Backrests and chairs

Abstract

To improve the appearance and style of a backrest.SOLUTION: A backrest includes: a back shell 5b provided with a hand hook part 23; a skin material 5f having an opening part 5f1 for exposing at least part of the hand hook part 23 and covering the back shell 5b; and a cover member 5g for shielding a peripheral edge part 5f2 of the opening part 5f1 of the skin material 5f and fixed to the back shell 5b while exposing part of the hand hook part 23.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD

[0001] The present invention relates to a backrest and a chair. BACKGROUND ART

[0002] For example, Patent Document 1 discloses a backrest provided with a back frame as a strength member. Further, the backrest disclosed in Patent Document 1 includes a handle fixed to the back frame. The handle is a separate member from the back frame and is fixed to the back frame. Patent Document 1 discloses that the backrest may include a upholstery material that covers the back frame. When the chair disclosed in Patent Document 1 is provided with the upholstery material, the upholstery material has an opening through which the handle is inserted. PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0003] PATENT DOCUMENT 1 Japanese Patent No. 5970951 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] By the way, the handle which is a separate member from the back frame is fixed to the back frame with bolts. When the chair is moved by gripping the handle, a large load is applied to the connection portion between the back frame and the handle. For this reason, the connection strength between the back frame and the handle gradually decreases with long-term use. Accordingly, the handle comes to move slightly relative to the back frame. In order to prevent such interference between the handle and the upholstery material, it is necessary to previously form a gap between the handle and the peripheral edge portion surrounding the opening formed in the upholstery material. However, such a gap allows the peripheral edge portion surrounding the opening formed in the upholstery material to be visually recognized from the outside, which becomes a factor of impairing the appearance quality of the backrest.

[0005] The present invention has been made in view of the above-described problems, and an object thereof is to improve the appearance quality of a backrest. [Means for solving the problem]

[0006] The present invention employs the following configuration as a means to solve the above problems.

[0007] A first aspect of the present invention provides a backrest comprising a frame with a handgrip, a surface material covering the frame and having an opening that exposes at least a part of the handgrip, and a shielding member fixed to the frame that shields the peripheral edge of the opening of the surface material while exposing the part of the handgrip.

[0008] In a first aspect of the present invention, the frame has a handle portion. That is, the handle portion is formed from a part of the frame. Therefore, the backrest can be moved without connecting a separate handle or the like to the frame. Thus, the first aspect of the present invention can prevent the handle or the like from interfering with the outer material. Furthermore, the first aspect of the present invention includes a shielding member. The shielding member shields the peripheral edge of the opening in the outer material. Therefore, the peripheral edge of the opening in the outer material is not visible from the outside. Thus, the first aspect of the present invention can improve the appearance of the backrest.

[0009] A second aspect of the present invention is a configuration in which, in the first embodiment described above, the handgrip portion consists of a recess formed by a part of the skeletal portion being recessed.

[0010] In a second aspect of the present invention, the handgrip portion is formed by a recess in a part of the skeletal portion. Therefore, in the second aspect of the present invention, the handgrip portion does not protrude from the opening in the outer material. This second aspect of the present invention eliminates the need to provide a member that protrudes from the opening in the outer material, and can improve the appearance of the backrest.

[0011] A third aspect of the present invention is a configuration in which, in the second aspect described above, the skeletal portion has a rear recess that extends forward from the rear surface of the skeletal portion, and the handgrip portion is formed by being recessed further forward from the inner surface of the rear recess.

[0012] In a third aspect of the present invention, the handgrip portion consists of a recess, which is formed by being recessed from the back surface of the rear recess provided on the rear surface of the frame toward the front of the backrest. Therefore, for example, the shielding member can be positioned relative to the rear recess. Accordingly, the third aspect of the present invention can suppress the amount of protrusion of the shielding member from the rear surface of the frame, thereby improving the appearance of the backrest. Furthermore, by suppressing the amount of protrusion of the shielding member from the rear surface of the frame, the third aspect of the present invention can prevent the hands of a person moving the backrest from coming into contact with the shielding member, and can prevent the shielding member from peeling off the frame.

[0013] A fourth aspect of the present invention adopts a configuration in which, in the third aspect described above, at least a portion of the peripheral edge is located outside the handle portion, between the inner surface of the rear recess and the shielding member.

[0014] In a fourth aspect of the present invention, the peripheral edge of the skin material around the opening is located between the back surface of the rear recess and the shielding member. Therefore, the skin material is sandwiched between the shielding member housed in the rear recess and the back surface of the rear recess. Thus, it is possible to prevent the peripheral edge of the skin material from being pulled out from between the shielding member and the back surface of the rear recess.

[0015] A fifth aspect of the present invention adopts a configuration in which, in the third or fourth aspect described above, the mounting portion is located outside the handgrip and inside the rear recess, and to which the shielding member is attached.

[0016] In a fifth aspect of the present invention, the mounting portion of the shielding member is located on the outside of the handgrip. Therefore, it is possible to prevent the mounting portion from coming into contact with the hand when the hand is placed in the handgrip. Thus, the fifth aspect of the present invention can prevent discomfort caused by fingertips or the like coming into contact with the mounting portion when moving on the backrest.

[0017] A sixth aspect of the present invention is a configuration in which, in the fifth aspect described above, the mounting portion is located above or below the entrance opening of the handgrip.

[0018] In a sixth aspect of the present invention, the mounting portion is located above or below the entrance opening of the handrail. Therefore, the handrail can be formed in a wide shape in the horizontal direction without considering the position of the mounting portion. Thus, the sixth aspect of the present invention allows for the provision of a handrail with a wide horizontal width, making it possible to easily move the backrest.

[0019] A seventh aspect of the present invention is a configuration in which, in the fifth or sixth aspect described above, the shielding member has a main body portion housed in the rear recess and fixed to the mounting portion, and a semi-annular portion housed inside the handle portion and forming a gap between itself and the main body portion that exposes a part of the handle portion.

[0020] In a seventh aspect of the present invention, the shielding member has a main body and a semi-annular portion. The main body is fixed to the mounting portion while housed in a rear recess. The semi-annular portion is housed inside the handle portion. Furthermore, the semi-annular portion forms a gap between itself and the main body that exposes a portion of the handle portion exposed through an opening in the surface material. This seventh aspect of the present invention allows the semi-annular portion to be positioned inside the handle portion while maintaining a state in which a portion of the handle portion is exposed, and allows the shielding member to be stabilized on the frame.

