JP2009106420A - Chair with backrest - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance cushion property and fitting property and enhance the adaptability to the difference among the body size of users in a chair in which the lower half portion of a backrest has a rigid structure and the upper half portion of the same has a flexible structure. <P>SOLUTION: The backrest 4 has an outer shell 13 of hard resin as a strength member and a large window opening 18 opening in fore and aft directions is arranged in the upper half portion of the outer shell 13. A rigid lower cover 14 is arranged in the lower half section of the outer shell 13 and an upper cover 15 composed of an elastomer is arranged in the upper half portion of the same. A space 65 is present between the top frame portion 13b of the outer shell 13 and the upper cover 15. The upper cover 15 is excellent in the fitting property and the cushion property because the upper cover is made of the elastomer and can expand and deform, and further the upper cover 15 is not broken even though a large person uses the chair because the expanding deformation of the upper cover 15 is regulated by the top frame portion 13b of the outer shell 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a chair with a backrest.

  In the chair, the cushioning of the backrest is an important factor that greatly influences the sitting comfort. On the other hand, the stability of the body in the sitting state is also important. If the backrest is excessively deformed, the posture stability of the user is deteriorated and the sitting comfort is worsened. In particular, in the case of chairs with a simple structure (many pipe chairs) installed in conference halls and lecture halls, users often have to maintain a certain posture for a long time, so ensuring posture stability is considerable. It becomes an important factor.

In this regard, Patent Document 1 discloses that a chair whose backrest has a shell made of hard resin as a strength member is provided with a reinforcing rib in the lower half of the shell, thereby increasing the rigidity of the user. It has been disclosed that the upper half of the shell can be bent and deformed by a seated person's leaning to improve cushioning and fit while ensuring body posture stability.
Japanese Patent No. 2708365

  Now, in general, a single chair is often only one size, but the user's physique varies. For this reason, in the configuration of Patent Document 1, if the softness (or hardness) of the upper half of the shell is matched to a small person, if the large person is drowning, it will be greatly deformed and unstable, In addition, if the softness is matched to a large person, there is a problem that it is too hard for a small person. Therefore, the softness of the upper half of the shell can be adjusted to that of a person with a standard physique, but it cannot be denied that the fit to a small person or a large person is poor.

  Further, in Patent Document 1, since the shell is basically a strength member, it is made of a hard resin. For this reason, the upper half of the shell is bent and deformed, but in reality, the degree of bending is limited. Therefore, it can be said that the fit to the body is not sufficient. On the other hand, in International Publication WO / 2007/021005 related to the application of the present applicant, it is disclosed that the backrest plate is manufactured from a flexible material made of an elastomer. Cushioning properties can be ensured.

  The invention of the present application is based on the idea of Patent Document 1 in that the backrest is separated into a rigid part and a flexible part, and the specific structure is improved with reference to the previous application. It is an object to provide a chair excellent in stability, fit to the body, adaptability to differences in physique and the like.

  In order to achieve the above object, the inventors of the present invention have made the inventions of claims 1 to 4. Among these, the invention of claim 1 comprises a seat and a backrest, and the backrest easily stretches and deforms and bends due to the rigid body portion that hardly bends and deforms even when the seated person leans on and the seated person leans on. A flexible portion that can be deformed, and the rigid body portion and the flexible portion are arranged such that the rigid body portion is located below and the flexible portion is located above, and the backrest is extended and deformed backwards of the flexible portion. There is a regulation section that regulates the above.

  According to a second aspect of the present invention, in the first aspect, the backrest has a rigid outer shell that does not easily deform even if a seated person leans over, while the flexible portion includes an elastomer or the same. It is made of a soft material, and there is a space between the flexible portion and the upper edge portion of the outer shell that allows the flexible portion to extend backward and deform, and at least the upper edge portion of the outer shell. Is the regulation part.

  According to a third aspect of the present invention, in the second aspect of the present invention, in the substantially upper half portion of the outer shell, a substantially square window hole opened in the front-rear direction is vacant. The part is a side frame part and the upper part of the window hole is a top frame part, and even if the person sitting on the lower half of the outer shell is lower than the window hole, it almost deforms On the other hand, an upper cover made of a material that can be easily deformed and deformed by the stagnation of a seated person is provided as the flexible portion on the upper half of the outer shell. The outer shell is mounted in a state of covering the window hole, and a space is provided between the top frame portion of the outer shell and the upper cover to allow the upper portion of the upper cover to extend rearward and deform. The top frame of the It has become part.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the overlapping portion sandwiched between the lower cover and the outer shell is integrally formed at the lower end of the upper cover, and the overlapping portion is fixed to the outer shell by the lower cover. Has been.

