Body support unit for chair and manufacturing method of the same

Abstract

To form a retractable part without occurrence of opening phenomenon of a cushioning material, in a seat and a backrest having the retractable part with upholstery pulled by the cushioning material, even if the cushioning material is in a three-dimensional network state composed of a countless fiber groups.SOLUTION: One end of a string material 19 is run up against the rear face of upholstery 11 and, the other end of the string material 19 is restrained in a rod-like retracting tool 23. The retracting tool 23 is tucked in engaging parts 26, 27 installed in an inner shell 9, after being inserted into the retracting holes 20, 21 of the cushioning material 10 and the inner shell 9. The retracting tool 23 is held on the engaging parts 26, 27 in a state strongly pulling the string material 19.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a body support unit having a structure in which a cushioning material is covered with upholstery, such as the seat or backrest of a chair. The body support unit includes not only the backrest and seat, 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 plastic inner shell, the cushion is covered with upholstery. The upholstery is partially pulled in toward the inner shell to prevent the upholstery from sagging, to maintain the overlap between the upholstery and cushion and the back panel, or for design reasons.

[0003] It has 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 of the fastener are fitted into a middle plate located on the back side of the cushion. Using a fastener in this way has the advantage of allowing the upholstery to be pulled in quickly. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-330398 A Summary of the Invention [Problem to be solved by the invention]

[0005] Now, foamed urethane is often used as the cushioning material for chair seats and backrests, but foamed urethane has problems such as poor breathability, its elasticity not necessarily being very high, and its tendency to sag, in which its elastic recovery decreases over time.

[0006] On the other hand, there exists a nonwoven three-dimensional net-like material made by intertwining and bonding highly elastic resin fibers, which has excellent breathability, high resilience, and durability. By selecting the fiber thickness and density, it is possible to achieve a fairly soft feel.

[0007] Therefore, this three-dimensional mesh body has been used as cushioning material for seats and backrests. However, when the three-dimensional mesh body is used as cushioning material, if the upholstery is pulled in using a plate-shaped fastener as in Patent Document 1, the fibers that make up the three-dimensional mesh body are cut by the grooves for inserting the fastener, causing the three-dimensional mesh body to spread at the pull-in point, resulting in problems such as impaired cushioning function and a poor appearance.

[0008] In addition, because the fasteners are directly attached to the inner shell, there were problems such as the inability to adjust the degree to which the upholstery is retracted, regardless of the structure of the cushioning material, and it being difficult to achieve pinpoint retraction.

[0009] The present invention has been made to improve this current situation. [Means for solving the problem]

[0010] The present invention includes various configurations, examples of which are specified in the claims. The invention of claim 1 relates to a body support unit for a chair, "The seat has an inner shell on which the weight of the seated person is applied via a cushioning material, and an upholstery that covers the cushioning material. A body support unit for a chair, the upholstery having a recessed portion that is pulled toward the inner shell, A string is fixed to the back surface of the upholstery at the retraction portion, the string passes through the cushion material and the inner shell and is pulled out to the back surface of the inner shell, and the pull-out portion of the string is held in place on the back surface of the inner shell so that it cannot come loose. The structure is as follows.

[0011] The invention of claim 2 is an example of the development of claim 1. "The cushioning material is a three-dimensional net-like body formed by intertwining a group of meandering synthetic resin elastic fibers, and the cushioning material is formed with a guide hole through which the string material is passed." The structure is as follows.

[0012] The invention of claim 3 is an embodiment of claim 1 or 2, "A retracting tool that is engaged with the back surface of the inner shell is attached to the string material, and the retracting tool is formed in a rod shape that can be inserted into the retracting holes provided in the cushion material and the inner shell." The structure is as follows.

