Folding chair

Abstract

To provide a chair excellent in operability of folding and development with a simple structure, which can be nested.SOLUTION: A front leg rod 5 and a rear leg rod 6 have a truncated chevron-shape posture in a side view. An upper end of a rear leg part 4 is connected to an arm part 5a provided at an upper end of a front leg part 3. Middle height members of the front and rear leg parts 3 and 4 of a seat 1 are connected through a link device 10 consisting of front and back link materials 11 and 12, and the seat 1 is attached to the front link material 11. By making a lateral interval of the front leg rod 5 and a lateral interval of the rear leg rod 6 different from each other, nesting is enabled. When the rear end of the seat 1 is lifted, the front and rear leg parts 3 and 4 are folded into a posture crossed in an X shape, thereby enabling the chair to be nested back and forth while causing the chair to stand by itself.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a folding chair. [Background technology]

[0002] For example, chairs for conference rooms that need to be stored in a warehouse or in a corner of a room when not in use have been designed to be able to be stored in as small a space as possible. These designs include folding chairs and stackable chairs, including nesting chairs that can be stacked one on top of the other.

[0003] Nesting chairs often have a flip-up seat and different widths for the front and rear legs, allowing multiple chairs to be stacked one on top of the other (see, for example, Patent Document 1).

[0004] Although folding chairs can reduce the space required for storage by folding, they have the problem of being prone to tipping over because they are stored against a wall, etc. Also, because they must be lifted and moved by hand, there is the problem that storing them and arranging them for use is time-consuming (the folding and unfolding processes are also troublesome).

[0005] On the other hand, nesting chairs can be moved by holding the backrest with your hands and pushing or pulling it across the floor, which has the advantage of significantly reducing the effort required for storing them after use and preparing them before use.Nesting chairs are often equipped with casters so that they can always stand on the floor and be easily moved.

[0006] Nesting-type chairs have the advantages described above, but if the chairs can simply be flipped up, there is a limit to how closely the chairs can be spaced together when nested, which poses a problem in that there is a limit to how much storage space can be reduced.

[0007] In contrast to this, Patent Document 2 discloses a folding chair in which the front and rear legs are connected in an X-link fashion and can be rotated relative to each other in a direction that overlaps each other, while the seat and backrest can be rotated closed, and a configuration in which a gap is set between the bottom ends of the front and rear legs when folded that allows the chair to stand on its own, thereby enabling nesting when folded. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-086364 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-210153 Summary of the Invention [Problem to be solved by the invention]

[0009] The chair in Patent Document 2 has a four-point link mechanism in which the four members of the backrest, seat, and front and rear legs are connected so that they can rotate relative to one another, and the lower end of the backrest and the rear end of the seat are connected by a hinge mechanism.When folded, the backrest is in an upside-down position compared to when in use, and the seat is in an elongated position with the rear end at the top and the front end at the bottom.

[0010] The front legs are formed in a V-shape that bulges diagonally forward in side view, and the rear legs are formed in a V-shape that bulges diagonally backward in side view, and are folded. State By crossing the lower parts of the front legs and rear legs in a side view, a gap is provided between the lower ends of the front legs and rear legs to allow the robot to stand on its own.

[0011] The chair in Patent Document 2 is self-supporting when folded, and has the advantage that it can be nested with close spacing between the front and back.

[0012] However, in Patent Document 2, the seat and backrest are connected so that they overlap each other, which means that the backrest has to be flat, resulting in limited design freedom. Also, because the backrest and seat overlap, when unfolding the chair into a usable state, it is necessary to lift it up and then unfold the front and rear legs, which is considered to be quite a tedious process.

[0013] The present invention aims to solve the above problems. [Means for solving the problem]

[0014] The chair of the present invention is a foldable chair, and the invention of claim 1 is as follows: "A chair comprising a backrest, a seat, and left and right front legs and left and right rear legs that directly or indirectly support the backrest and the seat. It , The aforementioned The front legs and rear legs are directly or indirectly connected to each other so that they can rotate relative to each other to change the included angle when viewed from the side. Along with The seat has left and right leg rods located on the left and right outer sides of the seat and extending above the seat, The upper ends of the left and right front leg rods constituting the front leg portion are provided with rearward-facing arm portions whose rear ends are connected to both left and right ends of the backrest, and the upper ends of the left and right rear leg rods constituting the rear leg portion are connected to the left and right arm portions so as to be rotatable relative to each other, The seat is connected to at least one of the front legs and the rear legs so that when the front legs and the rear legs are closed and rotated, the seat rotates in conjunction with the closing of the front legs and the rear legs to a vertically long position in a side view. And, Before the front legs and rear legs are closed and rotated, the lower ends of the front legs are located forward of the lower ends of the rear legs, and when the front legs and rear legs are closed and rotated, the front legs and rear legs cross each other, and the lower ends of the front legs are located behind the lower ends of the rear legs. " The structure is as follows.