  The “rigid portion” in the present invention means that it does not elastically deform as compared with the flexible portion, and does not exclude elastic deformation. Therefore, for example, a net structure is included. Further, the rigid body portion may have a cushion.

  By the way, it is preferable to set the flexible part of the backrest so that it can be deformed as easily as possible for people with small physiques, from the viewpoint of physique adaptability that can ensure high fit even if the physique is different, From the viewpoint of fit and posture followability, it is preferable that the flexible portion not only bend and deform (bend), but stretch and deform like rubber.

  However, if the flexible part is stretched and deformed with a light force, an excessive load may be applied to the flexible part and break if a large physique falls. On the other hand, in the present invention, since the restricting portion restricts the flexible portion from excessively extending and deforming, the flexible portion does not break. Therefore, according to the present invention, it is possible to reliably prevent breakage while ensuring high fit, cushioning, and physique adaptability by maintaining high flexibility and extensibility in the flexible portion.

  According to the second aspect of the present invention, the strength member function is held by the outer shell and the flexible portion function is held by the soft material, and each function is shared by different members. Securing of sex can be made more certain. In particular, it is preferable that the flexible part is made of an elastomer or a material including the same because the softness to the body can be secured.

  In claim 2, it is possible to directly support a human body at a portion below the flexible portion of the outer shell. However, if a lower cover is provided separately from the outer shell as in claim 3. The outer shell has an advantage that various accompanying structures such as a rib for increasing the strength can be easily added. Further, when the window hole is provided in the outer shell as in the third aspect, the upper cover can be more reliably deformed in the rearward direction, and the outer shell can be reduced in weight.

  If the structure of Claim 4 is employ | adopted, even if a seated person falls, even if an upper cover expands back and deform | transforms, an upper cover and a lower cover will be hold | maintained in the continuous state integrally, It is possible to prevent the gap between the lower cover and the appearance from deteriorating, and the user's shirt from being caught in the gap between the upper cover and the lower cover.

  Next, an embodiment will be described based on the drawings. 1 to 13 show the first embodiment, and FIG. 14 shows the second embodiment. Hereinafter, the first embodiment will be described sequentially.

(1). Basic Configuration of Chair First, the basic configuration of the chair will be described with reference to FIGS. FIG. 1 is a perspective view of the whole, FIG. 2A is a front view, FIG. 1B is a plan view, FIG. 3C is a side view, and FIG.

  The chair includes a leg 1, a back frame 2, a seat 3 and a backrest 4 as main elements, and the seat 3 and the backrest 4 are attached to the back frame 2. The leg 1 and the back frame 2 constitute a framework that receives a seating load and a backrest load. An armrest 5 as an optional product is attached to the back frame 2.

  The back frame 2 is tilted backward in a side view, and is fixed to the upper end of the leg 1 (the leg 1 and the back frame 2 may be integrated). The seat 3 is disposed at a position above the leg 1 and is attached to a lateral support shaft 6 of the back frame 2 with a bolt (not shown) so as to be able to flip up and rotate around the rear portion (see FIG. 2 (A) (C)).

  The leg 1 has a left and right forefoot 7 and two left and right rear legs 8 and has a four-leg system. The lower ends (tips) of the legs 7 and 8 are in a vertical posture. A caster 9 is attached to the main body. Further, the left and right front legs 7 and the left and right rear legs 8 have upper horizontal portions 7a and 8a that continuously extend to the left and right, respectively.

  On the other hand, the back frame 2 has left and right back posts 2a in a substantially frontal vertical position located on the left and right outer sides of the seat 3, an inclined portion 2b continuous to the lower end thereof, and a lower horizontal portion where the left and right inclined portions 2b are integrally connected. For this reason, the back frame 2 is substantially U-shaped when viewed from the front. The lower horizontal part 2c of the back frame 2 and the upper horizontal parts 7a, 8a of the legs 1 are fixed together in a bundled state. The three connecting portions are covered with a cover 10.

  The legs 7 and 8 are manufactured with pipes as main members, but the entire leg 1 is formed as an aluminum die cast or the like, and the back frame 2 is fixed thereto, or the legs 1 and the back frame 2 are entirely assembled. It is also possible to make an integrally molded product. Of course, the leg 1 and the back frame 2 may have other forms and structures.

