JP5408643B2 - Chair - Google Patents

Description

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

  Conventionally, a seat support that holds the seat on the support base supported by the legs is arranged, and a back support rod that supports the backrest is attached to the support base so as to be able to tilt backward, and a cover is attached to the back support rod The chair formed is proposed (for example, refer to Patent Document 1).

In order to improve the work efficiency, such a back support cover is a work that is assembled by an operator in the manufacturing process and a work that is temporarily removed during regular maintenance of the chair after shipment. In addition, there is a demand for a structure that allows easy and accurate assembly.
JP 2003-135203 A

  However, in the chair described in Patent Document 1 described above, the cover needs to be positioned at an accurate position when the cover of the back support rod is attached. In such a case, when the cover is temporarily removed for assembly of the cover at the time of manufacture or maintenance of the chair, it takes a lot of time and effort.

  This invention pays attention to such a malfunction, and provides the chair which can perform assembly | attachment and removal of a back support rod cover easily.

  In order to achieve such an object, the present invention takes the following measures. That is, the chair according to the present invention includes a seat support that holds a seat on a support base supported by a leg, and a back support rod that supports a backrest is attached to the support base so as to be able to tilt backward, A chair formed by attaching a cover to a back support rod, wherein the back support rod is provided with a second attachment portion at a first attachment portion, and one end side of the cover is disposed on an outer surface of the back support rod. The cover is supported so that it can be rotated along the other end, and the other end side of the cover is positioned on the second mounting portion by using the rotation and is fixed.

  In such a case, if the cover is simply positioned at the first mounting portion and can be rotated, the cover can be naturally positioned at the second mounting portion. The cover can be easily and accurately positioned when the cover is temporarily removed.

In order to effectively avoid the special configuration and processing for attaching the cover by effectively using the shape of the chair itself, the present invention pivots the first attachment portion of the back support rod to the rear portion of the seat. The second mounting portion is a nut portion having a screw hole . The present invention includes a first attachment portion of the back支桿is an axis pivotally supporting the rear seat support, the second mounting portion is characterized in that a stepped portion mutually involved elastic claws provided on the cover.

  In addition, the present invention can be suitably applied to a cover that covers the back side of the back support rod and a cover that covers the front side of the back support rod.

  As an example of a desirable configuration particularly when a shaft is employed as the first mounting portion, a bifurcated engagement in which the distal end side is narrowed in the cover so that the opening width of the distal end portion is smaller than the diameter of the shaft. A configuration may be mentioned in which a piece is provided and the bifurcated engagement piece is engaged with the shaft using temporary elastic deformation of a member.

  And in order to make positioning more accurate while facilitating the assembly of the cover, it is assumed that a contact portion that contacts the left and right side portions provided on the back support rod is provided inside the side wall of the cover. Is desirable.

  According to the present invention, it is possible to position the cover easily and accurately because the cover can be positioned on the second mounting portion by itself only by positioning the cover on the first mounting portion. It becomes possible. Therefore, the assembly of the cover in the manufacturing process and the work at the time of regular maintenance of the chair can be suitably performed quickly and accurately.

  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 seat support 3 that holds the seat 4 on the support base 2 supported by the legs 1 and supports the backrest 6 on the support base 2. 51 is a chair 100 which is attached so that it can be tilted backward and a back support rod cover 53 is attached to the back support rod 51, and a seat pivot which is a first attachment portion described later on the back support rod 51. A supporting shaft 51b3 and a nut portion 51a15 or a stepped portion 51b24, which is a second mounting portion, are provided, and one end of the back support rod cover 53 is connected to the seat receiving support shaft 51b3. The left and right positioning surfaces 51b11 and 51b12 that are the outer side surfaces of 51 are supported so as to be able to rotate, and the other end side is positioned on the second mounting portion by using the rotation and is fixed. It is a characteristic.

  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 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 abutting portion 53a3 is placed along the outer side surfaces 51b11 and 51b12 of the back support rod 51, the back side 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 abutting portion 53b3 is placed along the outer side surfaces 51b11 and 51b12 of the back support rod 51, the front side lower cover 53b is rotated upward about the seat receiving support shaft 51b3. The elastic claw 53b2 positioned at the upper end of the front wall 53ba is positioned at a position where it comes into contact with 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.

  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 are in contact with the right positioning surface 51b11 and the left positioning surface 51b12 with the contact portions 53a3 and 53b3, respectively. 53a and the front side lower cover 53b are accurately positioned in the width direction. 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.

