JP2023064535A - Foldable chair - Google Patents

Abstract

To provide a foldable chair having a simple design and excellent support stability of a seat.SOLUTION: A chair comprises a seat 1, a leg device 2 and a backrest 3. The leg device 2 is a four-leg type having horizontal upper frames 6, and the rear parts of the left and right upper frames 6 are connected by a beam material 8. The upper frames 6 are hidden below the seat 1, and the seat 1 is rotatably connected to a support bracket 29 disposed in the beam material 8. The chair can be used anywhere without discomfort due to that a member for folding is not viewed in a state that the seat 1 is leaned, and a four-leg type design is simple. The front and back two parts of the seat 1 are supported by the left and right upper frames 6 in a state that both ends are supported so as to secure high support strength without using a member such as a reinforcement frame.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a chair that can be folded by raising the seat upward and rotating it (flip-up rotation).

Folding chairs are often used for meetings and lectures because they can be nested back and forth when the seats are raised, turned and folded. .

In a folding chair, a leg device for supporting a seat has left and right leg frames. It is often done. In this case, the entire leg frame is exposed to the left and right outside of the seat, and two front and rear beam members are attached to the left and right leg frames, and the seat is connected to the rear beam member to create a front seat. The seat is supported by the beam material of the part.

On the other hand, in Patent Documents 2 to 4, the leg frame body is formed in a side view gate type (U-shaped opening downward) composed of the front and rear legs and the upper frame connected to the upper end thereof, and the rear legs are formed upward. The rear end of the seat is connected to the support shaft connected to the left and right back supports, while the front parts of the left and right upper frames are connected with left and right longitudinal beams, and the beams are used to form the seat. supports the front of the

Japanese Patent No. 6436750 Japanese Patent No. 4719902 Japanese Patent No. 6076700 Japanese Patent No. 6443962

In Patent Document 1, since the left and right leg frame bodies are entirely exposed to the left and right outsides of the seat, the overall left and right width must be considerably larger than the left and right width of the seat, and for this reason, there is a problem that it cannot be made compact. be. In addition, because the leg frame is too conspicuous, the folding function is overly exposed, giving people an impression of being ostentatious. be.

On the other hand, in Patent Documents 2 to 4, the front part of the leg frame body is hidden under the seat, but the upward part provided at the rear part of the seat is connected to the inner surface of the back support, so the leg frame The rear part of the body and the back support protrude from the seat to the left and right, so that the width of the chair must be considerably larger than the width of the seat as in Patent Document 1. There is a problem that it cannot be made compact.

In addition, since the leg frame is conspicuous as in Patent Document 1, it is not possible to prevent the folding function from appearing too much and giving people an ostentatious impression.

The present invention has been made against the background of such a situation, and intends to disclose a four-legged folding chair which can be made compact without changing the seating area from the conventional one and which is excellent in design. It is.

The present invention includes various configurations, typical examples of which are specified in each claim. Of these, the invention of claim 1 is
``The seat is connected to the leg device so that it can be raised and rotated with its rear part as a fulcrum, and multiple seats can be nested back and forth in a folded state in which the seat is raised and rotated.''
In the basic configuration of
"The leg apparatus comprises left and right leg frames connected between the upper ends of the front and rear legs by a horizontal upper frame in the front-rear longitudinal direction, and left and right legs connecting the upper frames of the left and right leg frames only at the rear end portions. It has a long beam material and
It is configured.

The invention of claim 2 is, in claim 1,
"The upper frame is arranged so as not to protrude to the left and right outer sides of the seat, and the seat is tilted forward and supported at its left and right sides by the upper frame."
It is configured.

The invention of claim 3 is, in claim 1 or 2,
"The rear portion of the seat is rotatably connected to the beam member, and in the forward tilted state, the portion in front of the beam member is supported by the left and right upper frames in a state of being supported at both ends."
It is configured.