[0021] An eighth aspect of the present invention is a chair comprising any one of the first to seventh backrests described above. Therefore, the eighth aspect of the present invention is a chair in which the appearance of the backrest is improved. [Effects of the Invention]

[0022] According to the present invention, the skeleton portion has a handle portion. That is, the handle portion is formed by a part of the skeleton portion. Therefore, the backrest can be moved without connecting a separate handle or the like to the skeleton portion. Accordingly, the present invention can prevent the handle or the like from interfering with the skin material. Furthermore, the present invention includes a shielding member. The shielding member shields the peripheral edge of the opening of the skin material. For this reason, the peripheral edge of the opening of the skin material is not visible from the outside. Therefore, the present invention can improve the appearance of the backrest. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] [Figure 1] It is a front view of the chair in the first embodiment of the present invention as viewed from the front. [Figure 2] It is a perspective view of the chair in the first embodiment of the present invention as viewed from an oblique rear direction. [Figure 3] It is a perspective view showing the internal structure of the backrest provided in the chair according to the first embodiment of the present invention. [Figure 4] It is a partially exploded perspective view of the rear side of the backrest provided in the chair according to the first embodiment of the present invention. [Figure 5] It is a perspective view of the connecting member provided in the chair according to the first embodiment of the present invention. [Figure 6] It is a rear view of the back shell provided in the chair according to the first embodiment of the present invention as viewed from the rear side. [Figure 7] It is a schematic view including the lumbar support moving recess and the through slit provided in the left side frame rod. [Figure 8] It is a schematic view seen from the rear of the back shell. [Figure 9] It is a B-B cross-sectional view of Figure 8. [Figure 10] It is a schematic cross-sectional view of the back shell including the handle portion. [Figure 11] It is a schematic cross-sectional view including the optional member mounting portion. [Figure 12] It is a perspective view of the lumbar support mechanism provided in the chair according to the first embodiment of the present invention. [Figure 13]This is a perspective view of the support plate provided in the chair according to the first embodiment of the present invention. [Figure 14] This is a perspective view of the back shell of the backrest in the second embodiment of the present invention, as seen from the rear. [Figure 15] This is an enlarged side view of the connection point between the central frame rod and the upper frame rod of the backrest in the second embodiment of the present invention. [Modes for carrying out the invention]

[0024] Hereinafter, an embodiment of the backrest and chair according to the present invention will be described with reference to the drawings.

[0025] (First Embodiment) Figure 1 is a front view of the chair 1 of this embodiment, seen from the front. Figure 2 is a perspective view of the chair 1 of this embodiment, seen from the rear at an angle. The chair 1 of this embodiment is a piece of furniture that supports a sitter in a seated position and is used, for example, in offices or stores. As shown in Figures 1 and 2, the chair 1 of this embodiment comprises legs 2, a base 3, a seat 4, and a backrest 5.

[0026] For the purposes of the following explanation, the direction of chair 1 will be defined as the direction as seen from the perspective of a person seated in a normal posture on seat 4. For example, the front side from the perspective of the seated person is the front side of chair 1. The back side from the perspective of the seated person is the back side of chair 1. The left side from the perspective of the seated person is the left side of chair 1. The right side from the perspective of the seated person is the right side of chair 1. The upper side from the perspective of the seated person is the upper side of chair 1. The lower side from the perspective of the seated person is the lower side of chair 1.

[0027] The leg portion 2 contacts the floor surface and directly or indirectly supports the base 3, seat 4, and backrest 5 from below. As shown in Figures 1 and 2, the leg portion 2 has a multi-branched leg 2a and a leg column 2b. The multi-branched leg 2a has a plurality of leg bodies 2a1 extending radially from the central part. A caster 2a2 is installed at the tip of each leg body 2a1. Each caster 2a2 is in rolling contact with the floor surface.

[0028] The leg column 2b is erected in the center of the multi-branch leg 2a and extends upward from the center of the multi-branch leg 2a. The leg column 2b has an outer cylinder 2b1 and an inner cylinder 2b2. The outer cylinder 2b1 is fixed to the multi-branch leg 2a. The lower part of the inner cylinder 2b2 is connected to the outer cylinder 2b1 and is connected to the outer cylinder 2b1 so as to be movable in the vertical direction. The inner cylinder 2b2 is supported by a spring (not shown) housed inside the leg column 2b. The upper end of the inner cylinder 2b2 is fixed to the support base 3. Such a leg column 2b supports the seat 4 so as to be movable in the vertical direction via the support base 3.

[0029] The support base 3 is a box-shaped part located above the leg portion 2. Inside the support base 3, for example, there is a lifting mechanism for the seat 4 and a tilting mechanism for the backrest 5. The support base 3 is located below the seat 4 and supports the seat 4 from below. The backrest 5 is connected to the rear of the support base 3. The seat 4 is the part on which the sitter sits directly, and its upper surface is the seating surface. The chair 1 may also be provided with armrests on which the sitter's elbows and arms are rested. Such armrests may be fixed to the side of the seat 4, for example.

[0030] The backrest 5 is the part that supports the seated person from the rear. Figure 3 is a perspective view showing the internal structure of the backrest 5. As shown in Figure 3, the backrest 5 comprises a connecting member 5a, a back shell 5b (skeleton part), a lumbar support mechanism 5c, a front core material 5d, and a rear core material 5e. Figure 4 is a partially exploded perspective view of the rear of the backrest 5. As shown in Figure 4, the backrest 5 comprises a surface material 5f, a cover member 5g (shielding member), and a cap 5h.

[0031] The connecting member 5a is a member for connecting the backrest 5 to the support base 3. Figure 5 is a perspective view of the connecting member 5a. As shown in Figure 5, the connecting member 5a has an insertion part 10, a back shell fixing part 11, and a connecting part 12. The connecting member 5a is an injection molded body formed, for example, by resin injection molding. In other words, the insertion part 10, the back shell fixing part 11, and the connecting part 12 are integrated together.

