JP4180489B2 - Chair - Google Patents

Description

The present invention relates to a chair child.

  A swivel chair with a locking function is often used for office work. This swivel chair with a locking function has a support base fixed to the upper end of the leg support, supports the seat on the support base, and a back frame that tilts backward against the spring means against the spring means on the shaft. The backrest is attached to the back frame via a back column or directly.

In recent years, the synchro type in which the seat moves backward and backward in conjunction with the back tilt of the backrest has become the mainstream. There are several types of synchro mechanisms that link the backrest and the seat, but in any case, the connection using the left and right horizontal shafts (pins) in the front view of the chair allows the members to rotate and retract. It is common.

  Also, many seats have a structure in which a cushion is stretched on a synthetic resin seat plate. From the viewpoint of ensuring workability and strength, the seat plate is directly attached to the metal seat frame or via an intermediate member. In many cases, the seat frame is connected to the support base by a shaft so as to be able to move backward and backward.

  When connecting the seat frame to the support base with a shaft or connecting the back frame to the support base with a shaft, conventionally, bearing holes have been made in the support base, the seat frame, and the back frame. The mainstream was to insert shafts into these holes.

  However, in the method of assembling a chair by inserting a shaft in this way, the shaft must be inserted while positioning the members one by one, so the efficiency of the assembly work is poor (when a member such as a spring receiver must be attached to the shaft) The work is particularly troublesome), and the shaft only penetrates the frame, so the frame has to be sturdy.

  Therefore, for example, the front and rear shafts of the seat frame body are structured such that the front and rear shafts made of a round pipe are fixed to the front end portion and the rear end portion of the left and right side members extending in the front-rear direction by welding. Is connected to the support base and the back frame by a screw-type bearing member.

  If the shaft is fixed to the frame body in advance by welding in this way, the frame body is unitized so that troublesome shaft insertion work becomes unnecessary, so that the workability of assembling the chair can be improved. Since it is a strength member of the body, the frame body is advantageous in that it can be made to be a lightweight yet robust structure.

  However, in a structure in which all of the plurality of shafts are pressed and fixed only by screw-type bearing members, there is a possibility that looseness may occur due to looseness of the screws. In particular, the shaft that slides back and forth located on the front side of the seat frame body may be subjected to an external force that causes it to move upward during locking, so the bearing member that holds and holds the shaft upwards by the shaft. Therefore, there is a strong concern about loosening of screws and deterioration of durability.

  An object of the present invention is to improve such a current situation.

Chair according to the invention of claim 1 comprises a leg, and a support base base provided at the upper end of the leg, a seat attached to the seat frame member, a backrest mounted to the back frame member The frame body for the seat is fixed to the left and right vertical members extending in the front-rear direction, the first shaft made of a round pipe fixed to the front of the left and right vertical members by welding, and fixed to the rear of the left and right vertical members by welding. And a round pipe-made second shaft. The back frame body is connected to the support base so as to be able to tilt backward, while the first shaft of the seat frame body is connected to the support base so as to be able to move backward, and the backward movement is supported by a spring. Further, the second shaft of the seat frame body is connected to the back frame body so as to be rotatable relative to the back frame body, and the seat is moved backward and backward in conjunction with the rearward tilting of the backrest. .

Further, the support base is formed in an upward opening box shape having a bottom plate and left and right side plates, and is formed so that a slit hole is opened forward in the front part of the left and right side plates of the support base. The first shaft of the seat frame body is fitted into the slit hole through the front bearing member so as to be slidable back and forth. The support base is formed in a box shape having an upward opening with a bottom plate and left and right side plates, and the front bearing member is composed of two members that are vertically overlapped. A long hole into which the first axis of the frame body is movably fitted back and forth is formed, and both members are formed with fitting means for fitting into the slit holes in the side plate in the support base, Two members constituting the front bearing member are fixed to the support base with screws.

According to a second aspect of the present invention, the front bearing member is fitted into a long hole with a rearward opening in which the first shaft of the seat frame body is movably fitted back and forth, and a slit in the side plate of the support base. A fitting means is formed, and the front bearing member is fixed to the support base with screws.

