Backrest and chair

Abstract

To provide a backrest and chair capable of preventing interference between armrests (armrest bodies) to be lifted / lowered and a backrest body.SOLUTION: A backrest 4 includes: a backrest body 41 where a seated person leans his / her back against; a backrest support part 24 positioned on a rear side of the backrest body 41 so as to support the backrest body 41; and armrest bodies 71 arranged on outer sides of the backrest body 41 in a width direction so as to be supported in a lifting / lowering possible manner by the backrest support part 24 at a position separated from the backrest body 41. A chair 1 includes the backrest 4.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] There is known a chair backrest that has a backrest body against which a seated person leans and armrests that are provided on the sides of the backrest body and on which the seated person rests their arms (see, for example, Patent Document 1). In such a backrest, the armrests are supported by a frame portion provided on the outer periphery of the backrest body, so that the armrests can be provided close to the backrest body, and the armrests can support the arms of a seated person who is seated and leaning their back against the backrest from a position close to the backrest. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 8-507935 Summary of the Invention [Problem to be solved by the invention]

[0004] In a backrest having such an armrest attached thereto, when the armrest is raised or lowered, the rising and lowering armrest may interfere with the backrest body, and the interference between the armrest and the backrest body may lead to damage or deterioration of the backrest body.

[0005] SUMMARY OF THE PRESENT DISCLOSURE OF THE PRESENT DISCLOSURE An object of the present invention is to provide a backrest and chair that can prevent interference between the rising and lowering armrest (armrest main body) and the backrest main body. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the backrest of the present invention is characterized in having a backrest main body against which a seated person leans, a backrest support part located on the rear side of the backrest main body and supporting the backrest main body, and an armrest main body provided on the outside in the width direction of the backrest main body and supported on the backrest support part at a position spaced apart from the backrest main body so as to be able to be raised and lowered.

[0007] Moreover, a chair according to the present invention is characterized by having the above-mentioned backrest.

[0008] In the present invention, the armrest body is supported on the backrest support part at a position spaced apart from the backrest body so that it can be raised and lowered, thereby preventing the armrest body from interfering with the backrest body when the armrest body is raised or lowered.

[0009] Furthermore, the backrest according to the present invention may have an armrest body support part attached to the backrest support part and to which the armrest body is attached so as to be able to be raised and lowered. With this configuration, the lifting mechanism for raising and lowering the armrest main body can be provided in the armrest main body support part, rather than in the backrest support part, so that the backrest support part can have a simpler structure than when a lifting mechanism is provided in the backrest support part.

[0010] In addition, in the backrest according to the present invention, the backrest support portion may have a connecting portion to which the armrest main body support portion is connected in a contacting state from the outer side in the width direction. With this configuration, the armrest body support portion can be firmly connected to the backrest support portion.

[0011] In addition, in the backrest of the present invention, the armrest main body support part may be provided on the rear side of the backrest main body, and the backrest main body may have a front shielding wall provided on the front side of the connecting part and the armrest main body support part, which shields the connection part between the connecting part and the armrest main body support part from the front. With this configuration, the front shielding wall prevents the connecting portion between the connecting portion and the armrest main body support portion from being exposed to the front, thereby improving the design of the backrest.

[0012] In addition, in the backrest of the present invention, the backrest support portion may have a rear shielding wall that protrudes outward in the width direction from the rear edge of the connecting portion and shields the connection portion between the connecting portion and the armrest main body support portion from the rear. With this configuration, the rear shielding wall prevents the connecting portion between the connecting portion and the armrest main body support portion from being exposed to the rear, thereby improving the design of the backrest.

[0013] In addition, in the backrest of the present invention, the backrest main body may have an outer peripheral frame portion and a surface material that is stretched over the outer peripheral frame portion and covers at least a portion of the outer edge of the outer peripheral frame portion. In the present invention, the armrest body is supported on the backrest support part at a position spaced apart from the backrest body so that it can be raised and lowered, thereby preventing the armrest body from interfering with the surface material of the backrest body when the armrest body is raised or lowered, even if the surface material of the backrest body covers the outer edge of the outer frame part. Effect of the Invention

[0014] According to the present invention, interference between the armrest body and the backrest body which rise and fall can be prevented. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing an example of a chair according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a front view of a chair according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a rear view of a chair according to an embodiment of the present invention. [Figure 4] 1 is a perspective view showing the connecting structure between the backrest support portion and the outer peripheral frame portion. FIG. [Diagram 5] FIG. [Figure 6]5 is a cross-sectional view taken along line AA in FIG. 4. [Figure 7] 5 is a cross-sectional view taken along line BB in FIG. 4. [Figure 8] 5 is a cross-sectional view taken along line CC in FIG. 4. [Figure 9] 5 is a cross-sectional view taken along line DD in FIG. 4. [Figure 10] 1 is a perspective view of the outer peripheral frame portion as viewed diagonally from the front. [Figure 11] This is an oblique view of the outer peripheral frame portion as seen diagonally from behind. [Figure 12] FIG. [Figure 13] FIG. [Figure 14] FIG. [Figure 15] 15 is a cross-sectional view taken along line EE in FIG. 14. [Figure 16] 15 is a cross-sectional view taken along the line FF in FIG. 14. [Figure 17] 15 is a cross-sectional view taken along line GG in FIG. 14. [Figure 18] FIG. [Figure 19] 19 is a cross-sectional view taken along line HH in FIG. 18. [Figure 20] 13 is a cross-sectional view taken along line II in FIG. 12. [Figure 21] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, a backrest and a chair according to an embodiment of the present invention will be described with reference to Figs. 1 to 21. As shown in FIGS. 1 to 3, a chair 1 according to this embodiment has a support structure 2, a seat 3, and a backrest 4. In the following description, the direction in which a person seated on chair 1 faces forward is referred to as the front side, and the opposite side as the rear side, and the horizontal direction connecting the front side and the rear side is referred to as the front-to-rear direction. The horizontal direction perpendicular to the front-to-rear direction is referred to as the width direction. Chair 1 has a shape that is symmetrical in the width direction. With regard to the width direction, both ends of chair 1 relative to the center in the width direction may be referred to as the "outside in the width direction," and the center in the width direction relative to the ends in the width direction may be referred to as the "inside in the width direction" (see Figures 2 and 3).

