Body support unit for chair and manufacturing method thereof

Abstract

To disclose a technology that uses a three-dimensional mesh body made of resin fiber as a cushioning material, yet provides a soft feel to the body and allows easy retraction of the upholstery. [Solution] The cushioning material (13) has a two-layer structure consisting of a base layer (15) made of a highly elastic three-dimensional mesh material and a buffer layer (16) made of thin fibers such as felt. A string (24) is attached to the buffer layer (16), and the upholstery (14) is sewn to the buffer layer (16) at the location where the string (24) is arranged. The string (24) has left and right downward portions (24a) that are inserted through the buffer layer (16), base layer (15), and inner shell (12), and the downward portions (24a) are tied on the back side of the inner shell (12). The buffer layer 16 is compressed and deformed, so it can strongly pull in the upholstery 14. Since the string material 24 is attached to the buffer layer 16 in advance and the upholstery 14 is also attached to the buffer layer 16 in advance, the upholstery 14, buffer layer 16, and base material layer 15 are attached to the inner shell 12 in a state where they are positioned relative to one another.

Description

[Technical Field]

[0001] The present invention relates to a body support unit with a structure in which cushioning material is covered with upholstery, like the seat or back of a chair. Here, the body support unit includes not only the back or seat as typical examples, but also headrests, shoulder rests, armrest pads, etc. [Background technology]

[0002] When the seat or back of a chair is constructed with a cushion stretched over a resin inner shell, the cushion is covered with upholstery. The upholstery is sometimes partially pulled in toward the inner shell to prevent slack in the upholstery, to maintain the overlap between the upholstery and cushion and the backboard, or for design reasons.

[0003] It has also been proposed to use a fastener as a means for pulling the upholstery in. For example, Patent Document 1 discloses a method in which a plate-shaped fastener is sewn to the back of the upholstery, and the claws on the fastener are fitted into a middle plate located on the back of the cushion.

[0004] Now, foamed urethane is often used as a cushioning material for the seats and backs of chairs, but foamed urethane has problems such as poor breathability, not necessarily high elasticity, and a tendency to sag, which means a decrease in elastic recovery over time.

[0005] On the other hand, there exists a nonwoven three-dimensional mesh material made by intertwining and bonding meandering highly elastic resin fibers, which has excellent breathability, high resilience, and durability, and is therefore being used as cushioning material for seats and backrests (e.g., Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-330398 [Patent Document 2] Japanese Patent Application Publication No. 10-128890 Summary of the Invention [Problem to be solved by the invention]

[0007] Three-dimensional mesh materials made from highly elastic resin fibers are widely used in mattresses and the like, and because they have excellent durability, high cushioning, and breathability, the applicant of the present application has focused on these properties and has long been considering using them as cushioning materials for chairs, and as part of this, Patent Document 2 was disclosed. However, there is a problem in that the surface is rough and does not make good contact with the human body.

[0008] Furthermore, when pulling the upholstery downward, if the upholstery is directly stacked on a three-dimensional mesh body, pulling the upholstery downward will not compress and deform the three-dimensional mesh body, preventing the surface from becoming concave, which creates the problem of the upholstery not being pulled in sufficiently.

[0009] The former problem can be solved by using a three-dimensional mesh as a base layer and layering a cushioning layer that is soft against the human body. do.

[0010] The present invention was made against this background, and when the cushioning material is configured as a multi-layered type, Good The present invention aims to disclose suitable techniques. [Means for solving the problem]

[0011] The present invention includes various configurations, examples of which are specified in each claim. Of these, the invention of claim 1 is as follows: " An inner shell made of synthetic resin, one side of which is a pressure-receiving surface that receives the load of a seated person, and a cushion material that overlaps the pressure-receiving surface of the inner shell; and an upholstery covering the cushion material, The cushioning material is overlapped with a substrate layer; and a buffer layer overlapping the base layer, the buffer layer being in the form of a sheet that is thinner and softer than the base layer. Body support unit for chairs In this basic configuration, "before record base The material layer is a three-dimensional mesh formed by entangling a group of winding synthetic resin elastic fibers. It is a single item consisting of The cushioning layer is a nonwoven material having a group of fibers extending in the thickness direction of the cushioning layer, or a felt material or knitted fabric. It consists of , The buffer layer directly overlies the substrate layer." It has the following characteristics.

