Chair upholstery attachment structure

Abstract

To provide a chair spread cloth fitting structure that makes it easy to insert a mesh spread cloth into a spread cloth groove.SOLUTION: There is provided a chair spread cloth fitting structure in which a mesh spread cloth 37(8) comprising a locking member 38(9) at its peripheral edge is inserted into a spread cloth groove 36(18) on a frame body of a seat or backrest of a chair to fix the mesh spread cloth 37(8). The locking member 38(9) is fitted on a front surface of the mesh spread cloth 37(8) along the peripheral edge. By rotating the locking member 38(9) by 360° to the rear surface side of the mesh spread cloth 37(8) and folding back the mesh spread cloth 37(8) to the rear surface side, a portion 46 on the peripheral edge side of a position 44 at which the mesh spread cloth 37(8) is fitted to the locking member 38(9) is covered with the folded mesh spread cloth 37(8) and a portion 45 on the tip side of the position 44 at which the locking member 38(9) is fitted to the mesh spread cloth 37(8) is exposed and inserted into the spread cloth groove 36(18).SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a structure for attaching upholstery to a chair. More specifically, the present invention relates to a structure for attaching upholstery to a seat frame or a back frame by utilizing a plate-shaped fastening member provided on the edge of the upholstery. [Background technology]

[0002] Conventionally, for the backrest and seat of a chair, a method has been used in which mesh-like upholstery (hereinafter referred to as mesh upholstery in this specification) that comes into contact with the seated person is inserted into grooves provided on the sides of the back frame and seat frame by wrapping a locking member sewn to the peripheral edge of the back of the upholstery around it (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-45573 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, with this method, the end of the mesh upholstery sewn to the fastening member is inserted into the groove in an exposed state, making it difficult to insert the end of the mesh upholstery properly. In some cases, the edge of the mesh upholstery that is on the tip side of the stitching point may be folded back when inserted into the groove. In this case, an additional effort and process is required to push the edge of the mesh upholstery that protrudes from the groove using a jig or the like.

[0005] In addition, since both the locking member and the mesh upholstery are inserted into the groove, the thickness of the inserted upholstery may vary depending on the location, and depending on the condition of the end of the mesh upholstery, there will be differences in the amount of upholstery inserted, resulting in variations in how difficult it is for the locking piece to come out.

[0006] Furthermore, when attempting to provide the fastening member with ears for screw fastening, it is difficult to provide the ears that protrude outward from the edge of the fastening member outside the perforations during the process of sewing to the mesh upholstery.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a structure for attaching chair upholstery that allows mesh upholstery to be easily inserted into upholstery grooves. [Means for solving the problem]

[0008] The present invention, which achieves this object, provides an attachment structure for chair upholstery, in which mesh upholstery with a locking member on its periphery is inserted into an upholstery groove in the frame of a chair seat or backrest to secure the mesh upholstery, the locking member being a flat plate with a rectangular cross section that is inserted with a gap between it and the upholstery groove, and having an ear on one side edge, while the other side edge where the ear is not provided is positioned along the periphery of the mesh upholstery and attached to the front side of the mesh upholstery, and when the locking member is folded back to the back side of the mesh upholstery and inserted into the upholstery groove, the mesh upholstery turns back from the attachment point between the mesh upholstery and the locking member as a starting point, covering the edge part closer to the periphery than the attachment point of the mesh upholstery and the base end part of the locking member, thereby shaping the edge of the mesh upholstery and leaving the tip end part of the locking member exposed, forming a terminal structure that functions as a guide when fitting into the upholstery groove, and when the locking member is inserted into the upholstery groove, the ear part is attached to the upholstery groove Protrudes inward and contacts the ear The fixing means fixes the frame.

[0009] Here, the fastening member is preferably sewn to the mesh upholstery.

[0010] In addition, the locking member is Seat or backrest frame It is preferable that the upholstery is pressed into an upholstery groove that opens on the side of the upholstery.

[0011] Furthermore, it is preferable that the fastening member is attached to the mesh upholstery at the center of the fastening member in the width direction.

[0013] In addition, it is preferable that the locking member has a curved shape that conforms to the upholstery groove that opens into the side of the corner portion of the frame body, and is fitted into the upholstery groove at the corner portion of the frame body in a state rotated 360 degrees.

[0014] Furthermore, the chair of the present invention is as follows: 5 It is preferable that the chair has a seat or backrest to which any one of the above-described mounting structures for chair upholstery is applied. Effect of the Invention

[0015] According to the mounting structure for the upholstery described in claim 1, when the fastening member is folded back to the back side of the mesh upholstery and inserted into the upholstery groove, the mesh upholstery turns back from the mounting point between the mesh upholstery and the fastening member as a starting point, covering the edge portion of the mesh upholstery closer to the peripheral side than the mounting point and the base end portion of the fastening member, thereby shaping the edge of the mesh upholstery and exposing the tip end portion of the fastening member to form a terminal structure that functions as a guide when fitting into the upholstery groove, and the ears are formed so that the fastening member is in contact with the upholstery groove. Protrudes inward and contacts the ear Since it is fixed to the frame by the fixing means, the locking member and the upholstery can be easily inserted into the upholstery groove, the edge of the upholstery does not protrude from the upholstery groove, eliminating the need to push the edge of the upholstery into the groove, and it looks good and completely prevents the mesh upholstery from slipping out. [Brief description of the drawings]

[0017] [Figure 1] 1 is a front top perspective view showing an embodiment of a chair to which the present invention is applied. [Diagram 2] FIG. 2 is a perspective view of the chair as seen from below and behind. [Diagram 3] FIG. 2 is an exploded perspective view of the backrest as seen from below and behind. [Figure 4] FIG. 2 is an exploded perspective view of the backrest from above and in front. [Diagram 5] 13 is an enlarged perspective view of a side portion of the back frame. FIG. [Figure 6] 1 is an explanatory diagram showing a vertical cross section of the vicinity of the connection point between the lower edge portion of the backrest and the back support member. [Figure 7] FIG. 2 is a front view showing an example of a mesh upholstery for a backrest. [Figure 8] FIG. 2 is an exploded perspective view showing an inner shell and a seat support member that constitute the seat structure. [Figure 9] 4 is an enlarged vertical cross-sectional view showing an assembled state of an inner shell and a seat support member. FIG. [Figure 10] FIG. 2 is a plan view showing an example of a mesh upholstery for a backrest. [Figure 11] This is an explanatory diagram showing the positional relationship between the upholstery and the locking member before they are inserted into the upholstery groove of the frame body according to the present invention. (A) shows the state before the locking member is folded back, (B) shows the state after the locking member has been folded back once (when rotated 180 degrees), (C) shows the state after the locking member has been folded back twice (when rotated 360 degrees), and (D) shows the state after the locking member and the edge of the upholstery have been inserted into the upholstery groove of the frame body. [Figure 12] This is an explanatory diagram showing the positional relationship between the upholstery and the locking member before they are inserted into the upholstery groove of the frame body using conventional methods. (A) shows the state before the mesh upholstery is folded back, and (B) shows the state after the upholstery has been folded back once (rotated 180 degrees) and the locking member and edge of the upholstery have been inserted into the upholstery groove of the frame body. [Figure 13] FIG. 2 is a perspective view showing one embodiment of an armrest body. [Figure 14] FIG. 2 is a perspective view showing one embodiment of a pad from the back side. [Figure 15] FIG. 2 is a cross-sectional view of the tip side of the pad. [Figure 16] FIG. 2 is a cross-sectional view of one embodiment of an armrest. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The configuration of the present invention will be described in detail below based on the embodiment shown in the drawings. In this specification, the front, back, left and right directions are defined with the seated person at the center, and "front or forward" means the front or forward facing direction for the armrest, seat and backrest, respectively, from the perspective of the chair and the seated person sitting on the seat of the chair, and "rear or rear" means the rear or rear facing direction for the chair and the seated person. In addition, the direction perpendicular to the front-rear direction in the horizontal plane is the left-right direction or width direction for the armrest, seat and backrest, respectively, from the perspective of the seated person or the chair. In addition, in the armrest, seat and backrest, the inside is the side facing the seated person or the vertical plane in the front-rear direction passing through the center of the chair, and the outside is the side away from the seated person or the side away from the vertical plane in the front-rear direction passing through the center of the chair. Furthermore, "upper" and "lower" are the upper and lower directions for the armrest, seat and backrest, respectively, from the perspective of the chair and the seated person, and are the upper and lower directions in the vertical plane.

