JP5928009B2 - Chair - Google Patents

Description

  The present invention relates to a chair that can be suitably used in reception counters, waiting rooms, office meeting rooms, schools, and other places such as stores, public offices, libraries, financial institutions, and hospitals.

  In the following Patent Document 1, a part of the left and right side edges of the resin back plate constituting the backrest is cut out inward, and a metal pipe material constituting the leg is passed through the cut-out portion. An aspect chair is disclosed. In this chair, the pipe material exposed in the notch part of the back plate can be used as a handle (or handle, handle), and this can be used to move or change the direction of the chair Is possible.

  However, it cannot be denied that the location of the handle suitable for grasping by hand is limited to a specific narrow range. For an elderly person or a person who has a handicap in the body, especially a person using a wheelchair, the hand is not always easily accessible to the part where the handle is located.

JP 2003-1111637 A

  The present invention is intended to realize a chair having a wide range of parts that are suitable for grasping by hand.

In the present invention, the chair has a seat and a backrest, and the backrest extends below the upper frame portion and the upper frame portion, which are curved so that the middle portion bulges backward while extending left and right. The lower frame part that is curved so that the middle part bulges backward while extending left and right, the left frame part that connects the left end part of the upper frame part and the left end part of the lower frame part, and the right end of the upper frame part The right frame part that connects the upper part and the right end of the lower frame part is paired with a backrest frame that forms a continuous loop shape, spaced apart from the left and right, and extends vertically above the seat , One upper end part is joined to a position located inward and rearward of the left end part in the lower frame part, and the other upper end part is joined to a place located inward and rearward of the right end part in the lower frame part And said dorsal fin And a plurality of back支桿supporting the frame, upper frame part, the lower frame portion, the inner periphery of the backrest frame surrounded by the left side frame section and a right frame portion is opened in the longitudinal direction, Or the chair which the space | gap interposed between the backplate attached to the said backrest frame and the backrest frame was comprised. A grip may be attached to the backrest frame.

  If this is the case, the upper frame part, the lower frame part (including the part located outside the back supporter and the part between the paired back supports), the left frame part and the right frame part Further, it becomes easy to move either the chair or change the direction of the chair by holding any one of the back supports and the handle.

  If the middle part of the upper frame part is located behind the middle part of the lower frame part and the height position of the lower frame part corresponds to the height of the waist of the seated person, It is possible for a person to lean the upper body backward and to lean the upper body deeply on the backrest frame.

  If the cross section of the backrest frame has a substantially cylindrical shape or a substantially columnar shape, it is easy to grip as a handle and has a good touch.

  If the seat has a substantially circular outer periphery in plan view, the direction of the body with respect to the chair is not limited to one direction when trying to sit down or when a seated person tries to stand up. , Improve usability. In other words, it becomes easy to go in and out of the chair. It is also easy to change the direction of the body while sitting.

  The back support rod has a width dimension along a first direction orthogonal to the extending direction, and a thickness dimension along a second direction orthogonal to the extending direction and the first direction. It is preferable that it is large. By doing so, the presence of the back support rod becomes conspicuous, and it becomes easy to visually recognize even for elderly people whose visual acuity has declined.

  If the seat and the backrest are supported by front and rear legs spaced apart in the front-rear direction, and the back support bar and the rear leg are integrated and continuous, the number of parts and assembly steps of the chair Can be reduced. It also leads to enhancing the style and beauty of furniture.

  ADVANTAGE OF THE INVENTION According to this invention, the chair which has the site | part used as the handle suitable for grasping with a hand over a wide range is realizable.