[0013] The invention of claim 4 is directed to a method for manufacturing a body support unit for a chair, "A method for manufacturing a body support unit for a chair in which a part of the upholstery overlapping the inner shell is pulled to the side of the inner shell with a string material, A first step of fixing the string material to the back surface of the upholstery; The method includes a second step of inserting the string material through the cushion material and the inner shell while overlapping the cushion material and the upholstery on the inner shell, and a third step of pulling the string material to the back side of the inner shell to prevent it from slipping out of the inner shell. The structure is as follows.

[0014] The invention of claim 5 is an example of the development of claim 4, "In the first step, a rod-shaped pulling tool is attached to the string material, In the second step, the string material is inserted through the cushion material and the inner shell by inserting a pull-in tool attached to the string material through a pull-in hole provided in the cushion material and the inner shell. The structure is as follows.

[0015] The invention of claim 6 is a specific example of claim 5, "The method includes a step of engaging the pulling tool pulled out to the rear side of the inner shell with the rear side of the inner shell." The structure is as follows. Effect of the Invention

[0016] In the present inventions, the string material is attached to the underside of the upholstery and nothing is exposed on the surface of the upholstery, which gives it a good appearance. Also, since there is no need to cut the cushioning material, even if it is used in a cushioning material made of a three-dimensional net-like structure, problems such as reduced cushioning function and poor appearance due to fiber breakage are unlikely to occur. Therefore, it can be applied to a cushioning material made of a three-dimensional net-like structure as in claim 2 without causing any particular problems.

[0017] Claim 2 employs a three-dimensional mesh-like cushioning material, which has holes for threading the strings, allowing the threading work to be done quickly and accurately. In other words, since the threading position is specified in advance, the specified position of the upholstery can be accurately threaded to prevent the appearance from deteriorating, and the threading can be easily done using a tool such as a threading tool.

[0018] It is convenient to use a retracting tool to retract the string material. In this case, if the configuration of claim 3 is adopted, the rod-shaped retracting tool also serves as a member for fixing the string material to the back surface of the inner shell, so that the string material can be retracted and locked in a single operation.

[0019] The manufacturing method of claim 4 also provides the same effect as claim 1. Moreover, when a pulling tool is used to pass the string material through the pull-in holes of the cushion material and the inner shell as in claim 5, the same effect as claim 2 is provided. That is, since the string material has no stiffness, it is troublesome to pass the string material as it is through the cushion material and the inner shell, but when a rod-shaped pulling tool is used as in claim 5, the work of passing the string material can be done quickly.

[0020] The invention of claim 6 corresponds to claim 3, and enables the work of drawing in and locking the string material to be performed accurately and quickly. [Brief description of the drawings]

[0021] [Figure 1] 1A and 1B are views of a chair equipped with a seat according to an embodiment of the present invention, in which (A) is a perspective view seen from the front, (B) is a front view, and (C) is a perspective view seen from below and behind. [Diagram 2] FIG. 2A is an exploded perspective view of the seat according to the first embodiment, and FIG. 2B is a perspective view seen from below. [Diagram 3] (A) is a partial bottom view of the upholstery, (B) is a partial bottom view of the cushioning material, and (C) is a bottom view of the entire seat. [Figure 4] (A) is an oblique view showing the string material being threaded, (B) is an oblique view after the work is completed, and (C) is a bottom view. [Diagram 5] FIG. 3(C) is a cross-sectional view taken along line V-V of FIG. [Figure 6] FIG. 1 is a diagram showing second to sixth embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] 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 widely used for office work. In this application, terms such as "front and back" and "left and 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 person sitting.

[0023] (1) Basic structure of chair and seat As shown in the figure, the chair to which this embodiment is applied is a swivel chair that is often used in offices, and the chair has as its basic elements a leg device 1, a seat 2, and a backrest 3. The leg device 1 has a structure in which a leg support 4 made of a gas cylinder is erected in the center of a base having five leg blades, and a caster is provided at the tip of each leg blade.