[0015]

[0016] Also, claims 2 The invention is 1 In "The seat is rotatably connected to the left and right leg rods of the front legs so that it can be folded with its front end down and its rear end up." The structure is as follows.

[0017] Claim 3 The invention is as follows in claim 1 or 2: "The left-right distance between the left and right front leg rods in the front legs is different from the left-right distance between the left and right rear leg rods in the rear legs, In the folded state where the front and rear legs are closed and rotated, it is possible to nest the product front and rear. The structure is as follows.

[0018] Claim 4 The invention is as follows: "Each of the legs is made of metal, The arm portion and the backrest are made of resin or wood. The structure is as follows. Claim 5 The invention is as follows: "Each of the legs is made of metal, The armrests, backrest and seat are each made of wood. The structure is as follows.

[0019] In the present invention, the embodiments and claims 3 By unfolding it as shown in Fig. 1, a large number of legs can be nested stably, even though it is a folding chair. Therefore, by unfolding it into a nesting chair, the storage space can be used more efficiently.

[0020] Furthermore, since the seat rotates in conjunction with the front and rear legs, it is possible to automatically fold it by, for example, grabbing the rear end of the seat or the backrest and lifting it, using the weight of the legs. Therefore, the folding operation can be performed easily, and the folded chair can also be easily unfolded.

[0021] Furthermore, when folding, the rear end of the seat can be lifted while the lower ends of the front and rear legs are in contact with the floor, allowing the front and rear legs to be closed and rotated, reducing the burden on the person during the folding process.The same is true for unfolding, where the front and rear legs can be opened and rotated by grabbing the backrest, lifting it, and tilting it, making unfolding easy.

[0022] Furthermore, as mentioned above, in the present invention, the folding and unfolding operations can be performed with the lower ends of the front and rear legs resting on the floor, but by providing casters as in the embodiment, there is no resistance to movement against the floor, making it easier to close and rotate the front and rear legs by lifting the chair, and also easier to open and rotate the front and rear legs by pushing the backrest downward in the folded state. This ensures improved operability in the folding and unfolding operations.

[0023] Claim 1 By adopting a configuration in which the front and rear legs are folded in a crossed position as shown in Fig. 1, even if force is applied from above to the backrest while it is folded, it can be maintained in the folded state without unfolding. Therefore, it is possible to prevent the chair from unfolding unexpectedly while in the folded state.

[0024] In addition, the front and rear legs are connected via arms at a position higher than the seat, and the seat can be directly connected to the front and rear legs to form a link mechanism, simplifying the structure. Furthermore, the backrest is connected to the arms, and the weight of a seated person acts to push the front and rear legs downward, improving the stability of the chair when in use.

[0025] In addition, since the backrest does not come into contact with the seat or legs when folded, the front and rear chairs can be placed close together when nested, which promotes compactness when folded and efficient use of storage space.

[0026] Claim 2When the seat is folded with its rear end facing up, as shown in the figure, the surface of the seat is exposed in the folded state, which has the advantage of making it look good when folded.

[0027] In the present invention, the upper body of the seated person is surrounded by the left and right arm sections and the backrest, improving the stability of the seated person's upper body. The arm sections can also be used as armrests or as support for the hands when sitting down or standing up from the chair, making it easy to use. Furthermore, as in the first embodiment, the distance between the top ends of the front and rear legs can be widened to create a V-shaped posture in a side view, which has the advantage of increasing the front-to-rear support span of the seat and improving support stability. [Brief explanation of the drawings]

