JPH084546B2 - Chair with backrest - Google Patents

Description

TECHNICAL FIELD The present invention relates to a chair with a backrest in which a plurality of shells are combined to integrally form a seat and a backrest.

[Prior Art] Conventionally, as a chair with a backrest of this type, an inner shell integrally formed with a seat-corresponding portion and a backrest-corresponding portion is provided, and a plurality of outer shells are attached to a lower surface and a back surface of the inner shell. What you have done is known.
That is, the conventional one has at least the outer shell,
It is divided into one for the backrest that covers the back of the backrest-corresponding part of the inner shell and one for the seat that covers the lower surface side of the seat-corresponding part of the innershell, especially for those with complicated seat movements with respect to the legs. In many cases, the outer shell for the seat is further divided into a plurality of pieces. In many cases, a large gap is formed between the pieces.

[Problems to be Solved by the Invention] When the outer shell is divided into a plurality of pieces in this way, it is difficult for the outer shell to exhibit the strength of the entire shell. That is, the conventional outer shell only has a function as a cover for covering the back surface and the lower surface of the inner shell, and the inner shell is designed mainly to exert the frame strength of the seat and the backrest. ing. Therefore, in the conventional inner shell, various complicated ribs for suppressing the deformation and various cutouts for promoting the deformation are formed, and the inner shell is devised to give necessary strength to each portion. There is a certain limit to making the strength of the inner shell, which is an integrally molded product, different in each part. Therefore, there is a problem that the degree of freedom in design is low.

The first object of the present invention is to solve such a problem by integrating the outer shell as well.

Another object of the present invention is to solve a further specific problem in integrating the outer shell. That is, a specific problem is that a large gap may be left between the support unit and the outer shell. What is specifically desired to make the strength of the backrest appropriate for a chair? When the backrest is supported by the back support rod, the boundary portion between the backrest and the seat needs to be deformed relatively easily, but the deformation of the outer shell may be difficult if it is integrated. It may be necessary to disassemble the support unit to remove the integrally molded outer shell from the chair. Since the operation part for adjusting the seat height etc. is usually attached to a specific outer shell, it is necessary to detach the operation part each time to remove the outer shell as a whole, which makes the work troublesome. In addition to the above, is there a possibility that it will be difficult to confirm the function of the mechanical section operated by the operating section with the outer shell removed?

And the like.

[Means for Solving the Problems] The present invention is intended to achieve the above objects. It adopts the following configuration.

That is, the chair with a backrest according to the present invention has a side view L formed by integrally molding a seat-corresponding portion and a backrest-corresponding portion.
An L-shaped outer shell formed by integrally molding a letter-shaped inner shell, a seat-corresponding portion having an opening and a backrest-corresponding portion, and a seat disposed at a position to close the opening of the outer shell. A fixed shell fixed to a supporting unit for supporting is provided, and the outer shell is attached to the inner shell without being in close contact with the entire surface.

In order to prevent a large gap from being formed between the outer shell and the support unit side, the trajectory of the front edge and the rear edge of the opening when the outer shell swings with respect to the support unit is approximated to It is desirable to mold the front and back of the fixed shell.

In order to allow the backrest to have a relatively high degree of rigidity and to allow appropriate deformation as a chair, at least the upper half portions of the backrest-corresponding portions of the inner shell and the outer shell have their respective left and right side edges forward. In addition to bending in the same direction, the degree of curvature of the outer shell is made larger than the degree of curvature of the inner shell, and the inner shell and outer shell are connected to the backrest corresponding portions in the vicinity of both side edges so that they can be relatively moved in the vertical direction by a certain distance. It is good to keep it.

To facilitate the deformation of the boundary between the backrest and the seat,
It is preferable that non-curved portions having a degree of curvature of substantially zero are formed near the base ends of the backrest corresponding portions of the inner shell and the outer shell, respectively, and the inner shell and the outer shell are brought close to each other near the non-curved portions.

The support unit is housed between a base formed by radially arranging five leg blades, a pedestal erected at the center of the base, and an inner shell and an outer shell provided at the upper end of the pedestal. If the outer shell can be detached from the inner shell without disassembling the supporting unit, the opening of the outer shell should be rectangular and When the corners on one end side in the longitudinal direction of the leg blades are positioned near the center of the base and the leg blades are rotated, all the tip ends of the leg blades may pass near the diagonal positions of the openings. The dimensions of the part and leg blades should be set in advance.

In order to facilitate the removal of the outer shell and to enable the operation of the corresponding manual operation section to be checked by operating the manual operation section even after the removal, the manual operation section and this manual operation section are used. It is preferable that the mechanism portion is provided on the inner shell and the support unit side and is independent from the outer shell and the fixed shell.

[Operation] According to such a configuration, the inner shell and the outer shell form one three-dimensional structure, and the rigidity of the seat and the backrest integrated with this structure is assumed. . However, in such a case, by appropriately selecting the degree of curvature of the inner shell and the outer shell, the distance between the shells, or the relative positional deviation range between the shells, the strength and deformation of each part can be reduced. It is possible to freely set the ease of use in a wide range.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the chair with a backrest has a seat 4 and a backrest 5 integrally formed on a support unit 1 using an inner shell 2 and an outer shell 3.