[0012] The invention of claim 2 is a preferred example of the invention of claim 1, " The outer periphery of the buffer layer wraps around the outer periphery of the base layer. " It has the following characteristics.

[0013] The invention of claim 3 is a development example of claim 1 or 2, " The base layer and the inner shell are recessed toward the user's body. " It has the following characteristics.

[0014] The invention of claim 4 is also a development example of claim 1 or 2, "The inner shell is a seat inner shell, and the front part of the seat inner shell is provided with the front part. downward A group of horizontally elongated second slits are formed that allow the material to be wrapped around and deformed. It has the following characteristics.

[0015] The invention of claim 5 is directed to the manufacturing method of body support units for chairs, " The method includes the steps of: preparing an inner shell made of synthetic resin and having an uneven pressure-receiving surface; preparing a cushioning material that overlaps the pressure-receiving surface of the inner shell; preparing an upholstery that covers the cushioning material; and attaching the cushioning material and the upholstery to the inner shell, The step of preparing the cushioning material includes a step of preparing a base layer made of a three-dimensional net-like body formed by entangling a group of meandering elastic synthetic resin fibers, and a step of preparing a buffer layer made of a nonwoven fabric-like material, a felt material, or a knitted fabric having a group of fibers extending in a thickness direction, The step of preparing the base material layer includes a step of preparing a sheet material and a step of processing the sheet material into a shape that overlaps the inner shell using a press device. " It has the following characteristics.

[0016] The invention of claim 6 is 1 or 2 This is an example of the expansion of "The inner shell is a seat inner shell, and a group of first slits is formed in the portion of the seat inner shell where the buttocks of the seated person overlap, to allow sinking due to the weight of the seated person, Furthermore, the above-mentioned Inner shell and cushioning material and Zhang The base is a portion where the group of first slits is formed and is recessed downward, and a part of the recessed portion of the upholstery is seat It's being pulled towards the inner shell." It has the following characteristics.

[0017]

[0018]

[0019] [Effects of the Invention]

[0020] In the present invention, the surface side of the cushioning material is made up of a buffer layer, so the base material layer is a three-dimensional mesh body. consists of Even though it has a highly elastic structure, it feels soft against the user's body, and therefore, a high level of comfort can be achieved while maintaining the properties of the base material layer. In addition, The base layer is a three-dimensional mesh consists of High elasticity makes it difficult to form recesses. When pulling the upholstery with string, There is a concern that the upholstery may not be fully pulled in, but the present invention allows the cushioning layer to be recessed precisely, When the upholstery is pulled in as in claim 6, It also ensures that the upholstery is pulled in properly.

[0021] In addition, When the upholstery is pulled by strings or the like, excessive tension is applied to specific narrow areas of the upholstery, which can cause the upholstery to twist. When the upholstery is pulled in as in claim 6, The buffer layer is pulled to form a recessed groove that serves as the pull-in section. It is possible This prevents excessive tension from being applied to one part of the upholstery, preventing twisting of the upholstery. is.

[0022]

[0023] loose By providing breathability to the cushioning layer and base layer, the user can be prevented from becoming stuffy and improve comfort. Furthermore, in the present invention, a three-dimensional mesh body made of synthetic resin is used as the base layer, ensuring high elasticity and durability. Furthermore, by using nonwoven fabric or felt as the cushioning layer, inexpensive commercially available products can be used, resulting in stable quality and cost reduction.

[0024]

[0025] In the case of claim 6, Although hooks made of resin or metal can also be used as the tensioning device, using a string as in the embodiment allows the string to be pulled tightly, thereby enabling the formation of a retraction section to be performed firmly. Furthermore, since tying the string can be done regardless of the structure of the underside of the inner shell, there is no need to apply special processing to the inner shell or change the existing structure, making this highly practical.