[0019] One embodiment of a chair to which the present invention is applied is shown in Figures 1 and 2. As shown in Figures 1 and 2, for example, this chair has legs 1 equipped with casters, a main frame 2 supported by the legs 1, a seat 3 and a backrest 4 supported so as to be able to swing relative to the main frame 2 and interlocking with each other, and armrests 5 fixed to both ends of a rear bridge frame 11 with screws or the like.

[0020] The chair of this embodiment uses, as its reaction force mechanism, a spring-based reaction force mechanism that obtains a reaction force by compressing the spring when the back frame 6 tilts backward, in combination with a weight-sensitive (or sensing) reaction force applying mechanism that makes the resistance to back rocking proportional to (sensitive to) the weight of the user by linking the mechanism to lift the rear side of the seat support member 30 when the backrest is tilted backward.

[0021] Here, in this embodiment, the main frame 2 is supported by the pillars of the legs 1 (in other words, gas springs) so as to be freely rotatable within a horizontal plane, while its front is rotatably connected to the bearing portion 34 of the front bridge frame 32 which supports the seat frame 31 via a pair of left and right front links 41, and the bearing portion 25 of the rear bridge frame 11 is connected to the rear bracket 42 via the backrest rotation shaft 43, thereby supporting the seat 3 and backrest 4 so as to be freely swingable.

[0022] In addition, the main frame 2 has a built-in reaction mechanism, not shown, which may include, for example, a compression coil spring, and is configured to generate a force that pushes the backrest 4 back in response to the backrest 4 being tilted backward between the backrest support member 7, which is supported so as to be freely swingable on the rear end side of the main frame 2, and a link shaft (not shown) on the front end side of the main frame 2.

[0023] (Backrest) In this embodiment, the backrest 4 is made up of a back frame 6 that forms a rectangular frame when viewed from the front with a hollow space on the inside, and a mesh upholstery 8 that is stretched across the back frame 6 to form the backrest surface, and is mounted swingably on the main frame 2 via a backrest support member 7. In this embodiment, the backrest 4 is mounted on the back frame 6 as the frame to which the mesh upholstery 8 is attached.

[0024] In order to ensure mechanical rigidity as a structure, the back frame 6 is preferably molded from a synthetic resin having rigidity, such as glass fiber reinforced nylon, for example, PA6-GF (polyamide 6).

[0025] In this embodiment, the back frame 6 is formed in a shape that is generally convex toward the front in a side view (i.e., a dogleg shape), and is also formed in a shape that is generally convex toward the rear in a plan view, forming a frame body that is a substantially vertically long rectangle with a hollow inside when viewed from the front, as shown in Figures 3 and 4. Here, the lower side portion 20 that forms the lower side of the frame body is located at a corner that bends forward of the L-shaped back frame 6 in a side view, and the lower side portion 20 and the connecting portion 21 of the back frame 6 that protrudes forward from the lower side portion 20 form a U-shape that surrounds the back frame mounting portion 12 of the backrest support member 7, and is inserted into the back frame mounting portion 12 from three directions, the left and right sides and the back, to be firmly connected to the back frame mounting portion 12.

[0026] In addition, a contact surface 17 that protrudes toward the space inside the frame is provided on the rear end side of the lower side 20. This contact surface 17 is made of a curved surface that is curved in the front-to-rear direction, and presses the mesh upholstery 8 stretched across the front side of the back frame 6, causing it to protrude rearward.

[0027] In addition, the back mounting seat 10 on the front surface of the lower side portion 20 is formed with a flange groove 22 into which the flange 13 of the back frame mounting portion 12 is inserted. A vertical rib 23 is formed in the middle of the flange groove 22, crossing the groove (i.e., the flange groove 22 is formed intermittently), and the vertical rib 23 is provided with a female screw 24 for screwing the back frame mounting portion 12. On the other hand, the flange 13 of the back frame mounting portion 12 is formed intermittently in the circumferential direction so that the flange 13 can be inserted into the flange groove 22 without interfering with the vertical rib 23 provided in the flange groove 22. In other words, the lower side portion 20 of the back frame 6 is also a portion that is fitted into the back frame mounting portion 12 of the backrest support member 7.

[0028] On the other hand, the backrest support member 7 has a rear bridge frame 11 and an annular back frame attachment part 12 (a rectangular frame with a void on the inside). The rear bridge frame 11 is a wing-like frame that extends left and right and curves upward, and together with the annular back frame attachment part 12 at the rear, creates a space under the seat at the rear of the seat 3. This allows the mesh and cushion that make up the seat structure (not shown) to bend vertically without interference.

[0029] Furthermore, the rear bridge frame 11 is provided at its center with a bearing 25 for inserting the backrest rotation shaft 43 of the bracket 42 at the rear end of the main frame 2 to connect the main frame 2 so as to be freely swingable, and an arm 26 that hangs down diagonally downward and forward to support one member of a spring-type backrest reaction mechanism (not shown), so that the spring-type backrest reaction mechanism pushes one member of the spring-type backrest reaction mechanism forward when the backrest 4 tilts backward. The rear bridge frame 11 is provided at its upper surface at both ends with mounting parts, i.e. brackets 28, for mounting the rear bracket 33 of the outer frame 31 so as to be freely swingable. The outer peripheral surface of the back frame mounting part 12 is formed with flanges 13 for inserting the back frame 6 from the rear, which are formed to surround the back frame mounting part 12 and protrude backward and to the left and right sides. In this way, the backrest support member 7 has a rational structure in which the rear bridge frame 11, bearing portion 25, arm portion 26, back frame mounting portion 12, seat frame mounting portion (bracket 28), and seat portion for mounting the armrest 5 (a recess that can be fastened with screws, hereafter referred to as the armrest mounting seat 29) are integrated into one.

[0030] Therefore, the flange groove 22 formed in the back mounting seat 10 on the front side of the lower side portion 20 forming the bottom side of the frame of the back frame 6 is fitted into the flange 13 of the back frame mounting portion 12 of the backrest support member 7 and screwed, so that the back frame 6 and the backrest support member 7 are integrated into a continuous L-shape in side view. For example, the screw (not shown) is screwed from the inside of the annular back frame mounting portion 12 toward the outer back mounting seat 10 to connect the back frame mounting portion 12 and the back frame 6 (i.e., the back mounting seat 10). In other words, the U-shaped back mounting seat 10 protruding forward of the back frame 6 and the back frame mounting portion 12 are connected and integrated without showing the screw on the outside. As a result, in this embodiment, the backrest support member 7 and the back frame 6 are configured into a neat L-shape in side view with a continuous appearance.

