JP5326118B2 - Chair - Google Patents

Description

  The present invention relates to an office swivel chair suitably used in an office or the like.

  Conventionally, in a chair in which the back support rod is supported on the support base, the load on the seated person and the direction in which the load is applied by changing the shape of the back support rod up and down, connecting different materials, etc. Various chairs to be suitably applied to have been proposed. In particular, various chairs have been proposed in which the back support rod is divided into an upper frame and a lower frame, and these upper and lower back frames are connected via a coupling portion (for example, Patent Documents). 1).

Such a chair is made by paying attention to the point that the strength and the bending method required for the upper and lower sides of the back support rod are different. That is, by making the shape and material of the upper back frame and the lower back frame different from each other, suitable characteristics can be imparted, and by appropriately adapting to the load and movement of the seated person's back, It is possible to provide a comfortable sitting comfort for the person.
JP 2004-129966 A

  However, due to the movement of the upper body of the seated person, not only the load in the front-rear direction, particularly the rear direction, but also the external force in the width direction and the torsional direction is always combined in the back support rod. It will be in the state where it took. And considering the strength required for the back support from such a point of view, in other words, the seated person responds to an action in which the external force in the various directions described above is applied with the upper body in the backrest. In view of this, it is necessary to appropriately cope with the load in the width direction in particular.

  That is, even with a back support rod having the same strength material, rigidity against a force in the width direction is more required.

  The present invention pays attention to such a problem, and provides a chair having a back support rod that can maintain the strength effectively against an external force in the width direction as a back support rod made of the same material as the conventional one. To do.

  In order to achieve such an object, the present invention takes the following measures. That is, in the chair according to the present invention, at least the portion of the back support rod that is visible from the rear is the back side thick plate portion that forms the back surface of the back support rod, and the front surface of the back side plank and the back surface. The side thick plate portion was provided with a front side narrow width portion provided at a position biased inward from the left and right side edges.

  If this is the case, while maintaining an effective mass appearance, while using the same material among the loads on the back support rod, while giving some flexibility to the load from the width direction Sufficient strength can be realized. By doing so, it is possible to effectively cope with a load that is simultaneously applied to the back support rod from a plurality of directions.

  In addition, in order to ensure that the load applied to the back support bar can be received in a well-balanced manner while ensuring a good appearance from the rear, the back support plate is made of a synthetic resin consisting of a back-side thick plate part and a front-side narrow part. It is desirable that it is integrally molded.

  In particular, in order to be able to suitably cope with the method of applying a load from different seats in the vertical direction, the back support rod is supported by the synthetic resin upper back frame and the upper back frame. As what comprises a lower back frame, it is preferable that an upper back frame is each provided with the said back side thick board part and the said front side narrow part.

In particular, as a specific configuration for favorably supporting the upper body of the seated person, the present invention assumes that the upper back frame has a bifurcated brim that branches into two branches, and each bifurcated brim has a thickness on the back side. It is characterized by having a plate part and a narrow part on the front side.

  Moreover, what can provide the upper surface side thick board part which continues the said back side thick board part in the upper end of each branch collar part as a structure which can ensure the appearance from back more effectively can be mentioned, respectively.

  A part mounting part for attaching a part for supporting a backrest to the branch saddle part under the back side thick plate part in each of the branch support parts is provided continuously to the narrow front part. In this case, a good appearance can be ensured without making the component mounting portion conspicuous.

  Specifically, the left and right arms of the elastic recumbent are the parts to be attached to the above described part attaching part as elastic reeds extending from the left and right to the arm part in which the two intermediate parts are supported by the branch support part. If the part is connected to the backrest, the back support can reliably support the back, and the elastic recumbent can be supported in response to the movement of the back of the seated person, making it comfortable for the seated person It is possible to give a comfortable sitting space.

  According to the present invention, even if the same material is used among the loads applied to the back support rod, the strength can be effectively improved with respect to the load from the width direction. By doing so, it is possible to provide a chair that can effectively cope with loads that are simultaneously applied to the back support rod from a plurality of directions.