[0026] Regarding chair seats, the depth is adjusted to accommodate differences in users' physiques and preferences. As in claim 4, Adjusting the depth by rolling up the front of the seat has the advantage of allowing adjustment without lifting your hips. However, rolling up and unrolling can easily induce slippage between the upholstery and the buffer layer, or between the buffer layer and the base layer, but by using string as a tensioning device as in the embodiment, the upholstery is fixed to the retraction part and the string passes through the buffer layer and the base layer, preventing slippage of the upholstery relative to the buffer layer or the buffer layer relative to the base layer, and maintaining high quality.

[0027] The thickness of the base layer and buffer layer can be set arbitrarily according to the characteristics of the target unit. Claim 1 As described above, when the buffer layer is thinner than the base layer (when the base layer is thicker than the buffer layer), the high elasticity of the base layer can be utilized, which is preferable. Specifically, when the base layer is set to a thickness of several centimeters (for example, 2 to 4 cm) and the buffer layer is set to a thickness of several millimeters to several tens of millimeters, it is preferable that the necessary cushioning and durability can be ensured and a soft feel can be ensured even when applied to a seat. [Brief explanation of the drawings]

[0028] [Figure 1] 1A and 1B are views of a chair equipped with a seat according to a first embodiment, in which (A) is a perspective view seen from the front, (B) is a side view, and (C) is a perspective view seen from below and behind. [Figure 2](A) is an exploded perspective view of the chair as seen from the front, (B) is an exploded perspective view of the chair as seen from the back, and (B) is a perspective view of the seat as seen from above and behind. [Figure 3] (A) is a perspective view from below of the seat, and (B) is a bottom view of the seat. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] (A) is a longitudinal front view of the lead-in portion and a cross-sectional view taken along the VIA-VIA line in FIG. 1(A), (B) is a cross-sectional view taken along the B-B line in (A), (C) and (D) are longitudinal front views showing a part of the manufacturing process, and (E) is a plan view of (D). [Figure 7] 10(F) is a cross-sectional view taken along the line FF of FIG. 10(E). DETAILED DESCRIPTION OF THE INVENTION

[0029] Next, an embodiment of the present invention will be described with reference to the drawings. This embodiment is applied to the seat of a swivel-type rocking chair that is commonly used for office work. In this application, terms such as "front, back" and "left, right" are used to specify directions, but these are based on the orientation of a person sitting in a normal posture. A front view is the direction facing the seated person.

[0030] (1) Basic structure of the chair and seat As can be seen from Figure 1, the chair to which this embodiment is applied is a swivel chair commonly used in offices, and the chair's basic elements are a leg device 1, a seat 2, and a backrest 3. The backrest 3 is made of an elastomer synthetic resin plate with numerous perforations. The leg device 1 has a base with five leg blades, and a leg support 4 made of a gas cylinder is erected in the center of the base, and a caster is attached to the tip of each leg blade.

[0031] A base 5 is fixed to the upper ends of the leg supports 4, and a second tilting frame 7 is connected to the base 5 via left and right first tilting frames 6, with the backrest 3 attached to the second tilting frame 7. A seat support mechanism is attached to the base 5 for moving the seat 2 backward and tilting it backward in conjunction with the backward tilting of the backrest 3, and a seat outer shell (seat support shell body) 8 is fixed to the seat support mechanism, with the seat 2 fixed to the outer shell 8.

[0032] The second tilting frame 7 has a back support 9 located in the left-right middle and extending up and down, and lower side sections 10 located at the bottom and extending left and right, with the lower side sections 10 tapering and rising toward their tips, forming a crescent shape overall. Therefore, the second tilting frame 7 has an anchor-like shape overall. A swing arm 11 is attached to the back support 9, and the upper end of the backrest 3 is fixed to both left and right ends of the swing arm 11, and the lower corners of the backrest 3 are fixed to the tips of the lower side sections 10.