The perspective view which looked at the chair of one embodiment of the present invention from the front side. The perspective view which looked at the chair of the embodiment from the back and bottom sides. The front view of the chair of the embodiment. The rear view of the chair of the embodiment. The top view of the chair of the embodiment. The bottom view of the state which cut | disconnected the front leg and the rear leg of the chair of the embodiment. The sectional side view of the chair of the embodiment. The front view which shows the modification of the chair which attached the grip to a part of backrest frame. The sectional side view of the chair of the modification. The principal part exploded perspective view which shows an example of the attachment structure of a backplate in the case of attaching a backplate to the inner periphery of a backrest frame. The front view which shows the modification of the chair which attached the back board to the inner periphery of the backrest frame. The sectional side view of the chair of the modification. The front view which shows the modification of the chair which attached the back board to the inner periphery of the backrest frame. The sectional side view of the chair of the modification. The front view which shows the modification of the chair which attached the back board to the inner periphery of the backrest frame. The sectional side view of the chair of the modification. The front view which shows the modification of the chair which attached the back board to the inner periphery of the backrest frame. The sectional side view of the chair of the modification. The front view which shows the modification of the chair from which the shape of a leg structure differs. The rear view of the chair of the modification. The perspective view seen from the front side which shows the modification of the chair from which the shape of a backrest frame differs. The perspective view seen from the back and bottom side of the chair of the modification. The sectional side view which shows the modification which provided the recessed part in the lower surface side of the front-end part of a seat. The sectional side view which shows the modification which provided the convex part in the lower surface side of the front-end part of a seat.

  An embodiment of the present invention will be described with reference to the drawings. The chair according to the present embodiment shown in FIGS. 1 to 7 is a so-called counter chair disposed in front of a reception counter in a store, a public office, a library, a financial institution, a hospital, or the like. This chair mainly comprises a seat 1 on which a seated person's buttocks rests, a backrest 2 that supports the upper body of the seated person, and a leg structure 3 that contacts the floor and supports the seat 1 and the backrest 2. To do.

  The seat 1 is formed by mounting a cushion body such as urethane sponge on an inner shell or a seat plate body and covering them with a tension fabric. The seat 1 forms an outer periphery of a substantially circular shape in a plan view (which may be a perfect circle or an ellipse). The seat 1 does not tilt forward or backward as viewed from the side, and takes a substantially horizontal posture along the front-rear direction. This is to make it easier for the seated person to stand up by raising the buttocks. However, the seat 1 is warped so that the left and right side edge portions are lifted upward from the center portion, although having a substantially rectangular outer shape when viewed from the front.

  The backrest 2 includes a back support rod 21 that extends vertically above the seat 1 and a backrest frame 22 that is supported by the back support rod 21.

  The back support rod 21 is made of, for example, a metal pipe material or bar material. There are a plurality of back supports 21, a pair of which are separated from each other in the present embodiment. The back support rods 21 are formed in a C shape such that the distance between them is gradually reduced as it goes upward in the rear view. Each back support rod 21 is slightly inclined forward when viewed from the side.

  The backrest frame 22 is a member that comes into contact with and directly supports the back and waist of the seated person. The backrest frame 22 is also formed by using, for example, a metal pipe or bar and bending the pipe or bar. In the present embodiment, the backrest frame 22 extends to the left and right while the upper frame portion 23 is curved so that the intermediate portion 231 bulges rearward, and is below the upper frame portion 23 and extends to the left and right. The lower frame portion 24 curved so that the intermediate portion 241 bulges back, the left frame portion 25 connecting the left end portion 232 of the upper frame portion 23 and the left end portion 242 of the lower frame portion 24, and the upper frame portion 23 And the right frame portion 26 connecting the right end portion 232 of the lower frame portion 24 to the right end portion 242 of the lower frame portion 24, and these form a continuous loop shape.

  The inner periphery surrounded by the upper frame portion 23, the lower frame portion 24, the left frame portion 25, and the right frame portion 26 is opened in the front-rear direction, in other words, penetrates. As a whole, the backrest frame 22 has a curved shape in which left and right ends protrude forward most and gradually displace toward the center from there. As shown in FIGS. 5 and 6, the curvature of the curvature of the frame portion 23 and the curvature of the curvature of the lower frame portion 24 are substantially matched in plan view. In addition, the curvature of curvature of the lower frame portion 24 in plan view and the curvature of the rear edge (and also the front edge) of the seat 1 substantially match.