  Hereinafter, an embodiment in which the present invention is applied to a synchro tilt type office rotary chair 100 will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the chair 100 includes a leg 1, a support base 2 that is supported on an upper portion of the leg 1 and can be turned horizontally, and a seat 3 that is disposed on the support base 2. The seat 4 held on the seat support 3, the back support 5 provided on the support base 2 so as to be able to tilt backward, the backrest 6 attached to the back support 5, and the seat support 3 And armrests 10 rising from both sides.

  As shown in FIGS. 1 and 2, the leg 1 includes a leg base 11 and a leg support 12 provided at the center of the leg base 11. The leg base 11 is provided by projecting leg wings radially from a hub provided at the center, and a caster is provided at each leg wing tip. The leg struts 12 are mainly composed of gas springs, and are normal ones that can elastically extend in the vertical direction and can be locked at a desired position.

  As shown in FIGS. 1, 2, 3, and 4, the support base 2 includes a housing 21 attached to an upper end portion of the leg support 12, and a rigid support to the housing 21 to connect the back support 5. It comprises a main shaft 22 that is supported so as to be able to tilt backward, and a tilting reaction force generating mechanism 23 that is provided in the housing 21 and generates a repulsive force against the backward tilting operation of the back support 5. The tilt reaction force generating mechanism 23 is a normal one that uses a coil spring, a gas spring, or the like, and thus the description thereof is omitted.

  As shown in FIGS. 1 and 2, the seat receiver 3 is a shell that holds the seat 4, and its front end is attached to the support base 2 so as to be movable back and forth, and its rear end is It is supported at the base end of the back support 5.

  As shown in FIGS. 1 to 5, the back support 5 is attached to a back support rod 51 supported on the main shaft 22 of the support base 2 so as to be able to tilt backward, and to an upper end portion of the back support rod 51. And mainly an elastic reed 52. The specific configuration of the back support 5 will be described in detail later.

  As shown in FIGS. 1, 2, and 5, the backrest 6 is mainly composed of a back plate 61. The back plate 61 includes a back plate main body 61a, side end attachment portions 61c provided on both right and left sides of the back plate main body 61a, and a lower end attachment portion 61b provided on a lower end portion of the back plate main body 61a. Thus, the side end mounting portion 61 c is connected to both ends of the elastic horizontal bar 52, and the lower end mounting portion 61 b is mounted to the lower back frame of the back support rod 51. The back plate body 61a is made of a synthetic resin, and includes a peripheral frame portion 61a1 having no holes and an intermediate surface portion 61a2 surrounded by the peripheral frame portion 61a1. The intermediate surface portion 61a2 includes a resin mesh region M provided with a plurality of holes and a resin shell region S having no holes. The resin mesh regions M and the resin shell regions S are alternately arranged. Yes. Specifically, the resin shell region S of the intermediate surface portion 61a2 has a horizontal belt shape and is arranged so as to connect the opposing portions of the peripheral frame portion 61a1. A plurality of the resin shell regions S having a belt shape are arranged in parallel in the vertical direction, and the resin mesh is formed between the resin shell regions S and between the resin shell region S and the peripheral frame portion 61a1. Regions M are formed respectively. The resin mesh region M is formed thinner than the resin shell region S and has a large number of holes 61d. The front surface of the resin shell region S and the front surface of the resin mesh region M are formed flush with each other.

  Here, the chair 100 according to the present embodiment includes a back side thick plate portion 51a11, 51a21 that forms the back side of the back support rod 51, and a back side thickness of the back support rod 51 that is visible from at least the back. It is characterized by comprising front side narrow portions 51a12, 51a22 provided on the front side of the plate and at positions offset inward from the left and right side edges of the back side thick plate portions 51a11, 51a21. Is.

  Hereinafter, a specific configuration of the chair 100, in particular, the back support rod 51 and the back support rod cover 53 will be described.