[0033] As shown in Figure 5, the seat 2 of the first embodiment comprises an inner shell (seat panel) 12 made of synthetic resin, a cushion material 13 placed on top of the inner shell, and an upholstery (skin material) 14 covering the cushion material 13. The cushion material 13 has a two-layer structure consisting of a base material layer 15 and a buffer layer 16 placed on top of it. The cushion material 13 has an overall thickness of approximately 35 to 40 mm, with the base material layer 15 being approximately 30 to 35 mm thick and the buffer layer 16 being approximately 5 to 10 mm thick. The upholstery 14 can be made of woven or knitted fabric (if breathability is not required, artificial or natural leather can also be used).

[0034] As shown in FIGS. 3 and 5, in this embodiment, the front part of the inner shell 12 is 、 Many landscapes The second slit 12cThe bending deformation allowance portion 12a is capable of being rolled up and deformed, but because the cushioning material 13 and upholstery 14 also bend and deform, the front portion 2a of the seat 2 also becomes a bending deformation allowance portion that can be rolled down. When the left and right brackets 17 that protrude downward from the front end of the inner shell 12 are pulled backward, the front portion 2a of the seat 2 is rolled down. This allows the front-to-rear position of the front end of the seat 2 to be adjusted. In other words, the depth of the seat 2 can be adjusted. Behind the bending deformation allowance portion 12a of the inner shell 12, there are numerous vertically long and left-to-right long curved brackets. No. 1 slit 12d The subduction deformation allowable portion 12b is formed.

[0035] For example, as shown in Fig. 3, a pair of left and right downward brackets 17 are integrally formed at the front end of the inner shell 12, while as shown in Fig. 2(A), a slider 18 is attached to the outer shell 8 so as to be movable back and forth, and the downward bracket 17 of the inner shell 12 is connected to a catch portion 18a at the front end of the slider 18. The slider 18 can be moved back and forth by operating a lever 19 shown in Fig. 1(C). Therefore, by adjusting the front-to-back position of the lever 19, the front portion 2a of the seat 2 can be rolled in or out, thereby adjusting the depth of the seat 2.

[0036] As shown in Fig. 3, the underside of the inner shell is provided with protrusions such as bosses 20 that come into contact with the outer shell and connecting claws 21. Also, as also shown in Fig. 3, the underside of the inner shell 12 is formed with a large number of groups of hook-shaped claws 22 for connecting the upholstery 14. The hook-shaped claws 22 are provided all around the outer periphery of the inner shell 12 and in a region behind the bending deformation-permitting portion 12a.

[0037] On the other hand, as shown in Figure 5, the upholstery 14 has a pocket portion 14a that wraps around the bending deformation-allowing portion 12a of the inner shell 12 from below, and a holding portion 14b behind it that wraps around the outer periphery of the inner shell 12, and a resin tape (not shown) is fixed around the entire circumference of the pocket portion 14a and the entire circumference of the holding portion 14b, and the resin tape has locking holes that engage with the hook-shaped claws 22.

[0038] (2) Upholstery retraction structure of the first embodiment For example, as shown in Figure 2(A)(C), seat 2 is Downward The rear end of the seat 2 is recessed in the center and is deeper in the side view, and the inner shell 12, cushioning material 13, and upholstery 14 are also shaped in the same way. Downward The seat 2 is in a deeply recessed state. A recessed portion 23 is formed in the deeply recessed portion of the seat 2 (generally in the front-to-back position where the tailbone of the seated person comes into contact), extending long to the left and right.

[0039] The base layer of the cushioning material 13 is made of a three-dimensional mesh structure in which numerous highly elastic, winding resin fibers, such as polyester fibers, are entangled and bonded, providing a breathable structure. On the other hand, the buffer layer 16 is made of a hardened felt material in which thin resin fibers are entangled, providing breathability while providing a soft feel to the buttocks and thighs of the seated person.

[0040] As shown in Figure 6(A), the buffer layer 16 is formed to a size that extends outside the outer periphery of the base material layer 15. The outer periphery of the base material layer 15 is designed to be located at the peripheral edge of the inner shell 12, and the outer periphery 16a of the buffer layer 16 is set to extend beyond the base material layer 15 and wrap around the outside of the inner shell 12. The buffer layer 16 undergoes compression deformation against its elasticity, so by attaching the upholstery 14 to the inner shell 12 with the buffer layer 16 compressed, the upholstery 14 is held taut.

