JPH0260607A - Chair having back rest - Google Patents

Abstract

PURPOSE:To engage the pins of an inner shell mounted on a horizontal bench, etc., with its face downward and the cylinder parts of an outer shell and to highly efficiently execute assembling work by covering the inner shell with the outer shell from a position approximately directly above the inner shell. CONSTITUTION:Pins 251, 252, 253, and 254 of an inner shell 2 stably mounted on the horizontal bench of a manufacture line with its face downward and cylinder parts 351, 352, 353, and 354 of an outer shell 3 can be engaged only by covering the inner shell 2 with the outer shell 3 from the position approximately right above the inner shell 2. Further, since a axis line S of a bolt 355 is also made into a corresponding state to a direction to engage the pins 251, 252, 253, and 254 and the cylinder parts 351, 352, 353, and 354, all the axis lines S are parallel. Therefore, it can be easier to simultaneously screw all the bolts at prescribed positions by a multishaft type screw tightening device to simultaneously rotate drivers arranged in parallel, and it also becomes possible to automatically execute screw fixing work in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a chair with a backrest, in which a seat and a backrest are integrally constructed using an inner shell and an outer shell.

[Prior Art] Conventionally, this type of chair with a backrest has an inner shell that is shaped like a letter when viewed from the side and has a seat-corresponding part and a backrest-corresponding part, and an outer shell is attached to the lower and back surfaces of this inner shell. It has been known.

However, in the conventional case, a lower outer shell that covers the lower surface of the seat-corresponding part of the inner shell is attached to the inner shell using multiple bolts, and a separate outer shell that covers the back of the backrest-corresponding part of the inner shell is attached to the inner shell using multiple bolts. The rear outer shell is attached by elastic engagement between the engagement protrusion and the engagement hole.

Note that the bolt for fixing the lower outer shell to the inner shell is usually threaded in a direction perpendicular to the outer surface of the lower outer shell.

[Problems to be Solved by the Invention] However, in such a device, the outer shell is curved, and if the outer surface is not flat, the axes of each bolt will not be aligned in parallel. Therefore, it is not possible to simultaneously tighten a plurality of bolts by moving a multi-axis driver toward and away from the screwdriver, which hinders the efficiency of assembly work.

In addition, if this is the only thing, only the bolted part of the outer shell will be fixed to the lower surface of the inner shell, so if there are few bolted parts, the middle part other than the bolted part will be fixed to the lower surface of the inner shell. There is a problem in that a vertical gap is likely to occur between the edge of the outer shell and the edge of the inner shell.

Furthermore, in such a joint structure, the outer shell
A problem arises when the seat-corresponding portion and the backrest-corresponding portion are integrally molded and have a cross-shaped shape when viewed from the side. In other words, when both the inner shell and the outer shell are shaped in a side view, in order for the backrest to be able to elastically deform appropriately backwards, when the backrest is tilted backwards, the outer shell must be able to accommodate the backrest. It is desirable that the portion of the inner shell be slightly misaligned downward with respect to the portion of the inner shell that corresponds to the backrest. However, in this case, when the backrest is tilted back, the seat-corresponding portion of the outer shell tends to move forward relative to the seat-corresponding portion of the inner shell. Therefore, a falling force acts on the threaded bolt from a direction perpendicular to the outer surface of the outer shell. Such a falling force is repeatedly applied to the bolt each time the backrest is tilted, so that the bolt is likely to loosen. In particular, when the bolt is screwed into a screw hole formed directly in the inner shell made of resin, the screw hole is deformed and the bolt is likely to come off.

The present invention aims to solve all of these problems.

[Means to solve the problem] The present invention has been made to achieve the above objects.

The following configuration is adopted.