  The upper end portion of the left back support rod 21 is joined to a location located on the inner side and the rear side of the left end portion 242 in the lower frame portion 24. Further, the upper end portion of the right back support rod 21 is joined to a position located on the inner side and the rear side of the right end portion 242 in the lower frame portion 24. Needless to say, the joint portion of the left back support rod 21 and the joint portion of the right back support rod 21 are separated from each other in the left-right direction. The back support rod 21 and the lower frame portion 24 may be fixed by welding or by fastening using bolts or screws.

  Both the upper frame part 23 and the lower frame part 24 extend substantially horizontally along the left-right direction when viewed from the front. However, the upper frame portion 23 is slightly warped so that the left and right side end portions 232 are lowered downward as compared with the intermediate portion 231. The lower frame portion 24 is spaced downward from the upper frame portion 23 and is spaced upward from the seat 1. The height position of the lower frame portion 24 corresponds to the height of the seated person's waist. Further, the intermediate part 231 of the frame part 23 in the side view is located behind the intermediate part 241 of the lower frame part 24. As a result, the seated person can tilt the upper body backward and lean the upper body deeply on the back frame 22. At this time, the lower frame portion 24 is in a state of supporting the waist of the seated person.

  Each of the left frame portion 25 and the right frame portion 26 has a substantially arc shape (may be a true arc or an elliptical arc) that bulges forward in a side view, and has an upper frame portion 23 and a lower frame portion. It is continuous with both of the 24 side end portions 232 and 242. The left frame portion 25, the right frame portion 26, the side end portion 232 of the upper frame portion 23, and the side end portion 242 of the lower frame portion 24 protrude forward from the upper end portions of the left and right back support rods 21.

  As shown in FIG. 7, the pipe material or the bar material constituting the backrest frame 22 has a cross section regardless of any of the upper frame portion 23, the lower frame portion 24, the left frame portion 25 and the right frame portion 26. The shape is substantially cylindrical or substantially columnar (cylindrical in the illustrated example). The outer diameter is thick enough to be gripped with fingers. When moving the chair, the upper frame portion 23, the lower frame portion 24 on the outer side of the left and right back support rods 21, the lower frame portion 24 between the left and right back support rods 21, Any part of the left frame part 25 and the right frame part 26 can be used as a handle.

  In addition, the pipe member or the bar constituting the back support rod 21 (and the rear leg 31) has a width dimension along the first direction orthogonal to the extending direction, and the extending direction and the first It is larger than the thickness dimension along the second direction orthogonal to the direction (details of the first direction and the second direction will be described later). The width dimension and the thickness dimension are large enough to be gripped with fingers. The back support rods 21 that are located between the frame part 24 under the back view and the seat 1 and are separated from each other to the left and right can also be used as handles for moving the chair.

  The leg structure 3 includes a plurality of rear legs 31, a plurality of front legs 32, and a connecting portion 33 that connects the rear legs 31 and the front legs 32.

  The rear leg 31 is made of, for example, a metal pipe material or bar material. There is a pair left and right. In this embodiment, the left rear leg 31 is continuous with the left back support rod 21 and the right rear leg 31 is continuous with the right back support rod 21. . The rear leg 31 and the back support rod 21 extend vertically in a substantially straight line with the same cross-sectional shape. That is, the two rear legs 31 are formed in a C shape such that the distance between the rear legs 31 gradually increases toward the lower side of the rear view. Further, each rear leg 31 is slightly inclined forward when viewed from the side.