[0028] [Figure 1] 1A and 1B are diagrams showing an embodiment, in which (A) is a perspective view seen from the front, (B) is a side view, (C) is a perspective view seen from below, and (D) is a bottom view. [Figure 2] 1A and 1B are exploded perspective views of an embodiment. [Figure 3] (A) is a longitudinal side view in the unfolded state, and (B) is a longitudinal side view in the folded state. [Figure 4] (A) and (B) are perspective views of the folded state, and (C) is a side view of the nested state. [Figure 5] FIG. 10 is a perspective view of a first reference example. [Figure 6] FIG. 2 is a plan view showing the backrest in virtual lines. [Figure 7] (A) is a side view, (B) is a longitudinal side view of the main part, and (C) is a cross-sectional view taken along the line CC of (B). [Figure 8] FIG. 10 is a schematic side view of the folding device in the middle of folding; [Figure 9] FIG. 10 is a side view of the folded and nested state. [Figure 10] FIG. 10 is a schematic side view of a second reference example. [Figure 11] FIG. 10 is a schematic side view of a third reference example. [Figure 12]FIG. 10 is a schematic side view of a fourth reference example. [Figure 13] FIG. 13 is a schematic side view of a fifth reference example. [Figure 14] FIG. 13 is a schematic side view of a sixth reference example. DETAILED DESCRIPTION OF THE INVENTION

[0029] Next, an embodiment of the present invention will be described with reference to the drawings. In the following, the terms "front, back, left, right" are used to specify directions, but these directions are based on the direction of a person normally sitting in a chair. A front view is the direction facing the seated person.

[0030] (1) First embodiment (Figs. 1 to 4) First, a first embodiment shown in Figures 1 to 4 will be described. The chair of this embodiment is a general-purpose type that can be used in conference rooms, lecture halls, restaurants, homes, etc., and as shown in Figure 1, it has a seat 1, a backrest 2, and front legs 3 and rear legs 4 that support them. The upper ends of the front legs 3 and rear legs 4 are located above the seat 1.

[0031] As shown in FIG. 1, the seat 1 is made of wood or resin and is in the shape of a plate. In other words, it has a single seat plate structure. However, the seat 1 can also be structured with a cushioning material stretched over the seat plate (inner plate), or a mesh type as in the second embodiment. The backrest 2 is a molded product made of synthetic resin, but it can also be made of wood. Alternatively, a structure with a cushioning material stretched over the front can also be used.

[0032] For example, as shown in FIG. 2, the front legs 3 include left and right front leg rods 5, and the rear legs 4 include left and right rear leg rods 6, with the left and right front leg rods 5 connected at mid-height by a front crossbar 7, and the left and right rear leg rods 6 connected at mid-height by a rear crossbar 8. Rearward-facing arm portions 5a are provided at the upper ends of the left and right front leg rods 5 that make up the front legs 3, and the backrest 2 is continuous with the rear ends of the arm portions 5a. Note that the arm portions 5a can also be regarded as the forward-facing portions of the backrest 2. Note that although the leg rods 5, 6 and crossbars 7, 8 in this embodiment are made of wood, metal or resin materials may also be used.

[0033] When the chair is unfolded, the front legs 3 are tilted backward and the rear legs 4 are tilted forward, resulting in a V-shaped posture in side view (the distance between the front legs 3 and rear legs 4 generally increases the closer to the bottom end). The front ends of the arms 5a are fixed to the front leg rods 5 that make up the front legs 3, while the upper ends of the rear leg rods 6 that make up the rear legs 4 are connected to the inner surfaces of the arms 5a by upper support shafts 9 so that they can tilt forward and backward. This allows the included angle between the front and rear legs 3, 4 to change, crossing in an X-shape in side view.

[0034] A link device 10 is disposed on the underside of the seat 1. The link device 10 comprises a front link member 11 connected to the front cross bar 7 so as to be able to pivot upward, and a rear link member 12 connected to the rear cross bar 8 so as to be able to pivot upward. Both have downward overlapping portions 11a, 12a that are interlocked in the front-to-rear direction, and these downward overlapping portions 11a, 12a are connected by a left-to-right longitudinal center support shaft 13 so as to be able to pivot relative to one another. The front and rear link members 11, 12 are formed in the shape of plates whose left-to-right width is greater than their front-to-rear width, but they may also be in the shape of rods or the like. It is also possible to separate the link device 10 into left and right halves.

[0035] For example, as shown in FIG. 2, the front and rear link members 11, 12 have a width shorter than that of the cross bars 7, 8, and the front end of the front link member 11 forms a semicircular front boss portion 14, while the front cross bar 7 has a front cutout portion 15 into which the front boss portion 14 fits, and the front boss portion 14 is connected to the front cross bar 7 by a front support shaft 16.