The invention of claim 4 is, in claim 3,
"The seat is connected to a support bracket projecting upwards from the beam."
It is configured. The upward projection specified in claim 4 means that the upper end of the bearing portion is higher than the beam member. Therefore, it includes both an attitude of projecting directly above the beam material when viewed from the side and an attitude of being inclined when viewed from the side.

The invention of claim 5 is, in claim 4,
"The support bracket is formed of a bar material and has a horizontal upper end, and the seat is connected to the horizontal part."
It is configured.

The invention of claim 6 is parallel to claim 1, and in the same basic configuration as claim 1,
"The leg device has left and right leg frame bodies to which horizontal upper frames are connected longitudinally between the upper ends of the front and rear legs, and the upper frames are entirely or mostly below the seat. It is arranged to be located in
The seat is tilted forward and supported by the left and right upper frames with both ends supported.”
It is configured.

According to the invention of claim 7, in any one of claims 1 to 6,
"The left and right hind legs are extended upward to form back supports, and the upper ends of the left and right supports are integrally connected."
It is configured.

According to the invention of claim 8, in any one of claims 2 to 7,
"The seat has an outer shell that is square-shaped in plan view and is open vertically and has left and right horizontally elongated parts, an inner shell that is attached to the outer shell from above, and a cushion material that is arranged on the upper surface of the inner shell. and
The outer shell is a strength member, and the horizontal front part is supported by the left and right upper frames.
It is configured.

In each of the inventions of the present application, the leg frame constituting the leg device has a roughly U-shaped opening downward when viewed from the side, and the rear portion of the seat is connected to the leg device. As in 7, it is easy to realize that most of the leg frame is hidden under the seat.

Therefore, it is possible to prevent the leg device from being exposed to the left and right outside of the seat. As a result, we were able to make the chair more compact while maintaining the functionality of the chair without reducing the seating area. realizable. In terms of design, it can present a simple appearance that blends in anywhere like a non-folding four-legged chair with a fixed seat.

In addition, if the upper frame of the leg frame is in a horizontal posture, in order to allow nesting, the left and right upper frames must be arranged in a V-shaped posture that spreads forward in plan view. The nesting pitch can be reduced because the material is connected only to the rear part of the upper frame. Therefore, the space can be effectively used for storage. In addition, it has a neat appearance even when it is folded.

In claim 2, the above-described compactness and design can be ensured. In addition, when the seat is tilted forward, the right and left sides are supported by the upper frame, which has the advantage of improving the stability of the seat when seated.

In addition, in each patent document, since the connection part of the seat also serves as a load support part, it must be a structure that secures both smooth rotation and strength, but in claim 2, the leg frame body Since the load of the seat can be supported, separating the connecting function and the supporting function has the advantage of improving the freedom of design of the connecting portion and ensuring smooth rotation.

Although it is possible to connect the seat to the leg frame by a member different from the beam material, the structure can be simplified by connecting the seat to the beam material as in claim 3. In this case, it is possible to connect the seat directly to the beam material, but if it is connected to a support bracket that protrudes upward as in claim 4, it has the advantage of increasing mounting accuracy and reducing the rotation fulcrum of the seat. Since it is high, there is an advantage that the seat can be folded to a height that does not interfere with nesting.

From the standpoint of the strength of the leg system, it is preferable to place the beams as far forward as possible while ensuring the necessary nesting pitch. Since the rotation fulcrum of the seat can be shifted backward while being placed forward, the nesting pitch can be made as small as possible by placing the seat in a folded state as far back as possible while ensuring the strength of the leg device. In addition, the seat can be easily raised and rotated without the rear edge of the seat coming into contact with the upper frame.

Various forms can be adopted for the support bracket, but if it is formed in a U-shape from a bar material such as a round bar as in claim 5, there is an advantage that the structure can be simplified while ensuring high strength. Another advantage is that the support bracket can be used to restrict the lateral movement of the seat.