[0017] The support structure 2 has legs 21, pillars 22, and a base 23. The legs 21 have a plurality of leg rods 211 arranged radially in a plan view. A caster 212 that comes into contact with the floor surface is provided at the tip of each leg rod 211. The leg pillar 22 stands upright in the center of the leg body 21. The leg pillar 22 is of an expandable type with a built-in gas spring, and has an outer cylinder 221 fixed to the leg body 21, and an inner cylinder 222 inserted into the outer cylinder 221 and extending above the outer cylinder 221. The inner cylinder 222 is configured to be able to move up and down with respect to the outer cylinder 221, and is also configured to be able to rotate relative to the outer cylinder 221.

[0018] The support base 23 is fixed to the upper end of the leg pillar 22. The seat portion 3 is disposed on the upper portion of the support base 23, and a backrest support portion 24 for the backrest 4 is disposed on the rear portion of the support base 23. The support base 23 supports the backrest support portion 24 so as to be tiltable (rotatable), and also supports the seat portion 3 forming the seating surface so as to be tiltable in conjunction with the backrest support portion 24.

[0019] (Backrest) As shown in Figures 1 to 4, the backrest 4 has a backrest main body 41 against which the seated person leans, a backrest support part 24 located behind the backrest main body 41 and supporting the backrest main body 41, and an armrest 7 located on the outer side in the width direction of the backrest main body 41 against which the seated person rests their elbow.

[0020] (Backrest support part) 4 and 5, the backrest support part 24 has a lower frame 241 that is connected to the support base 23 (see Figs. 1 to 3) and extends rearward from the support base 23, and a rear frame 242 that extends upward from the rear end of the lower frame 241. The lower frame 241 and the rear frame 242 are integrally formed. The backrest support part 24 is L-shaped in a side view seen from the width direction.

[0021] The lower frame 241 has a pair of rear extensions 243 that each extend in the front-rear direction and are spaced apart in the width direction, and a lower connecting portion 244 that connects front-rear middle portions of the pair of rear extensions 243. Of the pair of rear extensions 243, the rear extension 243 on one side in the width direction has a front end connected to one side in the width direction of the support base 23, and the rear extension 243 on the other side in the width direction has a front end connected to the other side in the width direction of the support base 23.

[0022] The rear frame 242 has a pair of upward extending portions 245 that extend upward from the rear ends of the pair of rear extending portions 243 and gradually toward the front, and an upper connecting portion 246 that connects the upper ends of the pair of upward extending portions 245. The upper connecting portion 246 is curved over its entire width such that the center in the width direction is recessed toward the rear.

[0023] The pair of upward extension parts 245 are provided with a gap in the width direction. One of the pair of upward extension parts 245 is located on one side in the width direction from the center in the width direction of the chair 1, and the other upward extension part 245 is located on the other side in the width direction from the center in the width direction of the chair 1. Therefore, the opposing sides of the pair of upward extension parts 245 are the inner sides in the width direction, and the sides spaced apart from each other are the outer sides in the width direction. The pair of upward extension portions 245 each have a connecting portion 5 formed in a rod shape extending gradually from the bottom toward the top toward the front, to which the backrest main body 41 is fixed, and a protruding plate portion 26 (rear shielding wall) that protrudes outward in the width direction from the rear edge portion 57 of the connecting portion 5.

[0024] As shown in Fig. 5, groove-shaped, concave-shaped, or hole-shaped hollowed-out portions are appropriately formed in the connecting portion 5. The outer circumferential surface of the connecting portion 5 is composed of a connecting portion front surface 51 that faces generally forward, a connecting portion rear surface 52 that faces generally backward, a connecting portion inner surface 53 that faces generally inward in the width direction, and a connecting portion outer surface 54 that faces generally outward in the width direction. A "surface facing the ·· side" or a "surface facing the ·· direction" refers to a surface whose normal extends to the "·· side" or "in the ·· direction".

[0025] The connecting portion rear surface 52 is formed as a surface that gradually approaches the front side from the lower side to the upper side and gradually approaches the rear side from the outer side to the inner side in the width direction. The connecting portion rear surface 52 is continuous with the rear surface of the upper connecting portion 246 without any corners or steps. The connecting portion front surface 51 is formed on a surface that gradually extends from the lower side to the upper side toward the front side and from the outer side to the inner side in the width direction toward the rear side. The connecting portion front surface 51 is approximately parallel to the connecting portion rear surface 52.

[0026] The connecting portion inner surface 53 is formed such that the vicinity of the rear end portion faces slightly rearward from the inside in the width direction, and the portion further forward faces the inside in the width direction. The connecting portion outer surface 54 is formed on a surface that gradually turns inward in the width direction from the rear side to the front side. The connecting portion outer surface 54 is a surface that is approximately perpendicular to the connecting portion rear surface 52 and the connecting portion front surface 51. The width of the connecting portion 5 gradually decreases from the rear side to the front side.

[0027] The connecting portion 5 has two first holes 55 spaced apart in the vertical direction, into which a first bolt 61 (see Figures 6 and 7) for fixing the backrest main body 41 is inserted, and two second holes 56 spaced apart in the vertical direction, into which a second bolt 62 (see Figures 8 and 9) for fixing the armrest main body support portion 72 of the armrest 7 is inserted. The two second holes 56 are formed between the two first holes 55 .

[0028] 6 and 7, the connecting portion 5 is formed with a front recess 551 that opens to the front and a rear recess 552 that is located behind the front recess 551 and opens to the rear, at two positions spaced apart in the up-down direction. The front recess 551 and the rear recess 552 are arranged side by side in the approximately front-to-rear direction via an intermediate plate portion 553. The intermediate plate portion 553 is formed in a plate shape with a plate surface facing the front-to-rear direction, and a hole portion penetrating in the front-to-rear direction is formed in the center portion in a front view. This hole portion is the first hole portion 55. 5, the connecting portion 5 has a notch 554 formed in the upper portion of the front recess 551 located on the upper side, and is configured so that the inside of the front recess 551 communicates with the upper portion of the connecting portion 5 via the notch 554. The notch 554 is located in the upper portion of the outer portion of the front recess 551 in the width direction.

[0029] As shown in Figs. 8 and 9, the connecting portion 5 has inner recesses 561 that open to the inside in the width direction formed at two locations spaced apart in the up-down direction between the two first hole portions 55 (see Fig. 5). In this embodiment, the inner recesses 561 also open to the rear. The bottom surface 562 of the inner recesses 561 is formed as a surface that gradually extends outward in the width direction from the front side to the rear side. The bottom surface 562 of the inner recesses 561 is disposed parallel to the connecting portion outer side surface 54.