[0036] The front support shaft 16 is held in an undetachable manner by bearing members 17 fixed to the rear surface of the front cross bar 7 on both the left and right sides of the cutout portion 15. Therefore, recessed grooves 18 into which half of the front support shaft 16 fits are formed in the bearing members 17 and the front cross bar 7. The front support shaft 16 may be fixed to the cross bar 7 or to the front boss portion 14. Alternatively, the front support shaft 16 may be rotatable relative to both the cross bar 7 and the front boss portion 14.

[0037] The rear end of the rear link member 12 is also formed with a rear boss 19 having a semicircular cross section, while the rear cross bar 8 is formed with a rear cutout 20 into which the rear boss 19 fits from above, and the rear boss 19 is rotatably connected to the cross bar 8 by a left-right elongated rear support shaft 21. The rear support shaft 21 is inserted into one of the rear leg rods 6.

[0038] As shown in Figure 3, the seat 1 is fixed to the front link member 11 via front and rear spacers 22, and the rear of the seat 1 is provided with a contact portion 23 that rests on the rear boss portion 19 of the rear link member 12. Because the seat 1 is somewhat flexible and deformable, even if the contact portion 23 is slightly raised above the rear link member 12 in its free state, when a person sits down, the contact portion 23 will come into contact with the rear boss portion 19, maintaining a constant posture.

[0039] (2) Summary of the first embodiment In this embodiment, when the chair is unfolded, the front and rear legs 3, 4 are in a V-shaped position when viewed from the side, which increases the front and rear support span of the seat 1. This increases the stability of the seat 1 and maintains high support strength.

[0040] On the other hand, as shown in Figure 3(B), when the backrest 2 is placed under the hand and lowered upward, the rear legs 4 tend to rotate forward due to their own weight, and the link device 10 bends so that its link members 11, 12 overlap, causing the front and rear leg rods 5, 6 to rotate relative to each other until they cross. In other words, the chair is folded. In the folded state, the rear legs 4 abut against the left and right side portions 7a of the front crosspiece 7, thereby maintaining the folded state.

[0041] 4(C), when the chair is folded, there is a certain amount of space E between the lower ends of the front and rear leg bars 5, 6, but the entire seat 1, link device 10, and rear leg 4 are all included within the range of E, and most of the front leg 3 and most of the arm 5a are also included within the range of E, so the center of gravity of the chair is generally located above the approximate middle point between the lower ends of the front and rear leg 3, 4. Therefore, the chair can stand stably when folded. Furthermore, when a downward force is applied to the backrest 2 in the folded state, the force acts to widen the gap between the lower ends of the front and rear legs 3, 4, but because the lower ends of the front and rear legs 3, 4 are held in a position that prevents them from spreading apart, they will not unexpectedly unfold from the folded state due to an external force. Therefore, the seatback has an excellent function of maintaining the folded position.

[0042] The rear legs 4 are connected to the inner surfaces of the arms 5a attached to the upper ends of the front legs 3, and the width of the rear leg rods 6 is greater than the distance between the front leg rods 5, so the rear leg rods 6 of the chair placed behind can fit between the front leg rods 5 of the chair placed in front. This allows multiple chairs to be nested in the front-to-rear direction.

[0043] In the present invention, as shown in FIG. 1(D), in plan and bottom views, there is a space 24 between the left and right sides of the seat 1 and the forward-facing portion 2a of the backrest 2, the space being slightly larger than the outer diameter of the rear leg portion 4. This allows chairs to be stacked one above the other. This is one of the advantages of this embodiment. When stacked, the upper chair will protrude forward from the lower chair.

[0044] When folding the chair, the rear end of the seat 1 is grasped with the hand and lightly lifted, and the rear legs 4 rotate in the folding direction, so that the chair can be easily folded.

[0045] The chair can also be folded by tilting the entire chair forward by lifting the backrest 2 with the lower ends of the front legs 3 in contact with the floor, lifting the rear end of the seat 1 backward in this state to trigger bending of the link device 10, and then lifting the entire chair.

[0046] Alternatively, as shown by arrow 25 in Figure 3, by inserting your hand from inside the backrest 2 and lifting the rear end of the seat 1, the seat can be folded with the lower ends of the front and rear legs 3, 4 resting on the floor. In other words, as the seat 1 is lifted and rotated, the lower ends of the front and rear legs 3, 4 slide along the floor, narrowing the included angle and changing into a crossed position.