Now, in a folding chair, the seat needs to be supported at two points in front and back when the seat is laid down and unfolded. are doing. Therefore, the entire beam material is exposed when the seat is folded, and it can be said that the simple design is lacking. In addition, since the beam member comes into direct contact with the seat, there is a concern that it may be necessary to provide a metal reinforcing frame as disclosed in Patent Documents 1 and 4.

On the other hand, in the invention of claim 6, since the seat is supported at both ends by the left and right upper frames, beam members for supporting the seat are not required. It can contribute to the improvement of marketability by presenting a nice appearance.

In addition, since the upper frame is positioned below the seat and the horizontal spacing between the upper frames is smaller than the horizontal width of the seat, the seat can be stably supported without special measures such as installing a metal reinforcing frame. can. Therefore, the required strength can be ensured while preventing the structure from becoming complicated.

As in claim 7, when the upper ends of the left and right back supports are integrally connected, the entire frame of the chair has a solid structure. , has the advantage of ensuring high strength.

The seat of a chair is often provided with an outer shell made of synthetic resin as a strength member, but in the eighth aspect of the invention, the outer shell is opened vertically, allowing bending of the seat and improving sitting comfort. At the same time, the front and rear horizontally long parts function as beams to ensure high strength. In addition, since the required strength can be secured, the material of the outer shell can be saved, which contributes to cost reduction.

In the folded state, the square-shaped outer shell is exposed and the inner shell can be seen through the opening. Therefore, for example, if a group of slits for promoting bending is formed in the inner shell, this can be visually recognized by a person. Therefore, it is possible to let people know that the cushioning property is excellent, and to improve marketability.

BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of the chair which concerns on embodiment, (A) is a perspective view of an expanded state, (B) is a perspective view of a folded state, (C) is a partial rear perspective view. (A) is a front view, (B) is a plan view, (C) is a bottom view, and (D) is a partially enlarged view of FIG. 1(B). It is an isolation|separation perspective view. (A) is a perspective view in which the seat and the cushioning material are separated, and (B) is a perspective view in which the cushioning material is turned over. (A) is an exploded perspective view showing the connection structure of the seat, (B) is a perspective view of the bearing portion, and (C) is a perspective view of the rear portion of the outer shell. (A) is a cross-sectional view taken along line VIA-VIA of FIG. 2(C), and (B) is a perspective view of the connecting portion of the seat with the beam material omitted. (A) is a sectional view seen from the VIIA-VIIA direction of FIG. 4(A), and (B) is a plan view showing a nesting state. It is a figure which shows other embodiment, (A) is a side view in the middle of nesting, (B) is a bottom view of a single chair, (C) is a partial perspective view of still another embodiment.

(1). Overview Next, embodiments of the present invention will be described with reference to the drawings. First, a first embodiment shown in FIGS. 1 to 7 will be described.

As shown in FIG. 1, the chair includes a seat 1, leg devices 2 supporting the seat, and a backrest 3. As shown in FIG. The leg device 2 includes left and right leg frames 7 in which horizontal upper frames 6 are connected between the upper ends of the front legs 4 and the rear legs 5, and the upper frames 6 of the left and right leg frames 7 are placed near the rear ends. The seat 1 is connected to the beam member 8 so as to be vertically rotatable.

The front legs 4 and the upper frame 6 are integrally formed by bending one metal pipe (steel pipe or aluminum pipe), and the rear end of the upper frame 6 is welded to the rear legs 5 . An upwardly extending back support 9 is formed integrally with the rear leg 5, and upper ends of the right and left back support 9 are integrally connected via a connecting rod 9a. The backrest 3 is made of plywood, resin, or the like, and is fixed to the back support 9 with two screws 10 on the top and bottom. In the case of the backrest 3 made of resin, as indicated by the dashed line in FIG. can be provided.