[0030] The connecting portion 5 has a hole formed therein that penetrates from the bottom surface 562 of the inner recess 561 to the connecting portion outer surface 54. This hole serves as the second hole 56. The second hole 56 penetrates the connecting portion 5 in an oblique direction that gradually moves forward from the inside toward the outside in the width direction. The penetration direction of the second hole 56 is a first oblique direction that extends along the connecting portion front surface 51 and the connecting portion rear surface 52 and gradually moves forward from the inside toward the outside in the width direction. The first oblique direction indicates a direction gradually moving from the inside to the outside in the width direction toward the front side, and an opposite direction gradually moving from the outside to the inside in the width direction toward the rear side. The first oblique direction is substantially horizontal. The side gradually moving from the inside to the outside in the width direction in the first direction toward the front is defined as the outside, and the opposite side, the side gradually moving from the outside to the inside in the width direction toward the rear is defined as the inside.

[0031] As shown in Figs. 5, 8 and 9, the protruding plate portion 26 is formed in a plate shape protruding in the first oblique direction from the rear edge portion 57 of the connecting portion 5, and its surface is a surface that follows the curvature of the upper connecting portion 246. The rear surface 261 of the protruding plate portion 26 is smoothly continuous with the connecting portion rear surface 52 without a step or a bent portion 462. The front surface 262 of the protruding plate portion 26 is located rearward of the second hole portion 56. This allows the protruding plate portion 26 to be configured not to interfere with the second hole portion 56. The protruding plate portion 26 has a dimension that protrudes outward in the width direction from the connecting portion 5 from the upper side to the lower side, and the plate surface has a substantially triangular shape in which the dimension in the width direction gradually decreases from the upper side to the lower side.

[0032] (Backrest body) The backrest main body 41 is disposed in front of the rear frame 242 of the backrest support portion 24. The backrest body 41 has a rectangular outer peripheral frame portion 42 with an opening 421 formed on the inside, and a surface material 43 (see Figs. 1 to 3) that covers the opening 421 and is engaged with the outer peripheral frame portion 42. In Fig. 4, the surface material 43 is omitted. The face material 43 is made of a membrane-like material such as mesh or cloth, and is formed larger than the shape of the outer peripheral frame portion 42 when viewed from the front side.

[0033] As shown in FIGS. 4, 10, and 11, the outer peripheral frame portion has an upper frame portion 44, a lower frame portion 45, and a pair of vertical frame portions . The pair of vertical frame portions 46 are provided with a gap in the width direction. One of the pair of vertical frame portions 46 is located on one side in the width direction from the center in the width direction of the chair 1, and the other vertical frame portion 46 is located on the other side in the width direction from the center in the width direction of the chair 1. Therefore, the sides of the pair of vertical frame portions 46 that face each other are the inner sides in the width direction, and the sides that are separated from each other are the outer sides in the width direction.

[0034] The upper frame portion 44 is a member extending in the width direction and is curved across the entire width direction so that the center in the width direction juts out upward when viewed from the front and the center in the width direction juts out rearward when viewed from above. An upper frame panel material locking groove 441 that locks the upper edge of the panel material 43 (see Figures 1 to 3) is formed in the upper frame portion 44. The upper frame panel material locking groove 441 is a groove that opens upward and is formed across the entire width direction of the upper frame portion 44. The lower frame portion 45 is a member extending in the width direction and is curved over the entire width direction so that the center in the width direction protrudes downward in a front view and the center in the width direction protrudes rearward in a plan view. The lower frame portion 45 is formed with a lower frame surface material locking groove portion 451 that locks the lower edge portion of the surface material 43. The lower frame surface material locking groove portion 451 is a groove portion that opens downward and is formed across the entire width direction of the lower frame portion 45.

[0035] The pair of vertical frame portions 46 have bent portions 462 formed in the middle in the up-down direction. In a side view from the width direction, the portions of the pair of vertical frame portions 46 below the bent portion 462 extend gradually toward the front from the bottom to the top, and the portions above the bent portion 462 extend gradually toward the rear from the bottom to the top. In addition, in a front view, the portions of the pair of vertical frame portions 46 below the bent portion 462 extend gradually toward the outside in the width direction from the bottom to the top, and the portions above the bent portion 462 extend gradually toward the inside in the width direction from the bottom to the top. The bent portion 462 is located below the center of each of the pair of vertical frame portions 46 in the up-down direction.

[0036] The pair of vertical frame portions 46 each have a panel material engaging portion 463 (front shielding wall) that engages the panel material 43, a backrest connecting portion 464 that is formed continuously with the panel material engaging portion 463 and is fixed to the backrest support portion 24, and a rib 465 that protrudes rearward from the panel material engaging portion 463.

[0037] The surface material locking portion 463 is provided over the entire vertical frame portion 46 in the up-down direction, with an upper end connected to the upper frame portion 44 and a lower end connected to the lower frame portion 45. The surface material locking portion 463 of one of the pair of vertical frame portions 46 has an upper end connected to one end of the upper frame portion 44 in the width direction and a lower end connected to one end of the lower frame portion 45 in the width direction. The surface material locking portion 463 of the other of the pair of vertical frame portions 46 has an upper end connected to the other end of the upper frame portion 44 in the width direction and a lower end connected to the other end of the lower frame portion 45 in the width direction.

[0038] A vertical frame panel locking groove 461 that locks the side edge of the panel 43 is formed in the panel locking portion 463. The vertical frame panel locking groove 461 is a groove that opens to the inside in the width direction and is formed over the entire vertical direction. The pair of vertical frame panel locking grooves 461 are respectively continuous with the upper frame panel locking groove 441 and the lower frame panel locking groove 451. As a result, grooves for locking the panel 43 are formed over the entire outer periphery of the outer periphery frame portion 42.

[0039] 10 and 11, the backrest connecting portion 464 is provided on the entire portion of the vertical frame portion 46 below the bent portion 462. The backrest connecting portion 464 is provided on the inside in the width direction of the panel engaging portion 463. The lower end portion of the backrest connecting portion 464 is connected to the lower frame portion 45. The backrest connecting portion 464 has a connecting plate portion 47 which extends gradually rearward from the rear edge portion of the portion lower than the bent portion 462 of the panel material engaging portion 463 toward the inside in the width direction, and a connecting protrusion portion 48 which protrudes rearward from the connecting plate portion 47.