[0047] To unfold the folded chair, for example, simply tilt the rear end of the seat 1 backward with your hands. In this case, if you press down on the rear end of the seat 1 while the lower ends of the front and rear legs 3, 4 are in contact with the floor, the lower ends of the front and rear legs 3, 4 will slide along the floor, causing the front and rear legs 3, 4 to transition from a crossed position to a V-shaped position. Alternatively, for example, you can also transition the front and rear legs 3, 4 from a crossed position to a V-shaped position by grabbing both arm portions 5a with both hands and lifting them upward while tilting the back side (the side facing the backrest) downward.

[0048] In this embodiment, the front and rear legs 3, 4 are in a V-shaped configuration, making the legs 3, 4 highly stable, and the seat 1 is supported by the cross bars 7, 8 of the front and rear legs 3, 4 in the unfolded state. In other words, the seat 1 is supported by the highly stable legs 3, 4 with a large front and rear support span. Therefore, the chair is sturdy and has excellent support strength.

[0049] In this embodiment, the arm portion 5a has a flat, rectangular shape with a width that is approximately the same as the outer diameter of the front leg portion 3. This allows the arm portion 5a to be used as an armrest. Casters may be provided at the lower ends of the front and rear legs 3, 4. By connecting the link device 10 to the cross bars 7, 8 as in this embodiment, the robustness of the chair can be significantly improved without directly connecting the front and rear legs 3, 4.

[0050] (3). First reference example (Figures 5 to 9) Next, as shown in Figures 5 to 9 First reference example The same reference numerals are used to denote components having the same functions as those in the first embodiment, and descriptions thereof will be omitted unless otherwise necessary. This reference example As shown in Figure 5, this chair has a seat 1, a backrest 2, and front and rear legs 3 and 4 that support them. The upper ends of the front and rear legs 3 and 4 are located above the seat 1.

[0051] As shown in Figure 5, the seat 1 has a structure in which a mesh material is stretched over a frame 27 that is roughly rectangular in plan view and has openings at the top and bottom. On the other hand, the backrest 2 is a molded product made of synthetic resin, and is integrally connected to the left and right arm portions 5a, just like the first embodiment.

[0052] Book Reference example In the example, casters 28a, 28b are attached to the lower ends of leg rods 5, 6 that make up the front and rear legs 3, 4. These leg rods 5, 6 are made of oval metal pipes such as aluminum or steel that are long in cross section, but round pipes, oval pipes, solid rods, aluminum die-cast products, etc. can also be used. It is also possible to use different materials and cross-sectional shapes for the front legs 3 and the rear legs 4.

[0053] As shown in Figure 8(A), the front leg rod 5 is linear and tilts backward in side view, and the front portion of the seat 1 is connected to its midpoint by a single, left-right, long support shaft 29. Therefore, the seat 1 can be rotated around (using the support shaft 29 as a fulcrum). The support shaft 29 is made of a circular metal tube such as a steel pipe. The support shaft 29 may be fixed to the front leg rod 5 so that it cannot rotate, or the support shaft 29 may be welded to the frame 27 of the seat 1 and then fixed to the rear leg 4, with both ends fitted into bearing pins fixed to the front leg rod 5. The left and right front leg rods 5 may also be connected by left-right, long front stays (reinforcement stays).

[0054] As shown in Figures 5 and 8(A), the rear leg rods 6 constituting the rear legs 4 are basically in a forward-leaning position with their rear ends positioned further back than their upper ends, and are bent in a V-shape in side view so that the apex 30 is positioned slightly lower than the seat 1. In other words, the rear leg rods 6 are bent in a state where they protrude (or bulge) forward relative to a reference line O connecting their upper and lower ends, and the upper and lower portions 6a and 6b on either side of the apex 12 are linear. The entire rod may be curved in an arched shape, or only the lower portion 6b may be curved.

[0055] A vertically elongated guide hole 31 is formed as an example of a guide means on the inner plate of the upper part 6a of the rear leg rod 6, which is located above the apex 30, and a slide pin 33 protruding sideways via a bracket plate 32 on the outer surface of the seat 1 is slidably fitted into this guide hole 31. As shown in Figure 8(C), a resin edge material 34 is attached to the guide hole 31 to allow the slide pin 33 to slide quietly and smoothly.

[0056] 8(A) and 8(B), the bracket plate 32 protrudes below the seat 1, and the slide pin 33 is positioned slightly below the bottom surface of the seat 1. In other words, the slide pin 33 is offset downward from the bottom surface of the seat 1.