  As shown in FIGS. 1 to 5, the back support rod 51 is coupled to a lower back frame 51b having a base end 51b4 attached to the support base 2 and a tip of the lower back frame 51b via a taper coupling portion 51c. The upper back frame 51a is provided. The lower back frame 51b is made of metal, and the outer side thereof is covered with a cover described later, that is, a back support cover 53. The outer surface of the back support cover 53 is positioned so as to be continuous with the outer surface of the upper back frame 51a. The upper back frame 51a is integrally formed of synthetic resin, and its upper part is branched into two.

  As shown in FIGS. 3 to 7 and FIGS. 9 to 11, the lower back frame 51b is formed, for example, by appropriately molding and welding a high-rigidity metal. As described above, the base frame 51b is attached to the support base 2. In addition to the end portion 51b4, a vertical frame portion 51b1 forming a left and right pair forming the outer shape of the lower back frame 51b, a connecting plate portion 51b2 connecting the vertical frame portion 51b1 forming the pair by welding, and a seat receiving support Shaft 51b3. In addition, the base end portion 51b4 has two holes up and down in a side view, but in this embodiment, the upper hole is the center of rotation with respect to the support base portion 2.

  As shown in the figure, the vertical frame portion 51b1 is provided in the vicinity of the shaft insertion hole 51b13 for inserting the shaft 51b3 for seat receiving support and the coupling plate portion 51b2 in a place where the center portion in the front-rear direction is raised upward. Has a fixed shaft for fixing the upper end of the tilt reaction force generating mechanism 23 described above. In the present embodiment, the right and left side surfaces of the vertical frame portion 51b1, that is, the right side surface of the right vertical frame portion 51b1 is used as the right positioning surface 51b11 according to the present invention, and the left side surface of the left vertical frame portion 51b1 is used. A back support cover 53 can be suitably attached as the left positioning surface 51b12 according to the present invention, but a detailed description will be given later.

  As shown in the figure, the coupling plate portion 51b2 is mainly composed of a coupling plate 51b21, which is a metal plate that is connected by welding while slightly bending the upper end front side of the vertical frame portion 51b1. Three nut portions are formed in each direction. Among the nut portions, the upper four screw holes are used as frame fixing holes 51b23 for fixing screws b in a taper coupling portion 51c described later to be coupled to the upper back frame 51a, and the lower two nut portions are The back fixing hole 51b22 for fixing the lower end mounting portion 61b of the backrest 6 is used. In the present embodiment, the lower end edge of the coupling plate 51b21 in the coupling plate portion 51b2 is a stepped portion 51b24 that constitutes a second attachment portion that is engaged with an elastic claw 53b2 of the front side lower cover 53b described later.

  As shown in the drawing, the seat receiving pivot support shaft 51b3 is for rotatably mounting the rear end portion of the seat receiving 3 as described above. In this embodiment, the seat receiving pivot support shaft 51b3 is used. By using the shaft 51b3 as the first mounting portion according to the present invention, the back support rod cover 53 is mounted together with the positioning surfaces 51b11 and 51b12 described above. The lower back frame 51b forms a taper projection 51c1 constituting a taper coupling portion 51c by gradually narrowing the tip portion toward the tip, and the taper coupling portion 51c will be described later. .

  As shown in FIGS. 3 to 7 and FIGS. 9 to 11, the upper back frame 51a is integrally formed of, for example, synthetic resin, and has a base 51a1 connected to the lower back frame 51b on the lower end side, and the base It has the branch collar part 51a2 which branches into two forks on the upper side of 51a1.

  As shown in the figure, the base portion 51a1 is provided with a tapered hole portion 51c2 constituting a tapered connecting portion, which will be described later, at the lower end portion, and at least a portion visible from the rear is formed on the back surface of the back support rod 51. A rear-side thick plate portion 51a11, and a front-side narrow portion 51a12 provided on the front surface of the rear-side thick plate portion 51a11 and at a position offset inward from the left and right side edges of the rear-side thick plate portion 51a11 , A screw insertion hole 51a13 for inserting the screw b into the tapered hole portion 51c2, a top cover insertion groove 51a14 for attaching a front side upper cover 53c described later, and a second for attaching a back side cover 53a described later. It has nut part 51a15 as an attaching part.