  Most of the forefoot 7 is tilted backward in side view and tilted outwardly from the top in front view, and most of the rear foot 8 is tilted backward in side view and in front view. The chairs are arranged side by side when the seat 3 is flipped up by making the left-right distance of the front foot 7 smaller than the left-right distance of the rear foot 8 overall. The legs 1 can be partially fitted and nested. A horizontally long receiving body 11 that supports the seat 3 in front of the center of rotation is fixed to the left and right inclined portions 2b of the back frame 2 by welding (the receiving body 11 is shown by a one-dot chain line in FIG. 2C). It may be provided on the leg 1 as shown.)

  The upper part of the back column 2a constituting the back frame 2 extends above the seat 3, and a boss body 12 protrudes from the back column 2a. Even if this boss body 12 is used, the backrest 4 and the elbow rest 5 Is installed. As can be understood from FIG. 3, the backrest 4 includes an outer shell (back support) 13 that functions as a strength member, a lower cover 14 that is attached to the lower half of the front surface of the outer shell 13, and an outer shell 13. The upper cover 15 mounted on substantially the upper half of the front surface is configured as a main member, and the upper cover 15 is a flexible portion described in the claims. Hereinafter, the backrest 4 will be described.

(2). Basic form and mounting structure of the backrest First, the basic form of the backrest 4 and the mounting structure to the back column 2a will be described with reference to FIGS. 4A is a front view of the outer shell 13, FIG. 4B is a plan view of the outer shell 13, and FIG. 5A is a partial front view of the lower cover 14 schematically showing a part thereof. (B) is a partial plan view of the lower cover 14, (C) is a front view of the lower portion of the upper cover 15, (D) is a partial plan sectional view of the outer shell 13, and FIG. It is a vertical side view. 7A is a longitudinal side view, FIG. 7B is a sectional view taken along the line VIIB-VIIB in FIG. 4A, and FIG. 7C is a sectional view taken along the line CC in FIG.

  In FIG. 4, a state where a spacer 17 is attached to the back column 2 a (or the boss body 12) instead of the elbow rest 5 is depicted. The spacer 17 is for aligning the height when the elbow rest 5 is not attached.

  The outer shell 13 constituting the backrest 4 is a strength member, and is manufactured from a relatively hard general-purpose resin such as polypropylene. Therefore, it can be bent and deformed when a large load is applied, but it has a rigid structure that does not essentially undergo elongation or compression. The outer shell 13 has a large window hole 18 close to a horizontally long rectangle in the substantially upper half of the outer shell 13, and therefore the outer shell 13 becomes a vertically long side frame portion 13 a outside the window hole 18. A portion above 18 is a top frame portion 13b having a substantially horizontal posture.

  Of the left and right side portions of the outer shell 13, a portion below the side frame portion 13 a is a mounting portion 13 c that opens downward, and the mounting portion 13 c is fitted to the boss body 12. For example, as shown in FIG. 7B, the mounting portion 13c of the outer shell 13 is basically in the shape of an ellipse having a longitudinal direction that is substantially the same as the plan view outline of the back column 2a.

  As shown in FIG. 7 (B), the boss body 12 is formed in an oblong shape of the longitudinal direction, while the mounting portion 13c has a boss hole 19 into which the boss body 12 is fitted. The hole 19 is formed in a copper bowl shape (or a bulky shape) in a plan view, and a rib 20 is formed on the inner surface of the hole 19 so as to hit the boss body 12 from front, rear, left and right. The reason why the rib 20 is applied to the boss body 12 in this way is to prevent stress from concentrating on a specific location due to a complicated force applied to the attachment portion 13c.

  Although not shown, the boss body 12 is screwed with a set screw inserted into the mounting portion 13c of the outer shell 13 from the rear side. A portion of the outer shell 13 between the left and right attachment portions 13c protrudes downward from the attachment portion 13c (or the attachment portion 13c is located above the lower end of the outer shell 13). For this reason, it is suppressed that the load by the person who seated leans down acts on the attachment part 13c as a big bending moment.

(3) Relationship between the outer shell and the lower cover Next, the relationship between the outer shell 13 and the lower cover 14 will be described with reference to FIGS. 8 is a cross-sectional plan view of the backrest 4 seen at the position VIII-VIII in FIG. 5A, and FIG. 9A is a plan view of the backrest 4 seen at the position IX-IX in FIG. Sectional drawing and (B) are the elements on larger scale of (A).

  Although the outer shell 13 is curved in a concave shape facing forward in plan view (to fit the human body), the top frame portion 13b is curved deeper than the lower portion of the window hole 18 to the rear side. It protrudes greatly.