The left and right front legs 4 and the left and right rear legs 5 are inclined at a slight angle with respect to the vertical line so as to form a V shape in the front view. In addition, the front legs 4 and the rear legs 5 are inclined at a slight angle with respect to the vertical line so as to form a V shape when viewed from the side (the front legs 4 are inclined backward and the rear legs 5 are inclined forward). ing.). By making the space between the left and right front legs 4 wider than the space between the left and right rear legs 5, a plurality of chairs can be nested back and forth with the seat 1 raised and rotated. Therefore, the left and right upper frames 6 form a V-shaped posture that spreads forward in a plan view.

A horizontally turnable caster 11 is attached to the lower end of each leg 4,5. Accordingly, the lower ends of the legs 4, 5 are in a vertical position. Note that casters 11 are not essential. There is also a type equipped with synthetic resin or rubber grounding bodies instead of casters.

The chair of this embodiment includes a memo pad 12 as an optional item. As shown in FIG. 1B, the memo pad 12 is attached to a frame member 13 welded to the right upper frame 6 . The frame member 13 is bent like a crank and has a horizontal portion 13a at its upper end. As a result, the memo pad 12 is rotatable, and a U-shaped attitude holder 15 surrounding the bearing cap 14 from below is fixed to the horizontal portion 13a of the frame member 13 by welding.

Therefore, the memo pad 12 is held in a horizontal position by contacting the position holding body 15 with its lower surface. The vertically raised posture is maintained by a part of the memo pad 12 coming into contact with the upright portion of the frame member 13 . In addition, the horizontal portion 13a of the frame member 13 is inclined so as to be displaced leftward and rightward toward the front in a plan view. Therefore, as shown in FIG. 7(B), the chair having the memo pad 12 can be nested.

As shown in FIG. 2(C), the memo pad 12 is tilted in plan view (and bottom view) so that the distance from the backrest 3 widens as it moves away from the fulcrum in a horizontal position. there is Then, with the seat 1 and the memo table 12 laid down and unfolded, the user of the chair moves laterally from the side (left side) on which the memo table is not installed to sit or leave the seat. Since the space between the table 12 and the backrest 3 is widened toward the side where the person enters and exits, the memo table 12 is prevented from becoming an obstacle when the person laterally moves his or her body, and the person sits down or leaves the seat. can be performed smoothly.

In addition, since the memo pad 12 is located on the right side of the seated person, the user uses the notebook computer or the like with the body slightly twisted sideways. When the backrest 3 is tilted away from the backrest 3, the user's body and the memo pad 12 face each other, so that a person can use the notebook computer or the like in a natural posture, and there is an advantage that the notebook computer or the like can be easily used.

As one of the features of this embodiment, most of the left and right upper frames 6 are arranged below the seat 1, and the seat 1 is supported by the upper frame 6 of the . On the upper surface of the upper frame 6, a cushioning material (bumper member) 16 made of synthetic resin and having an arcuate cross section is fixed with front and rear screws 17 in order to soften the contact with the seat 1. .

The front end 16a of the cushioning material 16 is bent downward to cover the upper end of the front foot 4, and the rear end 16b of the cushioning material 16 is bent inward to cover the end of the beam material 8. As shown in FIG. Further, as shown in FIG. 4(B), groups of left and right ribs 18 that contact the upper frame 6 are formed in multiple pairs in the front and rear of the cushioning material 16 .

(2) Seat and its mounting structure As shown in FIG. A cushioning material 22 is provided on the upper surface of the cushioning material 21, and the cushioning material 22 is covered with a skin material. The inner shell 21 is formed with a large number of slits 23 extending in the front-rear direction and in an inclined posture in order to allow downward bending (swelling) due to the load caused by seating.

Although not shown in detail, the inner shell 21 is attached to the outer shell 20 by fitting engaging claws provided on the front, rear, left, and right sides into engagement holes of the outer shell 20 . Since the outer shell 20 has a large rectangular opening 24, a person can visually recognize the lower surface of the inner shell 21 through the opening 24 in the folded state. Therefore, a person can visually recognize the slit 23 of the inner shell 21 through the opening 24 in the folded state.