In the present invention, since the first axis of the seat frame body is fitted in the opening hole of the forward opening in the support base , even if an upward external force acts on the first axis due to locking or the like, the external force is not limited to the opening hole. Therefore, the problem of loosening of the screw and deterioration of durability as in the case where the screw is held only by the screw-type pressing member does not occur.

Further, for example, if the first shaft of the seat frame body is held by a screw-type pressing member, it is necessary to screw the pressing member in a state where the seat frame body is positioned. However, in the present invention, since the frame body is positioned by fitting the first shaft into the notch hole of the support base , the first shaft and the second shaft are fixed to the vertical member in advance to unitize the frame body. As a result, the efficiency of the assembling work can be further improved.

In addition, since the first shaft that slides in the front-rear direction is fitted in the slit hole, even if an upward external force is applied to the first shaft during locking, an external force that is disengaged from the slit hole does not act on the front bearing member. For this reason, problems such as loosening of the front bearing member and a decrease in durability can be solved.

According to the configuration of claim 2, since the front bearing member 8 does not need to be divided into upper and lower parts, there are advantages that the number of parts can be suppressed, the strength is excellent, and the slide of the first shaft is also smooth.

  Next, embodiments of the present invention will be described with reference to the drawings.

(1). First embodiment (FIGS. 1 to 12)
1 to 12 show the first embodiment. Among these, FIG. 1 is a side view of the chair. As shown in FIG. 1, the chair includes a leg 1 with casters, a seat 2, a backrest 3, and an armrest device 4. The leg 1 is provided with a leg support 5 that is freely extendable and rotatable, and a support base 6 is fixed to the upper end of the leg support 5.

The seat 2 is attached to the seat frame body 8 via the outer shell 7, and the front end portion of the seat frame body 8 can be tilted and retracted backward by the first shaft 9 to the front end portion of the support base 6. Installed. Needless to say, the outer shell 7 is not an essential component.

  In addition, the front end portion of the back frame body 10 is connected to the rear base portion of the support base 6 so as to be able to tilt backward by the third shaft 11, and a back column 12 is provided at the rear portion of the back frame body 10, The backrest 3 is attached to the back column 12. A lumbar support 13 is disposed between the backrest 3 and the back column 12 so as to be movable up and down.

  Further, a portion of the back frame body 10 behind the third shaft 11 and the rear portion of the seat frame body 7 are connected by a second shaft 14 so as to be relatively rotatable. For this reason, when the backrest 3 tilts backward, the seat 2 also moves backward while tilting back together. This will be described in detail below with reference to the drawings of FIG.

(1) - a. Overview of Seat and Back Support Mechanism First, an overview of the seat and back support mechanism will be described with reference to FIGS. 2 is an exploded perspective view of the main member, FIG. 3 is a longitudinal side view of the seat, FIG. 4 is a plan view taken along the line IV-IV in FIG. 3, and FIG. 5 is a plan view of the rear as viewed at the same height as FIG. It is.

  For example, as is apparent from FIG. 2, the support base 6 is formed in a box shape with an upward opening having a bottom plate and left and right side plates 6 a, and an inner bracket 15 is fixed to the rear portion of the support base 6 via the inner bracket 15. The upper end of the leg support 5 is fixed. A slit 16 for pivotally supporting the first shaft 9 is formed in the front part of the left and right side plates 6a of the support base 6 so as to open forward.

  The seat frame body 8 includes a pair of left and right metal plate vertical members (side members) 17 extending in the front-rear direction, a first shaft 9 made of a round pipe that is fixed to the front portion of the left and right vertical members 17, It consists of a second shaft 14 made of a round pipe with a longitudinal length fixed to the rear part of the left and right vertical members 17. Both shafts 11 and 14 penetrate the vertical member 17 and are fixed to the vertical member 17 by welding.

  The longitudinal member 17 of the seat frame body 8 is formed with a flange 17a extending outward in the left and right directions. On the other hand, although not described in detail, the outer shell 7 is formed with claws (not shown) shaped so as to embrace the flange 17 a of the vertical member 17. It can be moved back and forth along. The outer shell 7 is made of synthetic resin.