[0040] The connecting plate portion 47 is formed long and extends in the up-down direction, and its lower end portion is connected to the lower frame portion 45. The connecting plate portion 47 has a connecting plate portion front surface 471 facing forward that faces slightly inward in the width direction than the front side in the front-to-rear direction, and a connecting plate portion rear surface 472 facing rearward that faces slightly outward in the width direction than the rear side in the front-to-rear direction. The connecting plate portion 47 is formed in a shape that follows the lower frame portion 45 in a plan view.

[0041] Two connecting protrusions 48 are provided at an interval in the up-down direction for each connecting plate portion 47. As shown in Fig. 11, each connecting protrusion 48 has a tubular portion 481 protruding rearward from the connecting plate portion 47, and a tip plate portion 482 connected to cover the tip end (rear end) of the tubular portion 481. The tip plate portion 482 is formed in a flat plate shape with a plate surface facing in the front-rear direction, and a third hole portion 483 penetrating in the front-rear direction is formed in the center of the plate surface. 6 and 7, the connecting protrusion 48 is formed in a shape that fits from the front side into the front recess 551 of the connecting part 5 of the backrest support part 24. When the connecting protrusion 48 fits into the front recess 551 of the connecting part 5 of the backrest support part 24, the third hole 483 is set to overlap with the first hole 55 of the front recess 551 in the front-rear direction.

[0042] 11, the rib 465 is provided in the vertical middle portion of the vertical frame portion 46, in a portion including the bent portion 462 and the areas above and below it. The rib 465 is formed in a plate shape with the plate surface facing the width direction. The lower end portion of the rib 465 is connected to the side surface of the cylindrical portion 481 of the connecting protrusion portion 48 disposed on the upper side. A notch portion 466 that opens rearward and downward is formed on the lower side of the rib 465.

[0043] 1 and 2, the surface material 43 is stretched on the front side of the vertical frame portion 46 so as to cover the inside of the outer peripheral frame portion 42, and wraps around the front faces of the upper frame portion 44, the lower frame portion 45 and the pair of vertical frame portions 46, with the outer edge portion being inserted into the surface material locking groove portions 441, 451, 461 and locked to the outer peripheral frame portion 42. The surface formed by the surface material 43 on which a seated person leans back is defined as a backrest surface 431. The backrest surface 431 is curved so that the center in the width direction is recessed further rearward than the outer end portions in the width direction. The surface material 43 stretched over the outer peripheral frame portion 42 is configured to be elastically deformable by a load applied from the front. The outer peripheral frame portion 42 is also configured to be elastically deformable by a load applied to the surface material 43.

[0044] The outer peripheral frame portion 42 is fixed to the backrest support portion 24 with the face material 43 stretched thereover. The outer peripheral frame portion 42 is fixed to the front side of the rear frame 242 of the backrest support portion 24. 4, the backrest connecting portion 464 of the pair of vertical frame portions 46 is disposed in front of the connecting portion 5 of the upward extending portion 245 of the rear frame 242. The connecting plate portion 47 of the backrest connecting portion 464 has a connecting plate portion rear surface 472 abutting against the connecting portion front surface 51 of the connecting portion 5. The connecting protrusion 48 of the backrest connecting portion 464 is inserted into the front recess 551 of the connecting portion 5.

[0045] The outer peripheral frame portion 42 is connected to the backrest support portion 24 by fastening the first bolt 61 inserted through the third hole portion 483 formed in the tip plate portion 482 of the connecting protrusion portion 48 of the backrest connecting portion 464 which overlaps in the fore-and-aft direction and the first hole portion 55 of the front recess portion 551 of the connecting portion 5 of the backrest support portion 24 to the nut. The ribs 465 of a pair of vertical frame portions 46 have their lower end portions connected to the upper connecting protrusion 48 inserted into cut-out portions 554 formed above the front recess 551 of the connecting portion 5, and the portions above these lower end portions are positioned above the connecting portion 5.

[0046] To fix the backrest main body 41 to the backrest support portion 24, first, the surface material 43 is attached to the outer peripheral frame portion 42. The backrest connecting portion 464 of the pair of vertical frame portions 46 of the outer peripheral frame portion 42 is disposed in front of the connecting portion 5 of the upward extending portion 245 of the rear frame 242. Then, the connecting plate portion rear surface 472 of the connecting plate portion 47 of the backrest connecting portion 464 is brought into contact with the connecting portion front surface 51 of the connecting portion 5. Also, the connecting protrusion 48 of the backrest connecting portion 464 is inserted into the front recess 551 of the connecting portion 5. In this way, the third hole 483 formed in the tip plate 482 of the connecting protrusion 48 of the backrest connecting part 464 and the first hole 55 of the front recess 551 of the connecting part 5 of the backrest support part 24 overlap in the front-rear direction, and the first bolt 61 is inserted through the first hole 55 and the third hole 483 and fastened with the nut 63. This connects the backrest main body 41 to the backrest support part 24. The nut 63 may be fixed inside the connecting protrusion 48. In this way, a recess 27 is formed between the backrest support part 24 and the backrest main body 41, which are connected to each other, and extends substantially in the vertical direction and opens outward in the first diagonal direction and is surrounded by the protruding plate part 26 of the backrest support part 24, the connecting part outer surface 54 of the connecting part 5, and the surface material engaging part 463 of the vertical frame part 46 of the backrest main body 41. The armrest main body support part 72 of the armrest 7 is inserted into this recess 27.

[0047] (Armrest) As shown in Figures 12 and 13, the armrest 7 has an armrest main body 71 on which the seated occupant rests their arm, an armrest main body support part 72 that is fixed to the backrest support part 24 and supports the armrest main body 71 so that it can be raised and lowered, and a cover member 73 that covers the armrest main body support part 72.

[0048] 13 and 14, the armrest body support part 72 has a front member 74 which is a long block-shaped member extending generally in the vertical direction, and a rear member 75 which is a long block-shaped member also extending generally in the vertical direction and connected to the rear side of the front member 74. The front member 74 and the rear member 75 are each formed from a metal such as an aluminum alloy, and are connected with connectors (not shown) such as bolts. The armrest body support portion 72, in which the front member 74 and the rear member 75 are connected, extends in a first oblique direction when viewed from the top-bottom direction.

[0049] The front member 74 has a front connecting portion 741 located on the inside in the first diagonal direction, and a front protruding piece 742 protruding from a front portion of the front connecting portion 741 toward the outside in the first diagonal direction. The front-facing surface of the front connecting portion 741 (front surface 741a) and the front-facing surface of the front protruding piece 742 (front surface 742a) are each formed so as to face slightly inward in the width direction from the front side in the front-to-rear direction. The front surface 741a of the front connecting portion 741 and the front surface 742a of the front protruding piece 742 are disposed flush with each other.