  As shown in the figure, the branch saddle 51a2 has at least a portion visible from the rear, like the base 51a1 described above, and a back-side thick plate 51a21 that forms the back of the back support rod 51, and the back side A front side narrow portion 51a22 provided on the front side of the thick plate and deviated inwardly from the left and right side edges of the back side thick plate portion 51a21, and the back side thick plate portion 51a21 are circulated to the upper end. A continuous upper surface side thick plate portion 51a23, and a component mounting portion 51a24 for attaching an elastic reed 52 provided continuously below the front surface side narrow portion 51a22 below the upper surface side thick plate portion 51a23. Yes. The specific configuration of the component mounting portion 51a24 will be described in detail later (FIG. 16).

  The taper coupling portion 51c is provided across the lower back frame 51b and the upper back frame 51a as described above, and the taper projection portion 51c1 provided on the vertical frame portion 51b1 of the lower back frame 51b and the taper projection portion 51c1. And a tapered hole portion 51c2 formed by denting the lower end of the upper back frame 51a so as to be taper-fitted.

  As shown in the drawing, the elastic recumbent 52 is obtained by extending an arm part 52a supporting two intermediate parts at the upper end of the above-described branch reed part 51a2 to the left and right, and the left and right arm parts 52a. Is connected to the backrest 6.

  As shown in FIGS. 3 to 11, the back support cover 53 is made of, for example, a synthetic resin that covers the metal lower back frame 51b, and the back side that covers the lower back frame 51b from the rear, that is, from the back side. Cover 53a, front-side lower cover 53b covering the lower back frame 51b from the front, that is, from the front side relative to the back-side cover 53a, mainly near the rising position of the backrest 6 and the lower front side of the upper back frame 51a And a front upper cover 53c that covers the surface.

  The back cover 53a is formed by raising side walls 53ab from both sides of the rear wall 53aa positioned behind the lower back frame 51b, as shown in FIG. A bifurcated engagement piece 53a1 engaged with the provided seat receiving support shaft 51b3, a screw insertion hole 53a2 for screwing the upper portion of the rear wall 53aa to the upper back frame 51a, and a lower back frame on the inner surface side of the side wall 53ab Both covers are guided by a contact portion 53a3 for positioning in the width direction by fitting to the left and right positioning surfaces 51b11 and 51b12 which are the left and right surface portions of 51b, and guide ribs 53b5 described later of the front side lower cover 53b. And a wedge piece 53a5 (FIGS. 9 and 11) for positioning in the width direction. The bifurcated engagement piece 53a1 is formed by constricting the distal end side so that the opening width of the distal end portion is smaller than the diameter of the shaft 51b3 for seat receiving support, and utilizes temporary elastic deformation of the member. Thus, it can be engaged with the shaft 51b3 for seat support. The screw insertion hole 53a2 is provided at the center of the portion where the center of the upper end of the rear wall 53aa is slightly recessed, and the nut portion is naturally engaged with the bifurcated engagement piece 53a1 engaged with the shaft 51b3 for seat receiving support. It communicates with 51a15. The contact portion 53a3 is provided on the inner surface side of the side wall 53ab in the vicinity of the bifurcated engagement piece 53a1, and the left and right surface portions of the lower back frame 51b, that is, the right side surface of the right vertical frame portion 51b1 and the left vertical frame portion. It contacts the left side surface of 51b1.