  In addition, a number of ribs 22 extending vertically and horizontally are formed in the outer shell 13 below the window hole 18 for reinforcement and the like, and the lower cover 14 is supported by a group of ribs 22. Therefore, even if a backrest load is applied to the lower cover 14, it hardly bends and deforms. The lower cover 14 is made of a relatively hard general-purpose resin such as polypropylene, like the outer shell 13, and a large number of horizontally elongated ribs 23 are formed on the front surface thereof in multiple stages. The horizontally long ribs 23 are mainly provided from the viewpoint of design, and thus have a protruding height (1 to several mm) that does not give a sense of incongruity even if a person is drowning.

  For example, as shown in FIG. 5, an overlapping portion 15 a sandwiched between the upper portion of the lower cover 14 and the outer shell 13 is formed at the lower end of the upper cover 15, and the overlapping portion 15 a is a laterally long holding metal (holder). It is pressed and fixed to the outer shell 13 via 24. A pair of right and left holding metal fittings 24 are arranged. As shown in FIGS. 6 and 7, a forward-facing upper edge rib 25 is formed at the lower edge of the window hole 18 in the outer shell 13, and the overlapping portion 15 a of the upper cover 15 overlaps the upper edge rib 25. After that, it enters the inside of the outer shell 13 backward.

  Therefore, a rearward stepped portion 26 is formed in the overlapping portion 15 a of the upper cover 15, and the upper end portion of the lower cover 14 is fitted into the stepped portion 26 of the upper cover 15. The presser fitting 24 is disposed below the step portion 26. Due to such a superposed structure of the upper and lower covers 14 and 15, the upper and lower covers 14 and 15 are held in a state where the surfaces are integrally continuous without being separated vertically even when a backrest load is applied.

  As shown in FIG. 6 and FIG. 7A, horizontally long ribs 23 similar to the lower cover 14 are formed in multiple stages on the front surface of the upper cover 15. A forward-facing lower edge rib 27 is formed at the lower end of the outer shell 13, and the lower end edge of the lower cover 14 enters the inner side of the lower edge rib 27 of the outer shell 13. Further, as shown in FIG. 7B, the left and right side portions of the outer shell 13 are formed with stepped portions 28 into which the edges of the lower cover 14 are inserted. It is continuous with the cover 14 so as to form the same surface.

  In the present embodiment, as a means for fixing the lower cover 14 to the outer shell 13, fitting of the engaging claw and the engaging hole and fixing with a screw are used in combination. First, the relationship between the engaging claw and the engaging hole will be described. For example, as shown in FIGS. 5, 8, and 9, the upper portion of the lower cover 14 has a pair of left and right end engaging claws 29 disposed at both left and right ends, and a pair of left and right interiors disposed slightly closer to the left and right intermediate portions. A total of four engaging claws with the engaging claws 30 are projected backward. On the other hand, the outer shell 13 is formed with an end engagement hole 31 into which the end engagement claw 29 is inserted and locked after elastically deforming, and an engagement rib 32 into which the internal engagement claw 30 is elastically deformed and locked. Has been.

  The end engagement claw 29 has a vertically long bowl shape that is long in the vertical direction, and the end engagement hole 31 communicates with the boss hole 19 of the mounting portion 13 c in the outer shell 13. Note that the end engagement claw 29 has a bowl shape that faces outward in plan view so that the end engagement claw 29 is strongly hooked by the end engagement hole 31 when a rearward load acting on the lower cover 14 is applied. This is because the end engagement claw 29 is easily removed from the end engagement hole 31 by a load when it is inwardly facing.

  As shown in FIG. 6 and FIG. 8 (B), the internal engagement claw 30 has a saddle shape that faces downward as viewed from the side, while the internal engagement claw 30 is caught by the engagement rib 32 provided on the outer shell 13 from above. The engaging hole 32a to be engaged is vacant. Further, for example, as shown in FIG. 8, a thin rib 30 a for reinforcement is formed on the upper surface of the internal engagement claw 30, and the internal engagement is slightly above the engagement rib 32 of the outer shell 13. An auxiliary rib 32a that prevents upward movement of the claw 30 is formed.

  For example, as shown in FIG. 6, the presser fitting 24 has a front plate 24 a and a rear plate 24 b and is formed in a bowl shape (U shape) with an upward opening, and the overlapping portion 15 a of the upper cover 15 is viewed from below. Embrace. 8 and 9, a pair of left and right portions of the rear plate 24b of the presser fitting 24 are formed in an upward nut portion 24b 'sandwiched between a pair of left and right slits, and the upward nut portion 24b'. Is inserted into a dovetail bag-shaped portion 33 formed on the outer shell 13 from below, and a screw 34 inserted into the front plate 24a of the presser fitting 24 is screwed into the upward nut portion 24b '.