[0024] A base 5 is fixed to the upper ends of the leg supports 4, and left and right first tilting frames 6 and a second tilting frame 7 are connected to the base 5, and a backrest 3 is attached to these tilting frames 6, 7. A seat support mechanism 8 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) (not shown) is fixed to the seat support mechanism 8, and the seat 2 is fixed to the outer shell.

[0025] As shown in Fig. 2(A), the seat 2 comprises an inner shell (seat plate) 9 made of synthetic resin, a cushioning material 10 placed on top of the inner shell, and an upholstery (skin material) 11 covering the cushioning material 10 from above. The inner shell 9 is concave upwards when viewed from the front and deeper at the rear when viewed from the side, and the cushioning material 10 and the upholstery 11 are also shaped in a similar manner. The upholstery 11 can be made of woven or knitted fabric, artificial or natural leather, or the like.

[0026] In this embodiment, the front part of the inner shell 9 is a deformation-permitting part 9a having many horizontally long slits, and when a bracket 12 protruding downward from the tip is pulled backward, the deformation-permitting part 9a is rolled downward. This allows the front-rear position of the front end of the seat 2 to be adjusted. In addition, a group of boss bodies 13 for fixing to the outer shell is protruding from the underside of the inner shell.

[0027] In addition, downward engaging protrusions 14 for fixing the front edge of the upholstery 11 are formed and scattered in the left and right direction on the front edge of the inner shell 9, and engaging holes 15 for fixing the left and right side edges and rear edge of the upholstery 11 are formed and scattered on the left and right side edges and rear edge of the inner shell 9.

[0028] 5, a band-shaped resin edge member 16 is attached or otherwise fixed to the peripheral portion of the upholstery 11, and the left, right, and rear end edge members 16 are formed with locking claws 17 that fit elastically from below into engagement holes 15 in the inner shell 9, and the front end edge member (not shown) is formed with an engagement hole that elastically fits into the engagement protrusion 14 of the inner shell 9. Therefore, by placing the upholstery 11 on the cushion material 10 and then pressing the edge members 16 against the inner shell 9, the upholstery 11 is held in a state in which it will not come off the inner shell 9.

[0029] The cushioning material 10 is made of a three-dimensional net-like structure in which numerous elastic and twisted resin fibers such as polyester fibers are entangled and bonded together. This allows for ventilation. In this case, as shown in FIG. 5, the cushioning material 10 is made of a tough base layer 10a made of thick fibers and a soft surface layer 10b made of fine fibers tightly entangled, and these two layers are heat-sealed together. The two-layer structure provides softness to the user's body while also providing elasticity and durability.

[0030] (2) Fabric retraction structure The rear parts of the inner shell 9 and the cushioning material 10 are significantly recessed downward, while the upholstery 11 is under some tension. For this reason, unless some measure is taken, the upholstery 11 will float, resulting in a poor appearance. Therefore, as shown in Figures 1(A) and 5, a basin-shaped retraction section 18 is provided at the rear of the upholstery 11 to bring the upholstery 11 into close contact with the cushioning material 10. A pair of retraction sections 18 are provided on the left and right sides, but the number and arrangement positions can be set as desired according to design and other requirements.

[0031] Specifically, one end of the string material 19 is fixed to the underside of the upholstery 11 by sewing or the like, and by pulling this string material 19 downward, the upholstery 11 is pulled in and adhered to the cushion material 10. For this reason, retraction holes 20, 21 are formed in the cushion material 10 and the inner shell 9. In addition, the other end of the string material 19 is engaged with a rod-shaped retraction tool 23, which is held on the underside of the inner shell 9 so that it cannot be removed.

[0032] The lead-in hole 20 of the cushioning material 10 can be formed by punching, but in order to prevent the fibers from being cut (disintegrated), it is preferable to form it by thermal deformation by passing a heated punch through it. Even if the punching method is used, it is preferable to heat press the inner periphery of the hole after punching with a punch to weld the fibers together. It is also possible to apply an adhesive to the inner periphery after punching with a punch to bond the fibers together.