  In this embodiment, as shown in FIGS. 7, 9, and 11, when the back cover 53a is attached to the lower back frame 51b, first, the forked engagement piece 53a153b1 is the first attachment portion. The member is elastically deformed by being pressed in accordance with the position of the shaft 51b3 for seat receiving support, and the forked engagement piece 53a1 is fitted. Thereafter, when the rear cover 53a is rotated upward about the seat receiving support shaft 51b3, the upper end of the rear wall 53aa comes into contact with the lower end of the upper back frame 51a. At this time, the screw insertion hole 51a13 naturally communicates with a nut portion 51a15 which is a second attachment portion provided in the upper back frame 51a. At the same time, since the abutting portion 53a3 inside the side wall 53ab abuts against the right side surface of the right vertical frame portion 51b1 and the left side surface of the left vertical frame portion 51b1 from the outside, positioning in the width direction is naturally performed. The above-mentioned rotation operation cannot be performed in a state where the front side lower cover 53b is attached in advance, but the bifurcated engagement piece 53a1 is set in the first attachment portion so as to be parallel to the direction of the front side lower cover 53b. If it is inserted toward the shaft 51b3 for seat receiving support, the bifurcated engagement piece 53a1 can be positioned in the vertical direction, the abutting portion 53a3 can be positioned in the width direction, and the end surface of the side wall 53ab contacts the front side lower cover 53b. Thus, the cover 53a on the back side is naturally positioned at an accurate position, and the screw b may be inserted and fixed to the screw insertion hole 51a13 and the nut portion 51a15 which is the second mounting portion communicating with the screw as it is.

  The front side lower cover 53b is formed by raising the side walls 53bb from both sides of the front wall 53ba positioned in front of the lower back frame 51b, as shown in FIGS. 3 to 5, 7, 9 and 11. A bifurcated engagement piece 53b1 engaged with a seat receiving pivot support shaft 51b3 provided on the back support rod 51, an elastic claw 53b2 for engaging the upper portion of the front wall 53ba with the coupling plate portion 51b2 of the lower back frame 51b, A contact portion 53b3 for positioning in the width direction by sandwiching the left and right surface portions of the lower back frame 51b from the outside on the inner surface side of the side wall 53bb, and a guide for guiding the wedge piece 53a5 in the width direction of the cover 53a on the back side Ribs 53a5 (FIGS. 9 and 11) are provided. The bifurcated engagement piece 53b1 is formed by constricting the distal end side so that the opening width of the distal end portion is smaller than the diameter of the shaft 51b3 for seat receiving support, and utilizes temporary elastic deformation of the member. It can be engaged with the shaft 51b3 for the seat support pivot. The elastic claw 53b2 is formed by projecting the two positions at the upper end of the front wall 53ba rearward. The coupling plate portion 51b2 is naturally in a state where the forked engagement piece 53b1 is engaged with the shaft 51b3 for seat support. The step portion 51b24 is engaged from the lower side. The contact portion 53b3 is provided on the inner surface side of the side wall 53bb in the vicinity of the bifurcated engagement piece 53b1, and the left and right surface portions of the lower back frame 51b, that is, the right side surface of the right vertical frame portion 51b1 and the left vertical frame portion. It contacts the left side surface of 51b1.

  In this embodiment, as shown in FIGS. 7, 9, and 11, when the rear cover 53 a is attached in advance, the bifurcated engagement is performed in a direction parallel to the direction of the rear cover 53 a. If the piece 53b1 is inserted toward the shaft 51b3 for seat receiving support that is the first mounting portion, the bifurcated engagement piece 53b1 can be positioned in the vertical direction and the contact portion 53b3 can be positioned in the width direction, and the end surface of the side wall 53bb can be By hitting the cover 53a on the back side, the elastic claw 53b2 positioned at the upper end of the front wall 53ba is naturally positioned at a position where the elastic claw 53b2 contacts the stepped portion 51b24 in the coupling plate portion 51b2 of the lower back frame 51b. . Then, by further pressing the front wall 53ba from the state in which the elastic claw 53b2 and the stepped portion 51b24 are in contact, the elastic claw 53b2 and the stepped portion 51b24 are engaged, and the attachment of the front side lower cover 53b is completed.

  Here, as shown in detail in FIGS. 9 and 11, when the front side lower cover 53b is fitted, the guide ribs of the front side lower cover 53b are provided on the rear side cover 53a in the vicinity of the seat receiving support shaft 51b3. Since the wedge piece 53a5 is mounted while being correctly positioned in the width direction while being guided into the front side lower cover 53b, the outer surface 53a4 of the back cover 53a and the front side lower cover 53b are mounted as shown in FIG. The outer side surface 53b4 is flush with the outer side surface. The wedge pieces 53a5 and the guide ribs 53b5 may be provided on the opposite sides of the back side cover 53a and the front side lower cover 53b.