[0031] In this embodiment, the mesh upholstery 8 is attached to the frame by providing a locking member 9 as a core material on the periphery of the mesh upholstery 8, and providing a groove (hereinafter referred to as a groove for upholstery 18) for inserting the edge of the mesh upholstery 8 and the locking member 9, which is opened in a direction changed from the tension applied to the mesh upholstery 8, preferably in the opposite direction, on the frame side, and inserting and hooking the mesh upholstery 8 and the locking member 9 into the groove for upholstery 18. Here, as the locking member 9, for example, a flat polypropylene cord (generally called a PP cord) with a rectangular cross section and a thickness of about 1 mm can be used. This flat PP cord with a rectangular cross section is relatively hard in the width direction (longitudinal direction) and flexible in the thickness direction (short direction). However, the locking member 9 is not limited to the above-mentioned PP cord. In this embodiment, the fastening member 9 is arranged and sewn along the periphery of the mesh upholstery 8, and is inserted vertically into the upholstery groove 18 together with the mesh upholstery 8 (i.e., the width direction in which the PP cord shows its rigidity is the insertion direction into the groove). The mesh upholstery 8 is given the desired tension by heat setting (meaning that the mesh upholstery part whose periphery is fixed by the back frame or seat frame is heat treated to give the desired tension by thermal shrinkage and shaping).

[0032] In the case of the backrest 4, upholstery grooves 18 are provided on the outward-facing sides and bottom of the top edge 6a and side edges 6b of the back frame 6, and the mesh upholstery 8 is fixed to the back frame 6 by inserting it while applying tension to the mesh upholstery 8.

[0033] Here, in this embodiment, the upholstery groove 18 in the lower edge portion 20 forming the bottom edge of the frame body is not formed in the back frame 6 itself, but is formed in a separate lower back mesh mounting member 14, and is provided so as to be attached to the lower edge portion 20 of the back frame 6 via the lower back mesh mounting member 14. In this embodiment, as shown in Fig. 6, the lower back mesh mounting member 14 has, for example, a roughly U-shaped cross section, and is fitted and fixed so as to cover the back surface of the lower edge portion 20 below the abutment surface 17. The inner surface of the lower back mesh mounting member 14 facing the back surface of the lower edge portion 20 is provided with an upholstery groove 15 into which the edge of the mesh upholstery 8 and the locking member 9 are inserted and fixed after being folded once or twice. Furthermore, holes are provided on the front surface of the lower back mesh mounting member 14, i.e., the surface facing the back surface of the lower side portion 20, for screwing in fastening screws 16 which are screwed in from the front side of the lower side portion 20, and the lower back mesh mounting member 14 is connected and integrated with the back frame 6 with the mesh upholstery 8 inserted into the upholstery groove 15. Therefore, the lower end portion of the mesh upholstery 8 stretched over the front surface of the back frame 6 is sandwiched between the back surface of the lower side portion 20 and the underside of the abutment surface 17, and in the vicinity of the abutment surface 17, as shown in Figure 2, it is applied to the back side of the abutment surface 17 to form a curved surface without corners.

[0034] 7, the locking member 9 of the backrest 4 in this embodiment is divided into four parts: a first cord 9a fitted into an area including the upper side 6a of the back frame 6 and the corner parts 6c at both ends thereof, a second cord 9b and a third cord 9c fitted into both sides of the back frame 6, and a fourth cord 9d fitted into the lower side (bottom side) of the back frame. In addition, the mesh upholstery 8 for the backrest has cuts (not shown) made along the end faces of each of the first to fourth cords 9a to 9d at the boundaries between them, allowing each of the cords 9a to 9d to be folded back.

[0035] The first cord 9a is substantially U-shaped similar to the contour of the back frame 6, which is a framework including the top side 6a of the back frame 6 and the corners 6c at both ends of the back frame 6, and has a substantially straight section along the top side 6a of the back frame 6 and a curved corner section 9e along the upholstery groove 18 that opens into the side of the corner section 6c. The first cord 9a is sewn to the surface of the mesh upholstery 8 along the edge.

[0036] On the other hand, the second and third cords 9b, 9c are inserted into the upholstery groove 18 in the substantially straight side edge 6 of the back frame 6. Here, in the case of the backrest 4, there is a risk that the mesh upholstery 8 may be easily torn at the outer edge of the side edge 6a that may collide with a relatively hard material such as a surrounding furniture, for example, a chair top. To prevent this, it is preferable to interpose a material that functions as a cushioning material, such as an elastomer material, between the mesh upholstery 8 outside the upholstery groove 18 and the back frame 6 at the outer edge of the side edge 6a of the back frame 6.

[0037] Therefore, in the present embodiment, a known PP cord with elastomer (see, for example, JP 2020-62350 A) having an insertion portion functioning as a locking member and an elastomer portion functioning as a buffer member is used for the second and third cords 9b and 9c. Although not shown, the insertion portion is formed of a synthetic resin, such as polypropylene (PP), that is hard enough to be easily pushed into the upholstery groove 18 when inserted and not easily bent so as to not come out of the fitted state. On the other hand, the elastomer portion is preferably made of a material, such as an olefin-based thermoplastic elastomer, that is interposed between the mesh upholstery 8 and the side edge 6b of the back frame 6 and functions as a buffer member against the collision of an object from the outside. Since it is preferable for the elastomer material and the locking member to be integrated in terms of handling, for example, the insertion portion and the elastomer portion are integrated by two-color extrusion molding to form a resin cord (i.e., a PP cord with elastomer). In this case, the elastomer part is folded back with the insertion part, which is the locking member, inserted into the groove of the back frame 6 and is arranged so as to be sandwiched between the mesh upholstery and the front surface of the back frame outside the upholstery groove 18, so that the elastomer part raises the mesh upholstery. Therefore, as shown in Fig. 5, a recess 19 is formed on the side edge 6a of the back frame 6, particularly from the edge of the upholstery groove 18 to the front side of the back frame 6, so that the recess 19 is lower than the surrounding surface by the amount of the elastomer part. This prevents a step from being generated between the mesh upholstery and the back frame even when the elastomer part is interposed between the mesh upholstery and the back frame, and reduces discomfort in terms of design and when touched.

[0038] Here, the second and third cords 9b, 9c, which are made of a fastening member with an elastomer part, are sewn to the surface of the mesh upholstery 8, and then folded back twice (rotated 360°), so that the elastomer part is positioned inside on the back side of the mesh upholstery, and the elastomer part is inserted into the upholstery groove 18. Thus, the second and third cords 9b, 9c are attached by sewn to the mesh upholstery 8, with the insertion part (the part of the fastening member) positioned outside and the elastomer part positioned inside, along the periphery of the back side of the mesh upholstery 8. Then, the cords are folded back once (rotated 180°) at the boundary between the insertion part (the part of the fastening member) and the elastomer part, and the insertion part (the part of the fastening member) and the mesh upholstery 8 are inserted into the upholstery groove 18.

[0039] Further, in the present embodiment, the fourth cord is attached via the lower back mesh attachment member 14 fixed to the bottom portion 20 of the back frame 6, as shown in FIG. 6 for example. In the present embodiment, the central portion of the lower back mesh attachment member 14 is gently curved backward when viewed from below. Therefore, the upholstery groove 15 formed on the inner surface of the lower back mesh attachment member 14 and the fourth cord 9d inserted therein are also gently curved backward overall. Therefore, like the first cord 9a, the fourth cord 9d is sewn to the surface of the mesh upholstery 8 and folded back twice to be curved in the same direction as the upholstery groove 15 of the lower back mesh attachment member 14 before being inserted. Then, for example, with the mesh upholstery and the PP cord 9 inserted, the lower back mesh attachment member 14 is placed over the back side of the back attachment seat 10 of the back frame 6 and fixed to the back frame 6 by screwing it from the front.