[0032] The insertion portion 10 is the part into which the support base 3 is inserted and fixed, and is located at the lower part of the connecting member 5a. The support base 3 comprises a main body and a tilting portion that tilts relative to the main body. The tilting portion is tiltably connected to the main body around an axis extending in the left-right direction. The insertion portion 10 is formed in a box shape that opens forward, and the tilting portion of the support base 3 is inserted and fixed into it. The tilting portion is fastened to the insertion portion 10, for example, by a screw (not shown).

[0033] The back shell fixing portion 11 is formed to be located above the insertion portion 10 via the connecting portion 12. The back shell fixing portion 11 is a flat portion that is inserted from below into the connecting member insertion recess 26 (see Figure 6) provided at the lower part of the back shell 5b. With the back shell fixing portion 11 inserted into the connecting member insertion recess 26 of the back shell 5b, it is fastened to the back shell 5b by a screw (not shown).

[0034] The connecting portion 12 is erected so as to branch out in two directions from the insertion portion 10, and supports the back shell fixing portion 11 from below. In this embodiment, the connecting portion 12 has a bifurcated shape considering mold design and appearance. However, the shape of this connecting portion 12 can be changed.

[0035] The back shell 5b is a skeletal structure that receives the load from the seated person from the rear and transmits it to the support base 3 and leg portion 2 via the connecting member 5a. Figure 6 is a rear view of the back shell 5b as seen from the rear. As shown in Figure 6, the back shell 5b has a frame 20, a flexible portion 21, a cover member receiving recess 22 (rear recess), a handgrip portion 23, a cover member mounting portion 24, and an optional member mounting portion 25. The back shell 5b is an injection-molded body formed, for example, by resin injection molding. In other words, the frame 20, the flexible portion 21, the cover member receiving recess 22, the handgrip portion 23, the cover member mounting portion 24, and the optional member mounting portion 25 are integrated together.

[0036] The frame 20 is a frame-shaped portion that surrounds the flexible portion 21. As shown in Figure 6, the frame 20 has an upper frame rod 20a, a lower frame rod 20b, a left frame rod 20c (side frame rod), and a right frame rod 20d (side frame rod). As shown in Figure 6, the frame 20 is formed in a substantially rectangular shape.

[0037] The upper frame rod 20a is located at the top of the frame body 20. The upper frame rod 20a is a rod-shaped portion that extends along the left-right direction. The upper frame rod 20a is provided with a cover member housing recess 22, a handle portion 23, a cover member mounting portion 24, and an optional member mounting portion 25. The lower frame rod 20b is located at the bottom of the frame body 20. The lower frame rod 20b is a rod-shaped portion that extends along the left-right direction. The lower frame rod 20b is provided with the aforementioned connecting member insertion recess 26 (a recess into which the back shell fixing portion 11 is inserted from below).

[0038] The left-side frame rod 20c is located on the left side of the frame 20. The left-side frame rod 20c extends vertically and connects the left end of the upper frame rod 20a to the left end of the lower frame rod 20b. The right-side frame rod 20d is located on the right side of the frame 20. The right-side frame rod 20d extends vertically and connects the right end of the upper frame rod 20a to the right end of the lower frame rod 20b.

[0039] Furthermore, as shown in Figure 3, for example, the frame 20 has lumbar support movement recesses 20e provided for each of the left frame rod 20c and the right frame rod 20d. The frame 20 also has a through slit 20f (see Figure 7) that penetrates from the outer wall surface of the frame 20 to the lumbar support movement recess 20e. Figure 7 is a schematic diagram including the lumbar support movement recess 20e and the through slit 20f provided in the left frame rod 20c. Figure 7(a) is a view of the lumbar support mechanism 5c from a direction (front) perpendicular to the direction of movement (up and down direction) of the support plate 30, which will be described later. Figure 7(b) is a cross-sectional view AA of Figure 7(a).

[0040] Here, with reference to Figure 7, the lumbar support movement recess 20e and through slit 20f provided in the left frame rod 20c will be described. Note that the lumbar support movement recess 20e and through slit 20f provided in the right frame rod 20d are symmetrical to the lumbar support movement recess 20e and through slit 20f provided in the left frame rod 20c, so a detailed explanation will be omitted.

[0041] As shown in Figure 7, the lumbar support retraction recess 20e is a recess that extends from the front to the rear of the left frame rod 20c. The lumbar support retraction recess 20e is formed to extend linearly along the vertical direction. The through slit 20f is provided so as to communicate with the lumbar support retraction recess 20e from the left outer wall surface of the left frame rod 20c. The through slit 20f is formed to extend linearly along the vertical direction. Also, as shown in Figure 7(b), the through slit 20f is located in front of the rear surface (rear bottom surface) of the lumbar support retraction recess 20e. The space inside the lumbar support retraction recess 20e, from the rear surface of the lumbar support retraction recess 20e to the through slit 20f, is the installation space for the corrugated sheet portion 33 of the lumbar support mechanism 5c, which will be described later.

[0042] Returning to Figure 6, the flexible portion 21 is located in the space enclosed by the frame 20 and is connected to the frame 20. The flexible portion 21 is formed in a plate shape with multiple rod-shaped openings 21a arranged in the vertical and horizontal directions. The upper end of the flexible portion 21 is connected to the upper frame rod 20a. The lower end of the flexible portion 21 is connected to the lower frame rod 20b. The left end of the flexible portion 21 is connected to the left side frame rod 20c. The right end of the flexible portion 21 is connected to the right side frame rod 20d. Note that the flexible portion 21 only needs to be partially connected to the frame 20, and does not necessarily need to be connected to all of the upper frame rod 20a, lower frame rod 20b, left side frame rod 20c, and right side frame rod 20d.

[0043] Furthermore, the flexible portion 21 is located in front of the rear end edge of the frame 20. As a result, a space is formed between the flexible portion 21 and the surface material 5f that abuts against the frame 20. Consequently, the flexible portion 21 can deform without interfering with the surface material 5f.

[0044] Furthermore, in this embodiment, each rod-shaped opening 21a extends straight along the vertical direction. These rod-shaped openings 21a are arranged in the vertical direction, for example, in groups of four to five (or more). Also, the width dimension in the left-right direction of each rod-shaped opening 21a is the same in this embodiment. However, the width dimension in the left-right direction of each rod-shaped opening 21a may be different.

[0045] Such a flexible portion 21 elastically deforms to widen each rod-shaped opening 21a in the left-right direction when subjected to a load from a seated person. Furthermore, when the load from the seated person is removed, the flexible portion 21 returns to its original shape. In other words, the flexible portion 21 deforms flexibly in response to the load from the seated person.