As shown in FIG. 1, the support unit 1 has a central boss portion.
A base 11 formed by radially projecting five leg blades 11b around the outer periphery of 11a, a column 12 standing on the center boss 11a of this base 11, and a support continuously provided on the upper end of this column 12. And a base portion 13. The pedestal 12 is the fixed outer cylinder 1 of the gas spring 12a.
2b through the taper fitting portion to the center boss portion 11 of the base 11.
a and the operating rod 12 of the gas spring 12a.
The upper end of c is joined to the support base 13 via a taper fitting portion, and a cylindrical cover 12d is attached to the outside of the fixed outer cylinder 12b. The gas spring 12a is a normal one that allows the lock position to be adjusted in the vertical direction by pressing the operating rod 12e protruding from the upper end of the operating rod 12c to open the internal valve. is there. The support base 13 is made of, for example, aluminum die-cast, and has a bottom wall 13a extending in the front-rear direction and having a taper fitting portion with the operating rod 12c, as shown in FIGS. 2 and 3.
And side walls 13b standing on both left and right edges of the bottom wall 13a. The balance member 101 is axially mounted on both side walls 13b of the support base 13. The balance member 101 is a long and thin plate extending in the front-rear direction, and has an intermediate portion rotatably mounted on the support base 13 via a shaft 102. And
The rear ends of the left and right balance members 101 are rigidly attached by a connection fitting 103, and the back support rod 104 extends rearward and upward from the connection portion. Also, on the support base 13,
A seat receiving frame 105 is provided. As shown in FIGS. 2 and 5, the seat receiving frame 105 includes a frame-shaped top plate 105a and side plates 105b hanging down from both left and right edges of the top plate 105a. The front end of the plate 105b is
Is connected to the front end portions of both side walls 13b of the support base 13 via the rear end portions of both side plates 105b.
Is connected to the rear end of the balance member 101 via the.
That is, the upper pivot ends of the left and right front link members 106 are pivotally attached to the front end portions of the both side plates 105a via the shafts 108, and the lower pivot ends of the front link members 106 are attached to the side walls of the support base 13. It is pivotally attached to 13b via a shaft 109. Also, the upper pivot ends of the left and right rear link members 107 are pivotally attached to the rear ends of both side plates 105b of the seat receiving frame 105 via shafts 111, and the lower pivot ends of the rear link members 107 are both attached to the balance. It is pivotally attached to the rear end of the member 101 via a shaft 112. Then, a long hole 113 extending in the front-rear direction is formed in the front end portion of the both balance members 101.
And the long holes 113 are formed in the front link member 106.
It is continuously connected to a shaft 110 provided at the rear pivot point so as to be slidably rotatable. An intermediate shaft 114 is provided at an intermediate portion of the side wall of the support base 13.
A main spring 115 is stretched between the intermediate shaft 114 and the shaft 108 to elastically bias the seat receiving frame 105 rearward. Further, an auxiliary spring 116 is wound around the shaft 109 so that the seat receiving frame 105 can be biased in the same direction by the auxiliary spring 116. Auxiliary spring 116
One end of is locked by a spring force adjusting mechanism 117, and the biasing force can be adjusted by the auxiliary spring 116 by changing the locking position.

Then, as shown in FIG. 5, a horizontally long bracket is provided on the front end portion of the seat receiving frame 105 and the upper end of the back support rod 104, respectively.
118 and 119 are fixed, and the inner shell 2 is attached to the horizontally long brackets 118 and 119.

The inner shell 2 is, as shown in FIGS. 2 to 5,
The seat-corresponding portion 21 and the backrest-corresponding portion 22 are integrally molded, and are L-shaped in a side view, and are made of an elastically deformable synthetic resin such as polypropylene. Seat corresponding part 21
The left and right side edges and the central portion have a slightly raised shape, and a nut 23 is fixed to a front portion near the both sides. Then, the inner shell 2 is attached to the seat receiving frame 105 by the bolts 24 which penetrate the vicinity of both ends of the lateral bracket 118 and are screwed to the nut 23. In this embodiment, a nut is also fixed to the central portion of the inner shell 2 near the center, and the seat receiving frame 105
The mounting strength of the inner shell 2 is enhanced by an auxiliary bolt (not shown) which penetrates the front end of the and is screwed to the nut 25 thereof. The backrest-corresponding portion 22 has a shape in which the left and right side edges 22a are slightly curved in the forward direction, and a nut 26 is fixedly attached to both side edge neighboring portions 22d at a position substantially the same height as the so-called backrest point. And the horizontal bracket
Insert the bolt 27 that penetrates the vicinity of both ends of 119 into the nut 26
This inner shell 2 can be attached to the back support rod by
Connected to 104. The boundary portion 28 between the seat-corresponding portion 21 and the backrest-corresponding portion 22 of the inner shell 2 has a degree of curvature in the direction in which the left and right side edges 28a are protruded set to substantially zero, and has a side view arc shape. It is curved so that it bulges backward. Then, the boundary portion 28 is provided with two parallel slits 29 extending vertically. The lower ends 29a of these slits 29 extend to the rear of the seat-corresponding portion 21, while the upper ends 29b thereof extend to a position higher than the backrest point of the backrest-corresponding portion 22, and between these slits 29. The positioned portion 22b is projected forward.