[0033] The drawing hole 21 of the inner shell 9 is formed during molding. The drawing hole 21 of the inner shell 9 needs to be large enough to allow the drawing tool 23 to pass through, but the drawing hole 20 of the cushion material 10 may be large enough to be expanded by the drawing tool 23.

[0034] As shown in FIG. 4, the pulling tool 23 is in the form of a square bar, with a through hole 24 formed near one end for passing and securing the string 19, and the other end having a cut groove 25 and formed in a bifurcated shape.

[0035] 4, a pair of front and rear locking portions 26, 27 for fixing the retracting tool 23 are integrally formed on the underside of the inner shell 9. The front and rear locking portions 26, 27 are disposed on either side of the retracting hole 21, with the front locking portion 26 being closer to the retracting hole 21 and the rear locking portion 27 being farther from the retracting hole 21. The locking portions 26, 27 can also be called pressing portions or holder portions.

[0036] The front locking portion 26 has a top plate 26a, an inner wall 26b, and a front wall 26c, and is open to the rear and inward, while the rear locking portion 27 has a top plate 27a and an inner wall 27b, and is open to both the front and rear sides and to the outside. That is, the front and rear locking portions 26, 27 open in opposite directions. Therefore, the pulling-in tool 23 can be held by the front and rear locking portions 26, 27 by rotating it around the axis of the pulling-in hole 21 while it is overlapped on the lower surface of the inner shell 9. A stopper rib 28 is provided on the outside of the rear locking portion 27 to prevent the pulling-in tool 23 from coming off.

[0037] An example of the procedure for assembling the seat 2 is as follows. First, as shown in Fig. 3(A), in the first step, one end of the string material 19 is fixed by sewing or the like to a predetermined position on the back surface of the upholstery 11. Next, each string material 19 is passed through an insertion hole 24 of a pulling tool 23, and the other end of the string material 19 is rounded to form a knot 19a, for example, to hold the string material 19 so that it cannot come out of the insertion hole 24.

[0038] Next, the cushion material 10 is placed on the inner shell 9, and the retracting tool 23 is inserted through the retracting holes 20, 21 between the cushion material 10 and the inner shell 9 to draw the string material 19 to the outside of the inner shell 9. Next, while the insertion hole 24 of the retracting tool 23 is placed on the retracting hole 21 of the inner shell 9 and the string material 19 is pulled out to the outside so that there is no slack in the string material 19, the excess part of the string material 19 exposed from the insertion hole 24 is inserted into the cut groove 25 of the retracting tool 23, and in this state, the retracting tool 23 is moved while being placed on the inner shell 9 while pulling the string material 19, and the retracting tool 23 is placed on the inner shell 9 and rotated around the axis of the retracting hole 21, whereby the retracting tool 23 is held by the front and rear locking parts 26, 27 so as not to slip.

[0039] When the pulling tool 23 is rotated, the pulling tool 23 climbs over the stopper rib 28 while the rear engaging portion 27 is elastically deformed, so that the pulling tool 23 is held in the set state.

[0040] In addition, by rotating the retracting device 23, the string material 19 is pulled outward from the retracting holes 20, 21, causing the cushion material 10 to elastically deform and the retracting portion 18 to deform into a basin shape. Due to this elastic deformation, as shown by the dotted arrow 29 in Figure 4(B), tension is applied to the portion of the string material 19 that has been pulled out to the outside of the retracting holes 20, 21. However, because the string material 19 is bent sharply at the insertion hole 24 of the retracting device 23 and because large friction is applied at the cut groove 25, the retracting portion 18 is fixed to the retracting device 23.

[0041] The retraction tool 23 is held by the front wall 26c of the front engagement portion 26 so as not to be able to move forward, and therefore the state in which the upholstery 11 is pulled by the string material 19 is maintained. Therefore, the retraction tool 23 is held in a state in which it does not come off the inner shell 9 by utilizing the elastic force of the cushion material 10.