[0050] A first step 741c is formed in the middle in the first diagonal direction on a surface (rear surface 741b) facing rearward of the front connecting part 741, and an outer part 741d that is more outward in the first diagonal direction than the first step 741c is located forward of an inner part 741e that is more inward in the first diagonal direction than the first step 741c. The outer part 741d and the inner part 741e on the rear surface 741b of the front connecting part 741 are both formed on a surface that faces slightly outward in the width direction than the rear side in the front-to-rear direction. The rearward facing surface of the front protruding piece 742 (referred to as rear surface 742b) is formed on a surface that faces slightly outward in the width direction relative to the rear side in the front-to-rear direction. The rear surface 742b of the front protruding piece 742 is located forward of an outer portion 741d on the rear surface of the front connecting portion 741. A second step portion 742c is formed between the rear surface 742b of the front protruding piece 742 and the rear surface 741b of the front connecting portion 741.

[0051] As shown in FIG. 13, an inner side surface in the first diagonal direction of the front coupling part 741 (referred to as a first side surface 741f) is formed on a surface facing inward in the first diagonal direction. 15 to 17, the front connecting part 741 has a recessed fourth hole 743 that opens inward in the first diagonal direction formed in the inner part in the first diagonal direction. A screw thread is formed on the circumferential surface of the fourth hole 743. Two fourth holes 743 are provided at intervals in the up-down direction.

[0052] As shown in FIG. 14, the rear member 75 is formed in a flat plate shape. The surface of the rear member 75 facing the front side (referred to as the front surface 75a) is formed so as to face slightly inward in the width direction than the front side in the front-to-rear direction. The surface of the rear member 75 facing the rear side (referred to as the rear surface 75b) is formed so as to face slightly outward in the width direction than the rear side in the front-to-rear direction. The rear member 75 is disposed so that its inner end 75c in the first diagonal direction is positioned at the first step portion 741c of the front member 74 and protrudes outward in the first diagonal direction beyond the front connecting portion 741 of the front member 74.

[0053] The rear member 75 has a rear connecting portion 751 that is arranged rearward of the front connecting portion 741 and connected to the front connecting portion 741, and a rear protruding piece 752 that is arranged outward in a first diagonal direction from the rear connecting portion 751 and protrudes outward in the first diagonal direction further than the front connecting portion 741. The front protruding piece 742 and the rear protruding piece 752 are arranged in parallel with a gap in the front-rear direction. An elevation groove 744 is formed in the armrest body support part 72, sandwiched between the front protruding piece 742 and the rear protruding piece 752, on the outer side in the first diagonal direction than the front connecting part 741.

[0054] The front connecting portion 741 of the front member 74 and the rear connecting portion 751 of the rear member 75, which are connected to each other, are collectively referred to as the first base portion 721. The front surface 721a of the first base portion 721 indicates the front surface 741a of the front connecting portion 741, the rear surface 721b of the first base portion 721 indicates the inner portion 741e of the rear surface 741b of the front connecting portion 741 and the rear surface 751b of the rear connecting portion 751, the upper surface 721c of the first base portion 721 indicates the upper surfaces of the front connecting portion 741 and the rear connecting portion 751, and the lower surface 721d of the first base portion 721 indicates the lower surfaces of the front connecting portion 741 and the rear connecting portion 751. Also, the first side surface 721e on the inside in the first diagonal direction of the first base portion 721 indicates the first side surface 741f of the front connecting portion 741.

[0055] As shown in FIG. 15, two front protruding piece grooves 745 extending in the vertical direction are formed at a distance in the vertical direction on the rear surface 742b of the front protruding piece 742. The cross section of the front protruding piece groove 745 is formed in a semicircular arc shape. The front protruding piece groove 745 does not reach the upper end and the lower end of the front protruding piece 742, and is configured not to communicate with the upper and lower parts of each of the front protruding pieces 742. The downward end faces located at the upper end of each of the two front protruding piece grooves 745 are the front protruding piece groove upper end face 745a, and the upward end faces located at the lower end of the front protruding piece groove 745 are the front protruding piece groove lower end face 745b. A first sliding member 761 is attached to the outer end face in the first diagonal direction and the rear face of the front protruding piece 742. The first sliding member 761 is attached at a position where it does not interfere with the front protruding piece groove portion 745.

[0056] As shown in FIG. 16, two rear protruding grooves 755 extending in the vertical direction are formed at a distance in the vertical direction on the front surface 752a of the rear protruding piece 752. The cross section of the rear protruding groove 755 is formed in a semicircular arc shape. The rear protruding groove 755 is disposed at a position facing the front protruding groove 745. The rear protruding groove 755 does not reach the upper end and the lower end of the rear protruding piece 752, and is configured not to communicate with the upper and lower parts of each of the rear protruding pieces 752. The downward end faces located at the upper end of each of the two rear protruding grooves 755 are the rear protruding groove upper end faces 755a, and the upward end faces located at the lower end of the rear protruding groove 755 are the rear protruding groove lower end faces 755b. A second sliding member 762 is attached to the outer end face in the first diagonal direction and the front face of the rear protruding piece 752. The second sliding member 762 is attached at a position where it does not interfere with the rear protruding piece groove portion 755.

[0057] As shown in Figure 18, the armrest main body 71 has an upper rod 711 provided on the upper side and extending in the front-to-rear direction, and a rear rod 712 provided on the rear side and extending diagonally from the rear end of the upper rod 711 downward and gradually toward the rear. An elbow rest 713 is provided on the upper part of the front portion of the upper rod 711. The rear rod 712 is configured so that the armrest body support part 72 (see FIG. 13) is attached to the inside in the width direction. The rear rod 712 is formed to be longer in the up-down direction than the armrest body support part 72. The armrest main body 71 has an armrest main body cover portion 714 which forms the outer shell, and the portion covering the upper rod 711 and the portion covering the rear rod 712 are formed integrally.

[0058] 18 and 19, the armrest body cover part 714 has two armrest body cover grooves 714a, 714b formed at a distance in the front-rear direction, which extend vertically on the inside widthwise of the part covering the rear rod 712. Each of the two armrest body cover grooves 714a, 714b is formed to be longer than the vertical dimension of the armrest body support part 72. Of the two armrest body cover grooves 714a, 714b, the front groove is referred to as the front armrest body cover groove 714a, and the rear groove is referred to as the rear armrest body cover groove 714b.