  As shown in FIG. 6, the cross-sectional shape of the rear leg 31, and thus the cross-sectional shape of the back support rod 21, has a substantially elliptic cylinder shape or a substantially elliptic cylinder shape (in the illustrated example, an elliptic cylinder shape). The major axis direction of the cross-sectional shape is the first direction, and the minor axis direction is the second direction. The second direction of each of the left and right back support rods 21 and the rear legs 31 is non-parallel to both the front-rear direction and the left-right direction (crossing both the front-rear direction and the left-right direction). It is facing diagonally, more specifically, diagonally forward toward the center of the bottom view chair.

  The front leg 32 is also made of, for example, a metal pipe or bar. A pair of front legs 32 are spaced apart from each other on the left and right, and extend up and down in a substantially straight line with the same cross-sectional shape. Although both front legs 32 are not as large as the rear legs 31 in front view, they are inclined inward so that the distance between them is gradually increased toward the lower side. Further, each front leg 32 is slightly tilted rearward as viewed from the side.

  The pipe material constituting the front leg 32 has a width dimension along a first direction orthogonal to the extending direction and a thickness along a second direction orthogonal to the extending direction and the first direction. It is larger than the dimensions. The width dimension and the thickness dimension are large enough to be gripped with fingers. As shown in FIG. 6, the cross-sectional shape of the front leg 32 in this embodiment is equivalent to that of the rear leg 31 and the back support rod 21. For each of the left and right front legs 32, the second direction, that is, the minor axis direction, is not parallel to the front-rear direction and the left-right direction (crosses both the front-rear direction and the left-right direction). It faces diagonally, more specifically, diagonally rearward toward the center of the bottom view chair.

  The connecting portion 33 includes one that connects the left rear leg 31 and the left front leg 32 and one that connects the right rear leg 31 and the right front leg 32. Each connecting portion 33 is formed by, for example, using a metal pipe material or bar, and bending the pipe material or bar. Each connecting portion 33 has a rear portion 331 whose rear end portion is joined to an upper end portion of the rear leg 31 (which is also a lower end portion of the back support rod 21), and a front end portion which is an upper end portion of the rear leg 31 (the back support rod 21). A front portion 332 that is joined to the lower portion, and an intermediate portion 333 that connects the rear portion 331 and the front portion 332.

  The rear portions 331 of the left and right connecting portions 33 extend obliquely forward toward the center of the chair so as to be close to each other when viewed from the bottom. The front portions 332 of the left and right connecting portions 33 extend obliquely rearward toward the center of the chair so as to be close to each other when viewed from the bottom. The middle part 333 of the left and right connecting parts 33 extends in the front-rear direction in contact with each other, the rear part 331 is connected to the rear end, and the front part 332 is connected to the front end. The connection between the connecting portion 33 and the rear leg 31 and the connection between the connecting portion 33 and the front leg 32 may be performed by welding, or may be performed by fastening using bolts or screws. The same applies to the fixation between the intermediate portion 333 of the left connecting portion 33 and the intermediate portion 333 of the right connecting portion 33.

  The connecting portion 33 not only connects the front leg 32 and the rear leg 31, but also serves as a seat support that supports the seat 1 from below. That is, the seat 1 is placed and fixed on the connecting portion 33.

  In the present embodiment, the chair is provided with a seat 1 and a backrest 2, and the backrest 2 extends to the left and right and is curved so that the intermediate portion 231 bulges backward, and the upper frame A lower frame portion 24 which is below the portion 23 and extends to the left and right while being curved so as to bulge backward, a left end portion 232 of the upper frame portion 23 and a left end portion 242 of the lower frame portion 24 The back frame 22 in which the left frame portion 25 to be connected, and the right frame portion 26 to connect the right end portion 232 of the upper frame portion 23 and the right end portion 242 of the lower frame portion 24 form a loop shape that is a continuous circuit, The left and right sides form a pair and extend vertically above the seat 1, and one upper end of the lower frame portion 24 is in contact with a position located inward and rearward of the left end 242. A chair provided with a plurality of back support rods 21 that support the back frame 22 by joining the other upper end of the lower frame portion 24 to a position located inward and rearward of the right end portion 242. Configured.