[0040] According to the above-described mesh upholstery mounting structure, the first cord 9a sewn onto the surface of the mesh upholstery 8 is folded back, so that the mesh upholstery 8 is turned up around the sewing point (i.e., the mounting point) 44 of the first cord 9a, and the portion 8e on the tip side (in other words, the edge side of the upholstery) of the sewing point 44 is folded back (see Figs. 11(A) and (B)). Then, by folding back once more, the mesh upholstery 8 is turned up around the tip of the first cord 9a (in other words, the edge side of the mesh upholstery 8), and the mesh upholstery 8 on the inside of the sewing point 44 is folded back (see Fig. 11(C)). At this time, the edge side portion 8e of the mesh upholstery 8 is rolled up in the folded back portion, and a part of the first cord 9a, i.e., the portion 45 on the inside of the sewing point 44, is exposed and bare. Therefore, it becomes easy to insert the fastening member, the first cord 9a, and the mesh upholstery 8 into the upholstery groove 18, and the edge of the mesh upholstery 8 does not protrude from the upholstery groove 18, eliminating the need to push the edge of the mesh upholstery 8 into the groove 18. The same applies to the fourth cord 9d.

[0041] Here, except for exceptional locking members such as locking members with elastomer parts (i.e., the second and third cords 9b and 9c), in the case of the locking member 9, particularly the first cord 9a having the corner portion 9e, it is important that the locking member 9 is attached to the mesh upholstery 8 on the front side of the mesh upholstery 8. When the locking member 9 is attached to the back side of the mesh upholstery 8 by sewing or the like, a locking member such as the first cord 9a including the corner portion 9e cannot be shaped to fit the locking member by wrapping it with the mesh upholstery. In other words, a locking member such as the corner portion 9e cannot be rotated 360° in the first place and cannot be fitted into the upholstery groove. In addition, even if the locking member is linear, even if the locking member is rotated 360° while folding back the mesh upholstery, the entire locking member is wrapped in the mesh upholstery 8, so the mesh upholstery 8 becomes double and its thickness increases, and it is not easy to fit into the upholstery groove like the terminal structure shown in this embodiment in which a part of the locking member is exposed and functions as a guide. Furthermore, since the entire fastening member is wrapped in the mesh upholstery 8, there is a problem in that it is not possible to create protrusions, such as ears 39, on the edges of the fastening member.

[0042] In addition, when the attachment position of the locking member 9 and the mesh upholstery 8, i.e., when sewing, the sewing point 44 is not limited to the center position in the width direction, but can be performed near the edge side or away from the edge, and the effect of facilitating insertion of the mesh upholstery 8 into the upholstery groove 18 is not lost. Furthermore, if the sewing point 44 of the first cord 9a to the mesh upholstery 8 is set to approximately the center position in the width direction of the cord 9a, the cord is folded back twice by a distance equivalent to the width of one piece of cord, so that the end of the first cord 9a, i.e., the end of the corner portion 9e, is located in the same position as when the second and third cords (PP cords with elastomer) 9b, 9c are folded back once. Therefore, in the folded state, the corner portions 9e at both ends of the first cord 9a and the ends of the second and third cords 9b, 9c are located in the same position, that is, there is no discrepancy in the cord position in the upholstery groove insertion direction. In addition, corner portions 9e at both ends of the first cord 9a, which curves inward, can be rotated 360° to return to their original curved state, so that the shape follows the curved shape of the upholstery groove 18 of the back frame 6 (corner portions 9c between the top edge 9a and the side edges 9b) and can be inserted into the upholstery groove 18 of the back frame 6. This eliminates the risk of the mesh upholstery 8 coming loose at the corner portions 9e.

[0043] (Location structure) 8 and 9, the seat 3 in this embodiment is composed of a mesh upholstery 37 forming the seat surface, an annular inner shell 35 to which the mesh upholstery 37 is attached, and a seat support member 30 including an outer shell 31, and is mounted on the main frame 2 so as to be able to swing between the front link 41 of the main frame 2 and the backrest support member 7 via the seat support member 30. Note that in the case of the seat 3 in this embodiment, the inner shell 35 as a frame body to which the mesh upholstery 37 is attached and the outer shell 31 are assembled by placing the inner shell 35 on the outer shell 31 and screwing it from below.

[0044] The seat support member 30 of this embodiment is not limited to a specific structure or shape, but may have, for example, an annular outer shell (a rectangular frame with a hollow inside) 31, a front bridge frame 32 that supports the front of the outer shell 31, and a bracket 33 for connecting a position slightly rearward of the middle of the outer shell 31 to the backrest support member 7, with a bearing portion 34 in the center of the front bridge frame 32 connected to and supported by the front link 41 of the main frame 2 so as to be able to swing, while the bracket 33 on the rear side of the outer shell 31 is connected to the bracket 28 of the backrest support member 7 by a rotating shaft (not shown) and supported so as to be able to swing. Therefore, the seat 3 moves in conjunction with the movement of the backrest 4.

[0045] The front bridge frame 32 is a wing-shaped frame that extends left and right and curves upward, and in combination with the rear bridge frame 11 and the back frame attachment portion 12 of the backrest support member 7, creates a space under the seat (see Figs. 1, 2 and 8). This allows the mesh upholstery 37 to bend vertically without interfering with the main frame 2. It also has the effect of making the design look lighter.

[0046] Here, the mounting position of the rear bracket 33 of the outer shell 31 relative to the rear bridge frame 11 is provided forward of the backrest rotation shaft 43 of the rear bridge frame 11, and is located at a position where the seat support member 30 (i.e., the seat 3) can be lifted when the backrest support member 7 tilts backward. That is, the seat 3 is lifted as the backrest 4 tilts backward, and a part of the body weight of the seated person acts as resistance against the backward tilting of the backrest 4 (rocking resistance is body weight sensitive), constituting a body weight sensing reaction force imparting mechanism (or called a body weight sensitive reaction force imparting mechanism).

[0047] The mesh upholstery 37 is attached to the inner shell 35 of the seat 3 of this embodiment in the same manner as in the case of the backrest 4 described above, for example, by fitting the mesh upholstery 37, which has fastening members 38 such as PP cords along its periphery, together with the fastening members 38, into the upholstery groove 36 formed on the outer peripheral side surface of the inner shell 35. In the case of the seat 3, the upholstery groove 36 is provided around the front edge 35a, the left and right sides 35b, the rear edge 35d, and the corner parts 35c between them, on the outward facing side surfaces, and the mesh upholstery 37 is inserted into the groove while being tensioned, and fixed.

[0048] As shown in FIG. 10, the locking member 38 is divided into four parts: a first cord 38a that is fitted into an area including the front edge 35a of the inner shell 35 and the corner portions 35c on both ends thereof; a second cord 38b and a third cord 38c that are fitted into the left and right side edges 35b of the inner shell 35; and a fourth cord 38d that is fitted into an area including the rear edge 35d of the inner shell 35 and the corner portions 35c on both ends thereof.

[0049] The first cord 38a is substantially U-shaped similar to the contour including the front side 35a of the inner shell 35 and the corner parts 35c at both ends, and is sewn along the edge of the surface of the mesh upholstery 37. On the other hand, the second and third cords 38b, 38c are substantially linear and are sewn along the edge of the surface of the mesh upholstery 37. Furthermore, the fourth cord is substantially U-shaped similar to the contour including the rear side 35d of the inner shell 35 and the corner parts 35c at both ends, and is sewn along the edge of the surface of the mesh upholstery 37. In this embodiment, the first cord 38a and the fourth cord 38d include the corner parts 38e at both ends, but this is not particularly limited. For example, the corner parts 38e may be included on the second and third cords 38b, 38c side, or in some cases, only the corner parts 38e may be independent as a locking member. In some cases, each of the first cord 38a to the fourth cord 38d may include a corner portion 38e at one end thereof.