As clearly shown in FIG. 3, the outer shell 20 has a shallow tray shape having a wall portion forming an outer periphery and a wall portion forming an inner periphery. A number of extending reinforcing ribs 25 are formed. The seat 1 is supported by the left and right upper frames 6 in a state of being supported at both ends, but due to the presence of a group of reinforcing ribs 25, a large opening 24 and high support strength are ensured (the left and right outer shells 20 are It is hidden below the seat 1, and the small support span of the seat 1 also contributes to the high support strength.).

As shown in FIGS. 4 and 7(A), on the left and right sides of the rear leg 5, contact members 26 are mounted on the cushioning material 16. As shown in FIG. The contact member 26 is made of a soft material such as rubber or elastomer, and is pushed into a mounting hole 27 provided in the outer shell 20 as shown in FIG. 7(A). Further, inside the abutting member 26 located in the front part behind the outer shell 20, a vibration-preventing projection 28 protruding downward close to the cushioning material 16 is provided. As a result, the seat 1 can be prevented from swaying to the left and right even if the user shifts the body in the seated state.

The inner shell 21 and the cushion material 22 have a downwardly swollen shape (downwardly concaved shape) so as to wrap the buttocks of the seated person from below. form. Therefore, as can be understood from FIG. 4, the beam member 8 is curved so as to bulge downward following the shape of the lower surface of the outer shell 20 .

A U-shaped support bracket 29 having a horizontal support shaft 29a and left and right arm portions 29b tilted backward in a side view is fixed to the beam member 8 by welding. of the outer shell 20 are connected. The support bracket 29 is made of a round bar material, and the seat 1 rotates up and down with a support shaft 29a of the support bracket 29 as a fulcrum. The support bracket 29 tilts the arm portion 29b rearward in a side view so that the support shaft 29a is positioned behind the beam member 8. As shown in FIG.

As can be understood from FIGS. 2(C) and 4(A), the seat 1 and a portion near the rear end thereof are connected to the support shaft 29a. , the seat 1 can be raised and rotated without hitting the rear edge against the outer shell 20. - 特許庁

More specifically, when connecting the left and right outer shells 20 with the beam member 8, it is preferable to place the beam member 8 as far forward as possible in order to increase the strength of the leg device 2. When the bracket 29 is tilted backward in a side view, the beam material 8 is arranged as far forward as possible within the range where the necessary nesting pitch can be secured, and the rear end of the seat 1 is connected to the support shaft 29a to raise the seat 1. Allows rotation.

In this embodiment, since the support shaft 29a is inserted into the outer shell 20, the seat 1 can be tilted forward so that the lower surface of the seat 1 is close to the outer shell 20, and the stability of the seat 1 in use is improved. In addition, the height of the seat 1 can be lowered while the seat 1 is raised and rotated to improve running stability during movement. It is possible to enter the inside of the outer shell 20. - 特許庁

(3) Details of Connection Structure As shown in FIGS. 4 and 5, the seat 1 is connected to the support shaft 29a via an upper bearing cap 31 made of a metal plate and a lower bearing cap 32 made of synthetic resin. . The lower bearing cap 32 has a lateral width that fits between the left and right arm portions 29b of the support bracket 29 with a slight gap, while the upper bearing cap 31 has a lateral width that is considerably smaller than that of the lower bearing cap 32. The upper and lower bearing caps 31 and 32 sandwich the support shaft 29a in half from above and below.

The upper bearing cap 31 has flanges 31a and 31b on the front and rear of the portion surrounding the spindle 29a, and these flanges 31a and 31b overlap the lower bearing cap 32. The lower bearing cap 32 bulges downward and has a large number of ribs 33 formed therein. A square positioning hole 34a is formed in the rear flange 31b of the upper bearing cap 31, and a positioning protrusion 34b is formed in the lower bearing cap 32 to fit into the positioning hole 34a from below. The positioning protrusion 34b is formed by a group of ribs.