[0059] As shown in Figure 20, the inside of the armrest body cover portion 714 of the rear rod 712 is configured so that the front protruding piece 742 of the armrest body support portion 72 is inserted into the front armrest body cover groove portion 714a, and the rear protruding piece 752 of the armrest body support portion 72 is inserted into the rear armrest body cover groove portion 714b. In this embodiment, the portion of the armrest main body cover part 714 where the two armrest main body cover grooves 714a, 714b are formed is formed as a member that is detachable from the other parts.

[0060] 19 and 20, a rail member 77 that engages with the armrest body support part 72 so as to be movable relative to the armrest body cover part 714 of the rear rod 712 is provided inside the rear rod 712. The rail member 77 is formed so that the vertical dimension is slightly smaller than the vertical dimension of the rear rod 712, and is formed so as to be longer than the vertical dimension of the armrest body support part 72. 19 to 21, rail member 77 has a rod-shaped second base portion 771 extending in the up-down direction, and a convex portion 772 protruding inward in a first oblique direction from the entire up-down direction of second base portion 771. Convex portion 772 protrudes inward in the first oblique direction from a middle portion of second base portion 771 in the front-rear direction. The surface facing the front side of the protruding portion 772 (referred to as the front surface 772a) is formed to face slightly inward in the width direction than the front side in the front-to-rear direction. The surface facing the rear side of the protruding portion 772 (referred to as the rear surface 772b) is formed to face slightly outward in the width direction than the rear side in the front-to-rear direction. The front surface 772a and the rear surface 772b of the protruding portion 772 are parallel to each other.

[0061] A protruding-stripe front groove 772c extending over the entire vertical direction is formed on a front surface 772a of the protruding strip 772. The cross section of the protruding-stripe front groove 772c is formed in an arc shape. A protruding-stripe rear groove 772d extending over the entire vertical direction is formed on a rear surface 772b of the protruding strip 772. The cross section of the protruding-stripe rear groove 772d is formed in an arc shape.

[0062] The rail member 77 is disposed at a position overlapping with the two armrest body cover grooves 714a, 714b inside the armrest body cover part 714. As shown in Fig. 20, the convex strip part 772 of the rail member 77 is inserted into the lift groove part 744 between the front protruding piece 742 and the rear protruding piece 752 of the armrest body support part 72, which is inserted through the armrest body cover grooves 714a, 714b into the armrest body cover part 714 of the rear rod 712. The second base part 771 of the rail member 77 abuts against the tip surfaces of the front protruding piece 742 and the rear protruding piece 752 via the sliding members 761, 762.

[0063] A front surface 772a of the protruding portion 772 faces, with a gap therebetween, a rear surface 742b of the front protruding piece 742. Protruding portion front grooves 772c of the front surface 772a of the protruding portion 772 face each of the two front protruding piece grooves 745 of the rear surface 742b of the front protruding piece 742. A cylindrical front retaining member 763 extending in the vertical direction is provided between the protruding rib front groove portion 772c and each of the two front protruding piece groove portions 745. The surface of the front retaining member 763 is formed into a sliding surface.

[0064] Front stopper member 763 is formed with a length dimension slightly shorter than the longitudinal dimension of front protruding piece groove portion 745, and its front half is inserted into each of the two front protruding piece groove portions 745. Front stopper member 763 inserted into front protruding piece groove portion 745 has its vertical displacement relative to front protruding piece 742 restricted by front protruding piece groove upper end face 745a and front protruding piece groove lower end face 745b of front protruding piece groove portion 745. The rear half of the front stopper member 763 is inserted into the convex-strip-front groove portion 772c of the convex-strip-part 772. The front stopper member 763 inserted into the convex-strip-front groove portion 772c is configured to be relatively displaceable in the up-down direction along the convex-strip-front groove portion 772c with respect to the convex-strip-part 772.

[0065] A rear surface 772b of the protruding portion 772 faces, with a gap therebetween, a front surface 752a of the rear protruding piece 752. The protruding portion rear grooves 772d of the rear surface 772b of the protruding portion 772 face each of the two rear protruding piece grooves 755 of the front surface 752a of the rear protruding piece 752. A cylindrical rear slip-out prevention member 764 extending in the vertical direction is provided between the protruding rib rear groove portion 772d and each of the two rear protruding piece groove portions 755. The surface of the rear slip-out prevention member 764 is formed into a sliding surface. A cylindrical rear slip-out prevention member 764 extending in the vertical direction is provided between the protruding rib front groove portion 772c and each of the two rear protruding piece groove portions 755. The surface of the rear slip-out prevention member 764 is formed into a sliding surface.

[0066] Rear-side fall-off prevention member 764 is formed with a length dimension slightly shorter than the longitudinal dimension of rear-side protruding piece groove portion 755, and its front half is inserted into each of the two rear-side protruding piece groove portions 755. Rear-side fall-off prevention member 764 inserted into rear-side protruding piece groove portion 755 is restricted from vertical displacement relative to rear-side protruding piece 752 by rear-side protruding piece groove upper end face 755a and rear-side protruding piece groove lower end face 755b of rear-side protruding piece groove portion 755. The rear half of the rear stopper member 764 is inserted into the convex portion rear groove portion 772d of the convex portion 772. The rear stopper member 764 inserted into the convex portion rear groove portion 772d is configured to be relatively displaceable in the up-down direction along the convex portion 772 and the convex portion rear groove portion 772d.

[0067] Such an armrest main body 71 is configured to be able to move up and down relative to the armrest main body support part 72, with the convex slit 772 of the rail member 77 inserted into the lifting groove 744 of the armrest main body support part 72. A front anti-slip member is provided between the convex slit 772 of the rail member 77 and the front protruding piece 742 of the armrest main body support part 72, and a rear anti-slip member is provided between the convex slit 772 of the rail member 77 and the rear protruding piece 752 of the armrest main body support part 72, thereby preventing the armrest main body support part 72 from separating from the rail member 77 and coming out of the armrest main body 71. Although not shown, a height adjustment section of known structure is provided to restrain the armrest body 71 at a desired height.

[0068] 12 and 13, the cover member 73 covers the first base portion 721 of the armrest body support portion 72. The cover member 73 is formed in a cylindrical shape and is disposed so as to open in a first oblique direction. The cover member 73 has a front plate portion 731 that covers the front surface 721a of the first base portion 721, a rear plate portion 732 that covers the rear surface 721b of the first base portion 721, an upper plate portion 733 that covers the upper surface 721c of the first base portion 721, and a lower plate portion 734 that covers the lower surface 721d of the first base portion 721.