[0050] In the conventional method of attaching the fastening member (PP cord) to the upholstery, as shown in Fig. 12, the mesh upholstery 37 is sewn to the back side along the edge of the upholstery. The mesh upholstery 37 is then folded once to encase the fastening member 38, and then inserted into the upholstery groove 36 (see Fig. 12(B)). However, with this method, if the mesh upholstery portion 37e beyond the sewing point (i.e., the attachment point) 44 separates from the fastening member 38 and floats up, it is difficult to insert it into the upholstery groove 36, or in some cases, the edge 37e of the mesh upholstery 37 on the tip side beyond the sewing point 44 is folded back and inserted into the groove 36, or even cannot be inserted at all. In addition, when the part that floats up from the fastening member 38 protrudes from the upholstery groove 36, it is necessary to use a jig or the like to fit it into the upholstery groove, which increases the number of work steps.

[0051] Furthermore, in the case of the curved locking member, i.e., the corner portion 38e, when the locking member is rotated once, the curve shape of the corner portion 38e faces outward (the direction of the curve is reversed) and it cannot enter the upholstery groove 36, so there is a problem that the locking member 38 cannot be used. Therefore, in the corner portion 38e, only the mesh upholstery 37 remains, so it is necessary to use a tool to push the mesh upholstery of the corner portion into the upholstery groove. This causes a problem that the effort and work process of pushing the mesh upholstery of the corner portion into the upholstery groove is required to improve the appearance. Moreover, since there is no locking member and only the mesh upholstery is pushed in, there is a problem that the mesh upholstery is easily pulled out.

[0052] Therefore, in this embodiment, the locking member 38 is sewn along the periphery to the surface of the mesh upholstery 37, and the locking member 38 is first folded once over to the back side of the mesh upholstery 37, and then the mesh upholstery 37 is folded once over to encase the locking member 38 (totaling two folds) before being inserted into the upholstery groove 36.

[0053] The above-mentioned first to fourth cords 38a, 38b, 38c, and 38d are sewn to the front side of the mesh upholstery 37. In addition, cuts parallel to the ends of the resin cords are made in the upholstery located at the boundaries between the first to fourth cords 38a, 38b, 38c, and 38d, so as to allow folding back of each cord.

[0054] In the case of the seat of this embodiment, each of the cords 38a, 38b, 38c, and 38d is folded twice on the back side of the mesh upholstery (the cords are rotated 360°), so that a part of each of the cords 38a, 38b, 38c, and 38d is wrapped in the mesh upholstery 37, and a tip side portion 45 of each of the cords 38a, 38b, 38c, and 38d is exposed beyond the sewing point 44 of the mesh upholstery 37, and the cords are inserted in the exposed state into the upholstery groove 36. In other words, as shown in Fig. 11, while the cords 38 sewn to the front side of the mesh upholstery 37 and the mesh upholstery 37 make two rotations, the mesh upholstery 37 is folded back from the sewing point 44 as a starting point and further wrapped around the edge of the base end portion 46 of the cords 38, so that the tip side portion 45 of the cords 38 is inserted in the upholstery groove 36 in an exposed state. Therefore, at the edge of the upholstery groove 36, the folded mesh upholstery 37 is formed to cover the base end portion 46 outside the sewing point 44 of the cord 38 and the edge 37e of the mesh upholstery, so that the edge of the mesh upholstery 37 is in a neat shape. Moreover, since the edge 37e of the mesh upholstery 37 is not exposed at the tip side of the insertion direction of the mesh upholstery 37, the mesh upholstery 37 does not protrude from the upholstery groove 36, and the process of pushing it in is unnecessary, which makes it possible to reduce one process and improves the appearance. In addition, since a part of the cord, i.e., the tip side portion 45, is exposed, the cord 38 can be inserted into the upholstery groove 36 first, making it easier to insert the edge 37e of the mesh upholstery 37 into the upholstery groove 36. Also, in the corner portion 38e, which is a locking member curved inward (towards the center of the upholstery), by rotating the cord 38 and the mesh upholstery 37 360°, the corner portion 38e returns to its original curved state, so that the shape follows the curved shape of the upholstery groove 36 of the inner shell 35 (corner portion 35c between the front edge 35a and the side edge 35b) and can be inserted into the upholstery groove 36 of the inner shell 35. This eliminates the risk of the mesh upholstery 37 coming loose at the corner portion 38e. The same is true for the corner portion 38e of the fourth cord 38d.

[0055] Furthermore, since the external force and load applied to the seat 3 is greater than that applied to the backrest 4, it is preferable that each of the cords 38a, 38b, 38c, and 38d for the seat is formed with ears 39 for screw fastening in order to take every possible measure to prevent the mesh upholstery from coming loose. The position of these ears 39 is arbitrary and may be provided in any location of any cord, but it is particularly preferable that the ears 39 are formed at both ends of the first cord 38a and the fourth cord 38d, i.e., at the ends of the corner parts 38e. The ears 39 are provided on the edges that will be on the inside when the cords 38a, 38b, 38c, and 38d are sewn to the surface of the mesh upholstery, folded back twice to the back side, and then inserted into the upholstery groove 36, so that the ears 39 protrude toward the inside of the frame body. Therefore, as shown in FIG. 11(D), the ears 39 are inserted into the upholstery grooves 36 and then fixed to the inner shell 35 by, for example, screwing in a fastening screw 40 from the underside of the inner shell 35. The ears 39 are arranged in a direction away from the edge of the mesh upholstery 37 (inward) when sewing the cords 38a, 38b, 38c, and 38d along the edge of the mesh upholstery 37 with a sewing machine, so they do not interfere with the sewing and do not reduce work efficiency. In this embodiment, the ears 39 of each cord are screwed in just in case (to increase the load-bearing capacity of the seat), and may not be provided in some cases. In addition, the ears 39 are not limited to the seat locking member 38, and may be provided in the back locking member 9 in some cases. In addition, the method of fixing the ears 39 to the inner shell 35 is not limited to the above-mentioned screwing, and may be tacked or other fixing means.

[0056] In this embodiment, the method of attaching the fastening members (e.g., PP cords) 9, 38 to the mesh upholstery 8, 37 is not limited to a specific method as long as it can be attached so that it can be reversed, and other methods such as sewing, adhesion, welding, etc. are also possible, but sewing is preferable.

[0057] In the present embodiment, the armrest 5 is composed of an aluminum die-cast armrest body 60 and a synthetic resin pad 50 attached to its upper surface, as shown in Figures 1 and 16. Of course, the materials of the armrest body 60 and the pad 50 are not particularly limited to those mentioned above, and may be selected as appropriate. Note that, although the present embodiment will be mainly described with reference to an example in which the armrest is applied to a fixed armrest, in which the position, height, orientation, etc. of the armrest are fixed relative to the chair, the present invention is not particularly limited thereto, and may of course be applied to a movable armrest, in which the position, height, orientation, etc. of the armrest are variable.

[0058] When the pad 50 is attached to the armrest body 60 by screws, a thickness of at least the length of the screw fastening part is required, which inevitably results in a thick pad 50 or armrest body 60, resulting in an unfashionable design. With the recent trend toward office chairs with a focus on design, and a preference for chairs with simple and clean appearances, there is a demand for armrest designs that are thin in thickness.

[0059] On the other hand, in the case of an attachment structure in which the pad 50 is fixed to the armrest body 60 by hooking it with a nail or the like, if the pad material is flexible, there is a risk that it may easily come off by applying force in the direction of rolling it up. In other words, the armrest pad 50 is the part that is most frequently touched by the fingers of the seated person, and there is a possibility that it may come off due to mischief, etc. In addition, there is a risk that it may easily come off if a strong force is applied. For example, if you try to lift your body from the chair while grabbing or pushing down near the front end of the armrest, the entire weight of the seated person will act as a force moving the pad forward (sliding force), and the pad may slip or fall off.