  According to the present embodiment, any one of the upper frame portion 23, the lower frame portion 24, the left frame portion 25, the right frame portion 26, and the back support rod 21 is used as a handle, and the chair is moved by grasping the handle. And changing the orientation of the chair.

  The intermediate part 231 of the upper frame part 23 is located behind the intermediate part 241 of the lower frame part 24, and the height position of the lower frame part 24 corresponds to the height of the waist of the seated person 1. Therefore, the seated person can tilt the upper body backward and lean the upper body deeply on the back frame 22. Further, in this state, the left and right side end portions 232 of the left frame portion 25, the right frame portion 26, or the upper frame portion 23 projecting forward can function as armrests.

  Since the cross section of the backrest frame 22 has a substantially cylindrical shape or a substantially columnar shape, it is easy to grip as a handle and has a good touch. The left frame portion 25 and the right frame portion 26 are arcuate, and may be continuous with the upper frame portion 23 and the lower frame portion 24 without a sharp refracted portion. There is no such thing as being caught on 22.

  Since the seat 1 has a substantially circular outer periphery in plan view, the body direction with respect to the chair is limited to one direction when trying to sit 1 or when a person who has been seated 1 tries to stand up. This improves usability. In other words, it becomes easy to go in and out of the chair. It is also easy to change the direction of the body while sitting 1.

  About each of the back support rod 21, the rear leg 31, and the front leg 32, the width dimension along the first direction orthogonal to the extending direction is orthogonal to the extending direction and the first direction. Because the thickness is larger than the thickness dimension along the second direction, the presence of the back support rod 21, the rear leg 31, and the front leg 32 becomes conspicuous, and it is easy to visually recognize even for elderly people with weak visual acuity. Become.

  The seat 1 and the backrest 2 are supported by a front leg 32 and a rear leg 31 that are separated from each other in the front-rear direction, and the back support bar 21 and the rear leg 31 are integrated and continuous. The number of parts and assembly man-hours can be reduced. The style and beauty of furniture can be enhanced.

  The present invention is not limited to the embodiment described in detail above. Hereinafter, modifications of the chair according to the present invention will be listed.

  As shown in FIGS. 8 and 9, grips 27 may be attached to appropriate portions of the backrest frame 22. 8 and 9, cylindrical grips 27 are attached to the outer surfaces of the intermediate portion 231 of the upper frame portion 23 and the intermediate portion 241 of the lower frame portion 24 so as to cover them. The grip 27 may be manufactured using a material that is relatively soft such as a soft resin or elastically deformable, or may be manufactured using a material that is difficult to elastically deform such as a hard resin. In particular, in the latter case, it is preferable to roughen the surface of the grip 27, provide an uneven shape on the surface, or employ a material having a high coefficient of friction so that the hand is difficult to slip when held in the hand. .

  In the above embodiment, the entire inner periphery of the backrest frame 22 surrounded by the upper frame portion 23, the lower frame portion 24, the left frame portion 25, and the right frame portion 26 is opened in the front-rear direction. On the other hand, as shown in FIG. 10 to FIG. The part may be closed.

  A method of attaching the back plate 29 to the backrest frame 22 is arbitrary. FIG. 10 is an example of a method for attaching the back plate 29. In the example shown in FIG. 10, the back plate support portion 28 is provided so as to protrude inward from the inner periphery of the backrest frame 22. The back plate support portion 28 in FIG. 10 protrudes downward from the lower edge of the upper frame portion 23 and protrudes upward from the upper edge of the lower frame portion 24. These back plate support portions 28 are positioned so as to be directly above the upper end portion of the back support rod 21 in front view or rear view. The back plate support portion 28 is provided with an insertion hole 281 through which a bolt or screw 296 used for fixing the back plate 29 is inserted.