That is, the chair with a backrest according to the present invention, as schematically shown in FIG. (2) and an outer shell (3) which is formed integrally with the seat corresponding part (31) and the backrest corresponding part (32) and is shaped like a letter when viewed from the side, so that the seat and the backrest are integrally constructed. The front edge (4) of the seat is attached to the lower surface of the seat corresponding portion (21) of the inner shell (2).
Virtual plane (P) connecting a) and the upper edge of the backrest (5a)
A plurality of pins (251, 252, 253
, 254) are provided protrudingly with their axes (R) parallel to each other, and the seat corresponding portion (3) of the outer shell (3)
1) on the top surface of the pins (251, 252, 253, 2)
The cylindrical part (351, 352, 353) is attached to the part corresponding to 54).
, 354), and its axis (T) is aligned with the pin (251, 2).
The cylinder portions (351, 352, 353,
354) to each of the pins (251, 252, 253, 25)
4), and the outer shell (3) is attached to the inner shell (2), and the outer shell ( 3) is fixed to the inner shell (2).

In order to make the fastening structure using the bolt (355) rational, the axis line (
A screw hole is provided along the pin (R), and the pin (25
A bolt insertion hole that opens on the lower surface side of the outer shell 3 is bored at the outer end of the cylindrical portion (351, 354) that fits into the pin (251, 254), and the pin (251, 354) is inserted through the bolt insertion hole.
, 2549) is preferably used to secure the seat-corresponding portion (31) of the rear outer shell (3) to the lower surface of the inner shell (3) using a bolt (355) screwed into the screw hole of the rear outer shell (3).

[Operation] According to such a configuration, as shown in FIG. 2, the inner shell (2) is stably placed face down on a predetermined workbench.
Just cover the outer shell (3) from almost directly above it.
The pins (251, 252, 2) of the inner shell (2)
53, 254) and the cylindrical portion (351, 254) of the outer shell 3.
352, 353, 354). The axis (S) of the bolt (355) is also connected to the pin (251, 252, 253, 254) and the cylindrical portion (351,
352, 353, 354), so they are all parallel.

Therefore, all the bolts (3
55) in a predetermined position at the same time.

Further, the pins (251, 252, 253, 254) and the cylindrical portion (351, 352, 353, 354) correspond to the seat corresponding portion (21) of the inner shell (2) and the seat of the outer shell (3). Approximately 4 to the joining edge of part (31)
They are engaged along a 5° angle axis (RST). Therefore, even in the part where the bolt (355) is not fixed, the pin (252, 253) and the cylindrical part (352, 3
53), it is possible to prevent a gap from being formed in the vertical direction between the joining edges of the inner shell (2) and the outer shell (3).

Furthermore, by tilting the backrest backward, the seat-equivalent portion (31) of the outer shell (3) is
) when trying to move forward with respect to the seat-equivalent portion (21), the behavior is similar to that of the cylindrical portion (351, 352, 353).
, 354) and pins (251, 252, 253, 254)
It acts to deepen the fit. Therefore, the seat corresponding portion (31) of the outer shell (3) is replaced with the inner shell (
Bolt (3) for fixing to the seat corresponding part (21) of (2)
55), only the force in the direction of the axis (S) acts on it, and there is no possibility that the falling moment will repeatedly act on it.

[Example 1] An example of the present invention will be described below with reference to FIGS. 3 to 15.

The chair with a backrest of this embodiment is as shown in Fig. 3.
A seat 4 and a backrest 5 integrally formed using an inner shell 2 and an outer shell 3 are disposed on a support unit 1.

As shown in FIG. 3, the support unit 1 includes a base 11 having leg blades projecting radially, a pedestal 12 erected at the center of the base 11, and a pedestal 12 connected to the upper end of the pedestal 12. The support base 13 is provided with a support base 13. A balance member 101 is pivoted on both sides of this support base 13, respectively.