  As shown in FIG. 3, the seat 2 has a structure in which a cushion 19 is stretched on an inner shell 18 made of synthetic resin. Needless to say, the cushion 19 is covered with a skin material such as a cloth.

The back frame body 10 includes a vertical member (side member) 21 made of a metal plate that extends substantially rearward from the lower rear portion of the support base 6, and the third shaft 11 is attached to the front end of the left and right vertical members 21. It is fixed. The vertical member 21 is formed in a U-shape with an outward cross section, and the third shaft 11 penetrates the vertical member 21 and is fixed by welding. The left and right vertical members 21 extend in a rearwardly-inclined manner while increasing the interval between them, and are integrally connected via a rear portion 21a. The back column 12 rises from the rear part 21a.

  The inner bracket 15 is provided with a front wall 15a that is substantially perpendicular to the bottom surface of the support base 6, and a left and right kinetic rear spring receiver 22 and a front and rear kinetic rear spring receiver 23 are provided on the front side of the front wall 15a. A spring (coil spring) 26 that supports the backward movement of the first shaft 9 is supported from the rear by the back-and-forth moving rear spring receiver 23. The laterally movable rear spring receiver 22 is supported by the front wall 15 a of the inner bracket 15.

  The laterally movable rear spring receiver 22 is fitted inside the longitudinally movable rear spring receiver 23, and the pressure contact surfaces (cam surfaces) 24 of the rear spring receivers 22, 23 are the shafts 9, 11 in plan view. , 14 is inclined with respect to the inclined surface. A left / right longitudinal handle 25 is screwed to the left / right rear spring receiver 22. A grip is attached to the handle 25, and the handle 25 is held so as not to move left and right.

  When the handle 25 is rotated, the left and right rear spring receiver 22 moves left and right, and then the front and rear movement rear spring receiver 23 moves back and forth, and the hardness (elastic force) of the spring 26 changes. The longitudinally moving rear spring receiver 23 is held so as not to be laterally movable by supporting one end surface thereof with the inner surface of the side plate 6 a of the support base 6.

  As partially shown in FIG. 5, a gas cylinder for adjusting the rearward tilt angle of the back frame body 10 and for rearward tilt locking is provided between the rear portion 21 a of the back frame body 10 and the rear portion of the support base 6. 27 is arranged, but the description is omitted because it is not related to the present invention.

(1) -b. Next, the mounting structure of the first shaft 9 will be described with reference to FIGS. 6 to 8 in addition to the previous drawings. 6 is a separated side sectional view for explaining the mounting structure of the first shaft 9 and the third shaft 11, FIG. 7 is a separated sectional view taken along line VII-VII in FIG. 4, and FIG. FIG.

The site of the internal support base base 6 of the first shaft 9, a front bearing member (2) 8 is fitted on. The left and right front bearing members 28 are made of synthetic resin and separated into two upper and lower parts (members) , and a long hole (long groove) 29 in which the first shaft 9 can slide back and forth without rattling is formed on the mating surface of the upper and lower members. Forming.

The left and right front bearing members 28 are formed with ribs 28 a as fitting means for fitting into the slit holes 16 of the support base 6. Further, on the mating surfaces of the upper and lower parts constituting the front bearing member 28, a protrusion 30 and a hole 31 are formed as an example of an engaging means for preventing mutual displacement.

A front spring bearing 32 is disposed between the left and right front bearing members 28 so as not to move left and right. The front spring receiver 32 is formed in a substantially U shape with a rearward opening in a side view so that the first shaft 9 is fitted from behind.

The left and right front bearing members 28 and the front spring bearings 32 are U-shaped in a front-facing opening and are fitted into the front metal fitting 33 made of a metal plate, and the front metal fitting 33 and the left and right front bearing members 28 Is fastened to the bottom plate of the support base 6 with screws 34. The front metal fitting 33 is positioned by fitting a downward claw 35 provided at the front portion thereof into a locking hole 36 formed in the bottom plate of the support base 6.