[0057] The left and right rear leg rods 6 are connected approximately at the vertex 30 by left and right longitudinal reinforcing rods 35. The reinforcing rods 35 are made of metal pipes such as round pipes, and are fixed to the rear leg rods 6 by welding or the like.

[0058] As a guide means, a guide rail such as a U-shaped or C-shaped rail may be used and fixed to the inner surface of the rear leg rod 6 with screws, while a pin or roller may be protruded from the side of the seat 2 so that it can slide freely into the guide rail.

[0059] The upper ends of the left and right rear leg rods 6 are provided with forward-facing sections 36, which are connected to the upper ends of the front leg rods 5 by left and right longitudinal pivot pins 37 so as to be able to rotate relative to each other. Therefore, the front and rear legs 3, 4 are basically connected in an inverted V shape, and the included angle changes as they rotate relative to each other around the pivot pins 37. In other words, the front and rear legs 3, 4 are folded and unfolded around the pivot pins 37.

[0060] A bracket plate 38 is fixed to the upper end of the front landing gear rod 5 by welding, and the forward portion 36 of the rear landing gear rod 6 and the bracket plate 38 are connected by a pivot pin 37. The forward portion 36 of the rear landing gear rod 6 is located inside the bracket plate 38.

[0061] As shown in Figure 6, the inner width L2 of the front legs 3 is larger than the outer width L1 of the rear legs 4. In other words, the rear legs 4 are located on the inner sides of the front legs 3, allowing chairs placed one behind the other to be nested. As shown in Figure 6, a pair of front casters 28a are located on each side of the front leg rod 5, while the rear caster 28b is located on the inner side of the rear leg rod 6.

[0062] Although not shown in the figures, a boss is provided at the front end of the arm 5a to fit into the front leg rod 5 from above, and the front leg rod 5 and the boss are fixed with a screw. In the embodiment, the front arm 5a and the backrest 2 are formed integrally, but the backrest 2 may also be formed separately from the arm 5a. Furthermore, it is possible to form a frame body that is U-shaped in plan view by connecting the rear ends of the left and right arm parts 5a integrally with horizontal rods, and attach the backrest 2 to the horizontal rods of the frame body.

[0063] (4). Part 1 Summary of the examples This reference example Since the front legs 3 and rear legs 4 are inclined in opposite directions to each other and basically form an inverted V-shape in side view, when the backrest 2 or the rear end of the seat 1 is grasped with the hands and the chair is lifted up, as shown by arrow 39 in Figure 8, the front legs 3 and rear legs 4 rotate toward each other (rotate to narrow the included angle), and in conjunction with this, the guiding action of the long guide holes 31 causes the seat 1 to rotate so that its front end descends and its rear end ascends.

[0064] 9, when the reinforcing rod 35 or the rear leg rod 6 hits the rear surface of the seat 1, the rotation of each component stops and the chair enters the folded state. In this state, the seat 1 overlaps the front leg rod 5 in a side view, but because the forward-facing portion 36 at the upper end of the rear leg rod 6 is connected to the front leg rod 5, the rear leg rod 6 overlaps the front leg 3 and the seat 1 from front to back. Furthermore, because the slide pin 33 protrudes below the seat 1, the seat 1 and the rear leg rod 6 can transition to a state where they overlap from front to back when folded.

[0065] Furthermore, since the front legs 3 and rear legs 4 are connected in an inverted V shape, when the chair is lifted by grabbing the backrest 2 or the rear end of the seat 1 with one's hands, the front and rear legs 3, 4 can be closed and rotated while the front casters 28a and rear casters 28b remain in the installed position, as shown in Figure 8.

[0066] That is, the stroller can be folded in three states: the front casters 28a barely move while the rear casters 28b roll on the floor; the rear casters 28b barely move while the front casters 28a roll on the floor; or the front and rear casters 28a, 28b roll on the floor and come close to each other. In any case, the stroller can be folded with the front and rear casters 28a, 28b touching the ground. Therefore, folding can be done easily and with little force.

[0067] This reference example In this case, the backrest 2 is attached to the upper end of the front legs 3, so when folded, the backrest 2 and seat 1 do not overlap. Therefore, as shown in Figure 9, multiple chairs can be nested closely together, with the reinforcing rod 35 of the rear chair overlapping the seat 1 of the front chair. This allows for efficient use of space.