As shown in FIGS. 4 and 5, the balance member 101 is an elongated plate-like member extending back and forth, and its middle portion is rotatably attached to the support base 13 via a shaft 102. . The rear ends of the left and right balance members 101 are connected to a connecting fitting 10.
3, and from the connecting part to the back support rod 10
4 extends rearward and upward. Furthermore, a floor support frame 105 is disposed on the support base 13. The front end of the floor support frame 105 is connected to the front end of the support base 13 via the front link member 106, and the rear end is connected to the rear end of both the balance members 101 via the rear link member 107. are doing. That is, the floor support frame 10
The upper pivot ends of left and right front link members 106 are pivotally attached to the front ends of the left and right front link members 106 via a shaft 108, and the lower pivot ends of both front link members 106 are attached to the support base 13, and the shaft 10
It is pivotally connected via 9. Further, the upper pivot ends of left and right rear link members 107 are pivotally connected to the rear end portions of the floor support frame 105 via shafts 111, and these post-rain link members 10
The lower pivot end of 7 is attached to the rear end of the balance member 101 on the shaft 112.
It is pivotally connected via. And the rain balance member 101
A long hole 113 extending back and forth is provided at the front end of the front link member 106, and the long hole 113 is slidably connected to a shaft 110 provided at the rear pivot point of the front link member 106. An intermediate shaft 114 is installed in the middle part of the side wall of the support base 13, and a main spring 115 is stretched between the intermediate shaft 114 and the shaft 108 to elastically bias the seat support frame 105 rearward. are doing. Further, an auxiliary spring 1 is attached to the shaft 109.
16, so that the auxiliary spring 116 can bias the seat support frame 105 in the same direction. One end of the auxiliary spring 116 is connected to the spring force adjustment mechanism 1.
17, and by changing the locking position, the biasing force of the auxiliary spring 116 can be adjusted.

The front end of the seat support frame 105 and the back support rod 10
As shown in FIGS. 4 and 5, horizontally long brackets 118 and 119 are fixed to the upper ends of the shells 4 and the inner shell 2 is attached to the horizontally long brackets 118 and 119, respectively.

As shown in FIGS. 4 to 7, the inner shell 2 is formed by integrally molding a seat corresponding portion 21 and a backrest corresponding portion 22, and is shaped like an elastically deformable material such as polypropylene. Made of synthetic resin. The seat-corresponding portion 21 has a shape in which both left and right side edges 21b and a central portion are slightly raised, and a nut 23 is fixedly installed in the front portion of the side edge vicinity portions 21s. Then, the nut 23 is inserted through the vicinity of both ends of the horizontally long bracket 118.
This inner shell 2 is attached to the seat support frame 105 by a bolt (not shown) screwed into the seat support frame 105.

In addition, in this embodiment, a nut 25 is also fixedly installed in the center front part of the inner shell 2, and the seat support frame 105
The mounting strength of the inner shell 2 is increased by an auxiliary bolt (not shown) that penetrates the front end of the inner shell 2 and is screwed onto the nut 25. The backrest corresponding portion 22 has left and right side edges 22a.
The nut 26 is slightly curved in the forward direction, and nuts 26 are fixed at the vicinity of both side edges 22d at approximately the same height as the so-called backrest point. Bolts 27 are passed through the vicinity of both ends of the horizontally long bracket 119.
This inner shell 2 is connected to the back support rod 104 by screwing into the nut 26. In addition, the seat corresponding part 21 and the backrest corresponding part 2 of this inner shell 2
2, the degree of curvature in the direction in which the left and right edges 28a move forward is set to approximately zero, and is curved so as to form a semicircular arc shape in side view and bulge rearward. and,
Two parallel slits 29 extending vertically are provided in this boundary portion 28. The lower end 29 of both these slits 29
The a side extends to the rear of the seat corresponding part 21, and the upper end 29b side extends to a position higher than the backrest point of the backrest corresponding part 22, and both of these slits 2
The portion 22b located between the 9 and 9 protrudes forward.

On the other hand, the outer shell 3 has a seat corresponding portion 31 and a backrest corresponding portion 3, as shown in FIGS. 4 to 6 and 8.
2 is integrally molded and has a letter-shaped shape when viewed from the side, and is made of elastically deformable synthetic resin such as polypropylene. The seat-corresponding portion 31 has a spherical shape that bulges downward, and is provided with a rectangular opening 33 that is long in the front and back at the center thereof. The backrest corresponding portion 32 has a shape in which left and right side edges 32a are curved in a forward direction.
As one approaches the backrest point from the upper edge 32b,
The degree of curvature is set to be large. The degree of curvature of the outer shell 3 near the backrest point is greater than the degree of curvature of the inner shell 2 at the same cross-sectional position.