  By the way, in this embodiment, there is a gap between the outer surface of the support base 6 and the vertical member 17 of the seat frame 7. For this reason, it is necessary to prevent the first shaft 9 from moving left and right. As this lateral movement preventing means, it is conceivable to arrange a screw-type collar body in a split shape on the outwardly exposed portion of the first shaft 9, but this increases the number of members and the assembly man-hours. is there.

Therefore, in the present embodiment, as shown in FIG. 8, the protrusion 37 is provided on the left and right intermediate portion of the first shaft 9 by welding or the like, while the protrusion 37 is fitted to the front spring receiver 32 so that the protrusion 37 cannot move left and right. 38 is formed. If comprised in this way, since the 1st axis | shaft 9 is hold | maintained by the right-and-left side board 6a of the support base 6 through the front part spring bearing 32 and the right-and-left front bearing member 28 so that it cannot move right and left, an increase in a number of members and an assembly There is an advantage that the process can be prevented from becoming complicated.

In order to attach the first shaft 9 to the support base 6, as shown in FIG. 7, first, the front metal fitting 33 is attached to the support base 6, and then the front bearing member 28 into which the first shaft 9 is fitted The front spring receiver 32 may be fitted into the front metal fitting 33, and then the front metal fitting 33, the front bearing member 28, and the support base 6 may be fastened together with screws 34.

By fitting the first shaft 9 to which the front bearing member 28 and the front spring bearing 32 are attached into the slit 16, the first shaft 9 is positioned, so that the attachment process becomes extremely simple. Further, since the external force in the state direction acting on the first shaft 9 is supported by the slit 16 through the front bearing member 28, no vertical force is applied to the front metal fitting 33, so that the screw 34 is loosened. Such a problem does not occur.

  As shown in FIG. 3, a synthetic resin backward tilt restricting stopper 39 is provided on the upper surface of the rear portion of the inner bracket 15, and when the backrest is fully tilted backward, the third shaft 11 hits the backward tilt restricting stopper. The maximum rearward tilt angle is set to be regulated.

(1) -c. FIG. 9 is a separated front view showing the mounting structure of the third shaft 11. The mounting structure of the third shaft 11 will be described with reference to FIG. The third shaft 11 is sandwiched from above and below by an upper center bush 40 and a lower center bush 41, and these upper and lower center bushes 40, 41 are covered from below with a hook-shaped center metal fitting 42 with a flap. The screw 50 is fastened to the lower surface of the support base 6. Therefore, in the present embodiment, the center receiving member is constituted by the upper and lower center bushes 40 and 41 and the center metal fitting 42.

  When the upper and lower center bushes 40 and 41 are overlapped, the outer surface is formed in a square shape in a side view as a whole. For this reason, the upper and lower center bushes 40 and 41 are held by the center metal fitting 42 so as not to be rattled. Moreover, although the depth of the upper center bush 40 is made deeper than the lower center bush 41, this improves the support function of the upper center bush 40 by the 3rd axis | shaft 11 becoming upwardly pressing at the time of locking. This is because it is preferable. Of course, the depths of the upper and lower center bushes 40 and 41 may be set to the same level.

The third shaft 11 is attached to the support base 6 by a simple operation in which the upper and lower center bushes 40 and 41 are overlapped and then fitted into the center metal fitting 42 and the center metal fitting 42 is fastened to the support base 6 with screws 50. be able to.

  By the way, since the third shaft 11 is also exposed to the outside of the support base 6, like the first shaft 9, some left-right movement preventing means is necessary. In that case, it is also possible to provide a split collar, but in this case, as described in the first shaft 9, the number of members increases and the man-hour increases.

Therefore, in the present embodiment, the lengths of the upper and lower center bushes 40, 41 are set to be substantially the same as the distance between the front portions of the left and right vertical members 21 in the back frame body 10, and the upper center bush 41 is supported by the upper center bush 41. It is provided an upward projection 40a abutting or close contact with the left and right side surfaces of the base the base 6 (upward projection 40a may extend Bitei to left and right ends). For this reason, the 3rd axis | shaft 11 is hold | maintained so that a left-right movement is impossible. That is, the center bushes 40 and 41 exhibit the function of preventing the third shaft 11 from moving to the left and right, which can contribute to the reduction in the number of members and the assembly man-hours.