  On the other hand, when the back cover 53a is not attached to the lower back frame 51b, first, the forked engagement piece 53b1 is pressed in accordance with the position of the seat receiving pivot support shaft 51b3 which is the first attachment portion. Thus, the member is elastically deformed to fit the forked engagement piece 53b1. Thereafter, when the front side lower cover 53b is pivoted upward about the seat receiving support shaft 51b3, the elastic claw 53b2 located at the upper end of the front wall 53ba becomes the step portion of the coupling plate portion 51b2 of the lower back frame 51b. It will be positioned at a position where it contacts 51b24. Then, by further pressing the front wall 53ba from the state in which the elastic claw 53b2 and the stepped portion 51b24 are in contact, the elastic claw 53b2 and the stepped portion 51b24 are engaged, and the attachment of the front side lower cover 53b is completed.

  Then, as shown in FIG. 10 in particular, the front upper cover 53c is located around the rising portion of the backrest 6 extending from the lower end of the joining plate portion of the lower back frame 51b to the screw insertion hole 51a13 on the lower front side of the upper back frame 51a. The covering plate portion 53c1 to be covered and the insertion plate portion 53c2 to be inserted into the cover insertion groove 51a14 provided in the upper back frame 51a from both sides of the covering plate portion 53c1 are provided. Then, as shown in the figure, the front upper cover 53c is inserted by inserting the covering plate portion 53c1 so as to be sandwiched from above the lower end mounting portion 61b of the backrest 6, and then inserting the insertion plate portion 53c2 into the cover insertion groove 51a14. If the cover 53a on the back side and the lower cover 53b on the front side are also attached, the surface of the lower back frame 51b can be covered over the front surface together with them.

  Thus, in the present embodiment, as shown in FIG. 11 in particular, in the state where both covers, that is, the back side cover 53a and the front side lower cover 53b are attached, the shaft for supporting the seat receiving support, which is a common first attachment portion. By engaging the bifurcated engagement pieces 53a1 and 53b1 with 51b3, not only accurate positioning with respect to the lower back frame 51b but also positioning in the front-rear direction between the back-side cover 53a and the front-side lower cover 53b is performed accurately. It has become. Further, the back side cover 53a and the front side lower cover 53b respectively contact the abutting portions 53a3 and 53b3 on the right side surface of the right vertical frame portion 51b1 and the left side surface of the left vertical frame portion 51b1, respectively. By being in contact with each other, positioning in the width direction of the lower and rear cover 53a and the front lower cover 53b is accurately performed. As a result, both the covers, that is, the rear side cover 53a and the side wall outer surfaces 53a4 and 53b4 of the front side lower cover 53b are substantially flush with each other.

  Here, as shown in FIGS. 12 and 13 in particular, the chair 100 according to the present embodiment employs a taper coupling portion 51c that uses a tapered surface to connect the lower back frame 51b and the upper back frame 51a. Thus, after the taper hole 51c2 is inserted from above the taper protrusion 51c1, the screw insertion hole 51a13 and the frame fixing hole 51b23, which are nut parts, are fixed by the screw b, whereby the taper protrusion 51c1 is fixed. It is prohibited from coming out of the tapered hole portion 51c2. In this state, the taper protrusion 51c1 is closely fitted in the front-rear direction with respect to the taper hole 51c2, so that the lower back frame 51b and the upper back frame 51a can be firmly connected.

  Furthermore, the chair 100 according to the present embodiment, as particularly shown in a cross-section in FIG. 14, the back-side thick plate portion 51 a 11 in the base portion 51 a 1 of the upper back frame 51 a forms the back surface of the back support rod 51 in a flat plate shape. A plurality of ribs extending upward and downward from the back side thick plate portion 51a11 are projected forward, and among the ribs, the width dimension between the ribs at both ends is set to the back side thickness. The front side narrow portion 51a12 is formed by making the size narrower than the width of the plate portion 51a11. By doing so, the strength with respect to the external force from the width direction applied to the back support rod 51 by the back surface side thick plate portion 51a11 is effectively increased.