Note that the boundary portion 34 between the seat corresponding portion 31 and the backrest corresponding portion 32 of the outer shell 3 is located at both left and right side edges 34a.
The degree of curvature in the forward direction is set to approximately zero, and is curved so as to form a semicircular arc shape in side view and bulge rearward. A portion near the base end of the backrest corresponding portion 32 in the outer shell 3, that is, the boundary portion 3
4 is brought close to a portion of the inner shell 2 near the proximal end of the backrest corresponding portion 22, that is, the upper portion of the boundary portion 28.

The attachment structure of the outer shell 3 to the inner shell 2 is as follows. First, the front edge vicinity part 31f and the side edge vicinity part 31s of the seat corresponding part 31 of the outer shell 3 are removable from the outside to the front edge vicinity part 21f and the side edge vicinity part 21s of the seat corresponding part 21 of the inner shell 2. It is secured with screws. That is, the lower surface 2 a s of the inner shell 2
Specifically, as shown in FIGS. 7 and 9, the front edge 4a of the seat 4 and the upper edge 5a of the backrest 5 are provided on the lower surface of the front edge vicinity portion 21f and the lower surface of the side edge vicinity portion 21s of the seat corresponding portion 21.
A plurality of pins 251 substantially perpendicular to the virtual plane P connecting
．． 252, 253, 254 are provided protrudingly with their axes R aligned in parallel, and the upper surface 3 of the outer shell 3
a % In detail, the front edge vicinity portion 3 of the seat corresponding portion 31
As shown in FIG. 6, FIG. 8, and FIG.
53.354, and its axis T is the pin 251.252.
．． The pins 251, 252, 253, and 254 are fitted into the cylindrical portions 351, 352, 353, and 354 so that the outer shell 3 is connected to the inner shell. It is installed on 2. The seat-corresponding portion 31 of the outer shell 3 is fixed to the seat-corresponding portion of the inner shell 2 by a bolt 355 threaded from a direction coinciding with the axes R and L.

Specifically, screw holes 251a and 254a are provided along the axis R on the tip end surface of a specific pin 251.254, and a cylindrical portion 351.35 that fits into the pin 251.254 is provided.
Bolt insertion holes 351a and 354a that open toward the lower surface 3b of the outer shell 3 are formed at the outer ends of the pins 251.
Bolts 35 screwed into screw holes 251a and 254a of 54
5 fixes the seat-corresponding portion 31 of the outer shell 3 to the seat-corresponding portion 21 of the inner shell 2.

On the other hand, the boundary portion 34 of the outer shell 3 is not connected to the boundary portion 28 of the inner shell 2.

Further, the side edge vicinity portion 32c and the upper edge vicinity portion 32d of the backrest corresponding portion 32 of the outer shell 3 have an engaging structure using claws. Specifically, Figure 6, Figure 10, Figure 1
As shown in FIG. 1, FIG. 13, and FIG. 14, there is an upward mold 301 bent in a cross-shaped shape when viewed from the side near the side edge portion 32c of the outer shell 3, and a first inward mold having an undercut portion on the inside. A mold 302 and a second inward mold 303, which also has an undercut portion on the inside, are provided protruding from the bottom at predetermined intervals, and a downward mold 303 having an undercut portion on the lower side is provided near the upper edge 32d. A wind 304 is integrally provided. In addition, the winter melon 301.302.303 of the inner shell 2
．． Engagement holes 201.202.2 are provided in the portion corresponding to 304.
03.204 is installed. Then, the upward type 30
1 is engaged with the upper edge of the corresponding engagement hole 201 so as to be movable in the vertical direction by the required amount, and both of the inward claws 302.
303 to the inner portions 202a, 203a of the opening edge of the corresponding engagement hole 202, 203, and the downward air 304 to the lower spine portion 204a of the opening edge of the corresponding engagement hole 204, respectively. It is engaged using. In addition,
The first inward type 302 has a straight wall shape extending in the vertical direction, and the corresponding inner part 20 of the opening edge of the engagement hole 202
2a is formed in a straight line, and even in the engaged state,
The inward mold 302 is configured to be able to slide vertically relative to the engagement hole 202. A tongue piece 202c that can be deformed in the thickness direction from the outer portion of the opening edge of the engagement hole 202
The free end 202d of the tongue piece 202C is brought into contact with the outer surface of the inward mold 302 that engages with the inner opening edge portion 202a. The second inward mold 303 has a half-moon shape similar to the downward wind 304, but the engagement hole 203 is designed so that the second inward mold 303 can also move slightly up and down in the engaged state. The dimensions are set.