  With the configuration as described above, the chair 100 according to the present embodiment can be rotated only by positioning the back side cover 53a on the seat receiving support shaft 51b3 which is the first mounting portion. Therefore, the screw insertion hole 53a2 can be naturally positioned in the nut portion 51a15 which is the second mounting portion, so that the positioning at the time of assembly in the manufacturing process or temporary removal for maintenance or the like can be performed easily and accurately. To get. Therefore, the manufacturing efficiency of the chair 100 can be effectively improved and maintenance can be easily performed.

  In this embodiment, in order to effectively use the shape of the chair 100 itself to attach the cover 53 of the back support rod, the first attachment portion is a shaft 51b3 for seat receiving support, and the second attachment portion is on the back side. In the case of the cover 53a, the nut portion 51a15 is used as the step portion 51b24 of the coupling plate portion 51b2 with which the elastic claw is engaged in the case of the front side lower cover 53b.

  As described above, in the present embodiment, the present invention is suitable not only for the back-side cover 53a that covers the back side of the back support rod 51 but also for the front-side lower cover 53b that covers the front side of the back support rod 51. It was shown that it can be applied.

  In the present embodiment in which the seat receiving pivot support shaft 51b3 is employed as the first attachment portion, the bifurcated engagement pieces 53a1 and 53b1 are provided and the elastic elastic deformation of the synthetic resin material is used for seat receiving pivot support. The easy positioning in association with the shaft 51b3 enables the assembling operation.

  In this embodiment, in order to facilitate the assembly of the back support cover 53 and to make positioning more accurate, the back support is provided inside the side walls 53ab and 53bb of the back cover 53a and the front lower cover 53b. It is assumed that contact portions 53a3 and 53b3 that contact the left and right surface portions provided on the collar 51, that is, the right positioning surface 51b11 and the left positioning surface 51b12, respectively, are provided.

  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, the first mounting portion is a shaft for seat receiving support, but another shaft may be used, and another shaft is also used for the second mounting portion. Also good. And of course, it is good also as what set another axis | shaft with the front and back covers as the axis | shaft of a 1st attachment part, respectively. Further, the position of the cover is not limited to the vicinity of the lower end of the back support rod as in this embodiment, and the present invention can be applied at various positions above.

  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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Chair 1 ... Leg 2 Support base 3 ... Seat receiver 4 ... Seat 51 ... Back support rod 51b24 ... 2nd attachment part (step part)
51b3 ... 1st attachment part (shaft for seat support pivot)
53 ... Back support cover 53a ... Back side cover 53a15 ... Second mounting part (nut part)
53a1, 53b1 ... forked engagement piece 53ab, 53bb ... side wall 53b ... front side cover (front side lower cover)
53b3, 53a3 ... contact part 6 ... backrest

Claims (6)

A seat support that holds the seat on the support base supported by the legs is arranged, and a back support rod that supports the backrest is attached to the support base so as to be able to tilt backward, and a cover is attached to the back support rod. A first mounting portion and a second mounting portion are provided on the back support rod, and one end side of the cover is rotated to the first mounting portion along the outer surface of the back support rod. The other end side of the cover is positioned on the second mounting portion using its rotation, and is fastened .
The chair characterized in that the first mounting portion of the back support rod is a shaft that pivotally supports the rear portion of the seat support, and the second mounting portion is a nut portion having a screw hole . A seat support that holds the seat on the support base supported by the legs is arranged, and a back support rod that supports the backrest is attached to the support base so as to be able to tilt backward, and a cover is attached to the back support rod. A first mounting portion and a second mounting portion are provided on the back support rod, and one end side of the cover is rotated to the first mounting portion along the outer surface of the back support rod. The other end side of the cover is positioned on the second mounting portion using its rotation, and is fastened.
The chair characterized in that the first mounting portion of the back support rod is a shaft that pivotally supports the rear portion of the seat support, and the second mounting portion is a step portion with which an elastic claw provided on the cover is engaged . The chair according to claim 1, wherein the cover covers a back side of the back support rod . The chair according to claim 2, wherein the cover covers a front side of the back support rod . The cover is provided with a bifurcated engagement piece whose front end is narrowed so that the opening width of the distal end is smaller than the diameter of the shaft, and the bifurcated engagement piece is used for temporary elastic deformation of a member. The chair according to claim 1, wherein the chair is engaged with the shaft . The chair according to claim 1, 2, 3, 4, or 5, wherein an abutting portion that abuts on left and right side portions provided on the back support rod is provided inside a side wall of the cover .

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