As shown in FIGS. 4 and 5, the outer shell 20 is formed with a recess 36 into which the bearing cap 32 is inserted. A relief hole 37 is provided to prevent interference with the protrusion 34b, and the lower bearing cap 32 overlaps the step surrounding the relief hole 37 with the upper bearing cap 31 interposed therebetween.

As shown in FIG. 5(A), the front portion of the lower bearing cap 32 is formed with three cylindrical portions 34c arranged side by side. 31 passes through the front flange 31a. As can be understood from FIG. 5A, the upward screws 38 are screwed into a pair of left and right female screw holes 38a provided in the outer shell 20. As shown in FIG. In the upper bearing cap 31, a through hole through which the upward screw 38 passes is denoted by reference numeral 38b. Although the female threaded hole 38a is shown tapped in the bearing outer shell 20, it is preferable to attach a nut such as a push nut or a plate-shaped nut to the outer shell 20. As shown in FIG.

Three upward screws 38 are arranged on the left and right, and two upward screws 38 at the left end and the right end are used to fasten the upper and lower bearing caps 31, 32 and the outer shell 20 together. It is used to temporarily hold the upper and lower bearing caps 31 and 32 to the support bracket 29. Accordingly, the front flange 31a of the upper bearing cap 31 is formed with a tapped hole 38c (see, for example, FIG. 6A) into which the intermediate upward screw 38 is screwed.

The rear portion of the lower bearing cap 32 is fastened together with the outer shell 20 and the upper bearing cap 31 by two downward screws 39 on the left and right sides shown in FIG. 5(C). Therefore, as shown in FIGS. 5A and 5B, the rear end portion of the outer shell 20 and the rear flange 31b of the upper bearing cap 31 are provided with screw insertion holes 40. As shown in FIGS. As shown in the right end of FIG. 5A, the lower bearing cap 32 has a pair of left and right female screw holes 41 into which downward screws 39 are screwed.

As clearly shown in FIG. 6(A), a C-shaped sleeve 42 is fitted to the support shaft 29a of the support bracket 29 and fixed with a screw 43. As shown in FIG. The sleeve 42 is for smooth rotation of the seat 1, and is made of a synthetic resin having a small coefficient of friction, such as POM resin. The sleeve 42 has a length shorter than the lateral length of the support shaft 29a, so the lower bearing cap 32 is formed with a first recess 46 in which the sleeve 42 is fitted so as not to be displaced laterally.

The first recesses 46 are formed in a group of ribs 33, and on the left and right outsides of the first recesses 46, second recesses surrounding the support shaft 29a from below are formed by notching the upper ends of the ribs 33 in an arc shape. 45 are formed. In this embodiment, the lower bearing cap 32 is held against the support bracket 29 so as not to shift left and right, so that the rear portion of the seat 1 is held so as not to shift left and right.

Furthermore, the bottom of the first recess 46 is formed with a third recess 47 in which an elastic cylinder 48 made of rubber or elastomer is fitted in a lying state. The elastic column 48 has both the function of a damper means that gives resistance to the rotation of the seat 1 and the function of a stopper that holds the seat 1 in a raised and rotated state. That is, since the seat 1 is rotated while the elastic cylinders 48 are compressed and deformed, a moderate resistance is applied to the rotation of the seat 1, and the seat 1 is tilted and rotated (deployed). halfway), it will not suddenly fall down with a bang even if you release your hand. Further, in the state of use in which it is tilted and rotated, as can be understood from FIG. 6, the elastic column 48 is compressed and deformed, so that rattling and floating can be prevented.

On the other hand, when the seat 1 is raised and rotated, the elastic column 48 is positioned at the cut portion of the sleeve 42 and restored. Therefore, in order to tilt and rotate the seat 1, a certain amount of force must be applied to the seat 1 to compress and deform the elastic column 48, so that the seat 1 is held in the raised state. Therefore, when the seat 1 is raised and rotated, the center of gravity can be positioned directly above the support shaft 29a or positioned in front of the support shaft (the seat 1 does not fall down due to its own weight).