[0068] This reference example This chair is equipped with casters 28a, 28b, so the folded chair can be moved by holding onto the backrest 2 and pushing or pulling it. This reduces the burden of moving the chair compared to the chair that needs to be lifted and moved as in Patent Document 1. It is also possible to move multiple nested chairs together.

[0069] Furthermore, since the rear casters 28b are arranged only on the inside of the rear leg rods 6, there is an advantage in that the left-right inner width L2 of the front legs 3 can be reduced. Note that, if the front casters 28a are arranged only on the outside of the front leg rods 5, the left-right inner width L2 of the front legs 3 can be further reduced, which is preferable.

[0070] This reference exampleIn this case, the chair can also be folded by grasping and lifting the rear end of seat 1, as shown by arrow 43 in Figure 8. In this case, seat 1 is forcibly rotated, so folding can be ensured by simply lifting it. Whether lifting backrest 2 or seat 1, the ratio of rotation of seat 1 and the ratio of closing of front and rear legs 3, 4 are not very different, so resistance does not increase during folding, allowing for a smooth and comfortable folding operation.

[0071] To unfold the chair from the folded position, the seat 1 can be pushed backward and downward, or the rear end of the backrest 2 can be pushed downward to open and rotate the front and rear legs 3, 4. By grasping the backrest 2 with your hands and pushing the backrest 2 downward with the rear casters 28b on the ground and the front casters 28a slightly raised, a forward tilting load is applied to the rear legs 4, allowing the chair to be easily opened and rotated.

[0072] In the folded state, the upper part 6a of the rear leg rod 6 is tilted backward, so in order to open and rotate the front and rear legs 3, 4, the upper part 6a of the rear leg rod 6 must be shifted to a forward tilting position. Therefore, the rear leg 4 plays a role in maintaining the folded state.

[0073] Now, since the center of gravity of the chair is located above the area between the front and rear casters 28a, 28b, the chair can stand on its own, but the downward load of the center of gravity has a horizontal component that pushes the front and rear casters 28a, 28b apart. In this case, the closer the center of gravity is to the front, the larger the rearward horizontal component of force on the rear caster 28b becomes, making it easier for the legs to spread apart. This reference example In the case of the 2006 model, the backrest 2 projects rearward significantly, so the center of gravity can be moved as far back as possible, reducing the rearward horizontal force component on the rear casters 28b. This improves the ability to maintain the folded state.

[0074] It is possible to provide an elastic locking mechanism to maintain the folded state. For example, a magnet can be placed on the overlapping members in the folded state, so that the folded state can be maintained by magnetic force, while the device can be unfolded by applying a certain amount of force. If at least one of the overlapping members is made of a magnetic material such as steel plate, the magnet can be provided only on the other member.

[0075] It is also possible to use a ball catch in which the ball is pressed by a spring, or a locking claw made of a leaf spring or resin, and engage a catch member such as a ball or locking claw with the engaging portion of the mating member against its elasticity.

[0076] (5). Other reference examples Next, other methods shown in Figure 10 and below Reference example Explain each Reference example In First embodiment and first reference example The same parts as those in the previous example are designated by the same reference numerals, and the explanation thereof is omitted.

[0077] As shown in Figure 10 Second reference example In this embodiment, the front and rear leg rods 5, 6 are formed in a straight line in a side view, and the folding angle is restricted by a stopper 41 provided on one of the front and rear leg rods 5, 6. As in the second embodiment, the front portion of the seat 1 is connected to the front leg rod 5 by a support shaft 29, and the rear portion is slidably engaged with the long guide hole 31 of the rear leg rod 6 by a slide pin 33.

[0078] As shown in Figure 11 Third reference example In this embodiment, when the front and rear leg rods 5, 6 are formed linearly in side view, the slide pin 33 protrudes from the side of the seat 1, a forward widening portion 42 is formed at the top of the rear leg rod 6, and a forward extension portion 31a is formed in the guide slot 31 that overlaps with the front leg rod 5 in side view. In this embodiment, the front and rear leg rods 5, 6 are formed linearly and can be folded to a position where the seat 1 and front leg portion 3 overlap. Although not shown, a stopper 44 similar to that in the third embodiment is also provided in this embodiment.