[0046] Furthermore, the flexible portion 21 has a vertically elongated slit 21b (vertical opening) located in the center in the left-right direction. The vertically elongated slit 21b is provided extending linearly in the vertical direction. In this embodiment, the vertically elongated slit 21b is provided continuously from the upper end to the lower end of the flexible portion 21. In this embodiment, the width dimension of the vertically elongated slit 21b in the left-right direction is the same as the width dimension of the rod-shaped opening 21a in the left-right direction. However, in this embodiment, the width dimension of the vertically elongated slit 21b in the left-right direction may differ from the width dimension of the rod-shaped opening 21a in the left-right direction. Also, the vertical dimension of the vertically elongated slit 21b is greater than the vertical dimension of any of the rod-shaped openings 21a.

[0047] Figure 8 is a schematic diagram of the back shell 5b viewed from the rear. In Figure 8, the width dimension of the vertical slit 21b in the left-right direction is shown enlarged, and the rod-shaped opening 21a is omitted. Figure 9 is a cross-sectional view of BB in Figure 8.

[0048] As shown in Figure 8, the flexible portion 21 has a left portion 21c (first portion) located to the left of the elongated slit 21b and a right portion 21d (second portion) located to the right of the elongated slit 21b. When the flexible portion 21 is subjected to a load from a seated person, the edge 21c1 on the elongated slit 21b side of the left portion 21c elastically deforms backward. This edge 21c1 on the elongated slit 21b side of the left portion 21c has a weak restraining force against movement in the front-rear direction, and when the flexible portion 21 is subjected to a load from a seated person, it deforms more backward than other parts of the left portion 21c. When the flexible portion 21 is subjected to a load from a seated person, the edge 21d1 on the elongated slit 21b side of the right portion 21d elastically deforms backward. The edge 21d1 on the side of the vertically elongated slit 21b of this right-side portion 21d has a weak restraining force against movement in the front-rear direction, and when the flexible portion 21 receives a load from a seated person, it deforms more significantly towards the rear than other parts of the right-side portion 21d.

[0049] As shown in Figure 9, the left portion 21c has a protrusion 21e, an upper portion 21f, and a lower portion 21g. The protrusion 21e is the foremost portion of the left portion 21c. The protrusion 21e is located below the center of the left portion 21c in the vertical direction. The upper portion 21f is part of the left portion 21c and is located above the protrusion 21e. The upper portion 21f is inclined to move backward as it goes upward. The lower portion 21g is part of the left portion 21c and is located below the protrusion 21e. The lower portion 21g is inclined to move backward as it goes downward.

[0050] As described above, the protruding portion 21e is located below the center position of the left portion 21c in the vertical direction. Therefore, the vertical dimension of the lower portion 21g is smaller than the vertical dimension of the upper portion 21f. Consequently, the rigidity of the lower portion 21g is higher than that of the upper portion 21f.

[0051] Furthermore, the right-side portion 21d has the same shape as the left-side portion 21c. That is, the right-side portion 21d has a protruding portion 21e, an upper portion 21f, and a lower portion 21g. For this reason, a detailed explanation of the shape of the right-side portion 21d is omitted.

[0052] As shown in Figure 8, the flexible portion 21 has four parts: the upper part 21f of the left portion 21c, the lower part 21g of the left portion 21c, the upper part 21f of the right portion 21d, and the lower part 21g of the right portion 21d. In this embodiment, the protrusion 21e of the left portion 21c and the protrusion 21e of the right portion 21d are located at the same height in the vertical direction. Therefore, the vertical dimensions of the upper part 21f of the left portion 21c and the upper part 21f of the right portion 21d are the same. Also, the vertical dimensions of the lower part 21g of the left portion 21c and the lower part 21g of the right portion 21d are the same.

[0053] For example, as shown in Figures 4 and 6, the cover member housing recess 22 is provided on the rear side of the upper frame rod 20a. The cover member housing recess 22 is a recess that extends forward from the rear outer wall surface 20a1 (rear surface of the skeletal part) of the upper frame rod 20a, and the cover member 5g is placed in it. In other words, the cover member 5g is positioned to be housed in the cover member housing recess 22.

[0054] Multiple material-removing recesses 22a are provided on the back surface (front side) of the cover member housing recess 22. The multiple material-removing recesses 22a are arranged in the left-right direction. A handle portion 23, a cover member mounting portion 24, and an optional member mounting portion 25 are located inside the cover member housing recess 22.

[0055] The handle portion 23 is the part that the worker places their hand on when moving the backrest 5 (i.e., the chair 1). Figure 10 is a schematic cross-sectional view of the back shell 5b including the handle portion 23. As shown in this figure, the handle portion 23 is formed by recessing from the back surface of the cover member housing recess 22 toward the front. In other words, in this embodiment, the handle portion 23 consists of a recess formed by recessing a part of the back shell 5b.

[0056] As shown in Figure 10, the handle portion 23 has an upper surface that slopes upward as it extends forward. This upper surface is the surface that the pads of the worker's fingers touch. This upper surface is part of the handle portion 23 and is referred to as the finger rest surface 23a. Also, as shown in Figure 10, the handle portion 23 has a lower surface that slopes upward as it extends forward. This lower surface is the surface that the semi-annular portion 5g2 of the cover member 5g, which will be described later, abuts against. This lower surface is part of the handle portion 23 and is referred to as the cover member contact surface 23b. Furthermore, as shown in Figures 4 and 6, the entrance opening 23c of the handle portion 23 is located below the cover member mounting portion 24 and the optional member mounting portion 25.

[0057] The cover member mounting portion 24 is a portion to which the cover member 5g can be attached. As shown in Figures 4 and 6, the back shell 5b has three cover member mounting portions 24. These cover member mounting portions 24 are located above the handle portion 23 and are arranged in the left-right direction. In other words, when viewed from the rear, the cover member mounting portions 24 are located outside the handle portion 23 and inside the cover member housing recess 22.

[0058] Each cover member mounting portion 24 is provided so as to protrude rearward from the back surface of the cover member housing recess 22. Each cover member mounting portion 24 is formed in a substantially cylindrical shape and has a female threaded portion provided along the axis of the cylindrical shape. Each cover member mounting portion 24 is fitted with a cover member fixing screw 5i (see Figure 4) for fastening the cover member 5g to the back shell 5b.