[0042] As mentioned above, the peripheral portion of the upholstery 11 is engaged with the inner shell 9 by the edge member 16, but the process of engaging the edge member 16 may be performed before or after the process of attaching the retraction device 23 to the inner shell 9.

[0043] In the embodiment, the string 19 is held in the slit groove 25 of the retracting tool 23 to prevent it from slipping out of the retracting tool 23, but it is also possible to prevent the string 19 from moving out of the insertion hole 24 by forming a knot in the outer exposed part of the string 19 with the insertion hole 24 of the retracting tool 23 overlapping with the retracting hole 21 of the inner shell 9. In any case, in this embodiment, the retracting tool 23 is set in the inner shell 9 with the insertion hole 24 misaligned with the retracting hole 21 of the inner shell 9 by rotating it, so that the string 19 can be pulled to retract the upholstery 11 easily and reliably.

[0044] In addition, the pair of locking portions 26, 27 can be opened in the same direction, either inward or outward, but if they are opened in opposite directions as in the embodiment and the retracting tool 23 is rotated and attached, the effect of preventing them from coming off can be significantly improved. In addition, in the embodiment, the portion of the string material 19 that is pulled out from the retracting hole 21 of the inner shell 9 is held down by the retracting tool 23 against the inner shell 9, preventing the string material 19 from slipping and ensuring the tension of the upholstery 11.

[0045] (3) Other embodiments Next, another embodiment shown in Fig. 6 will be described. In the second embodiment shown in Fig. 6(A), a middle portion of one string material 19 is sewn to the upholstery 11 over an appropriate range, and both sides of the sewn portion are pulled out to the outside of the inner shell 9. Therefore, in this example, a linear pull-in portion 18 can be formed. As a means for forming a linear pull-in portion, it is also possible to fix a shape-retaining material such as a hard rod material or tape material to the back surface of the upholstery 11 by sewing or the like, and pull the shape-retaining material with one or two string materials 19.

[0046] In the second embodiment shown in Fig. 6(B), when there are two string materials 19, the two string materials 19 are tied together. In this case, by tying the string materials 19 while the cushion material 10 is in a compressed and deformed state, the upholstery 11 can be held in a tensioned state.

[0047] In the fourth embodiment shown in Fig. 6(C), a pair of protrusions 30 are provided on the back surface of the inner shell 9, and two string materials 19 are wound around the protrusions 30 and then tied. In this case, the string materials 19 are pulled out while the cushion material 10 is compressed, and then sandwiched between the pair of protrusions 30, so that the string materials 19 can be held in a taut state.

[0048] A fifth embodiment shown in Fig. 6(D) is different from the retracting tool 23. The retracting tool 23 is cylindrical with a pointed tip 31 at the tip, and an interrupted groove 32 for holding the string 19 is formed at the base end. The string 19 may be held in the interrupted groove 32 by using friction, or may be prevented from slipping out by forming a knot. In this embodiment, the retracting hole of the cushion material 10 is set to a smaller diameter than the retracting tool 23, and the retracting tool 23 can be inserted while pushing and widening the retracting hole.

[0049] 6(E) shows an example of a fastener that holds the string material 19 in a taut state. This fastener is composed of a plug 34 having a slot 33 into which the string material 19 is sandwiched, and a cap 35 that covers the plug 34. The outer peripheral surface of the plug 34 and the inner peripheral surface of the cap 35 are tapered, so that the string material 19 can be held in a sandwiched state by the plug 34.

[0050] The string 19 is pulled strongly and then sandwiched in the slot 33 of the plug 34, and then the cap 35 is fitted. In the figure, two strings 19 are fastened, but it is also possible to fasten only one.