  The back plate 29 is formed by mounting a cushion material 294 such as urethane sponge on a back plate body 291 and covering them with a tension fabric 295. Incidentally, in FIG. 10, the cushion material 294 is arranged not only on the front side of the back plate 291 but also on the rear side. The back plate body 291 is a plate-like body that is curved with the same degree of curvature as the upper frame portion 23 and the lower frame portion 24 of the backrest frame 22. The back plate body 291 abuts on the back plate support portion 28 from the front or rear (front in the illustrated example). In the back plate body 291, a concave portion 292 is formed at the position of the rear surface or the front surface (front surface in the illustrated example) that contacts the back plate support portion 28 so that all or part of the back plate support portion 28 can be accommodated. A nut hole 293 is formed in the recess 292.

  Thus, the back plate body 291 is disposed on the inner periphery of the backrest frame 22 so that the back plate support portion 28 is accommodated in the recess 292 of the back plate body 291, and a bolt or a screw 296 is inserted through the insertion hole 281 and a nut hole is inserted. The back plate body 291 is fixed to the backrest frame 22 by being screwed into the 293 and tightened. Further, the back plate 291 and the cushion material 294 are covered with the tension fabric 295 from the front and back so as not to be exposed, and the front and rear tension fabrics 295 are sewn or welded so that they cannot be detached. 29 is completed.

  Various shapes of the back plate 29 can be considered. In the example shown in FIGS. 11 to 12, the left and right side edges of the back plate 29 are inward of the left and right ends 232 of the upper frame portion 23 and the left and right ends 242 of the lower frame portion 24. The left and right end portions 232, the left and right end portions 242 of the lower frame portion 24, the left frame portion 25, the right frame portion 26, and the back plate 29 are interposed. Therefore, the right and left end portions 232 of the upper frame portion 23, the left and right end portions 242 of the lower frame portion 24, the left frame portion 25, or the right frame portion 26 are not hindered from being held. In addition, the upper edge of the back plate 29 is cut out at a portion between the back plate support portion 28 and the concave portion 292 that are spaced apart from each other right and left. The cutout portion 297 has a vertical width that allows a finger to be inserted, and is open in the front-rear direction. Due to the presence of the cutout portion 297, it is allowed to hold the intermediate portion 231 of the upper frame portion 23 as a handle.

  In the example shown in FIGS. 13 and 14, similar notch portions 297 are provided not only on the upper edge portion of the back plate 29 but also on the lower edge portion. Due to the presence of the cutout portion 297, it is allowed to hold the intermediate portion 241 of the lower frame portion 24 as a handle.

  In the example shown in FIGS. 15 and 16, the vertical dimension of the entire back plate 29 is set to be smaller than the separation distance between the upper frame portion 23 and the lower frame portion 24. As a result, a gap 20 is formed between the upper edge of the back plate 29 and the upper frame portion 23 over the entire width dimension of the back plate 29, and any part of the upper frame portion 23 can be gripped as a handle. Permissible.

  In other words, in the example shown in FIGS. 17 and 18, the back plate 29 closes the inner periphery of the backrest frame 22 except for the notch portion 297 in the upper edge portion of the back plate 29. In this case, the parts that can be used as a handle are limited to the intermediate portion 231 and the back support rod 21 of the upper frame portion 23.

  In the above embodiment, the leg structure 3 that supports the seat 1 and the backrest 2 includes the rear legs 31 and the front legs 32 that are separated from each other in the front-rear direction. However, as illustrated in FIGS. 19 and 20, the leg structures 3 include the rear legs 31. It is also conceivable that the leg structure 3 has no aspect. 19 and 20, the lower end portion of the left back support rod 21 is connected to the rear end portion of the rear portion 331 of the left connecting portion 33, and the lower end portion of the right back support rod 21 is the right end. The connecting portion 33 is connected to the rear end portion of the rear portion 331. The connecting portion 33 connects the lower end portion of the back support rod 21 and the upper end portion of the front leg 32. The point that the connecting portion 33 also serves as a seat is the same as in the above embodiment.