  Further, as shown in the cross section of FIG. 15, similarly in the branch collar 51a2 of the upper back frame 51a, the back-side thick plate 51a21 is formed with a flat plate on the back of the back support collar 51 and has the largest dimension in the width direction. A plurality of ribs that are formed to be large and extend forward from the back side thick plate portion 51a21 to the front are projected forward, and the width dimension between the ribs at both ends of the ribs is set to the width of the back side thick plate portion 51a21. The front side narrow portion 51a22 is formed by making the size narrower than the width. By doing so, also in this branch collar part 51a2, the intensity | strength with respect to the external force from the width direction applied to the back support collar 51 is effectively raised by the back side thick board part 51a21.

  And as shown in FIG. 16, the component attachment part 51a24 mainly consists of the attachment part connection part 51a25 concave in side view. In the present embodiment, this attachment portion connection portion constitutes an upper attachment portion 51a26 provided by raising between the rear side thick plate portion 51a21 and the upper surface side thick plate portion 51a23, and a front side narrow portion 51a22. It is formed by providing a lower mounting portion 51a27 provided as a solid so as to fill between the ribs. The elastic recumbent 52 is sandwiched between the upper mounting part 51a26 and the lower mounting part 51a27 so that the elastic recumbent is firmly attached. Specifically, the upper mounting portion 51a25 is provided with shaft receiving holes 51a28 and 51a29 on the lower surface side and the upper surface side of the lower mounting portion, respectively, and elastic shafts 51a28 and 51a29 are elastically lateralized by screwing shafts (not shown). The flange 52 is attached so as to be rotatable about the axis. And as above-mentioned, since the back side thick board part 51a21 is larger than the front side narrow part 51a22, it can conceal the contact location of the attachment part connection part 51a25 and an elastic recumbent from the back side. It has become a thing. In addition, it is good also as a structure which attaches another option member using the structure which can support the components of such a component attachment part 51a24 reliably. In that case, what was comprised so that another optional member could be attached, such as providing an internal thread part separately in the said axis | shaft, can be mentioned.

  By setting it as the above structures, the chair 100 which concerns on this embodiment is the back side thick board part 51a11, 51a21 and the front side narrow part 51a12, 51a22 in the site | part which can be visually recognized at least from back. Therefore, even when the same material is used among the loads applied to the back support rod 51, the strength can be effectively improved particularly with respect to the load from the width direction. By doing so, a substantial load applied from the seated person on the back support rod 51 via the backrest 6, that is, a composite force is applied to the back support rod 51 in all directions from the front-rear direction, the width direction, and the vertical direction. It is possible to cope with the load with good balance.

  Moreover, in order to be able to receive the load applied to the back support rod 51 in a well-balanced manner while ensuring a good appearance from the back, in this embodiment, the back support plate 51 is connected to the back-side thick plate portions 51a11, 51a21 and the front surface. The narrow side portions 51a12 and 51a22 are integrally formed of synthetic resin.

  In addition, in the present embodiment, specifically, the load of the normal seated person is on the upper side of the backrest 6 having a large operating range so that it can suitably cope with the load applied from different seated persons in the vertical direction. Paying attention to the point that the load is irregular, the back support rod 51 is provided with an upper back frame 51a made of synthetic resin and a lower back frame 51b supporting the upper back frame 51a. The upper back frame 51a is provided with rear side thick plate portions 51a11 and 51a21 and the front side narrower portions 51a12 and 51a22, respectively.

  In particular, in order to support the upper body of the backrest more preferably so that the upper body of the seated person can be supported appropriately, in the present embodiment, the back side thick plate parts 51a11, 51a21 and the front side narrow width parts 51a12, 51a22 are provided. Each upper back frame 51a includes a bifurcated collar 51a2 that bifurcates.