[0051] Although the embodiment of the present invention has been described above, the present invention can be embodied in various other ways. For example, as a method of inserting the string material, a guide cylinder (e.g., with an inner diameter of about 5 mm) through which the string material can be easily inserted is prepared as a jig, and while pushing aside the fibers, the guide cylinder is inserted into the cushion material and exposed to the back side of the inner shell, the string material is inserted through the guide cylinder, and then the guide cylinder is pulled out to the back side of the inner shell, and then the string material is tied to the inner shell to fix it.

[0052] The method of fixing the string to the inner shell may be to form a slit (cut line) in the inner shell that is connected to the pull-in hole, and then the string may be pinched in the slit while being pulled, so that it will not come off due to friction. In this case, it is preferable to form a knot in the string or use a fastener in combination, which will ensure that it does not come off.

[0053] Also, by hardening a certain area of ​​the tip of the string (for example, about 5 cm) by coating it with resin, it is possible to insert it into the cushioning material and the inner shell without using a retracting tool. In this case, the string pulled out of the inner shell can be prevented from coming out by a method such as that shown in Figure 6(C). The retracting tool can be formed into a hairpin shape, whether it is a dedicated insertion tool or a dual-purpose retracting tool. It is also versatile to use metal wire as the string.

[0054] The present invention can be applied not only to seats, but also to backrests, headrests, and shoulder rests. Furthermore, chairs include single-seater or multi-seater sofas and benches. Therefore, the present invention also applies to fixed chairs and car seats that are not movable. [Industrial Applicability]

[0055] The present invention can be embodied in a body support unit for a chair, and therefore has industrial applicability. [Explanation of symbols]

[0056] 2nd seat 9 Inner shell (seat) 10 Cushioning material 10a base layer 10b Surface layer 14 Engagement protrusions for fixing upholstery 15 Engagement holes for fixing upholstery 16 Edge material for fixing upholstery 17 Locking claw 18 Retraction section 19 String material 19a Knotting section 20 Cushioning hole 21 Inner shell draw hole 23 Retractable device 24 Insertion hole 25 Groove 26 Front locking part 27 Rear stopper

Claims

1. The seat has an inner shell on which the weight of a seated person is applied via a cushion material, and an upholstery that covers the cushion material, A body support unit for a chair, the upholstery having a recessed portion that is pulled toward the inner shell, A string material is fixed to the back surface of the upholstery at the location of the retraction portion, the string material passes through the cushion material and the inner shell and is pulled out to the back side of the inner shell, and the pull-out portion of the string material is held in place on the back surface of the inner shell so as not to come off. Body support unit for chairs.

2. The cushioning material is a three-dimensional net-like body formed by intertwining a group of meandering synthetic resin elastic fibers, and a guide hole for passing the string material is formed in the cushioning material.

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

3. A retracting tool that is engaged with the back surface of the inner shell is attached to the string material, and the retracting tool is formed in a rod shape that can be inserted into the retracting holes provided in the cushion material and the inner shell.

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

4. A method for manufacturing a body support unit for a chair, in which a part of an upholstery overlapping an inner shell is pulled to the side of the inner shell with a string material, comprising: A first step of fixing the string material to the back surface of the upholstery; The method includes a second step of inserting the string material through the cushion material and the inner shell while overlapping a cushion material and an upholstery on the inner shell, and a third step of pulling the string material to the back side of the inner shell to prevent it from slipping out of the inner shell. A method for manufacturing a body support unit for a chair.

5. In the first step, a rod-shaped pulling tool is attached to the string material, In the second step, the string material is inserted into the cushion material and the inner shell by inserting a pull-in tool attached to the string material into a pull-in hole provided in the cushion material and the inner shell. A method for manufacturing the body support unit for a chair according to claim 4.

6. The method further includes a step of engaging the pulling tool pulled out to the rear side of the inner shell with the rear side of the inner shell. A method for manufacturing the body support unit for a chair according to claim 5.

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