[0060] Therefore, in the case of this embodiment, the pad 50 is slid sideways to attach it to the armrest body 60, and the armrest body 60 and the pad material 50 are fitted together without using screws. Of course, although not shown, the pad 50 may also be slid forward and backward to attach it to the armrest body 60.

[0061] As shown in Fig. 13, the armrest body 60 of this embodiment has a trapezoid shape in side view with a top side 70, a front side 71, a rear side 72 and a bottom side 73, the inside of which forms a hollow frame shape, and is screwed to the armrest mounting base 29 via mounting arms 74 and supported by the backrest support member 7. The armrest body 60 also has a recess 75 formed from the top side 70 to the front side 71, with a portion of the top surface 66 and the inner side wall (hereinafter referred to as the inner wall 67) removed, and the pad 50 is placed in this recess 75 to form the surface of the armrest (i.e. the top surface). In this embodiment, the armrest body 60 is molded from aluminum die casting, but the material is not particularly limited.

[0062] In the present embodiment, the recess 75 is formed with a locking rib 61 that supports the resin pad 50 in the width direction of the chair between the outer side wall (hereinafter referred to as the outer wall 68) of the upper side 70 of the armrest body 60. In addition, at least one support rib 62 is formed between the outer wall 68 of the upper side 70 of the armrest body 60 and the locking rib 61 to vertically support the middle of the upper part 51 of the pad 50 so that the pad 50 does not become indented when an external force is applied to the pad 50. In some cases, this support rib 62 may not be provided. Needless to say, these ribs 61, 62 also fulfill the original role of a rib, which is to reinforce the loss of rigidity caused by the loss of the inner wall 67 and the upper surface 66 of the armrest body 60.

[0063] The locking rib 61 is provided on the outside (i.e., the seated person side) of the locking rib 61 so that the bottom 69 of the upper edge 70 of the armrest body can support the inner side wall portion (hereinafter referred to as the inner wall portion 53) of the resin pad 50. Specifically, the locking rib 61 is provided at a position offset outward from the inner end of the bottom 69 of the armrest body 60 by approximately the thickness of the inner wall portion 53 of the resin pad 50. Of course, the position of the locking rib 61 is not particularly limited to the above and can be changed as appropriate, but it is preferable to ensure at least a space sufficient to support the inner wall portion 53 of the resin pad 50. On the other hand, the support rib 62 is provided at a position offset further inward than the locking rib 61. In the illustrated case, the support rib 62 is formed thicker than the locking rib 61, but it goes without saying that the thickness or number of the support ribs 62 is not particularly limited to this and may be any thickness or number. Furthermore, these ribs 61, 62 are formed lower than the actual height of the top surface of the upper side 70 of the armrest body 60 so that the pad 50 fits into the recess 75 of the upper side 70 of the armrest body 60. Specifically, for example, they are formed at a height lower by the thickness of the upper part 51 of the pad 50 or a slightly thinner thickness, and are provided so that when the pad 50 is attached so as to cover the armrest, the resin pad 50 fits flush with the top surface of the upper side 70 of the armrest body 60 or rises slightly higher than that.

[0064] The pad 50 is attached to the armrest body 60 by using a three-axis concave-convex engagement structure that is perpendicular to each other. For example, the pad 50 is provided with a front locking claw 57 at the tip edge, and a first side locking claw 55 is formed on the inner surface of the inner wall 53, and a second side locking claw 56 is formed on the outer surface of the outer side wall (hereinafter referred to as the outer wall 52). On the other hand, the armrest body 60 is formed with a through hole 63 in the locking rib 61 through which the first side locking claw 55 protruding outward from the inner wall 53 of the pad 50 penetrates, an engagement recess 64 in the outer wall 68 into which the second side locking claw 56 protruding outward from the outer wall 52 of the pad 50 is fitted, and a downward engagement recess 65 in which the front locking claw 57 of the pad 50 is fitted at the front end of a recess 75 extending to the front edge 71. The engagement recess 65 restricts the front locking claw 57 of the pad 50 from moving forward, but is a cavity that allows movement in the width direction at least by the amount of lateral sliding for attaching and detaching the pad 50.

[0065] The first side locking claw 55 is formed, for example, as an integral part of the pad 50 (and therefore as a part formed of resin) so as to protrude from the inner surface of the inner wall portion 53 of the pad 50 toward the opposite outer wall surface 52. The first side locking claw 55 is an elastically deformable protrusion having a return that narrows when passing through the through hole 63 and widens after passing through the through hole 63 so as not to come out of the through hole 63, for example, a wedge portion 55c obliquely intersecting with the insertion direction into the through hole 63, a return portion 55b that is locked to the edge of the through hole 63 of the locking rib 61, and a leg portion 55a having a length that passes through the locking rib 61, and is an elastically deformable body that is elastically deformable in a direction perpendicular to the insertion direction into the through hole 63 (see FIG. 15). In other words, the first lateral engagement claw 55 is a so-called house- or mushroom-shaped elastic protrusion that passes through the through hole 63 while narrowing the wedge-shaped expanding return portion 55b, and after passing through the through hole 63, the return portion expands and functions to catch.

[0066] In the example shown in the figure, the first side locking claws 55 are provided at five locations at approximately regular intervals on the inner surface of the inner wall portion 53 of the pad 50. The number of first side locking claws 55 is not limited to the example shown in the figure, and may be appropriately set to an appropriate number, for example, taking into consideration whether the engagement force between the pad 50 and the armrest body 60 can be secured.

[0067] In addition, a rib 58 that protrudes slightly in the width direction of the armrest is formed at approximately the center position between the adjacent first side locking claws 55. This rib 58 is, for example, a linear projection extending in a direction perpendicular to the upper portion 51 of the pad 50. In other words, by alternately forming the ribs 58 and the first side locking claws 55, a reaction force is applied to the first side locking claws 55 that penetrate the through holes 63 of the locking rib 61, so that the play is absorbed. The inner side wall portion 53 of the pad 50 that abuts against the rib 58 is pulled by the engagement between the first side locking claws 55 between the ribs 58 and the through holes 63, so that it receives a force that causes it to bend slightly, and a load is constantly applied so that no play occurs between the first side locking claws 55 and the through holes 63.

[0068] The direction in which the first side locking claws 55 are formed is not particularly limited, but depends on the direction of the through hole 63 opened in the locking rib 61 of the armrest body 60. For example, when a horizontally long rectangular through hole 63 is provided for the locking rib 61 along the bottom 69 of the armrest body 60, the first side locking claws 55 in the illustrated example are formed to protrude from the inner wall 53 to the outer wall 52 of the pad 50 so that the elastic deformation direction is set in the horizontal direction. The directions in which the first side locking claws 55 are formed may all be the same, or may be adjusted so that the first side locking claws 55 as a whole can firmly respond to external forces, or may be adjusted by assuming and taking into account the direction of external forces applied depending on the parts of the pad 50.

[0069] The engagement recess 65 formed on the front edge of the armrest body 60 has a clearance in the width direction so that the pad 50 can slide in the width direction while the front locking claw 57 at the tip of the pad 50 is engaged. The front locking claw 57 has an inclined surface at its tip to create a wedge effect between the armrest body 60 and the front locking claw 57 when inserted into the engagement recess 65, so that a force biasing the pad 50 backward is generated between the front locking claw 57 and the armrest body 60. Therefore, when the front locking claw 57 is inserted into the engagement recess 65, the front side of the front locking claw 57 comes into close contact with the front inner surface of the engagement recess 65 with no gap in the front-rear direction, and a force biasing the pad 50 backward is applied and the pad 50 is positioned so as not to shift forward.

