13, chair sets 1a each including the chair 2, the optional member 3, and the optional-accessory attaching member 4a can also be stacked with the respective optional accessories 3 attached to the corresponding chairs 2, similarly to the chair sets 1 of the above-described embodiment.

(5i) In the above-described embodiment, the optional member 3 is rotatable, relative to the optional-accessory attaching member 4 attached to the chair 2, about the rotation axis B, of the fixing portion 33, extending in the substantially up-down direction. However, the optional member may be fixed so as not to be moved relative to the chair 2.

For example, as shown in FIG. 14, a chair set 1b of a second modified example may comprise the chair 2, an optional member 3b, and an optional-accessory attaching member 4b. The optional member 3b, in which a fixing portion 33b has no rotation axis, may be fixed so as not to be moved relative to the optional-accessory attaching member 4b attached to the chair 2. The optional member 3b comprises the upper portion 31, the lower portion 32, and the fixing portion 33b. Since the upper portion 31 and the lower portion 32 are formed similarly to those of the optional member 3 of the above-described embodiment, the same reference numerals are used and the description is omitted.

The fixing portion 33b extends rearward from the upper portion 31, and the extending end is fixed to the optional-accessory attaching member 4b. Further, the optional-accessory attaching member 4b is attached to the chair 2, thereby fixing the upper portion 31 and the lower portion 32 to the chair 2 via the fixing portion 33b.

The optional-accessory attaching member 4b comprises, for example, the first holding portion 41, the second holding portion 42, the coupling portion 43, and the rear wall portion 45, similarly to the optional-accessory attaching member 4a described above. The fixing portion 33b of the optional member 3b described above is fixed to a front surface of the coupling portion 43.

The optional member 3b is located in an area below and frontward of the seat 40 of the chair 2 so as not to overlap with the seat 40 in the substantially up-down direction. In this state, the optional member 3b is arranged such that the bottom part 321 of the lower portion 32 extends in the left-right direction. That is, the optional member 3b is fixed to the chair 2 so as to be capable of holding the given object 5 and so as to be stackable. Thus, as shown in FIG. 15, the chair sets 1b each including the optional member 3b and the optional-accessory attaching member 4b can be stacked with the respective optional accessories 3b attached to the corresponding chairs 2, similarly to the chair sets 1 and 1a described above.

(5j) In the above-described embodiment and the first modified example, the optional member 3 is attached to the right front leg 11 and the coupling rod 30 of the chair 2 via the optional-accessory attaching members 4 and 4a, respectively, and in the second modified example, the optional member 3b is attached to the right front leg 11 and the coupling rod 30 of the chair 2 via the optional-accessory attaching member 4b. However, the position at which the optional member is attached to the chair 2 and the method of attaching the optional member to the chair 2 are not limited thereto.

For example, the optional member may be attached to the left front leg 21 and the coupling rod 30 via the optional-accessory attaching member. In the case where the optional-accessory attaching member holds the left front leg 21 and the coupling rod 30, the optional-accessory attaching member is formed such that, in the above-described embodiment, the first holding portion 41, the lock portion 44, and the optional member 3 are mirror symmetrical relative to the coupling portion 43 of the optional-accessory attaching member 4, and in the first modified example, the first holding portion 41, the lock portion 44a, and the optional member 3 are mirror symmetrical relative to the coupling portion 43 of the optional-accessory attaching member 4a, and in the second modified example, the first holding portion 41, the lock portion 44, and the optional member 3b are mirror symmetrical relative to the coupling portion 43 of the optional-accessory attaching member 4b.

Alternatively, for example, as shown in FIG. 16, in a chair set 1c of a third modified example, an optional member 3c may be arranged in an area below and rearward of the seat 40 of the chair 2 so as not to overlap with the seat 40 in the substantially up-down direction and also may be fixed directly to the left leg body 20 of the chair 2.

Specifically, the chair set 1c comprises the chair 2 and the optional member 3c.

The optional member 3c comprises the upper portion 31, a lower portion 32c, and a fixing portion 33c. The lower portion 32c comprises a bottom part 321c and a single side part 322c, thus being formed in a substantially L-shape as viewed in the front-rear direction. The bottom part 321c is located below the upper portion 31 so as to be spaced apart from the upper portion 31 and extends in the left-right direction. The side part 322c extends upward from a left end of the bottom part 321c to be continuous with the upper portion 31. The fixing portion 33c is located on the right side of the upper portion 31 and extends forward from the upper portion 31, and its extending end is fixed to the left rear leg 22 of the left leg body 20.