If the seat surface hits the backrest 3 while the seat 1 is raised and rotated, the backrest 3 may be easily damaged or the upholstery of the seat 1 may be easily damaged. Therefore, it is preferable to keep the seat 1 in such a way that it does not hit the front surface of the backrest 3 . Regarding this point, in this embodiment, as shown in FIG. 6B (see also FIG. 5A), support brackets are provided on the left and right sides of the recess 36 in the outer shell 20 with the seat 1 raised. A stopper portion 49 against which the arm portion 29b of the seat 29 abuts is formed to regulate the raising and rotating posture of the seat 1. As shown in FIG.

As shown in FIG. 6(A) (see also FIG. 3), the rear end of the inner shell 21 is formed with a laterally elongate relief slot 50 into which the upper end of the upper bearing cap 31 is inserted. That is, by inserting the upper end of the upper bearing cap 31 into the inner shell 21, the support shaft 29a is arranged as high as possible.

(4).Summary The four-legged form of a chair with a fixed seat is the most popular form, and is used in various places. In this state, it has the appearance of such a popular chair, and does not look like a folding chair (members for folding are not exposed). Therefore, although it is a foldable chair, it does not have the "likeness of a foldable chair" and presents a simple and neat appearance.

And when the function of the folding type can be seen from the appearance, it may be too functional and not suitable for the environment or atmosphere depending on the place, but in this embodiment, the function as the folding type is outside when in use. Since it does not appear at all, it can be used in various places without any discomfort. Therefore, the commercial value can be improved.

In the unfolded state, the seat 1 is supported at both ends by the left and right upper frames 6, but since the space between the left and right upper frames 6 is narrower than the space between the left and right sides of the seat 1, it looks like a metal support frame. Even if the outer shell 20 is made of synthetic resin, the necessary support strength can be ensured by simply providing the reinforcing ribs 25 without requiring any special members. Therefore, it is also advantageous in terms of cost.

The advantages of arranging the beam material 8 at the rear part and the advantages of having the fulcrum of rotation of the seat 1 located inside the seat 1 have already been described. Although it is possible to place another beam member behind the illustrated beam member 8, in this case, it is necessary to bend it downward so as not to interfere with the raising and turning of the seat 1. Become.

When the outer shell 20 is formed into a rectangular loop structure (frame structure) as in the embodiment, the lower surface of the inner shell 21 can be seen through the opening 24 in the folded state, but many slits 23 are visible to the human eye. As a result, the bending function of the inner shell 21 is intuitively felt, unlike the simplicity of the unfolded state. In other words, the appearance is greatly different between the unfolded state and the folded state, which is rich in unexpectedness. Such novelty can improve commercial value. As already mentioned, the material can be saved.

In this embodiment, since the left and right back supports 9 are integrally connected at the upper end, even if the left and right upper frames 6 are connected with only one beam member 8, the robustness of the chair as a whole can be secured. . That is, when the upper ends of the left and right back supports 9 are integrally connected, the backrest 3 also serves as a reinforcing member, and the stability of the left and right back supports 9 can be significantly improved (in particular, the resistance to twisting in a plan view can be improved. Therefore, the left and right upper frames 6 are connected with two front and rear beam members 8, so that the left and right upper frames 6 are connected with only one beam member 8. Even so, high rigidity can be secured as the whole chair.

(5).Other Embodiments In the first embodiment, the upper frame 6 is in a horizontal posture with a constant height, but in the second embodiment shown in FIGS. A portion in front of the beam member 8 is inclined downward at a slight angle. Therefore, the left and right upper frames 6 can be nested while maintaining a parallel attitude. Since the upper frame 6 is slanted, a downward protrusion 51 that rests on the slanted portion of the upper frame 6 is provided at the front part of the seat 1 in order to hold the seat 1 in a predetermined posture.