[0070] The pad 50 is engaged with the second side locking claw 56 inserted into the engagement recess 64 and the first side locking claw 55 inserted into the through hole 63. At the same time, the first side locking claw 55 elastically deforms and penetrates the through hole 63, and then expands again, thereby functioning as a mechanism for preventing the pad 50 from slipping out in the width direction, i.e., preventing the pad 50 from sliding sideways. On the other hand, the rear end edge 54 of the pad 50 abuts against the wall surface of the recess 75 of the armrest body 60 (the end surface of the upper side 70 exposed by the recess 75), while the front end edge 59 abuts against the wall surface of the engagement recess 65 (the end surface of the front side 71 exposed by the engagement recess 65) and the tip side locking claw 57 fits into the engagement recess 65 to function as a stopper, thereby fixing the pad 50 so that it cannot move in the front-rear direction. That is, the engagement recess 64 and the second side locking claw 56 are engaged with each other in a direction perpendicular to the sliding direction of the pad 50.

[0071] The engaging recess 64 in the outer wall 68 of the armrest body 60 made of aluminum die-cast is a recess that does not penetrate the outer wall 68 so as not to impair the appearance, and is therefore formed by post-processing such as cutting or grinding. Also, the through hole 63 in the locking rib 61 is a through hole, for example a rectangular hole, and is therefore formed at the same time as the die-cast molding.

[0072] The second side locking claw 56 is a so-called protrusion that fits into the engagement recess 64, and by fitting into the engagement recess 64, it engages the armrest body 60 and the pad 50 in a direction perpendicular to the sliding direction of the pad 50. In other words, the second side locking claw 56 is not limited to a specific form such as the protrusion shown in the figure, so long as it serves to position the pad 50 in the front-rear direction and prevent it from floating up.

[0073] In this embodiment, the second lateral locking claw 56 and the engagement recess 64 are positioned approximately on an extension of the position where the first lateral locking claw 55 and the through hole 63 engage, but this is not particularly limited and they may be positioned at any position, for example, shifted in the front-to-rear direction from the engagement position between the first lateral locking claw 55 and the through hole 63.

[0074] In addition, in the example shown in the figure, the first side locking claw 55 and the second side locking claw 56 are provided on the pad 50 side, and the through hole 63 and the engagement recess 64 are provided on the armrest body 60 side, but the arrangement of the first side locking claw 55 and the through hole 63, as well as the second side locking claw 56 and the engagement recess 64 is not limited to the example shown in the figure. In addition, the arrangement is not limited to the arrangement in which the second side locking claw 56 is provided on the side where the first side locking claw 55 is provided, as in the example shown in the figure. Specifically, for example, as one example only, the first side locking claw 55 may be provided on the pad 50, and the second side locking claw 56 may be provided on the armrest body 60.

[0075] In this embodiment, the first and second side locking claws 55 and 56 are provided on the pad 50, while the through hole 63 and the engagement recess 64 are provided on the armrest body 60, and the armrest is attached by sliding in the width direction, but the present invention is not limited to this. The first and second side locking claws 55, 56, the through hole 63, and the engagement recess 64 may be provided on at least one of the armrest body 60 and the pad 50. For example, although not shown, the armrest body 60 may be provided with the second side locking claw 56 protruding inward, and the outer wall 52 of the pad 50 may be provided with a recess or a through hole engagement recess. Of course, the first side locking claw 55 may be provided on the armrest body 60, and the through hole 63 may be provided on the pad 50.

[0076] In this embodiment, the mounting structure of the pad 50 to the armrest main body 60 is removably provided by the first lateral locking claw 55 which elastically deforms and engages with the through hole 63 of the armrest main body 60, but is not limited to this and may also be a non-detachable connecting structure.

[0077] The first side locking claw 55 fitted into the through hole 63 is not easily removed from the through hole 63 of the armrest body 60, but can be removed by pulling it with an appropriate force. That is, the first side locking claw 55 is pulled out of the through hole 63 while narrowing the wedge-shaped return portion.

[0078] The first side locking claw 55 and the through hole 63 ensure an appropriate joining force between the pad 50 and the armrest body 60, and also make it possible to remove the pad 50 from the armrest body 60 when necessary, such as for replacing the pad. In other words, an engagement / connection that is detachable and difficult to come off easily is realized.

[0079] According to the armrest pad mounting structure configured as described above, the outer wall portion 52 of the pad 50 is fitted between the outer wall portion 68 of the armrest main body 60 and the support rib 62, and the pad 50 is placed over the recess 75 of the armrest main body 60 so that the inner wall portion 53 of the pad 50 is positioned inside the locking rib 61. When the front locking claw 57 on the front end of the pad 50 slides inside the locking recess 65, the pad 50 is slid widthwise from the inside to the outside of the armrest 5, and the first lateral locking claw 55 of the pad 50 elastically deforms and penetrates and engages with the through hole 63 of the armrest main body 60, and the second lateral locking claw 56 engages with the locking recess 64 of the armrest main body 60, and the pad is fixed in three axial directions, that is, the front-to-back, left-right and up-down directions.

[0080] When using the product, forward forces are likely to act on the armrest 5. However, since the pad 50 does not move forward, there is no risk of it coming off the armrest body 60. In addition, since the pad 50 is fixed without using screws, the pad 50 and the armrest body 60 can be made thin.

[0081] This makes it possible to prevent the first lateral locking claw 55 from being displaced or deformed and accidentally losing engagement with the through hole 63, thereby improving the usefulness and reliability of the engagement structure and improving the safety and comfort of use of the backrest to which the engagement structure is applied, and ultimately of the chair.

[0082] In addition, in the illustrated embodiment, the pad 50 is attached to the armrest body 60 by sliding it in the width direction from the inside to the outside of the armrest 5, but this is not particularly limited, and in some cases, it may be attached to the armrest body 60 by sliding it in the width direction from the outside to the inside of the armrest 5. In this case, it goes without saying that the positional relationship of the locking rib 61, the support rib 62, the remaining outer wall portion 68, and the first side locking claw 55 and the second side locking claw 56 of the pad will be symmetrical about the front-rear axis with respect to the illustrated embodiment.

[0083] Therefore, the pad 50 is attached to the armrest body 60 by fitting the front locking claw 57 at the tip edge of the pad 50 into the locking recess 65 of the front side 71 of the armrest body 60, while the outer wall part 52 of the pad 50 is placed between the outer wall part 68 of the armrest body 60 and the support rib 62, and the pad 50 is placed over the recess 75 of the upper side 70 of the armrest body 60 so that the first side locking claw 55 of the inner wall part 53 is placed in the through hole 63 of the locking rib 61, and then sliding the pad 50 laterally, so that the first side locking claw 55 of the inner wall part 53 of the pad 50 and the second side locking claw 56 of the outer wall part 52 are fitted into the through hole 63 of the locking rib 61 of the armrest body 60 and the locking recess 64 of the outer wall part 68. As a result, the pad 50 is locked in three axial directions, namely, front-rear, left-right, and up-down, and fixed to the armrest body 60.