The depth and direction of engagement between these claws 301, 302, 303, 304 and the corresponding engagement holes 201, 202, 203, 204 are set so that they will not come off during normal use. However, the engaged state can be released by applying a disengagement operation from the outside.

That is, first, the downward wind 304 and the second inward claw 303
As shown in FIG.
2a and elastically deforms the upper edge or side edge of the outer shell 3 by prying it backward, the corresponding downward claw 304 or 303 is deflected to raise the chin. 204 and 203 to separate from the engagement holes 204 and 203. on the other hand,
For the first inward type 302, as shown in FIG. 15, a rigid rod D such as a screwdriver is inserted between the side edge 22a of the inner shell 2 and the side edge 32a of the outer shell 3. , its tip is brought into contact with the vicinity of the tip of the tongue piece 202a. In this state, the side edge 2 of the outer shell 3
When the rod D is rotated backward using 2a as a fulcrum, the tip of the rod D presses the tongue piece 202C forward, and the tongue piece 202C deforms in the thickness direction, and its free end 202d moves to a position where it cannot come into contact with the inward mold 302. At that moment, the inward mold 302 is deflected to raise its jaw according to the deformation of the outer shell 3 and is removed from the engagement hole 202.

The outer shell 3 is removably attached to the inner shell 2 as described above, but the position where the opening 33 of the outer shell 3 is closed is shown in FIGS.
As shown in the figure, a fixed shell 6 is provided. Thus, this fixed shell 6 is removably attached to the lower surface of the support base 13 of the support unit 1 using bolts.

Note that an exterior material 8 is stretched on the front side of the inner shell 2 with a cushion material 7 interposed therebetween.

The peripheral edge of the exterior material 8 is guided to the back side of the inner shell 2 and fixed with a tacker or the like (not shown).

Next, the operation of this chair will be explained.

In the reference posture shown by solid lines in FIGS. 3 and 4, the backrest 5 is erected and the seat 4 is held at the most retracted position. This standard posture is suitable for working, etc. When the user presses the backrest 5 backward with his/her back from this reference posture, the backrest 5 and the
The balance member 101 rotates rearward about a shaft 102 that serves as a fulcrum. As a result, the front end of the balance member 101 moves upward, and the front link member 106 is rotated forward. As a result, the ischial frame 105 moves forward, and the rear link member 107 supported by the rear end of the balance member 101 also rotates forward. At this time, the degree to which the entire rear link member 107 descends as the balance member 101 rotates is set to be greater than the degree that the shaft 111 at the upper pivot point rises due to the rotation of the rear link member 107. Therefore, the seat 4 apparently moves forward while gradually sinking its rear end, and reaches the resting position shown by the imaginary line in FIG. 4.