[0041] As shown in FIGS. 4 to 6, the buffer layer 16 has a portion corresponding to the recess 23. PullA single string 24, which is an example of a tensioning material, is arranged, and the string 24 penetrates the buffer layer 16 at both left and right ends thereof and is pulled downward. Furthermore, left and right downward portions 24a of the string 24 penetrate the base material layer 15 and the inner shell 12 and are pulled below the inner shell 12, and as shown in Figures 3, 5, and 6, the left and right downward portions 24a are tied together at the underside of the inner shell 12. As mentioned above, the seat 2 is concave downward when viewed from the front so that its rear is deeper, and the sinking-permitting portion 12b consisting of a group of first slits 12d is formed in the area where the buttocks of the seated person come into contact, and as shown in Figure 3(B), the string material 24 is arranged at the sinking-permitting portion 12b.

[0042] and, As shown in Figures 6(A) and 6(B), by pulling the downward portion 24a of the string material 24 strongly, a groove-shaped pull-in portion 23 is formed in the upper surface of the buffer layer 16. The upholstery 14 is then sewn to the upper surface of the buffer layer 16 at the pull-in portion 23 by sewing. In Figures 2(C) and 6(E), the thread exposed by sewing is indicated by the symbol 23a.

[0043] The upholstery 14 can be sewn only to the surface of the buffer layer 16, or it can be sewn by passing a sewing needle through the buffer layer 16 and embracing the upholstery 14 and buffer layer 16 with sewing thread. Alternatively, it is possible to sew a strip of fabric as a reinforcing material to the top surface of the buffer layer 16, and then sew the upholstery 14 to this strip of fabric. Furthermore, it is also possible to press and fix the string material 24 to the top surface of the buffer layer 16 by a method such as overlocking, and then sew the upholstery 14 to this string material 24. be. For example, as shown in FIG. 3(B), the inner shell 12 has left and right lead-in holes 25 through which the string material 24 is passed.

[0044] It is also possible to attach a plug that presses the downward portion 24a of the string material 24 into the lead-in hole 25. A push rivet, for example, can be used as the plug. In Figures 6(C) and (D), holes 26 through which the string material 24 passes are shown in the buffer layer 16, but this is for convenience only, and the holes 26 may be omitted.

[0045] (3) Summary of the first embodiment The seat 2 is manufactured (assembled) in the following steps: First, the upholstery 14, buffer layer 16, base layer 15, and inner shell 12 are manufactured, and then the string 24 is attached to the buffer layer 16. In this case, although one string 24 is used in the drawing, if one string 24 is used, it is sufficient to simply insert the downward portion 24a into the buffer layer 16; it is not necessary to fix the string 24 to the buffer layer 16.

[0046] On the other hand, it is also possible to use two strings 24, in which case the upper ends of the left and right strings 24 need to be fixed to the upper surface of the buffer layer 16. In order to form a groove-shaped pull-in portion 23 in the buffer layer 16, it is preferable to use one string 24 and use the string 24 to recess the buffer layer 16 downward. The string 24 needs to be inserted into the buffer layer 16, but the string 24 can also be inserted by using a needle-shaped jig such as a sewing needle and penetrating the jig into the buffer layer 16 to pull it out.

[0047] Alternatively, it is possible to spread the buffer layer 16 with a funnel-shaped jig and then pass the string material 24 through the jig. The same applies to insertion into the base layer 15. In either case, it is preferable to fix both the buffer layer 16 and the base layer 15 to the jig and use a mask or the like to accurately pass the string material 24 through to the predetermined position.

[0048] After attaching the string material 24 to the buffer layer 16, the upholstery 14 is placed on the buffer layer 16 while being accurately positioned, and then, as shown in Figure 6(E), the retractable portions 23 are sewn together to secure the upholstery 14 to the buffer layer 16. Next, with the downward portions 24a of the string material 24 inserted through the base material layer 15 and inner shell 12, the upholstery 14 is placed over the buffer layer 16, base material layer 15, and inner shell 12 and secured to the inner shell 12, and then the left and right downward portions 24a of the string material 24 are pulled to form the retractable portions 23, which are then tied together in this state. This completes the two-layer seat 2 with the retractable portions 23 formed.