[0084] The above-mentioned embodiment of the mounting structure of the mesh upholstery is one example of a preferred embodiment of the present invention, but is not limited thereto and can be modified in various ways without departing from the gist of the present invention. For example, in the above-mentioned embodiment, the locking member at the upper edge of the backrest or the locking members at the front and rear ends of the seat are described as an example of a locking member in which a straight portion and a curved corner portion are continuously formed, but this is not particularly limited. For example, in the above-mentioned embodiment, the corner portion is included at both ends of the first cord, but this is not particularly limited, and it may be included only at one end or on other cords, such as the second and third cords, or in some cases, only the corner portions 9e and 38e may be independent as locking members. In any case, the locking members at the corner portions are provided on the surface of the upholstery, and by folding it twice, it is in the same direction as before it was folded, so it fits into the upholstery groove. Also, an example was described in which a PP cord with an elastomer was used for the side of the backrest, but this is not particularly limited thereto, and for example, a PP cord without an elastomer portion may be used. In this case, it is preferable to sew the locking member to the surface side of the mesh upholstery and fold it twice to insert it into the groove. In this case, the corner portion 9c may be included at one end of the first cord 9a and at the other end of the second or third cord 9b, 9c. In this embodiment, the corner portion 38e is included at both ends of the first cord 38a and the fourth cord 38d, but this is not particularly limited. For example, the corner portion 38e may be included on the side of the second and third cords 38b, 38c, or only the corner portion 38e may be independent as a locking member in some cases. In some cases, the corner portion 38e may be included at one end of each of the first cord 38a to the fourth cord 38d.

[0085] Furthermore, the configuration of a chair to which the present invention can be applied, in particular the specific shapes and aspects of each component such as the inner shell 35 or back frame 6 that form the frame across which the mesh upholstery is stretched, are not limited to those in the above-described embodiments, but may be selected as appropriate taking into account the purpose and design of the chair.

[0086] Furthermore, in this embodiment, an example has been given in which upholstery is made of a highly elastic mesh material, but this is not particularly limited to this, and it may also be applied to an embodiment in which the back frame 6 or the seat inner shell 35 is covered in a fully wrapped manner (a method in which the inner shell and cushion are completely wrapped in the upholstery).

[0087] Furthermore, the armrests 5 are fixed by screws or the like to armrest mounting seats 29 at both ends of the rear bridge frame 11 as required. Therefore, when the armrests 5 are not needed, the armrest mounting seats 29 are covered with a cover, that is, a cover formed with a surface that is flush with the outer shell surface of the rear bridge frame 11.

[0088] Furthermore, in the above-mentioned embodiment, an example has been given of an application to a synchronous rocking mechanism that combines a body weight-sensitive reaction force application mechanism that generates a force that pushes back the backrest by raising the seat in conjunction with the backward tilt of the chair backrest, and a reaction force application mechanism that utilizes a compression spring. However, the chairs to which the present invention is applicable are not limited to this, and it goes without saying that the present invention can be applied to chairs that have only one of a body weight-responsive reaction force application mechanism or a reaction force application mechanism with a coil spring, for example, a non-body weight-sensing synchronous rocking mechanism in which the seat moves backward in conjunction with the backward tilt of the backrest and the rear end sinks, a rocking mechanism in which only the backrest tilts backward alone, or a rocking mechanism in which only the seat performs a rocking action, and even chairs that do not have a rocking mechanism. [Explanation of symbols]

[0089] 1 leg 2. Mainframe 3 seats 4 Backrest 5 Armrest 6 Back frame 6a Top 6b Side 6c Corner part 7 Backrest support member 8 Mesh upholstery (for backrest) 9 Locking member 9a 1st chord 9b 2nd chord 9c 3rd chord 9d 4th chord 9e Corner part 10 Back mounting seat 11 Rear bridge frame 12 Back frame attachment part 13 Flange (back frame mounting part) 14 Lower back mesh mounting part (part of the back frame) 15 Groove for upholstery (for mesh mounting material under the back) 16 Fastening screw 17 Contact surface (back frame) 18 Groove for upholstery (back frame) 19 Front recess of side of back frame 20 Bottom of spine frame 21 Connecting part 22 Flange groove (for flange 13) 23 Vertical rib (groove for flange 22) 24 Female thread (groove for flange 22) 25 Bearing portion (for backrest support member) 26 Arm portion (backrest support member) 27 Reaction receiving portion (of backrest support member) 28 Bracket (supports the outer shell) 29 Elbow mounting base 30 Seat support member 31 Outer frame 32 Front bridge frame 33 Bracket (rear of seat frame) 34 Bearing section 35 Inner Shell 35a front side 35b side 35c corner part 35d rear side 36 Groove for upholstery (inner shell) 37 Mesh upholstery (for seat) 38 Locking member (for seat) 38a 1st chord 38b 2nd chord 38c 3rd chord 38d 5th chord 38e Corner parts 39 Ears 40 Screw 41 Previous link 42 Rear bracket 43 Backrest rotation axis 44 The sewn part between the fastening member and the mesh upholstery (i.e., the attachment part) 45 The tip side part on the inside (opposite edge side) of the sewing point of the locking member 46 Base end portion on the outer side (edge ​​side) of the sewing point of the locking member 50 pads 51 Top of the pad (top surface) 52 Outer side wall of pad 53 Inner wall of pad 54 Rear edge of pad 55 First side locking claw 55a Legs 55b Return part 55c Wedge 56 Second lateral locking claw 57 Front locking claw 58 Ribs 59 Front edge of pad 60 Armrest body 61 Locking rib 62 Support rib 63 A through hole through which the first side locking claw of the pad passes 64 An engagement recess into which the second side locking claw of the pad fits 65 Engagement recess into which the front locking claw of the pad fits 66 Upper surface of upper edge of armrest body 67 Inner side of upper edge of armrest body 68 Outer side wall of upper edge of armrest body 69 Bottom of upper edge of armrest body 70 Upper edge of armrest body 71 Front edge of armrest body 72 Rear edge of armrest body 73 Bottom edge of armrest body 74 Armrest body attachment arm 75 Recess on top of armrest body

Claims

1. A structure for attaching a mesh upholstery to a chair, the mesh upholstery having a locking member on its periphery being inserted into an upholstery groove in a frame of a seat or backrest of a chair to fix the mesh upholstery, The fastening member is a flat plate with a rectangular cross section that is inserted with a gap between it and the upholstery groove, and has an ear portion on one side edge, and the other side edge on which the ear portion is not provided is disposed along the periphery of the mesh upholstery and attached to the front side of the mesh upholstery, When the locking member is folded back onto the back side of the mesh upholstery and inserted into the upholstery groove, the mesh upholstery is rolled back starting from the attachment point between the mesh upholstery and the locking member, covering the edge portion of the mesh upholstery closer to the peripheral side than the attachment point and the base end portion of the locking member, thereby shaping the edge of the mesh upholstery and leaving the tip end portion of the locking member exposed, forming a terminal structure that functions as a guide when fitting into the upholstery groove, The ears are fixed to the frame by a fixing means that protrudes into the upholstery groove and abuts against the ears when the locking member is inserted into the upholstery groove. A structure for attaching chair upholstery.

2. 2. The upholstery mounting structure for a chair according to claim 1, wherein said fastening member is sewn to said mesh upholstery.

3. 3. The structure for attaching upholstery to a chair according to claim 1, wherein the engaging member is pressed into the upholstery groove that opens into a side surface of the frame of the seat or backrest.

4. 2. The structure for attaching upholstery to a chair according to claim 1, wherein the fastening member is attached to the mesh upholstery at the center in the width direction of the fastening member.

5. The upholstery mounting structure for a chair described in any one of claims 1 to 4, characterized in that the locking member has a curved shape that conforms to the upholstery groove that opens into the side of the corner portion of the frame body, and is fitted into the upholstery groove of the corner portion of the frame body in a 360° rotated state.

6. A chair comprising a seat or a backrest to which the mounting structure for chair upholstery according to any one of claims 1 to 5 is applied.

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