  Therefore, the overlapping portion 15 a of the upper cover 15 is fixed to the outer shell 13 while being firmly held from the front and rear by the pressing metal 24. The rear plate 24 b of the pressing metal 24 is partially cut away so as not to interfere with the reinforcing rib 22 of the outer shell 13. For example, as shown in FIGS. 5, 8, and 9, the overlap portion 15 a of the upper cover 15 is formed with a notch 15 b and a relief hole 15 c for avoiding interference with the screw 34 and the internal engagement claw 30. ing. Similarly, a notch or a hole is formed in the front and rear plates 24 a and 24 b of the presser fitting 24 so as not to interfere with the internal engagement claw 30.

  Next, fixing with screws will be described. As shown in FIG. 7C, a pocket-shaped nut holding portion 36 that protrudes rearward is integrally provided on both the left and right side portions and the lower portion of the lower cover 14, and a plate nut is formed on the nut holding portion 36 from the left and right lateral directions. 37, the left and right lower portions of the outer shell 13 form a receiving portion 38 that supports the nut holding portion 36 from below, and a screw 39 inserted into the receiving portion 38 from below is attached to the plate nut 37. Screwed in. Therefore, the lower cover 14 is firmly fixed to the outer shell 13 at the lower left and right ends of the lower cover 14.

(4). Form and attachment structure of upper cover Next, the form and attachment structure of the upper cover 15 will be described mainly with reference to FIGS. 10A is a separated front view of the upper cover, the reinforcing member, and the outer shell, FIG. 10B is a separated perspective view, FIG. 11 is a diagram showing the shape of the member, and FIG. Sectional drawing, (B) is a plane sectional view in the assembled state, and FIG. 13 is a diagram showing the form of the member. The upper cover 15 is made of a material such as an elastomer that has high flexibility and stretches and deforms so as to increase in area.

  The side frame portion 13a of the outer shell 13 is smoothly continuous with the mounting portion 13c. For example, as clearly shown in FIGS. 4 (A) and 10 (A), the front side of the side frame portion 13a is opened forward. The vertical groove (receiving groove) 41 is opened over substantially the entire length. On the other hand, lateral grooves 42 continuous with the longitudinal grooves 41 are opened forward at both left and right ends of the top frame portion 13b of the outer shell 13. On the other hand, for example, as shown in FIG. 10 (B), the upper cover 15 is fitted into a vertically long main fitting portion 43 fitted into the longitudinal groove 41 of the outer shell 13 from the front and a horizontally elongated groove 42 of the outer shell 13. A horizontally long auxiliary fitting portion 44 that protrudes is projected backward.

  A resin reinforcing member 45 is fitted and attached to the main fitting portion 43 of the upper cover 15, and the main fitting portion 43 and the reinforcing member 45 are screwed into the side frame portion 13 a of the outer shell 13 from the inside. The portion 43 is fastened to the side frame portion 13a. Further details will be described. 11A is a side view of the upper cover 15, FIG. 11B is a rear view of the reinforcing member 45, and FIG. 11C is a rear view of FIG. 11A (that is, a rear view of the side portion of the upper cover 15). , (D) is a right side view of (B) (a view of the reinforcing member 45 viewed from the left and right inside), and (E) is a front view of the reinforcing member 45 in the EE view of (D).

  As can be understood from FIG. 10, the vertical groove 41 of the side frame portion 13a has a groove width that is gradually reduced from the top to the bottom, and the bottom width is slightly smaller than the width of the opening. The main fitting portion 43 of the cover 15 basically has a form corresponding to the vertical groove 41. In FIG. 10A, the rough front view shape of the main fitting portion 43 and the auxiliary fitting portion 44 is indicated by a solid line, but this is an accurate drawing method that was a typical display method. Is not.

  The main fitting portion 43 of the upper cover 15 includes an inner plate 47 that protrudes backward from the board portion against which a person hits, a back plate 48 that extends continuously outward from the inner plate 47, the inner plate 47, and the back plate. 48, and a plurality of upper and lower partition plates 49 arranged in a portion surrounded by 48. For this reason, the main fitting portion 43 is formed with a plurality of pocket portions 50 opened in the left and right directions in multiple stages. . The upper end of the inner plate 47 is connected to the auxiliary fitting portion 44, and therefore the uppermost pocket portion 50 is partitioned by the auxiliary fitting portion 44.