Although it can be operated and used in this way, this chair has a pin 251. which engages the seat corresponding portion 21 of the inner shell 2 and the seat corresponding portion 31 of the outer shell 3.
The axes R of 252, 253, and 254 are aligned parallel to each other in the manner described above, and the outer shell 3
Since the axes T of the cylindrical portions 351, 352, 353, and 354 are aligned with the axis R, the assembly work can be performed efficiently. That is, according to such a configuration, the pins 251 of the inner shell 2 can be easily placed on the inner shell 2 stably placed face down on a horizontal workbench on the production line by simply covering the outer shell 3 from almost directly above it.
．． 252.253.254 and the cylindrical portion 351.352.353.354 of the outer shell 3 can be engaged with each other. The axis S of the bolt 355 also extends to its pin 2.
51.252.253.254 and cylindrical part 351.352.
353 and 354, so they are all parallel. Therefore, using a multi-axis screw tightening device that simultaneously rotates drivers arranged in parallel, it is now easy to screw all the bolts into place at the same time, automatically completing the screw fixing work in a short time. It is also possible to make it happen.

Further, the pin 251.252.253.254 and the cylindrical portion 351.352.353.354 are the side edges of the seat corresponding portion 21 of the inner shell 2 and the seat corresponding portion 31 of the outer shell 3 that are joined to each other. For 21b and 31a,
251.252.253.254 along the axis RSL forming an angle of approximately 45".
Due to the engagement of the cylindrical portion 351.352.353.354,
Side edges 21 of the inner shell 2 and outer shell 3
It is possible to prevent a gap from being formed in the vertical direction between b and 31a. That is, in this embodiment, the bolt 355- screwed onto the front pin 251 and the rear pin 25-
The seat-corresponding portion 31 of the outer shell 3 is fixed to the inner shell 2 only by a bolt 355 screwed into the bolt 355, and an intermediate position in the longitudinal direction is not screwed. However, at the intermediate position in the longitudinal direction, the pin 252.
253 and the cylindrical portions 352 and 353 prevent the outer shell 3 from separating downward from the inner shell 2, thereby preventing a gap from being formed between the side edges 21b and 31a. can be effectively prevented. Therefore, the seat corresponding portion 31 of the outer shell 3 can be reliably fixed to the seat corresponding portion 21 of the inner shell 2 with a small number of bolts 355.

Furthermore, when the backrest 5 is tilted backwards as described above, the backrest corresponding portion 32 of the outer shell 3 is displaced downward relative to the backrest corresponding portion 21 of the inner shell 2, and the outer shell 3 The seat corresponding portion 31 tries to move forward with respect to the seat corresponding portion 21 of the inner shell 2. In this case, the behavior is similar to that between the cylinder part 351.352.353.354 and the pin 251.252.
．． This acts to deepen the fit with 253 and 254.

Therefore, the bolt 3 for fixing the seat corresponding portion 31 of the outer shell 3 to the seat corresponding portion 21 of the inner shell 2 is provided.
55, only a force in the axial direction acts on it, and no falling moment acts on it. Therefore, even if the backrest 4 is repeatedly tilted, no unreasonable falling force is applied to the threaded portion of the bolt 355, and problems such as the bolt 355 loosening are unlikely to occur.

It should be noted that the present invention is of course not limited to the embodiments described above, and may be applied to those in which the seat simply swings up and down relative to the support unit, or in which the back support rod is pivoted to the support base of the support unit. The present invention can also be applied to chairs that have only a support rod or a chair that does not have a back support.

Furthermore, the present invention can of course be applied to chairs other than chairs in which the exterior material is sandwiched between the inner shell and the outer shell. When the present invention is applied to a structure in which the outer shell is guided and fixed to the back side of the inner shell, it is possible to use exterior materials of various thicknesses without changing the dimensions of the outer shell. can get. In other words, when using an inner shell with a side-viewing shape and an outer shell with a side-viewing shape, and sandwiching the exterior material between them,
In the conventional fastening structure described above, when a thick exterior material is used, the outer shell must be made larger than when a thin exterior material is used. However, according to the present invention, the outer shell Since the attachment position of the outer shell to the inner shell can be changed in the direction along the axes (R, T), even if the thickness of the exterior material is slightly different, a common outer shell can be used.