  From the lower ends of the left and right front legs 32, the leg base 34 is extended backward and bent. Further, the rear end portions of the left and right leg bases 34 are connected to each other via a base connecting portion 35 that extends to the left and right. In the example shown in FIGS. 19 and 20, the lower end portion of the front leg 32, the leg base 34 and the base connecting portion 35 are in contact with the floor surface to support the seat 1 and the backrest 2. In the example shown in FIGS. 19 and 20, the left and right back support rods 21 and the connecting portion 33, the front leg 32, the leg base 34, and the base connecting portion 35 are integrated and continuous. That is, the left and right back support rods 21 and the connecting portion 33, the front leg 32, the leg base 34, and the base connecting portion 35 can be manufactured by bending one pipe material or bar material. In this case, the cross-sectional shape of the back support rod 21 or the like is substantially cylindrical or substantially columnar.

  In the above embodiment, the backrest frame 22 is produced by bending a pipe material or a bar material. However, as shown in FIGS. 21 and 22, the back shape is such that the center portion of the curved plate material is cut out. The drowning frame 22 may be used. In short, the cross-sectional shape of each part 23, 24, 25, 26 of the backrest frame 22 is not limited to a substantially cylindrical shape or a substantially columnar shape.

  As shown in FIG. 23 or FIG. 24, a concave portion 11 or a convex portion 12 on which a finger can be hung may be provided on the lower surface side of the front end portion of the seat 1.

  Other specific configurations of each part can be variously modified without departing from the spirit of the present invention.

  The present invention can be used for, for example, a chair provided in a reception counter, a waiting room, a conference room, a school, or the like.

DESCRIPTION OF SYMBOLS 1 ... Seat 2 ... Backrest 21 ... Back support frame 22 ... Backrest frame 23 ... Upper frame part 231 ... Middle part 232 ... Left side edge part, right side edge part 24 ... Lower frame part 241 ... Middle part 242 ... Left side edge part, Right end 25 ... Left frame 26 ... Right frame 3 ... Leg structure 31 ... Rear leg 32 ... Front leg 33 ... Connecting part W ... Width dimension along first direction T ... Thickness along second direction Size

Claims (7)

A chair with a seat and a backrest, the backrest of which is
Upper frame part curved so that the middle part bulges backward while extending left and right, and lower frame part curved so that the middle part bulges rearward while extending left and right below the upper frame part A loop in which the left frame portion connecting the left end portion of the upper frame portion and the left end portion of the lower frame portion, and the right frame portion connecting the right end portion of the upper frame portion and the right end portion of the lower frame portion are made one round. A back frame that forms a shape;
Paired apart from the left and right, extending up and down above the seat, one upper end joined to a position located inward and rearward of the left end in the lower frame, and the other upper end A plurality of back support rods that support the back frame by joining the portion located inward and rearward than the right end portion of the lower frame portion ;
An inner periphery of the back frame surrounded by the upper frame portion, the lower frame portion, the left frame portion and the right frame portion is opened in the front-rear direction, or a back plate and a back frame attached to the back frame; A chair with a gap in between . The middle part of the upper frame part is located behind the middle part of the lower frame part,
The chair according to claim 1, wherein a height position of the lower frame portion corresponds to a height of a waist portion of a seated person. The chair according to claim 1 or 2, wherein a cross section of the backrest frame is substantially cylindrical or substantially columnar. The chair according to claim 1, 2, or 3, wherein the seat has a substantially circular outer periphery in plan view. The back support rod has a width dimension along a first direction orthogonal to the extending direction, and a thickness dimension along a second direction orthogonal to the extending direction and the first direction. The chair according to claim 1, 2, 3 or 4, which is enlarged. The seat and the backrest are supported by front and rear legs spaced forward and backward;
The chair according to claim 1, 2, 3, 4 or 5, wherein the back support rod and the rear leg are integrated and continuous. The chair according to claim 1, 2, 3, 4, 5 or 6, wherein a grip is attached to the backrest frame.

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