  Between the first pocket portion 50 and the second pocket portion 50 from above, there is an upper space 51 where no pocket portion 50 exists, and the first pocket portion 50 and the second pocket portion 50 from the bottom. Is a lower space 52 where the pocket portion 50 does not exist. The inner plate 47 is cut and opened in a circular arc shape when viewed from the side at the location of the lower space 52. In addition, the back plate 48 is formed with a notch groove 53 that opens to the outside at each pocket portion 50.

  On the other hand, the reinforcing member 45 includes a substrate 55 that overlaps the bottom of the vertical groove 41 and an outer plate 56 that protrudes rearward from the outer edge thereof, and is fitted to the outer plate 56 and the pocket portion 50 of the upper cover 15 from the left and right outer sides. A matching block 57 is formed. A slit 58 for avoiding interference with the partition plate 49 of the main fitting portion 43 is vacant between the block portions 57 adjacent in the vertical direction. For this reason, the group of the block part 57 has a form close to a comb-tooth shape. The reinforcing member 45 is formed with an upper fastening portion 59 that fits in the upper space 51 of the main fitting portion 43 and a lower fastening portion 60 that fits in the lower space 52 of the main fitting portion 43.

  As shown in FIG. 12, the main fitting portion 43 of the upper cover 15 is fitted into the vertical groove 41 of the outer shell 13 with the reinforcing member 45 fitted from the lateral outer side. Therefore, when the reinforcing member 45 is fastened to the side frame portion 13 a of the outer shell 13, the left and right side portions of the upper cover 15 are firmly held by the side frame portion 13 a of the outer shell 13. As shown in FIG. 12, the reinforcing member 45 is formed with a connecting portion 61 that fits into the slit 58 of the main fitting portion 43, and the presence of this connecting portion 61 causes the main fitting portion 43 of the reinforcing member 45 to be connected. The holding strength is high.

  The reinforcing member 45 is fastened to the side frame portion 13a of the outer shell 13 by screws 46 at the upper and lower fastening portions 59, 60, and the fastening structure at the lower fastening portion 60 is shown in FIG. B).

  That is, FIG. 13 (A) is a cross-sectional plan view at the location of the lower fastening portion 60, and FIG. 13 (B) is a view of the reinforcing member 45 as viewed from the direction B-B of (A). The lower fastening portion 60 is formed with a nut receiving seat 63 into which a hexagonal nut 62 is fitted so as not to be rotatable from the left and right outer sides. A screw 46 inserted from the left and right inner sides into the side frame portion 13a of the outer shell 13 is screwed into the nut 62. ing. A boss portion 64 that supports the head of the screw 46 is formed on the side frame portion 13 a of the outer shell 13.

  The form of the upper fastening portion 59 is shown in FIGS. 13 (C) to (E). (C) is a front sectional view, (D) is a DD view of (C), (E) is an EE view of (D), and a nut receiving seat 63 is also formed on the upper fastening portion 59. Has been. As can be easily estimated from these (C) to (E), the screw 46 is screwed into the nut 62 also at the location of the upper fastening portion 59.

  As can be understood from FIG. 13A, the screw 46 is inclined so that the distance from the axis increases with increasing distance from the left and right inner sides of the upper cover 15 toward the inner side. For this reason, it is easy to rotate the screw 46 with a wrench (driver). Further, the rotation operation of the screw 46 is facilitated by providing the window hole 18 in the outer shell 13.

  FIG. 13F is a partial plan view of the backrest 4, and FIG. 13G is a sectional view taken along line GG of FIG. Then, as shown in FIG. 13F, FIG. 2B, and FIG. 7A, between the upper end edge of the upper cover 15 and the top frame portion 13b of the outer shell 13, it faces toward the left and right intermediate portion. In this way, a space 65 that widens the interval is vacant.

  More precisely, although the upper cover 15 is gently curved in a forward-facing concave shape at the upper end, the top frame portion 13b of the outer shell 13 is curved backward larger than the degree of curvature of the upper cover 15, As a result, a crescent-shaped space 65 in plan view is vacant between the upper end of the upper cover 15 and the top frame portion 13 b of the outer shell 13. A rearward facing upper rib 66 is formed at the upper end edge of the upper cover 15.

  The upper cover 15 may be opaque or translucent. In any case, the colors of the upper cover 15 and the lower cover 14 may be the same or different. Furthermore, cushions can be stretched on the front surfaces of the upper and lower covers 14 and 15, and in this case, the cushions may be stretched individually on the upper and lower covers 14 and 15, or the upper and lower covers 14 and 15 may be attached to one cushion. It may be covered with. Needless to say, a skin material such as a cloth is provided when the cushion is stretched.