As described above, the optional member 3c is located in the area below and rearward of the seat 40 of the chair 2 so as not to overlap with the seat 40 in the substantially up-down direction. In this state, the optional member 3c is arranged such that the bottom part 321c of the lower portion 32c extends in the left-right direction. That is, the optional member 3c is fixed to the chair 2 so as to be capable of holding the given object 5 and so as to be stackable. Thus, as shown in FIG. 17, the chair sets 1c each including the optional member 3c also can be stacked with the respective optional accessories 3c attached to the corresponding chairs 2, similarly to the chair sets 1, 1a, and 1b described above.

In the chair set 1c of the third modified example shown as an example, the optional member 3c is fixed to the left rear leg 22 in the left leg body 20 of the chair 2. However, for example, the optional member may be fixed to the right rear leg 12 in the right leg body 10 of the chair 2. In this case, the optional member is formed such that the upper portion 31 and the lower portion 32c are mirror symmetrical relative to the fixing portion 33c.

Alternatively, for example, as shown in FIG. 18, in a chair set 1d of a fourth modified example, the optional member 3c may be arranged in an area above and rearward of the seat 40 of the chair 2 so as not to overlap with the seat 40 in the substantially up-down direction and also may be fixed directly to the backrest 50 of the chair 2.

Specifically, the chair set 1d comprises the chair 2 and the optional member 3c. The fixing portion 33c of the optional member 3c is fixed to a left end of the backrest 50 via an extending end of the fixing portion 33c.

As described above, the optional member 3c is located in the area above and rearward of the seat 40 of the chair 2 so as not to overlap with the seat 40 in the substantially up-down direction. In this state, the optional member 3c is arranged such that the bottom part 321c of the lower portion 32c extends in the left-right direction. That is, the optional member 3c is fixed to the chair 2 so as to be capable of holding the given object 5 and so as to be stackable. Thus, as shown in FIG. 19, the chair sets 1d each including the optional member 3c also can be stacked with the respective optional accessories 3c attached to the corresponding chairs 2, similarly to the chair sets 1 and 1a to 1c described above.

In the chair set 1d of the fourth modified example shown as an example, the optional member 3c is fixed to the left end of the backrest 50 of the chair 2. However, for example, the optional member may be fixed to a right end of the backrest 50 of the chair 2. In this case, the optional member is formed such that the upper portion 31 and the lower portion 32c are mirror symmetrical relative to the fixing portion 33c.

Alternatively, for example, as shown in FIG. 20, in a chair set 1e of a fifth modified example, an optional member 3e may be directly provided to a front end of an armrest 60, which will be described below, of a chair 2e.

Specifically, the chair set 1e comprises the chair 2e and two optional accessories 3e. Similarly to the chair 2 described above, the chair 2e comprises the right leg body 10, the left leg body 20, the coupling rod 30, the seat 40, and the backrest 50, and further comprises two armrests 60. The chair 2e is formed to be stackable.

The respective armrests 60 are provided to the left leg body 20 and to the right leg body 10, and are arranged, respectively, in an area above and leftward of the seat 40 of the chair 2e and in an area above and rightward of the seat 40 so as not to overlap with the seat 40 in the substantially up-down direction. The armrests 60 each comprise a support part 61 and an elbow receiving part 62. The respective support parts 61 are provided to the left rear leg 22 of the left leg body 20 and to the right rear leg 12 of the right leg body 10 so as to extend upward. The respective elbow receiving parts 62 are provided to upper ends of the corresponding support parts 61 so as to extend forward and substantially horizontally.

The respective optional accessories 3e are each formed such that the upper portion 31 is continuous with an extending end of the elbow receiving part 62. In other words, a part of the upper portion 31 continuous with the elbow receiving part 62 functions as the fixing portion. The optional accessories 3e are each located at the extending end of the corresponding elbow receiving part 62 of the chair 2e so as not to overlap with the seat 40 of the chair 2e in the substantially up-down direction. In this state, the optional member 3e is arranged such that the bottom part 321 of the lower portion 32 extends in the left-right direction. That is, the optional member 3e is provided to the chair 2e so as to be capable of holding the given object 5 and so as to be stackable. Thus, as shown in FIG. 21, the chair sets 1e each including the optional member 3e also can be stacked with the respective optional accessories 3e attached to the corresponding chairs 2e, similarly to the chair sets 1 and 1a to 1d described above.

In the chair set 1e of the fifth modified example shown as an example, each optional member 3e is provided to the corresponding armrest 60. However, for example, the optional member 3e may be provided to one of the two armrests 60 alone. In this case, the armrest 60 not provided with the optional member 3e may or may not be present.

(5k) A function/functions that a single element in the above-described embodiments has may be implemented by a plurality of elements in a distributed manner, and a function/functions that a plurality of elements has may be implemented by a single element in an integrated manner. A portion of the configuration in the above-described embodiments may be omitted. At least a portion of the configuration in the above-described embodiments may be added to or replace the configuration in other embodiments.