[Effects of the Invention] Since the present invention has the above-described configuration, the inner shell can be easily covered by simply covering the inner shell from approximately directly above the inner shell, which is placed face down on a horizontal workbench or the like. The pin can be engaged with the cylindrical portion of the outer shell. Since the axes of the bolts also correspond to the direction of engagement between the pin and the cylindrical portion, they are all parallel to each other.

Therefore, it becomes easy to screw all the bolts into predetermined positions at the same time using a multi-axis screw tightening device that simultaneously rotates drivers arranged in parallel. Therefore, it is possible to achieve the effect of increasing the efficiency of the assembly work.

In addition, the engagement between the pin and the cylindrical portion prevents vertical gaps from forming between the joint edges of the inner shell and outer shell, thereby minimizing the number of locations where bolts are attached. can. Therefore, ff,%
The structure can be simplified by reducing the number of points, and the deformation of the shell can be made as smooth as possible.

Furthermore, even when the backrest is tilted, only axial force is applied to the bolts, so the bolts used to secure the outer shell to the inner shell may shake or the screw holes may become deformed. It is possible to effectively suppress the occurrence of problems such as failure to perform functions.

[Brief explanation of the drawing]

1 and 2 are drawings for clearly showing the structure of the present invention, with FIG. 1 being a schematic side sectional view showing an inner shell and an outer shell, and FIG. 2 being an explanatory view of the operation. Figures 3 to 15 show an embodiment of the present invention, with Figure 3 being a partially cutaway side view, Figure 4 being a side sectional view showing the inside, and Figure 5 being a partially cutaway plan cross section. Figure 6 is an exploded perspective view, Figure 7 is a bottom view showing the lower side of the inner shell, Figure 8 is a plan view showing the upper side of the outer shell, and Figure 9 is a portion of the inner shell corresponding to the seat and the outer shell. Fig. 10 is a partial front view showing the vicinity of the upper edge of the inner shell, Fig. 11 is a sectional view taken along the line A-A in Fig. 10, Fig. 12 13 is a partial front view showing the vicinity of the side edge of the inner shell, FIG. 14 is a sectional view taken along the line B-B in FIG. 13, and FIG. 15 is a diagram showing FIG. 14. FIG. 2... Inner shell 3... Outer shell 4.
...Seat 4a...Front edge 5...Backrest 5a...Upper edge 21...Seat corresponding part 22
... Backrest corresponding part 31 ... Seat corresponding part 32
... Backrest corresponding part 251, 252, 253, 25
4... Pin 251a, 254a... Screw hole 351.352, 353.354... Cylindrical portion 351a,
354a,... Bolt insertion hole 355... Bolt
P... Virtual plane R, T... Axis line

Claims (1)

[Scope of Claims] 1. An L-shaped inner shell in side view formed by integrally molding a seat corresponding part and a backrest corresponding part, and an L-shaped inner shell in side view formed by integrally molding the seat corresponding part and backrest corresponding part. A chair in which a seat and a backrest are integrally constructed using an outer shell, the lower surface of the seat-corresponding portion of the inner shell being provided with an imaginary plane connecting the front edge of the seat and the upper edge of the backrest. A plurality of substantially perpendicular pins are protruded with their axes aligned parallel to each other, and a cylindrical portion is provided on the upper surface of the seat-corresponding portion of the outer shell at a portion corresponding to the pins, and the axis thereof is aligned with the axis of the pins. The outer shell is attached to the inner shell by fitting the pins into the cylindrical portions of the outer shell, and attaching the outer shell to the inner shell using bolts threaded from a direction parallel to or coinciding with the axis. A chair with a backrest, which is fixed to an inner shell. 2. A screw hole is provided along the axis on the tip surface of a specific pin, and a bolt insertion hole that opens on the lower surface side of the outer shell is drilled at the outer end of the cylindrical portion that fits into the pin, and the bolt Claim 1, wherein the seat-corresponding portion of the outer shell is fixed to the seat-corresponding portion of the inner shell by a bolt screwed into the threaded hole of the pin through the insertion hole.
Chair with backrest as described.