(5) Summary Since the lower cover 14 is made of a flexible material such as elastomer and easily extended by a load, the fact that a seated person leans on the backrest 4 is indicated by a one-dot chain line in FIG. Thus, the upper cover 15 mainly extends and deforms so that the left and right lengths are longer. Thereby, high fit property and cushioning property can be imparted to the seated person. Since the maximum extension amount of the upper cover 15 is regulated by the upper end of the upper cover 15 hitting the top frame portion 13b of the outer shell 13, the upper cover 15 may be broken even if an excessive load is applied to the upper cover 15. There is no problem and the seated person does not feel anxious because the upper body tilts too far backward.

  When the upper rib 66 is provided at the upper end of the upper cover 15 as in the present embodiment, the upper rib 66 itself can be deformed so as to be crushed in the front-rear direction, so that the upper rib 66 further touches the top frame portion 13b. Since the cover 15 can be deformed so as to sink slightly backward, the upper rib 66 performs a kind of shock absorbing function, and as a result, the body is prevented from strongly hitting the top frame portion 13b via the upper cover 15. And you can get a high feeling of drowning.

  Although it is possible to fix the upper cover 15 directly to the side frame portion 13a of the outer shell 13 with screws or the like, when the reinforcing member 45 is used as in the present embodiment, the upper cover 15 is made of a flexible material. There is an advantage that it can be fixed firmly. Further, when the reinforcing member is used, it is possible to press and fix the side portion of the upper cover 15 from the front side with the reinforcing member, but the main fitting portion that protrudes rearward from the upper cover 15 as in this embodiment. When the reinforcing member 45 is fitted into 43 from the left and right outer sides, the reinforcing member 45 is not exposed to the outside after assembly, which is excellent in aesthetics. This is also one of the advantages of this embodiment. The reinforcing member 45 can be fitted into the main fitting portion 43 of the upper cover 15 from the left and right inner sides.

  As described above, the provision of the overlapping portion 15a in the upper cover 15 can prevent a gap from being formed between the upper and lower covers 14 and 15, as described above. Is particularly preferable because the overlapping portion 15a can be firmly pressed and held over the entire length of the left and right. In addition, it is preferable that the upper cover 15 is flexible enough to be easily bent by a general adult (even a woman) with both hands in a single state.

  The screw 46 for fixing the reinforcing member 45 can be inserted into the side frame portion 13a from the rear (in this case, the structure of the fastening portions 59 and 60 of the reinforcing member 45 is also changed). If inserted, the head of the screw 46 is not so conspicuous, and there is an advantage that it is excellent in aesthetics.

  It should be noted that a slight space is provided between the outer cover 13 and a portion of the lower cover 14 excluding the left and right side portions, and the lower cover 14 may be set to be slightly deformed or deformed by a backrest load. (It is possible to form a group of vertically long slits in the lower cover 14 if it is desired to promote elastic deformation of the lower cover 14).

  The horizontally long ribs 23 of the upper and lower covers 14 and 15 also have a reinforcing function. In particular, the upper cover 15 extends so that the length in the left-right direction becomes longer due to the person who sits down, so that the reinforcing function by the horizontally long ribs 23 appears remarkably. The backrest 4 can be constituted by the outer shell 13 and the upper cover 15 without using the lower cover 14. In this case, it is preferable to maintain the integrity of the upper cover 15 and the outer shell 13 by taking connecting means such as fitting the lower end of the upper cover 15 into a groove formed in the outer shell 13. 23 is formed directly on the outer shell 13.

(6). Second Embodiment FIG. 14 shows a second embodiment. (A) is a longitudinal side view, (B) is a partial rear view. This embodiment is provided with one inner shell (back plate) 68 with a cushion 69 stretched, and the inner shell 68 is made of a relatively hard material such as polypropylene, and extends over substantially the entire length of the outer shell 13. It extends.

  A large number of end slits 70 that open upward and internal slits 71 that are vertically long and closed vertically are formed in a portion of the inner shell 68 that is located in the window hole 18 of the outer shell 13. A portion of the shell 68 that is desired for the window hole 24 is a flexible portion that extends and deforms in the left-right direction. The internal slits 70 adjacent to each other on the left and right are displaced in the vertical direction, and therefore the inner shell 68 can be stretched and deformed substantially uniformly throughout. Although the cushion is covered with a cloth (not shown), the group of slits 70 and 71 can be concealed by forming the cloth in a bag shape, so that the appearance is not deteriorated.