  Further, the lower center bush 41 is provided with upward protrusions 41 a that are in contact with or in close contact with the left and right side surfaces of the center metal fitting 42. For this reason, the upper and lower center bushes 40 and 41 are precisely positioned so that they cannot move left and right. You may provide engagement means, such as an unevenness | corrugation which mutually fit in the mating surface of the upper and lower center bushes 40 and 41. FIG.

(1) -d. Next, the mounting structure of the second shaft 14 will be described with reference to FIGS. 10 to 12 in addition to FIGS. 3 and 5. 10 is a separated front view showing the mounting structure of the second shaft 14, FIG. 11 is a separated side sectional view showing the mounting structure of the second shaft 14, and FIG. 12 is a sectional view taken along line XII-XII in FIG.

  In this embodiment, the rear bearing member is a synthetic resin upper and lower made by sandwiching the bridge member 43 arranged so as to span the left and right vertical members 21 of the back frame body 10 and the third shaft 11 at two left and right positions. The rear bush 44 includes a rear metal fitting 45 that presses and fixes the rear bush 44 to the bridge member 43, and a screw 46 that fastens the rear metal fitting 45 to the bridge member 43. The bridge member 43 is fixed to the vertical member 21 by welding (screwing or integral molding may be used).

The upper and lower rear bushes 44 are formed so that the outer diameter becomes a substantially square shape when they overlap each other, and a standing portion 43 a for positioning the upper and lower rear bushes 44 is bent at the front portion of the bridge member 43. Yes. A horizontal piece 43b is formed on the standing portion 43a by bending, and the rear metal fitting 45 is formed in a step shape in a side view so as to overlap the horizontal piece 43b.

  The upper and lower rear bushes 44 are formed so that the protrusions 44a and the recesses 44b are symmetrical in the front-rear direction so as to be held so as not to be relatively movable in the left-right direction. For this reason, only one type of rear bush 44 is required.

  When the backrest 3 is locked, an external force that pulls backward acts on the second shaft 14. When the standing piece 43a of the bridge member 43 is formed on the front side and the rear bush 44 is supported on the rear surface of the standing piece 43a as in the present embodiment, an external force in the front-rear direction acts on the rear bush 44 and the rear fitting 45. Therefore, there is an advantage that the mounting strength of the second shaft 14 can be ensured without increasing the number of screws 46 or making the parts have a robust structure.

  By forming the front and rear standing pieces on the bridge member 43 by bending or cutting, it is possible to hold the upper and lower rear bushes 44 so that they cannot move back and forth. In this case, the rear fitting 45 may be a simple flat plate. . Further, the bridge member 43 is not necessarily required, and the second shaft 14 may be pivotally supported on the left and right vertical members 21 of the back frame body 10.

  Further, the back frame body 10 does not necessarily need to include the left and right vertical members 21, and may have a structure in which the third shaft 11 is fixed to one main member extending in the front-rear direction. In short, the shape of each member can vary depending on the design of the chair.

  By the way, it is necessary to hold the second shaft 14 so as not to move left and right. In this case, it is preferable that the slip prevention means is made of a synthetic resin in order to prevent a rubbing sound. However, providing a dedicated member for preventing deviation is not preferable because it increases costs and man-hours for assembly.

  Therefore, in the present invention, the rear bush 44 made of synthetic resin is provided with a radially outward projection 44c that overlaps the side surface of the vertical member 21 of the seat frame 7, while the bridge member 43 has a radially outward projection of the rear bush 44. An escape hole 47 is formed in which 44c fits and is held so as not to move left and right. In this way, by using the rear bush 44 also as a left-right shift prevention means, it is possible to contribute to the suppression of the number of parts and the reduction of assembly man-hours.

  In order to prevent interference between the bridge member 43 and the seat frame body 7, the escape hole 47 is set so that the rear portion of the vertical member 17 in the seat frame body 7 is also loosely fitted. The downward projection 44 c of the rear bush 44 can be brought into contact with the end surface of the bridge member 43.