[0049] The majority of the cushioning material 13 is made up of the base material layer 15, which allows it to maintain high resilience and durability. Meanwhile, the buffer layer 16 is made of a dense, soft-to-the-touch material, such as felt, which provides a soft feel against the seated person's buttocks and thighs and a comfortable feel. Furthermore, both the cushioning material 13 and the base material layer 15 are made up of countless fibers, with continuous pores within, providing excellent breathability and preventing stuffiness. In particular, by using a material for the buffer layer 16 in which fibers are woven vertically (the direction in which the base material layer 15 and the buffer layer 16 are layered), the cushioning properties of the buffer layer 16 can be improved, making it less likely for the seated person to feel the unevenness of the base material layer 15. A specific example of such a material is V-lap (registered trademark) manufactured by Teijin Limited.

[0050] Furthermore, because it has retraction section 23, it is possible to prevent upholstery 14 from floating, ensuring a beautiful appearance, even for seats 2 with a highly three-dimensional shape where the upper surface of the rear section is significantly recessed. If the front section 2a of seat 2 is retractable as in the embodiment, the upholstery 14 is pulled forward with the front section 2a of seat 2 retracted, and without retraction section 23, there is a risk that the upholstery 14 will float significantly when not being seated, which would result in a poor appearance. However, with retraction section 23, even when the front section 2a of seat 2 is retracted, it remains overlapping buffer layer 16 of the upholstery 14, which is an aesthetically pleasing treatment and is particularly preferable.

[0051] In this embodiment, since the string material 24 is attached to the buffer layer 16, the buffer layer 16 is attached to the base layer 15 in an accurately positioned state, while since the upholstery 14 is fixed to the buffer layer 16 in advance, the buffer layer 16 is also attached to the base layer 15 in an accurately positioned state. Furthermore, since the upholstery 14 is attached to the buffer layer 16 in advance, the assembly work can be carried out quickly.

[0052] The thickness of the base layer 15 and the buffer layer 16 can be set arbitrarily to suit the characteristics of the target unit, but when applied to the seat 2 as in the embodiment, the base layer is set to a thickness of several centimeters (for example, 2 to 5 cm) and the buffer layer is set to a thickness of several mm to several tens of mm, which is preferable because it ensures the cushioning and durability required for the seat 2 while also providing a soft feel.

[0053] As mentioned above, when the outer peripheral portion 16a of the buffer layer 16 is wrapped around the outside of the inner shell 12, the elastic deformation of the buffer layer 16 is utilized to keep the upholstery 14 taut, thereby maintaining a beautiful appearance. Furthermore, even when the periphery of the upholstery 14 is fitted into the hook-shaped claws 22 of the inner shell 12, it can be kept in a state where it will not come off.

[0054] In this embodiment, the retraction section 23 is formed in a groove shape, but it is not necessarily required to form the retraction section 23 in a groove shape. It is also possible to make the location where the string material 24 is attached to the buffer layer 16 different from the location where the upholstery 14 is sewn, and it is also possible to attach the upholstery 14 to the buffer layer 16 at both the front and rear locations sandwiching the attachment portion of the string material 24 to the buffer layer 16.

[0055] In the embodiment, the bending deformation allowance portion 12a at the front of the inner shell 12 has an uneven shape, but it is possible to thin the portion of the base material layer 15 where the inner shell 12 overlaps the uneven portion. Alternatively, it is also possible to form the lower surface of the base material layer 15 into an uneven shape that fits into the uneven portion of the inner shell 12. teeth, It can be made by cutting out a commercially available sheet material, but it can be made thinner or have an uneven underside by pressing it while heating it.

[0056] (4) Other embodiments and others 7 shows other embodiments as modified examples. In the second embodiment shown in (A), long grooves 27 are formed in advance on the surface of the buffer layer 16 by pressure. In the third embodiment shown in (B), the retracted portions 23 are formed in a dotted shape, and multiple retracted portions 23 are formed. A string material 24 is attached to the retracted portions 23 via a stopper. What is Although different, it is also possible to form a plurality of linear lead-in portions 23.