[0079] As shown in Figure 12 4th reference exampleIn this embodiment, the front and rear leg rods 5, 6 are formed linearly in a side view, and the front portion of the seat 1 is connected to the front leg rod 5 by a support shaft 29. Guide pins 46 protrude laterally from links 45 rotatably suspended from the left and right rear leg rods 6, and the guide pins 46 are slidably fitted into elongated guide holes 47 formed in the seat 1 in the front-rear direction. It is preferable that the left and right guide pins 46 are integrally continuous. In this embodiment, the link 45 rotates at the end of the folding of the front and rear legs 3, 4, allowing the seat 1 to be folded so that it overlaps the front leg 3 in a side view.

[0080] Figures 10-12 Reference examples In the figure, the front and rear legs 5 and 6 are in a straight line when viewed from the side. As can be seen by comparing Figures 10 to 12 with Figure 9, First reference example In this case, the upper part 6a of the rear leg rod 6 and the front leg rod 5 are brought into close contact with each other in a side view, which has the advantage of making the folded thickness as thin as possible.

[0081] As shown in Figure 13 5th reference example Unlike the second embodiment, the front legs 3 are formed with long guide holes 47 and the seat 1 is provided with slide pins 33. The seat 1 is connected to the left and right rear leg rods 6 by left and right support shafts 29 via brackets 49 that protrude upward. In this embodiment, the seat 1 is flipped up and rotated so that the front end is facing up.

[0082] As shown in Figure 14 6th reference example So, First reference example Unlike the previous model, the front legs 3 are bent in a V-shape when viewed from the side, and a guide slot 50 is formed in the upper part 5c of the front leg rod 5, and the rear of the seat 1 is connected to the rear leg rod 6 by a support shaft 29 via a bracket 49. Reference example When folding, it is preferable to place your hands on the front end of the seat 1 and flip the seat up and rotate it.

[0083] Although the embodiments of the present invention have been described above, the present invention can be embodied in various other ways. For example, both the front and rear leg rods can be bent into an L-shape. To allow for nesting, the outer width of the front legs can be made smaller than the inner width of the rear legs. As a modification of the first embodiment, the front end of the seat 1 can be rotatably connected to the front crosspiece 7 or the left and right front leg rods 5, and the front link member 11 can be fixed to the underside of the seat 1. [Industrial Applicability]

[0084] The present invention can be embodied in a folding chair, and therefore has industrial applicability. [Explanation of symbols]

[0085] 1 seat 2 backrest 3 Front legs 4 Hind leg 5 Front leg rod 5a Arm section 6 hind leg rod 10 Link device 11 Front link material 12 Rear link material 28a, 28b Caster 30 Peak of bend 31 Guide slot as an example of guide means 33 Slide pin

Claims

1. The chair comprises a backrest, a seat, and left and right front legs and left and right rear legs that directly or indirectly support the backrest and the seat, The front legs and the rear legs are directly or indirectly connected to each other so as to be rotatable relative to each other so that the included angle can be changed in a side view, and each of the front legs and the rear legs has left and right leg rods located on the left and right outer sides of the seat and extending above the seat, The upper ends of the left and right front leg rods constituting the front leg portion are provided with rearward-facing arm portions whose rear ends are connected to both left and right ends of the backrest, and the upper ends of the left and right rear leg rods constituting the rear leg portion are connected to the left and right arm portions so as to be rotatable relative to each other, the seat is connected to at least one of the front legs and the rear legs so that when the front legs and the rear legs are closed and rotated, the seat rotates in conjunction with the closing of the front legs and the rear legs to a vertically longitudinal position in a side view, Before the front legs and the rear legs are closed and rotated, the lower ends of the front legs are located forward of the lower ends of the rear legs, and when the front legs and the rear legs are closed and rotated, the front legs and the rear legs cross each other, and the lower ends of the front legs are located rearward of the lower ends of the rear legs. Folding chair.

2. The seat is rotatably connected to the left and right leg rods of the front legs so that it can be folded into a position where the front end is down and the rear end is up.

2. A folding chair according to claim 1.

3. The left-right distance between the left and right front leg rods in the front legs is different from the left-right distance between the left and right rear leg rods in the rear legs, In a folded state in which the front and rear legs are closed and rotated, the platform can be nested front and rear.

3. A folding chair according to claim 1 or 2.

4. Each of the leg rods is made of metal, The arm portion and the backrest are made of resin or wood.

3. A folding chair according to claim 1 or 2.

5. Each of the leg rods is made of metal, The arm portions, the backrest and the seat are each made of wood.

3. A folding chair according to claim 1 or 2.

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