[0059] The optional member mounting section 25 is a part for attaching optional members. As shown in Figures 4 and 6, the back shell 5b has two optional member mounting sections 25. These optional member mounting sections 25 are located above the handle section 23 and are arranged in the left-right direction. In other words, when viewed from the rear, the optional member mounting sections 25 are located outside the handle section 23 and inside the cover member housing recess 22.

[0060] Figure 11 is a schematic cross-sectional view including the optional member mounting portion 25. As shown in this figure, it has a cylindrical portion 25a and a nut holding portion 25b. The cylindrical portion 25a is located behind the nut holding portion 25b. The cylindrical portion 25a is formed in a cylindrical shape with its axis aligned in the front-rear direction and has a through hole 25a1 that penetrates in the front-rear direction. The shaft portion of an optional member (not shown) is inserted through the through hole 25a1 from the rear. In other words, the optional member mounting portion 25 has a cylindrical portion 25a through which the shaft portion of an optional member can be inserted from rear to front.

[0061] Furthermore, the rear end surface 25a2 of the cylindrical portion 25a is the rear end surface of the optional member mounting portion 25. This rear end surface 25a2 of the cylindrical portion 25a is located behind the back surface of the handgrip portion 23. In other words, in this embodiment, the rear end surface 25a2 of the optional member mounting portion 25 is located behind the back surface of the handgrip portion 23. If the seated person or someone nearby touches an optional member such as a headrest, a moment may act on the contact point between the cylindrical portion 25a and the optional member. In this case, if the rear end surface 25a2 of the optional member mounting portion 25 is located behind the back surface of the handgrip portion 23, the load on the optional member mounting portion 25 due to the moment can be reduced compared to when the rear end surface 25a2 is located in front of the back surface of the handgrip portion 23.

[0062] The nut holding portion 25b is located in front of the cylindrical portion 25a and is connected to the front end surface of the cylindrical portion 25a. When viewed from a direction along the axis of the cylindrical portion 25a, the nut holding portion 25b has a plurality of claw portions, each of which is elastically deformable in the radial direction centered on the axis. The nut holding portion 25b can hold the nut 5j with these claw portions. The shaft portion of the optional member can be screwed onto the nut 5j. In this embodiment, the optional member is not provided. Therefore, the backrest 5 can also be configured without the nut 5j or the optional member mounting portion 25.

[0063] Furthermore, as shown in Figure 11, the back shell 5b has a nut insertion hole 27 (hole) that allows the optional member mounting portion 25 to be exposed from the front. The nut insertion hole 27 is provided in the upper frame rod 20a of the frame body 20. The nut insertion hole 27 is a hole formed so as to extend from the front to the rear of the back shell 5b. The diameter of the nut insertion hole 27 is larger than the outer dimensions of the nut 5j, but may be approximately equal to the outer dimensions of the nut 5j through a small clearance. By providing such a nut insertion hole 27, the state of the optional member mounting portion 25 can be visually inspected from the front of the back shell 5b. Therefore, the person assembling the chair 1 can visually check whether the optional member is correctly attached to the optional member mounting portion 25. In addition, the nut 5j can be held in the optional member mounting portion 25 via the nut insertion hole 27 after the back shell 5b has been molded. Furthermore, in cases where the back shell 5b is not covered with the outer material 5f, the nut insertion hole 27 may be shielded by a cover member or the like that engages with the back shell 5b from the front.

[0064] As shown in Figure 3, the lumbar support mechanism 5c is located in the center of the backrest 5 in the vertical direction and supports the sitter's waist. Figure 12 is a perspective view of the lumbar support mechanism 5c. As shown in this figure, the lumbar support mechanism 5c comprises a support plate 30, an operating part 31, and a guide part 32. Although not shown in Figure 12, the lumbar support mechanism 5c also includes a corrugated plate part 33 (see Figure 7).

[0065] The support plate 30 is a plate member that supports the waist area of ​​the seated person. The support plate 30 can be moved vertically by operating the operating part 31. Figure 13 is a perspective view of the support plate 30. As shown in this figure, the support plate 30 has a base portion 30a and an insertion end portion 30b.

[0066] The base portion 30a is formed in a plate shape with its longitudinal direction running horizontally. The base portion 30a is located in front of the back shell 5b and is movable vertically while facing the front surface of the back shell 5b. Insertion ends 30b are provided at each of the left and right ends of the base portion 30a. Each insertion end 30b protrudes from the base portion 30a toward the rear.

[0067] Each insertion end 30b is formed in a hollow, bottomed cylindrical shape and has a side opening 30b1 that opens outward. For example, the insertion end 30b provided at the left end of the base 30a has a side opening 30b1 that opens to the left. Similarly, the insertion end 30b provided at the right end of the base 30a has a side opening 30b1 that opens to the right.

[0068] Each insertion end 30b is inserted into a lumbar support movement recess 20e provided in the frame 20. For example, the insertion end 30b provided at the left end of the base 30a is inserted from the front into a lumbar support movement recess 20e formed in the left frame rod 20c of the frame 20. Similarly, the insertion end 30b provided at the right end of the base 30a is inserted from the front into a lumbar support movement recess 20e formed in the right frame rod 20d of the frame 20. Each lumbar support movement recess 20e is formed to extend along the vertical direction. Therefore, the support plate 30, with each insertion end 30b inserted into its respective lumbar support movement recess 20e, is movable in the vertical direction.

[0069] Furthermore, each insertion end 30b has a plurality of protrusions 30b2 located on the tip side of the insertion end 30b (opposite side of the base 30a) relative to the side opening 30b1. Each protrusion 30b2 projects outward. For example, the insertion end 30b provided at the left end of the base 30a has a protrusion 30b2 that projects to the left. Similarly, the insertion end 30b provided at the right end of the base 30a has a protrusion 30b2 that projects to the right.

[0070] In this embodiment, each insertion end 30b has two projections 30b2. The two projections 30b2 provided on the same insertion end 30b are arranged in the vertical direction. Each projection 30b2 is formed so that its surface is spherical. These projections 30b2 slidably contact the corrugated sheet portion 33 located inside the lumber support movable recess 20e.