[0069] An upper end of the front plate portion 731 is located above an upper surface 721c of the first base portion 721, and a lower end is located below a lower surface 721d of the first base portion 721. An inner end of the front plate portion 731 in the first diagonal direction is disposed at a position overlapping with a first side surface 721e of the first base portion 721. An outer edge of the front plate portion 731 in the first diagonal direction is disposed at a position overlapping an outer edge of the first base portion 721 in the first diagonal direction. A front plate step 731b extending in the up-down direction is formed in the middle in the first diagonal direction on a front surface 731a of the front plate 731. An outer portion 731c of the front plate 731 that is outer than the front plate step 731b in the first diagonal direction is located forward of an inner portion 731d that is inner than the front plate step 731b in the first diagonal direction.

[0070] The upper end of the rear plate portion 732 is located above an upper surface 721c of the first base portion 721, and the lower end is located below a lower surface 721d of the first base portion 721. An inner end of the front plate portion 731 in the first oblique direction is disposed at a position overlapping with a first side surface 721e of the first base portion 721. An outer edge of the front plate portion 731 in the first diagonal direction is disposed at a position overlapping an outer edge of the first base portion 721 in the first diagonal direction.

[0071] The upper plate portion 733 has a front edge connected to an upper edge of the front plate portion 731 and a rear edge connected to an upper edge of the rear plate portion 732. An outer edge of the upper plate portion 733 in the first diagonal direction is disposed at a position overlapping with a vicinity of an outer edge of the first base portion 721 in the first diagonal direction. The upper plate portion 733 protrudes inward in the width direction more than the front plate portion 731 and the rear plate portion 732. A portion of the upper plate portion 733 that protrudes inward in the width direction more than the front plate portion 731 and the rear plate portion 732 is referred to as a protruding plate portion 733b. The protruding plate portion 733b protrudes inward in the width direction more than the first base portion 721. A plurality of upper ribs 735 are formed on the lower side of the upper plate portion 733, protruding downward from the lower surface of the upper plate portion 733. The upper ribs 735 are configured so that their lower ends come into contact with the upper surface 721c of the first base portion 721.

[0072] The lower plate portion 734 has a front edge connected to the lower edge of the front plate portion 731 and a rear edge connected to the lower edge of the rear plate portion 732. The outer edge of the lower plate portion 734 in the width direction is disposed at a position overlapping with the vicinity of the outer edge of the first base portion 721 in the width direction. The inner edge of the lower plate portion 734 in the width direction is disposed at a position overlapping with the underside of the first side surface 721e of the first base portion 721. A plurality of lower ribs 736 protruding upward from the upper surface of the lower plate portion 734, and an inner plate portion 737 provided on the upper side of the lower plate portion 734 are provided. The inner plate portion 737 has a plate surface facing substantially in the vertical direction, with a front edge portion connected to the front plate portion 731 and a rear edge portion connected to the rear plate portion 732. The upper surface of the inner plate portion 737 is configured to abut against a lower surface 721d of the first base portion 721.

[0073] In the armrest 7, the armrest main body support part 72 and the armrest main body 71 are connected to each other, and a cover member 73 is attached to a first base part 721 of the armrest main body support part 72, with the armrest main body support part 72 fixed to the backrest support part 24. In the following, it is assumed that the armrest main body support part 72 and the armrest main body 71 are connected to each other, and a cover member 73 is attached to the first base part 721 of the armrest main body support part 72. Moreover, after the backrest main body 41 is fixed to the backrest support part 24, the armrest 7 is fixed to the backrest support part 24 by inserting the armrest main body support part 72 and the cover member 73 into the recess 27 between the backrest support part 24 and the backrest main body 41 which are connected to each other. As described above, the recess 27 is surrounded by the protruding plate part 26 of the backrest support part 24, the connecting part outer surface 54 of the connecting part 5, and the surface material engaging part 463 of the vertical frame part 46 of the backrest main body 41, and opens outward in the first diagonal direction.

[0074] As shown in FIGS. 8 and 9, to fix the armrest 7 to the backrest support part 24, first, the inner part in the first diagonal direction of the armrest main body support part 72 is inserted into the recess 27. At this time, the armrest 7 is inserted into the recess 27 so that the two upper and lower fourth hole portions 743 of the armrest body support part 72 overlap with the two upper and lower second hole portions 56 of the connecting part 5 in the first diagonal direction, respectively. Then, the first side surface 721e of the first base portion 721 is brought into contact with the connecting portion outer side surface 54 of the connecting portion 5 of the backrest support portion 24, and the inner edges in the first diagonal direction of the front plate portion 731, the rear plate portion 732 and the lower plate portion 734 (see FIG. 13) of the cover member 73 are brought into contact with the connecting portion outer side surface 54. The protruding plate portion 733b of the upper plate portion 733 of the cover member 73 is disposed above the connecting portion 5, and the lower surface of the protruding plate portion 733b is brought into contact with the upper surface of the connecting portion 5. The inner portion 731d of the front surface 731a of the front plate portion 731 of the cover member 73 is brought into contact with the rear surface of the panel engaging portion 463 of the vertical frame portion 46 of the backrest main body 41.

[0075] The connecting part 5 and the armrest body support part 72 are located on the rear side of the panel 43, and the second hole 56 of the connecting part 5 and the fourth hole 743 of the armrest body support part 72 open in an oblique direction facing forward rather than outward in the width direction. The opening direction of the second hole 56 and the fourth hole 743 is along the backrest body 41. The opening direction of the second hole 56 and the fourth hole 743 is from the inside to the outside in the width direction, approaching the backrest surface 431. The second bolt 62 is inserted from the inside to the outside in the width direction into the second hole portion 56 and the fourth hole portion 743. Therefore, the second bolt 62 is configured to be inserted into the second hole portion 56 and the fourth hole portion 743 from the side away from the backrest surface 431 toward the side close to the backrest surface 431. The armrest body support portion 72 is fixed to the backrest support portion 24 by inserting the second bolt 62 through the second hole portion 56 and the fourth hole portion 743 from the inside in the width direction and fastening it with a nut. At this time, the connecting portion front surface 51 and the inner portion 731d of the front surface 731a of the front plate portion 731 of the cover member 73 are disposed so as to be substantially flush with each other.