[0057] In the fourth embodiment shown in (C), a narrow resin tape 28 is placed on the buffer layer 16, and the resin tape 28 is pulled downward by the string material 24. In this case, the upholstery 14 is sewn to the resin tape 28. The fifth embodiment shown in (D) is a modification of the fourth embodiment, in which a long groove 27 is formed in advance in the buffer layer 16, and the resin tape 28 is placed in the long groove 27. In any embodiment, the resin tape 28 can be pulled downward by three or more string materials 24.

[0058] In the sixth embodiment shown in (E) and (F), a footed resin tape 29 is used as the tensile material. That is, the footed resin tape 29 has a band plate portion 30 and multiple pairs of foot portions 31 provided on its longitudinal side edges, and the foot portions 31 penetrate through the buffer layer 16, the base material layer 15, and the inner shell 12. At least the downward exposed portions of the foot portions 31 are formed into sawtooth-shaped interlocking portions 31a, and a catch 32 is fitted into the interlocking portions 31a from below, thereby holding the footed resin tape 29 in a state where it is pulled downward.

[0059] The catch 32 has a ratchet structure that engages with the meshing portion 31a, allowing it to be pushed into the meshing portion 31a but not allowing it to be pulled back. Therefore, by pulling the meshing portion 31a with the catch 32 in contact with the underside of the inner shell 12, the cushioning layer 16 can be maintained in a compressed and deformed state. The upholstery 14 is sewn to the strip portion 30 of the footed resin tape 29.

[0060] The foot portions 31 can be inserted into the buffer layer 16 and the base layer 15 using a jig that pierces the buffer layer 16 and the base layer 15 from below, or by utilizing the rigidity of the foot portions 31. In the latter case, if pilot holes are made in the buffer layer 16 and the base layer 15 using an awl-like piercing tool, the foot portions 31 can be inserted easily and accurately positioned. Instead of using the dedicated footed resin tape 29, it is also possible to use the strip-shaped resin tape 28 in combination with a commercially available resin fastener.

[0061] In the seventh embodiment shown in (G), the upholstery 14 is sewn to the buffer layer 16 also at the auxiliary attachment portion 33, which is different from the retraction portion 23 (the auxiliary attachment portion 33 can be seen as part of the retraction portion). In this embodiment, the integrity of the upholstery 14 and the buffer layer 16 is improved, improving the slippage prevention function of the upholstery 14.

[0062] Now, when a retractable section is provided in the seat or backrest, it can be said that consideration is given to making the retractable section as inconspicuous as possible. Therefore, if the retractable section is constructed using sewing thread, the sewing thread will be the same color as the upholstery 14. On the other hand, variations in the upholstery of the seat or backrest are sometimes used as a means of increasing the commercial value of a chair. One example of this is to provide upholstery in multiple colors, but it can be said that merely changing the color scheme is not enough to attract consumer attention.

[0063] In this regard, when the auxiliary joining portion 33 is provided as in the seventh embodiment, the auxiliary joining portion 33 can function as a stitch pattern by using a thread of a different, more noticeable color than the upholstery 14, which can strongly attract the consumer's attention and improve the product value. Therefore, the auxiliary joining portion 33 can adopt various forms without abstracting the retraction function.

[0064] For example, various shapes can be formed and embroidered. ByIt is also possible to use it for PR purposes by printing company names, logos, trademarks, and product names. If there are many seats, numbers can be displayed with stitching to function as seat numbers. In either case, since it is not printed, there is no problem with color fading with use, and the high design quality can be maintained for a long time.

[0065] From this design point of view, For reference, The buffer layer 16 is not necessarily required, and a structure in which threads are sewn to the upholstery 14 in an embroidered state can also be adopted (sewing to the buffer layer 16 is preferable in that it can prevent the upholstery 14 from shifting or deforming). Using threads of different colors is preferable as it enhances the function of the pattern.

[0066] Although the embodiments of the present invention have been described above, the present invention can be embodied in various other ways. For example, the application is not limited to the seat of a swivel chair, but can also be applied to a single-seater or multi-seater sofa, or to a theater seat, etc. fixed chair It can also be applied to seats and backrests.