  The inner shell 68 is attached to the outer shell 13 in the same manner as in the first embodiment. However, since the upper cover 15 is not present, no pressing metal is required. Further, since the inner shell 68 has a much higher strength per unit volume than the elastomer, the fitting portions provided on the left and right side portions can be fitted into the vertical grooves 41 of the outer shell 13 and directly fixed with screws.

(7). Others The present invention can be embodied in various ways other than the above embodiment. For example, the flexible part can be formed of a net-like member. Further, as the strength member of the backrest, it is possible to use a back frame that opens in the front and rear directions in addition to the outer shell. For example, the back frame may be formed in the shape of a substantially Japanese character in front view with an intermediate bar, and an upper support may be attached to the upper half and a lower support may be attached to the lower half.

  When the outer shell as in the embodiment is used as the strength member, it is not always necessary to form a window hole (however, if the window hole 18 is provided, an object is not formed between the upper cover 15 and the top frame portion 13b. If it enters, it will fall outside as it is, so there is no problem that it is difficult to take out.) Further, the present invention can be applied to a rotary chair having a gas cylinder as a pedestal, a fixed chair such as a theater or a stadium, or a multiple bench.

It is a perspective view of the chair concerning a 1st embodiment. (A) is a front view, (B) is a plan view, and (C) is a side view. It is a separation front view of a chair. It is a figure which shows an outer shell, (A) is a front view, (B) is a top view. (A) is a partial front view of the lower cover schematically showing a part, (B) is a partial plan view of the lower cover, (C) is a front view of the lower portion of the upper cover, and (D) is a portion of the outer shell. FIG. It is a vertical side view in the state where a member was separated. (A) is a longitudinal side view, (B) is a VIIB-VIIB cross-sectional view of FIG. 4 (A), and (C) is a CC cross-sectional view of (B). It is the plane sectional view of the backrest seen in the VIII-VIII view part of Drawing 5 (A). (A) is the plane sectional view of the backrest seen in the IX-IX view location of FIG. 5 (A), (B) is the elements on larger scale of (A). (A) is a separated front view of an upper cover, a reinforcing member, and an outer shell, and (B) is a separated perspective view. It is a figure which shows the shape of the main fitting part and reinforcement member of an upper cover. (A) is a separated flat sectional view, and (B) is a flat sectional view after assembling vertically. (A)-(E) is a figure which shows the structure of the fastening part in a reinforcement member, (F) is a partial top view of a backrest, (G) is GG view sectional drawing of (F). It is a vertical side view which shows 2nd Embodiment.

Explanation of symbols

1 leg 2 back frame 2a back column 3 seat 4 backrest 13 outer shell constituting the backrest 14 lower cover constituting the rigid body portion of the backrest 15 upper cover constituting the flexible portion of the backrest 18 window hole 45 reinforcing member 65 allowing deformation Space for

Claims (4)

A seat and a backrest, and the backrest has a rigid portion that hardly bends and deforms even when a seated person leans over and a flexible portion that can easily stretch and bend and deform when the seated person leans over. The rigid body portion and the flexible portion are arranged such that the rigid body portion is located below and the flexible portion is located above, and the backrest is provided with a restricting portion that regulates backward deformation of the flexible portion. Yes,
Chair with backrest. The backrest has a rigid outer shell that is not easily deformed even if a seated person leans over, while the flexible portion is made of an elastomer or a soft material including the same, and the flexible portion and the outer shell Between the upper edge portion, there is a space that allows the flexible portion to extend rearward and deform, and at least the upper edge portion of the outer shell is the restriction portion,
A chair with a backrest according to claim 1. The substantially upper half of the outer shell has a substantially square-shaped window hole opened in the front-rear direction. Therefore, the left and right outer portions of the outer shell are side frame portions of the outer shell. The upper part is a top frame, and the lower half of the outer shell below the window hole is fitted with a resin lower cover that hardly deforms even if a seated person falls ,
An upper cover made of a material that can be easily deformed and deformed by the stagnation of a seated person is attached to the upper half of the outer shell so as to cover the window hole. Between the top frame part of the shell and the upper cover, there is a space that allows the upper part of the upper cover to extend rearward and deform, and the top frame part of the outer shell is the restriction part,
A chair with a backrest according to claim 2. The overlapping portion sandwiched between the lower cover and the outer shell is integrally formed at the lower end of the upper cover, and the overlapping portion is pressed and fixed to the outer shell by the lower cover.
A chair with a backrest according to claim 3.

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