[0071] The operating section 31 is the part operated by the seated person and is provided for each insertion end 30b. In other words, in this embodiment, there are two operating sections 31. One operating section 31 is fixed to the left insertion end 30b. The other operating section 31 is fixed to the right insertion end 30b.

[0072] As shown in Figure 7, each operating part 31 has a gripping part 31a and an engaging claw part 31b. The gripping part 31a is the part that is operated, for example, when grasped by a seated person. Here, operation means moving the operating part 31 in the vertical direction. These gripping parts 31a are located on the outside of the back shell 5b, for example, as shown in Figure 1. The engaging claw part 31b is a claw that protrudes toward the back shell 5b side. Each engaging claw part 31b is inserted through a through slit 20f provided in the frame 20, and its tip is inserted into the side opening 30b1 of the insertion end 30b. The tip of the engaging claw part 31b is locked to the insertion end 30b by being inserted into the side opening 30b1. As a result, the operating part 31 is fixed to the insertion end 30b while inserted through the through slit 20f.

[0073] The guide portion 32 is a part that is fitted into each through slit 20f provided in the frame 20, and guides the movement of the operating portion 31. In other words, in this embodiment, there are two guide portions 32. One guide portion 32 is fitted into the through slit 20f provided in the left frame rod 20c. The other guide portion 32 is fitted into the through slit 20f provided in the right frame rod 20d. Each guide portion 32 has a guide opening 32a. The guide opening 32a allows the operating portion 31 to be inserted in the left-right direction and to move in the up-down direction. The guide portion 32 also has a flexible claw portion 32b that engages with the inner wall surface of the lumber support movement recess 20e.

[0074] The corrugated sheet portion 33 is located inside each of the lumber support movement recesses 20e. In other words, in this embodiment, two corrugated sheet portions 33 are provided. One corrugated sheet portion 33 is located inside the lumber support movement recess 20e provided in the left frame rod 20c. The other corrugated sheet portion 33 is located inside the lumber support movement recess 20e provided in the right frame rod 20d. In this embodiment, the corrugated sheet portion 33 is provided integrally with the back shell 5b. However, the corrugated sheet portion 33 may be formed separately from the back shell 5b and joined to the back shell 5b by post-processing.

[0075] Each corrugated sheet portion 33 is formed to have a wavy shape when viewed from the front-to-back direction, as shown in Figure 7(b), for example, and is elastically deformable in the left-to-right direction. Such corrugated sheet portions 33 are formed with a wavy shape in which peaks and troughs are repeated in the vertical direction, and the protrusions 30b2 of the support plate 30 come into contact with them from the left-to-right direction. Each corrugated sheet portion 33 elastically deforms when the support plate 30 moves in the vertical direction and the protrusions 30b2 pass through a peak. Also, each corrugated sheet portion 33 returns to its original shape when the protrusions 30b2 are located in a trough. Such corrugated sheet portions 33 restrict the easy vertical movement of the protrusions 30b2 when they are located in a trough. As a result, the support plate 30 is prevented from moving in the vertical direction when the seated person is not operating the control unit 31.

[0076] This lumbar support mechanism 5c allows the sitter to change the vertical position of the support plate 30 by operating the control unit 31. Therefore, the sitter can position the support plate 30 in a position that feels comfortable to them, according to their sitting posture and body type.

[0077] Returning to Figure 3, the front core material 5d and the rear core material 5e are strength members located at the boundary between the back shell 5b and the connecting member 5a. The front core material 5d is located in front of the back shell 5b and the connecting member 5a and is fixed to the back shell 5b and the connecting member 5a. The rear core material 5e is located behind the back shell 5b and the connecting member 5a and is fixed to the back shell 5b and the connecting member 5a.

[0078] For example, as shown in Figures 1 and 2, the surface material 5f forms the outer surface of the backrest 5 that comes into contact with the seated person. The material of the surface material 5f is not particularly limited, but it can be made of, for example, fabric or leather. This surface material 5f is provided so as to cover the back shell 5b, as shown in Figure 4, for example.

[0079] As shown in Figure 4, the outer material 5f has an opening 5f1 that exposes at least a portion of the handgrip portion 23. Specifically, in this embodiment, the opening 5f1 exposes the finger rest surface 23a of the handgrip portion 23. Here, "exposing the finger rest surface 23a" means that the outer material 5f is not positioned in the path of movement of a worker's hand that has been inserted into the handgrip portion 23 from the outside and is not obstructed from contacting the finger rest surface 23a. In other words, it means that the outer material 5f is not positioned in the path of movement of a hand that is trying to place its fingertips on the finger rest surface 23a. Therefore, "exposing the finger rest surface 23a" here does not mean that the finger rest surface 23a is visible from the outside.

[0080] As shown in Figures 4 and 10, at least a portion of the peripheral edge 5f2 of the opening 5f1 of the outer material 5f is located outside the handle portion 23, between the back surface of the cover member housing recess 22 and the cover member 5g. In this embodiment, the upper part of the peripheral edge 5f2 is located between the back surface of the cover member housing recess 22 and the cover member 5g. This peripheral edge 5f2 of the outer material 5f is sandwiched between the back shell 5b and the cover member 5g. The lower part of the peripheral edge 5f2 is attached to the surface of the semi-annular portion 5g2 of the cover member 5g, which will be described later.

[0081] The cover member 5g is a member that shields at least a portion of the peripheral edge 5f2 of the opening 5f1 of the outer material 5f. As shown in Figures 4 and 10, the cover member 5g has a main body portion 5g1 and a semi-annular portion 5g2. The cover member 5g is made of an injection-molded body formed, for example, by injection molding resin. In other words, the main body portion 5g1 and the semi-annular portion 5g2 are integrated.

[0082] The main body portion 5g1 is fitted into the portion of the cover member receiving recess 22 that does not have a handle portion 23. For example, as shown in Figure 4, the main body portion 5g1 is formed in a strip shape with its length in the left-right direction. The main body portion 5g1 also has a cap receiving recess 5g3 that is recessed from the rear to the front. Furthermore, the main body portion 5g1 has an opening 5g4 for the cover member and an opening 5g5 for the optional member.

[0083] The cap housing recess 5g3 is a recess in which the cap 5h is housed. The cover member opening 5g4 is an opening that exposes the cover member mounting portion 24. In this embodiment, since there are three cover member mounting portions 24, there are also three cover member openings 5g4. The optional member opening 5g5 is an opening that exposes the optional member mounting portion 25. In this embodiment, since there are two optional member mounting portions 25, there are also two optional member openings 5g5.