[0076] The armrest main body support part 72 and cover member 73 are sandwiched from the front and rear between the protruding plate part 26 of the backrest support part 24 and the surface material locking part 463 of the vertical frame part 46, covering the connecting part between the armrest main body support part 72 and the cover member 73 and the connecting part 5. The outer end part in the width direction of the surface material locking part 463 of the vertical frame part 46 is arranged along the front plate step part 731b of the front plate part 731 of the cover member 73, and is in contact with the front plate step part 731b from the inside in the width direction. This prevents the cover member 73 and the vertical frame part 46 from shifting in the width direction.

[0077] 2, the armrest body support part 72 and the cover member 73 protrude outward in the width direction further than the backrest body 41, and the armrest body 71 supported by the armrest body support part is spaced apart from the backrest body 41 and positioned outward in the width direction further than the outer periphery frame part 42. The upper rod 711 of the armrest body 71 extends in the front-to-rear direction. The armrest rest part 713 of the upper rod 711 of the armrest body 71 is positioned further forward than the backrest body 41, and is therefore spaced apart from the backrest body 41. In addition, after the armrest 7 is fixed to the backrest support part 24, the backrest main body 41 may be fixed to the backrest support part 24.

[0078] Next, the action and effect of the backrest and chair according to the above-described embodiment will be described with reference to the drawings. In the backrest 4 and chair 1 of the present embodiment described above, the armrest main body 71 is supported on the backrest support portion 24 at a position spaced apart from the backrest main body 41 so that it can be raised and lowered, thereby preventing the armrest main body 71 from interfering with the backrest main body 41 when the armrest main body 71 is raised or lowered.

[0079] In addition, by having the armrest body support part 72 which is supported by the backrest support part 24 and supports the armrest body 71 so that it can be raised and lowered, the lifting mechanism for raising and lowering the armrest body 71 can be provided in the armrest body support part 72 rather than in the backrest support part 24, so that the backrest support part 24 can have a simpler structure than when a lifting mechanism is provided in the backrest support part 24.

[0080] In addition, since the backrest support part 24 has a connecting part 5 to which the armrest main body support part 72 is connected in contact from the outside in the width direction, the armrest main body support part 72 can be firmly connected to the backrest support part 24.

[0081] In addition, the armrest main body support part 72 is provided on the rear side of the backrest main body 41, and the backrest main body 41 has a protruding plate part 26 that is integrally provided on the front side of the connecting part 5 and the armrest main body support part 72.Since the protruding plate part 26 prevents the connecting part between the connecting part 5 and the armrest main body support part 72 from being exposed on the front side, the design of the backrest 4 can be improved.

[0082] In addition, since the backrest support portion 24 has a rear shielding wall that protrudes outward in the width direction from the rear edge portion 57 of the connecting portion 5, the rear shielding wall prevents the connection portion between the connecting portion 5 and the armrest main body support portion 72 from being exposed to the rear, thereby improving the design of the backrest 4.

[0083] In addition, since the backrest main body 41 has an outer peripheral frame portion 42 and a surface material 43 that is stretched over the outer peripheral frame portion 42 and covers the outer edge of the outer peripheral frame portion 42, even though the surface material 43 of the backrest main body 41 covers the outer edge of the outer peripheral frame portion 42, it is possible to prevent the armrest main body 71 from interfering with the surface material 43 of the backrest main body 41 when the armrest main body 71 is raised or lowered.

[0084] Although the embodiments of the backrest and chair according to the present invention have been described above, the present invention is not limited to the above-mentioned embodiments and can be modified as appropriate without departing from the spirit of the present invention. For example, in the above embodiment, an armrest body support part 72 is provided which is supported by the backrest support part 24 and supports the armrest body 71 so that it can be raised and lowered, but the armrest body 71 may be directly supported by the backrest support part 24. In addition, in the above embodiment, the backrest support portion 24 is provided with a connecting portion 5 to which the armrest main body support portion 72 is connected in contact with the outside in the width direction, but such a connecting portion 5 does not necessarily have to be provided.

[0085] In addition, in the above embodiment, the armrest main body support portion 72 is provided on the rear side of the backrest main body 41, and the backrest main body 41 has a protruding plate portion 26 that is integrally provided on the front side of the connecting portion 5 and the armrest main body support portion 72, but such a protruding plate portion 26 does not necessarily have to be provided.

[0086] In addition, in the above embodiment, the backrest support portion 24 is provided with a panel material engaging portion 463 that protrudes outward in the width direction from the rear edge portion 57 of the connecting portion 5, but such a panel material engaging portion 463 does not necessarily have to be provided.

[0087] In addition, in the above embodiment, the backrest main body 41 has an outer peripheral frame portion 42 and a surface material 43 that is stretched over the outer peripheral frame portion 42 and covers the outer edge portion of the outer peripheral frame portion 42, but the shape of the backrest main body may be other than that described above. [Explanation of symbols]

[0088] 1 Chair 2 Support structure 4 Backrest 5 Connecting part 7 Armrest 24 Backrest support part 26 Projecting plate part (rear shielding wall) 41 Backrest body 42 Outer frame 43 Surface material 57 Trailing edge 62 Second Bolt 71 Armrest body 72 Armrest body support part 431 Backrest 463 Surface material locking part (front shielding wall)

Claims

1. A backrest body having a backrest surface on which a seated person rests; A backrest support portion that is supported by a base provided on the leg portion and supports the backrest main body; An armrest supported by the backrest support portion, The armrest is An armrest body provided on the outer side of the backrest surface of the backrest body in the width direction; An armrest body support portion that supports the armrest body and is supported by the backrest support portion, The backrest support portion includes: A lower frame extending in a width direction and connected to the support base; a pair of upward extensions spaced apart from each other in the width direction and extending upward from one side and the other side of the lower frame in the width direction; an upper connecting portion connecting the pair of upward extending portions to each other above the lower frame, The backrest main body and the armrest main body support portion are each supported by the upward extension portion.

2. A backrest as described in Claim 1, wherein at least a portion of the backrest main body and the armrest main body support portion are supported within the same range in the vertical direction in the upward extension portion.

3. A backrest as described in claim 1 or 2, wherein the backrest main body has a bent portion that protrudes forward at the middle part in the vertical direction, and is provided with a backrest connecting portion below the bent portion that is connected to the upward extension portion.

4. A backrest described in any one of claims 1 to 3, wherein the backrest main body and the backrest main body support portion are each connected to the upward extension portion by different fixing members.

5. A backrest described in any one of claims 1 to 4, wherein the armrest main body and the armrest main body support part are separate members.

6. A chair having a backrest described in any one of claims 1 to 5.

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