  In addition, as a configuration that can effectively ensure the appearance from the rear and the strength of the back support rod, the upper-side thick plate portion 51a23 that is continuous with the rear-side thick plate portions 51a11 and 51a21 is provided at the upper end of each branch flange 51a2, respectively. It is assumed that it was provided. A component attachment portion 51a24 for attaching a component for supporting the backrest 6 to the branch flange portion 51a2 under the back side thick plate portions 51a11 and 51a21 in each of the branch support portions is continuous to the narrow front portion. By providing them, it is assumed that a good appearance can be ensured without making the component mounting portions 51a24 conspicuous.

  The parts to be attached to the parts attaching part 51a24 are made as elastic recumbent limbs 52 extending left and right from the arm part 52a having the two intermediate parts supported by the branching fulcrum part. 52a is connected to the backrest 6 so that the back support rod 51 can support the back reliably and the elastic recumbent 52 can support the seated person's back appropriately. A comfortable seating feeling can be given to the seated person.

  Although the embodiment of the present invention has been described above, the specific configuration of each unit is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above embodiment, a configuration in which an elastic recumbent is attached to the component attaching part is applied, but in addition to the elastic recumbent, various options that can be attached to a chair such as a hanger or a headrest are attached. Also good. Moreover, in the said embodiment, although the cross-sectional shape of the back support rod was formed in the general | schematic T shape by the back side thick board part and the front side narrow part, this invention is not limited to the said shape, For example, a cross section Various cross-sectional shapes can be adopted as long as the width of the back side thick plate portion is set to be relatively large, such as a L-shaped view or a cross-shaped view. It is.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

The external view of the chair which concerns on one Embodiment of this invention. The side view of the chair which concerns on the same embodiment. The figure which shows the principal part of the chair which concerns on the same embodiment. The structure explanatory view of the chair concerning the embodiment. The figure which decomposes | disassembles and shows the principal part of the chair which concerns on the same embodiment. The principal part enlarged view of the chair which concerns on the same embodiment. The other principal part enlarged view of the chair which concerns on the same embodiment. The figure which shows the cover of the back side of the chair which concerns on the same embodiment. The enlarged view which shows the cover of the back support rod which concerns on the same embodiment. The principal part enlarged view of the back support rod which concerns on the same embodiment. The typical sectional view which shows the axis | shaft for the cover of a back support rod, and a seat receiving pivot. The typical sectional view showing the taper joint part of the same back support. The other typical sectional view of the taper joint part. The typical sectional view showing the base of the upper back frame of the same back support. A typical sectional view of a branching trunk of the upper back frame. The enlarged view of the component attachment part of the same upper back frame.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Chair 51 ... Back support rod 51a ... Upper back frame 51a11, 51a21 ... Back side thick board part 51a12, 51a22 ... Front side narrow part 51a2 ... Branch collar part 51a23 ... Upper surface side thick board part 51a24 ... Component attachment part 51b ... Lower back frame 52 ... Parts (elastic side)
52a ... arm part 6 ... backrest

Claims (4)

From at least the rear side of the back support rod, the part visible from the rear side is formed from the back side thick plate portion that forms the back surface of the back support rod, and from the left and right side edges of the back side thick plate portion on the front side of the back side thick plate portion Is also provided with a front side narrow part provided at a position biased inward ,
The back side thick plate part and the front side narrow part are molded integrally with a synthetic resin,
The back support rod comprises an upper back frame made of synthetic resin and a lower back frame that supports the upper back frame, and the upper back frame has a bifurcated collar portion that branches into two branches, Each of the branch saddles includes the back-side thick plate part and the front-side narrow part, respectively . The chair according to claim 1, wherein an upper surface side thick plate portion that is continuous with the rear surface side thick plate portion is provided at an upper end of each branch saddle . A component mounting portion for mounting a component for supporting a backrest on the branch saddle portion is provided under the back side thick plate portion in each branch support portion so as to be continuous with the narrow front portion. 2. The chair according to 2 . The component is an elastic reed obtained by extending left and right an arm part in which two intermediate parts are supported by the branch support part, and the left and right arm parts of the elastic reed are connected to the backrest. Item 3. The chair according to item 3 .

Images