[0084] The semi-annular portion 5g2 is a curved section whose ends are connected to the main body portion 5g1. This semi-annular portion 5g2 forms a gap K between itself and the main body portion 5g1. This gap K allows the finger rest surface 23a of the handle portion 23 to be exposed when the cover member 5g is fixed to the back shell 5b. This semi-annular portion 5g2 is housed inside the handle portion 23 and is in contact with the cover member contact surface 23b of the handle portion 23.

[0085] Such a cover member 5g is fastened to the back shell 5b by cover member fixing screws 5i. The cover member fixing screws 5i are inserted into the cover member opening 5g4 from the rear side and screwed into the cover member mounting portion 24.

[0086] The cap 5h is a component that fits into the cap housing recess 5g3 of the cover component 5g. By fitting the cap 5h into the cap housing recess 5g3, the cap 5h conceals the opening 5g4 for the cover component and the opening 5g5 for the optional component from being visible from the outside. Such a cap 5h can be used, for example, as a nameplate.

[0087] In this embodiment, when a worker moves the backrest 5 of the chair 1, the worker inserts their hand into the handle portion 23 and places the pads of their fingers in contact with the finger rest surface 23a of the handle portion 23. With the pads of their fingers in contact with the finger rest surface 23a of the handle portion 23, the worker can move the chair 1 by pushing or pulling it.

[0088] The backrest 5 in this embodiment comprises a back shell 5b, a surface material 5f, and a cover member 5g. The back shell 5b is provided with a handgrip portion 23. The surface material 5f has an opening 5f1 that exposes at least a part of the handgrip portion 23 and covers the back shell 5b. The cover member 5g shields the peripheral edge 5f2 of the opening 5f1 of the surface material 5f. The cover member 5g is fixed to the back shell 5b with a part of the handgrip portion 23 exposed.

[0089] In this embodiment of the backrest 5, the back shell 5b has a handle portion 23. That is, the handle portion 23 is formed from a part of the back shell 5b. Therefore, the backrest 5 can be moved without connecting a separate handle or the like to the back shell 5b. Thus, the backrest 5 in this embodiment can prevent the handle or the like from interfering with the surface material 5f. Furthermore, the backrest 5 in this embodiment is equipped with a cover member 5g. The cover member 5g shields the peripheral edge 5f2 of the opening 5f1 of the surface material 5f. Therefore, the peripheral edge 5f2 of the opening 5f1 of the surface material 5f is not visible from the outside. Thus, the backrest 5 in this embodiment can improve the overall appearance of the backrest 5.

[0090] Furthermore, in this embodiment, the backrest 5 has a handgrip portion 23 which is formed by a recess in a part of the back shell 5b. In this embodiment, the handgrip portion 23 is formed by a recess in a part of the back shell 5b. Therefore, in this embodiment, the handgrip portion 23 does not protrude from the opening 5f1 of the surface material 5f. In this embodiment, there is no need to provide a member that protrudes from the opening 5f1 of the surface material 5f, and the overall appearance of the backrest 5 can be improved.

[0091] Furthermore, in this embodiment, the backrest 5 has a back shell 5b that has a cover member receiving recess 22. The cover member receiving recess 22 is formed so as to be recessed from the rear surface of the back shell 5b toward the front. The handgrip portion 23 is formed so as to be recessed from the back surface of the cover member receiving recess 22 toward the front. In this embodiment, the handgrip portion 23 is made up of a recess and is formed so as to be recessed from the back surface of the cover member receiving recess 22 provided on the rear surface of the back shell 5b toward the front of the backrest 5. For this reason, for example, the cover member 5g can be positioned relative to the cover member receiving recess 22. Therefore, in this embodiment, the amount of protrusion of the cover member 5g from the rear surface of the back shell 5b can be suppressed, and the overall appearance of the backrest 5 can be improved. Furthermore, in this embodiment, the backrest 5 suppresses the amount of protrusion of the cover member 5g from the rear surface of the back shell 5b, thereby preventing the hands of a person moving the backrest 5 from coming into contact with the cover member 5g, and preventing the cover member 5g from peeling off the back shell 5b.

[0092] Furthermore, in this embodiment, at least a portion of the peripheral edge 5f2 of the backrest 5 is located outside the handgrip 23, between the back surface of the cover member housing recess 22 and the cover member 5g. In this embodiment, the peripheral edge 5f2 around the opening 5f1 of the surface material 5f is located between the back surface of the cover member housing recess 22 and the cover member 5g. Therefore, the surface material 5f is sandwiched between the cover member 5g housed in the cover member housing recess 22 and the back surface of the cover member housing recess 22. Thus, it is possible to prevent the peripheral edge 5f2 of the surface material 5f from being pulled out from between the cover member 5g and the back surface of the cover member housing recess 22.

[0093] Furthermore, the backrest 5 in this embodiment includes a cover member mounting portion 24. The cover member mounting portion 24 is located outside the handgrip portion 23 and inside the cover member housing recess 22, and the cover member 5g is attached to it. In the backrest 5 in this embodiment, the cover member mounting portion 24 is located outside the handgrip portion 23. Therefore, it is possible to prevent the hand from coming into contact with the cover member mounting portion 24 when the hand is placed in the handgrip portion 23. Thus, the backrest 5 in this embodiment can prevent the person moving the backrest 5 from experiencing discomfort due to their fingertips or other body parts coming into contact with the cover member mounting portion 24.

[0094] Furthermore, in this embodiment, the backrest 5 has the cover member mounting portion 24 located above the entrance opening 23c of the handgrip portion 23. In this embodiment, the backrest 5 has the cover member mounting portion 24 located above the entrance opening 23c of the handgrip portion 23. Therefore, the handgrip portion 23 can be formed in a wide shape in the horizontal direction without considering the position of the cover member mounting portion 24. Thus, the backrest 5 in this embodiment can be provided with a handgrip portion 23 that is wide in the horizontal direction, making it possible to move the backrest 5 easily. Note that the cover member mounting portion 24 may be located below the handgrip portion 23.