[0067] The buffer layer is not limited to nonwoven fabric or felt material, and for example, a thick knitted fabric such as rib knitting can also be used. The base layer may be made up of multiple layers. The buffer layer does not need to be placed on the entire surface of the base layer, but may be placed only in areas where the body pressure of the seated person acts. The tensioning device can also be made of metal (for example, sheet metal such as aluminum).

[0068] It is also possible to temporarily fix the buffer layer to the base layer by gluing, etc. In this case, it is possible to temporarily fix the buffer layer to the base layer and then attach the upholstery to the buffer layer, or it is also possible to first attach the upholstery to the buffer layer and then temporarily fix the buffer layer to the base layer. ru. The buffer layer may be made of a nonwoven fabric made of synthetic resin fibers or a compressed cotton material made by intertwining resin fibers or natural fibers and compressing them. [Industrial Applicability]

[0069] The present invention can be embodied in a body support unit for a chair, such as a seat or backrest, and is therefore industrially applicable. [Explanation of symbols]

[0070] 2nd seat 2a Front section (section that allows for deformation due to entrapment) 3 Backrest 6,7 tilting frame 8 outer shell 12 Inner shell 12a Bending deformation allowance section 13 Cushioning material 14 Upholstery 15 Base material layer 16 Buffer layer 17 Downward Bracket 18 Slider 18a Catch part 22 Hook-shaped claws for fixing upholstery 23 Retraction section 24 String material as an example of a tensioning device 24a Downward part 25 Retraction hole

Claims

1. A seat cushion comprising an inner shell made of synthetic resin, one side of which is a pressure-receiving surface that receives the weight of a seated person, a cushioning material that overlaps the pressure-receiving surface of the inner shell, and an upholstery that covers the cushioning material, a cushioning material including a base layer overlaid on the inner shell and a buffer layer overlaid on the base layer, the buffer layer being a sheet-like layer that is thinner and softer than the base layer; the base layer is a single piece made of a three-dimensional net formed by entangling a group of meandering elastic synthetic resin fibers, and the buffer layer is made of a nonwoven material, a felt material, or a knitted fabric having a group of fibers extending in the thickness direction of the buffer layer; The buffer layer directly overlies the substrate layer. Body support unit for chairs.

2. The outer periphery of the buffer layer wraps around the outer periphery of the base material layer.

2. A body support unit for a chair according to claim 1.

3. The base layer and the inner shell are recessed toward the user's body.

3. A body support unit for a chair according to claim 1 or 2.

4. The inner shell is a seat inner shell, and a group of horizontally elongated second slits is formed in a front portion of the seat inner shell, allowing the front portion to be folded downward and deformed.

3. A body support unit for a chair according to claim 1 or 2.

5. A method for manufacturing a pressure-receiving device, comprising the steps of: preparing an inner shell made of synthetic resin and having an uneven pressure-receiving surface; preparing a cushioning material that overlaps the pressure-receiving surface of the inner shell; preparing upholstery that covers the cushioning material; and attaching the cushioning material and upholstery to the inner shell; The step of preparing the cushioning material includes a step of preparing a base layer made of a three-dimensional net-like body formed by entangling a group of meandering elastic synthetic resin fibers, and a step of preparing a buffer layer made of a nonwoven fabric-like material, a felt material, or a knitted fabric having a group of fibers extending in a thickness direction, The step of preparing the base material layer includes a step of preparing a sheet material and a step of processing the sheet material into a shape that overlaps the inner shell using a press device. A method for manufacturing a body support unit for a chair.

6. The inner shell is a seat inner shell, and a group of first slits is formed in the portion of the seat inner shell where the buttocks of the seated person overlap, to allow sinking due to the weight of the seated person, Furthermore, the seat inner shell, the cushion material, and the upholstery are recessed downward at the portion where the group of first slits is formed, and a part of the downward recessed portion of the upholstery is pulled toward the seat inner shell.

3. A body support unit for a chair according to claim 1 or 2.

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