For nesting, the left-right spacing of the front legs 4 and the left-right spacing of the rear legs 5 must be different. It is set to a dimension smaller than the left and right spacing of Nesting is possible even if the portion of the upper frame 6 in front of the beam member 8 is stepped down to form the upper frame 6 in a stepped shape when viewed from the side. Alternatively, the entire upper frame 6 may be tilted forward and downward.

In both of the above-described embodiments, the beam 8 is provided with the support bracket 29 facing obliquely upward. It is also possible to In this case, the fulcrum of rotation of the seat 1 is positioned below the lower surface of the seat.

The seat 1 does not necessarily have to be of the cushion type, and may be of a single structure made of resin or wood. On the other hand, although the backrest 3 of the embodiment has a single structure, a cushion material may be arranged on the front surface of the backrest 3 .

As a means for positioning the pivot point of the seat inside the seat, a plate-shaped bearing bracket which enters the outer shell 20 at the rear part of the upper frame 6 as shown in FIG. 8(C) as a third embodiment. 52 (preferably an inverted L shape in a side view with the upper end facing backward) may be projected, and a bearing rib provided inside the outer shell may be connected to the bearing bracket 52 with a pin 54 . Therefore, the outer shell 20 is formed with a slit 53 into which the bearing blanket 52 is inserted.

Further, the present invention can be embodied in various forms other than those described above. For example, the front and rear legs and the upper frame can be made of synthetic resin.

The present invention can be embodied in a folding chair. Therefore, it can be used industrially.

1 seat 2 leg device 3 backrest 4 front legs 5 rear legs 6 upper frame 7 leg frame body 8 beam material 9 back strut 16 cushioning material 20 outer shell 21 inner shell 23 slit 24 opening 29 support bracket 29a spindle 31 upper bearing cap 32 lower part bearing cap 42 sleeve

Claims (8)

A seat is connected to a leg device so that it can be raised and rotated with its rear portion as a fulcrum, and a plurality of chairs can be nested back and forth in a folded state in which the seat is raised and rotated,
The leg device includes left and right leg frames connected between the upper ends of the front and rear legs by a horizontal upper frame in the front-rear longitudinal direction, and left and right long legs connecting the upper frames of the left and right leg frames only at the rear ends. of beams and
folding chair. The upper frame is arranged so as not to protrude to the left and right outer sides of the seat, and the seat is supported by the upper frame at its left and right sides in a forward tilted state.
A folding chair according to claim 1. The rear portion of the seat is rotatably connected to the beam member, and in the forward tilted state, the portion in front of the beam member is supported by the left and right upper frames in a state of being supported at both ends.
A folding chair according to claim 1 or 2. The seat is connected to a support bracket projecting upward from the beam.
A folding chair according to claim 3. The support bracket is formed of a bar material and has a horizontal upper end, and the seat is connected to the horizontal portion.
A folding chair according to claim 4. A seat is connected to a leg device so that it can be raised and rotated with its rear portion as a fulcrum, and a plurality of chairs can be nested back and forth in a folded state in which the seat is raised and rotated,
The leg device has left and right leg frame bodies in which horizontal upper frames are connected in the front-rear direction between the upper ends of the front and rear legs, and the upper frames are entirely or mostly below the seat. are positioned so that
The seat is tilted forward and supported by the left and right upper frames in a state of being supported at both ends.
folding chair. The left and right hind legs extend upward to form back supports, and the upper ends of the left and right supports are integrally connected.
A folding chair according to any of claims 1-6. The seat has an outer shell that is square-shaped in a plan view and is open vertically and has left and right horizontally long portions, an inner shell that is attached to the outer shell from above, and a cushion material that is arranged on the upper surface of the inner shell. and
The outer shell is a strength member, and the horizontally elongated front part is supported by the left and right upper frames.
A folding chair according to any one of claims 2-7.

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