If the pair of the upper and lower rear bushes 44 and the rear metal fitting 45 are arranged at two places on the left and right as in the present embodiment, there are advantages in that the second shaft 14 can absorb the twist and the weight can be reduced. Of course, the rear bush 44 may be only a pair. Further, the rear bush 44 can be provided in two pairs on the left and right sides, and the rear metal fitting 45 can be provided only in one piece.

  The bridge member 43 is provided with a left and right projecting portion 43c, and the elbow strut of the armrest device 4 is fixed to the projecting portion 43c. However, the description is omitted because it is not related to the present invention.

(1) -e . Advantages of the spring support structure By the way, when providing a spring support means having a left and right motion spring receiver, conventionally, as a means for holding the front and rear motion spring receiver so as not to be movable left and right, a support base A stopper was fixed to the inside of the steel plate 6 by welding, or a stopper piece was integrally formed on the aluminum die-cast support base 6. However, this causes a problem that the number of members increases and the support base becomes complicated.

When the structure for supporting the front and rear-acting spring bearing as in this embodiment in the side plate 6a of the support base base 6 with respect to this, it is not necessary to specially provide a stopper, Ru advantage der capable simplified structure.

(2). Second embodiment (FIG. 13)
In Figure 1 3 shows a second embodiment. ( A) is a separated plan view, (B) is a perspective view of the front bearing member 28, (C) is a rear view of the front spring receiver 32, and (D) is a side view of the front spring receiver 32.

In this embodiment, the front bearing member 28 is formed in the opened form retrospectively. If comprised in this way, since it is not necessary to make the front bearing member 28 into an up-and-down division system, there is an advantage that the number of parts can be suppressed, the strength is excellent, and the sliding of the first shaft 9 is also smooth.

Further, the front bearing member 28 is formed with a groove 28 a as a fitting means for fitting to the side plate 6 a of the support base 6. For this reason, the positioning function of the front bearing member 28 can be remarkably improved. Further, in addition to providing the front bearing member 28 with a fitting means such as the groove 28a such as the groove 28a, the front spring bearing 32 and the first shaft 9 are engaged with the left and right motion preventing projections 30 and the like. By providing the means, the first shaft 9 can be held so as not to be laterally shaken without requiring a steadying member such as a collar.

In the present embodiment, the front spring receiver 32 is partially provided with a positioning protrusion 32 a of the spring 25. Further, as shown in (B), a number of shallow grooves 29 a are appropriately formed on the inner surface of the front bearing member 28. This is to facilitate contact of the first shaft 9, and by storing the grease groove 29a, it is possible to makes it smooth sliding and rotation of the first shaft 9. Such a groove 29a is also formed in other bushes. The groove 29 is preferably formed so as to extend in the sliding direction or the rotational direction of the shaft.

It is also possible to provide engagement means for preventing relative movement in the axial direction on the first shaft 9 and the front bearing member 28. Further, the front bearing member 28 can be provided with an outwardly exposed portion that contacts the side plate of the vertical member 17 in the seat frame 8 .

(3) Third embodiment (Fig. 14 )
In FIG. 14 , 3rd Embodiment which is another example of the bearing mechanism of the 3rd axis | shaft 11 is shown. (A) is a partially broken separated view seen from the front direction, (B) is a separated view seen from the side direction. In this embodiment, the upper center bush 40 is formed with an upward projection 40b as an anti-left / right steadying means, while the bottom plate of the support base 6 is formed with an engagement hole 6b into which the projection 40b is fitted. Yes. For this reason, positioning is ensured.

  When the bushes overlap with the support base 6 or the like, as a steadying means for preventing the shaft from shifting in the longitudinal direction, a male fitting part and a female fitting, such as a combination of a projection and a hole, are used. A combination with a part can also be adopted, and such a steadying means can also be applied to other bearing parts.

In this embodiment, the lower surface of the lower center bush 41 is formed in an arc shape, and accordingly, the bottom portion of the center metal fitting 42 is formed in an arc shape. A shallow groove 40c is formed on the inner surface of the upper center bush 40 (the function is the same as the groove 29a of the front bearing member 28).