[0095] In this embodiment, the backrest 5 has a cover member 5g which has a main body portion 5g1 and a semi-annular portion 5g2. The main body portion 5g1 is housed in a cover member housing recess 22 and fixed to the cover member mounting portion 24. The semi-annular portion 5g2 is housed inside the handgrip portion 23 and forms a gap K between it and the main body portion 5g1 that exposes a part of the handgrip portion 23. In this embodiment, the backrest 5 can maintain a state in which a part of the handgrip 23 is exposed while positioning the semi-annular portion 5g2 inside the handgrip 23, and the cover member 5g can be stabilized on the back shell 5b.

[0096] The chair 1 of this embodiment is equipped with the backrest 5 described above. Therefore, the chair 1 of this embodiment is a chair 1 in which the appearance of the backrest 5 is improved.

[0097] (Second Embodiment) Next, a second embodiment of the present invention will be described. In this description of the second embodiment, parts that are the same as those of the first embodiment described above will be omitted or simplified.

[0098] Figure 14 is a rearward perspective view of the back shell 5b of the backrest in this embodiment. As shown in this figure, the frame 20 of the back shell 5b in this embodiment has an upper frame rod 20a, a lower frame rod 20b, a left side frame rod 20c, a right side frame rod 20d, and a central frame rod 20g.

[0099] The central frame rod 20g is a rod-shaped member that connects the upper frame rod 20a and the lower frame rod 20b, and is formed to extend linearly along the vertical direction. The upper end of the central frame rod 20g is connected to the upper frame rod 20a, and the lower end is connected to the lower frame rod 20b. The central frame rod 20g is also located behind the flexible portion 21. By providing such a central frame rod 20g, the strength of the frame 20 and furthermore the backrest 5 is improved.

[0100] In this embodiment, the width dimension of the elongated slit 21b in the left-right direction, as described in the first embodiment, may be the same as the width dimension of the central frame rod 20g. By matching the width dimension of the elongated slit 21b with that of the central frame rod 20g, the elongated slit 21b and the flexible portion 21 side of the central frame rod 20g can be formed during injection molding without using a slide mold, thereby facilitating the manufacturing of the back shell 5b.

[0101] Figure 15 is an enlarged side view of the connection point between the central frame rod 20g and the upper frame rod 20a. As shown in this figure, the rear end surface 20g1 of the central frame rod 20g is located in front of the rear end surface 20a2 of the upper frame rod 20a. With this backrest of the embodiment, it is possible to prevent the surface material 5f supported by the rear end surface 20a2 of the upper frame rod 20a from coming into contact with the central frame rod 20g. Therefore, the backrest of this embodiment can prevent the surface material 5f from deforming to match the shape of the central frame rod 20g.

[0102] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but it goes without saying that the present invention is not limited to the above embodiments. The shapes and combinations of the various components shown in the above embodiments are examples, and can be modified in various ways based on design requirements, etc., without departing from the spirit of the present invention.

[0103] For example, in the above embodiment, a configuration in which the flexible portion 21 has a rod-shaped opening 21a was described. However, the present invention is not limited thereto, and it is also possible to adopt a configuration in which the flexible portion 21 does not have a rod-shaped opening 21a. For example, it is also possible to impart flexibility to the flexible portion 21 by making the thickness dimension of the flexible portion 21 thinner compared to other parts of the back shell 5b.

[0104] Furthermore, in the above embodiment, a configuration in which a cover member receiving recess 22 is provided in the frame 20 has been described. However, the present invention is not limited thereto, and it is also possible to adopt a configuration in which the frame 20 is not provided with a cover member receiving recess 22.

[0105] Furthermore, in the above embodiment, a configuration in which the backrest 5 is equipped with a lumbar support mechanism 5c has been described. However, the present invention is not limited thereto, and it is also possible to adopt a configuration without a lumbar support mechanism 5c. [Explanation of Symbols]

[0106] 1...Chair, 5...Backrest, 5a...Connecting member, 5b...Back shell (frame part), 5g...Cover member (covering member), 5g1...Main body part, 5g2...Semi-ring part, 5g3...Cap housing recess, 5g4...Opening for cover member, 5g5...Opening for optional member, 5h...Cap, 5i...Cover member fixing screw, 5j...Nut, 20...Frame body, 20a...Upper frame rod, 20a2...Rear end face, 20b...Lower frame rod, 20c...Left side frame rod (side frame rod), 20d...Right side frame rod (side frame rod), 20e...Lumbar support movement recess, 20f...Through slit, 20g...Central frame rod, 20g1...Rear end face, 21...Flexible part 21a...rod-shaped opening, 21b...vertical slit (vertical opening), 21c...left side part (first part), 21c1...edge, 21d...right side part (second part), 21d1...edge, 21e...protruding part, 21f...upper part, 21g...lower part, 22...cover member housing recess, 23...handle part, 23a...finger rest surface, 23b...cover member contact surface (partial), 24...cover member mounting part (mounting part), 25...option member mounting part, 25a...cylindrical part, 25a1...insertion hole, 25a2...rear end surface, 25b...nut holding part, 26...connecting member insertion recess, 27...nut insertion hole part (hole), 30...support plate, K...gap

Claims

1. A skeletal part having a handle, Having an opening that exposes at least a part of the handle portion, and a surface material that covers the skeletal portion, A shielding member fixed to the frame portion while shielding the peripheral edge of the opening of the surface material and exposing a part of the handle portion. Equipped with, The aforementioned handle portion consists of a recess formed by a part of the skeletal portion being indented. Backrest.

2. The aforementioned skeletal portion has a rear recess that extends forward from the rear surface of the skeletal portion, The aforementioned handle portion is formed by recessing from the inner surface of the rear recess toward the front. The backrest according to claim 1.

3. The backrest according to claim 2, wherein at least a portion of the peripheral edge is located outside the handgrip between the inner surface of the rear recess and the shielding member.

4. The backrest according to claim 2 or 3, which is located outside the handgrip and inside the rear recess, and includes a mounting portion to which the shielding member is attached.

5. The mounting portion is located above or below the entrance opening of the handrail portion, as described in claim 4.

6. The shielding member is, The main body portion is housed in the rear recess and fixed to the mounting portion, A semi-annular portion is housed inside the handle portion and forms a gap between it and the main body portion, exposing a part of the handle portion. has The backrest according to claim 4.

7. A chair having a backrest as described in any one of claims 1 to 3.

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