(4). Others The present invention can be embodied in various ways other than the above embodiment. For example, the front bearing members and bushes are not limited to being pressed and fixed to the support base or the like with metal fittings, but can be directly fastened with screws.

It is a side view of the chair concerning a 1st embodiment. It is a separation perspective view of a main member. It is a vertical side view of a seat part. FIG. 4 is a plan view taken along line IV-IV in FIG. 3. FIG. 5 is a plan view of a rear portion viewed at the same height as FIG. 4. It is a separation side sectional view for explaining the attachment structure of the 1st axis and the 3rd axis. FIG. 5 is a sectional view taken along line VI-VI in FIG. 4. It is VIII-VIII sectional view taken on the line of FIG. It is a separation front view showing the attachment structure of the 3rd axis. It is a separation front view showing the attachment structure of the 2nd axis. It is a separation side sectional view showing the attachment structure of the 2nd axis. It is XII-XII sectional view taken on the line of FIG. It is a figure which shows 2nd Embodiment. It is a figure which shows 3rd Embodiment.

Explanation of symbols

1 leg 2 seat 3 backrest 6 support base
6a Support base base side plate 8 Seat frame body 9 First shaft 10 Back frame body 11 Third shaft 14 Second shaft 16 Opening hole of the support base 17 Vertical member of the seat frame body 28 Front bearing member
28a Rib or groove 32 as fitting means 32 Front spring receiver 40, 41 Center bush 42 Center bracket 43 Bridge member 44 Rear bush 45 Rear bracket

Claims (2)

And legs, and a support base base provided at the upper end of the leg, a seat attached to the seat frame member, and a backrest attached to the back frame body, the seat frame body, the front-rear direction Two left and right vertical members, a round pipe first shaft fixed to the front of the left and right vertical members by welding, and a round pipe second shaft fixed to the rear of the left and right vertical members by welding. And
The back frame body is connected to the support base so as to be able to tilt backward, while the first shaft of the seat frame body is connected to the support base so as to be able to move backward, and the backward movement is supported by a spring. Further, the second shaft of the seat frame body is connected to the back frame body so as to be relatively rotatable, and the seat is moved backward and backward in conjunction with the rear tilt of the backrest. And
The support base is formed in a box shape with an upward opening provided with a bottom plate and left and right side plates, and a slit hole is formed in the front part of the left and right side plates of the support base so as to open forward. The first shaft of the seat frame body is slidably inserted in the slit hole through the front bearing member.
In the configuration
The front bearing member is composed of two members that are vertically overlapped. An elongated hole is formed on the mating surface of both members so that the first shaft of the seat frame body can be freely moved back and forth. The member is formed with a fitting means for fitting into a slit hole in the side plate of the support base, and the two members constituting the front bearing member are fixed to the support base with screws.
Chair. A leg base, a support base provided at the upper end of the leg, a seat attached to the seat frame body, and a backrest attached to the back frame body, the seat frame body in the front-rear direction Two left and right vertical members, a round pipe first shaft fixed to the front of the left and right vertical members by welding, and a round pipe second shaft fixed to the rear of the left and right vertical members by welding. And
The back frame body is connected to the support base so as to be able to tilt backward, while the first shaft of the seat frame body is connected to the support base so as to be able to move backward, and the backward movement is supported by a spring. Further, the second shaft of the seat frame body is connected to the back frame body so as to be relatively rotatable, and the seat is moved backward and backward in conjunction with the rear tilt of the backrest. ,And,
The support base is formed in a box shape with an upward opening provided with a bottom plate and left and right side plates, and a slit hole is formed in the front part of the left and right side plates of the support base so as to open forward. The first shaft of the seat frame body is slidably inserted in the slit hole through the front bearing member.
In the configuration
The front bearing member is formed with an elongated hole of a rearward opening in which the first shaft of the seat frame body is movably fitted back and forth, and a fitting means for fitting into a slit hole of a side plate in the support base. The front bearing member is fixed to the support base with screws,
Chair.

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