On the other hand, as shown in FIGS. 1 to 4, the outer shell 3 is an L-shaped side view formed by integrally molding a seat corresponding portion 31 and a backrest corresponding portion 32. Made of possible synthetic resin. The seat corresponding portion 31 has a shape bulging downward spherically,
A rectangular opening 33 that is long in the front and back is provided in the center thereof. The backrest-corresponding portion 32 has a curved shape in a direction in which the left and right side edges 32a protrude, and is set so that the degree of curvature increases as approaching the backrest point from the upper end 32c. The degree of curvature near the backrest point of the outer shell 3 is larger than the degree of curvature of the inner shell 2 at the same cross-sectional position. In the boundary portion 34 between the seat corresponding portion 31 and the backrest corresponding portion 32 of the outer shell 3, the degree of curvature in the direction in which the left and right side edges 34a protrude is set to substantially zero, and a semi-circular shape in a side view is shown. It is curved so as to bulge backward. Then, the backrest-corresponding portion 32 of the outer shell 3
The portion 34a near the base end, that is, the upper portion of the boundary portion 34 is brought close to the portion near the base end of the backrest corresponding portion 22 of the inner shell 2, that is, the upper portion of the boundary portion 28.

The mounting structure of the outer shell 3 to the inner shell 2 is as follows. First, a portion near the front edge and a portion near the side edge of the portion 31 corresponding to the seat of the outer shell 3 are detachably screwed to a portion near the front edge and a portion near the side edge of the inner shell 2 from the outside. The boundary 34 of the outer shell 3 is not connected to the boundary 28 of the inner shell 2. The portion 32c near the side edge and the portion 32d near the upper edge of the portion 32 corresponding to the backrest of the outer shell 3 have an engagement structure using claws. Specifically, as shown in FIG. 4, an upward claw 301 that bends in an L shape in a side view at a side edge vicinity portion 32c of the outer shell 3 and a first inward claw 302 that has an undercut portion inside. And a second inward claw 303 that also has an undercut portion inside
Are projected from the bottom at predetermined intervals, and a downward claw 304 having an undercut portion on the lower side is integrally projected at the upper edge vicinity portion 32d. In addition, the engaging holes 201, 2 are formed at the portions of the inner shell 2 corresponding to the claws 301, 302, 303, 304.
02, 203 and 204 are drilled. And the upward claws 301
Is engaged with the upper edge of the corresponding engaging hole 201 so as to be movable in the vertical direction by a required amount, and the inward claws 302 and 303 are respectively provided with the opening edge inward portions 202a and 203a of the corresponding engaging holes 202 and 203. To
Further, the downward claw 304 is engaged with the opening edge lower side portion 204a of the corresponding engaging hole 204 by utilizing elastic deformation of each member. As shown in FIGS. 9 and 10, the first inward claw 302 has a straight wall shape extending in the vertical direction, and the opening edge inner portion 202a of the corresponding engaging hole 202 has a straight line. The inward claw 302 is formed into a shape even in the engaged state.
Can slide vertically with respect to the engagement hole 202. Then, a tongue piece 202c that can be deformed in the thickness direction is integrally protruded from an opening edge outer portion 202b of the engagement hole 202, and a free end 202d of the tongue piece 202c is engaged with the opening edge inner portion 202a. The outer nail 302 is in contact with the outer surface. Second inward claw 3
03 is a half-moon shape similar to the downward nail 304 as shown in FIG. 6 and FIG.
In the engaged state, the dimensions of the engaging hole 203 are set so as to be able to move slightly up and down. These nails 301, 30
The engagement depth and the engagement direction with each of the engagement holes 201, 202, 203, and 204 corresponding to 2, 303, and 304 are set so as not to come off in a normal use state. The engagement state can be released by performing a disengagement operation. That is, first, the downward claws
8, the rod A having a rigidity such as a screwdriver is attached to the upper edge 22c or the side edge 22a of the inner shell 2 and the upper edge 32 of the outer shell 3 as shown in FIG.
b or between the side edge 32a and the outer shell 3
When the upper edge portion or the side edge portion is elastically deformed by twisting backward, the corresponding downward claw 304 or inward claw 303 is deflected to raise the jaw and disengages from the engaging holes 204, 203. On the other hand, for the first inward claws 302, as shown in FIG. 11, a rod A having rigidity such as a screwdriver is inserted from between the side edge 22a of the inner shell 2 and the side edge 32a of the outer shell 3. Then, the tip is brought into contact with the vicinity of the tip of the tongue piece 202c. In this state, when the rod A is rotated rearward with the side edge 22a of the outer shell 3 as a fulcrum, the tip of the rod A pushes the tongue piece 202c forward, and the tongue piece 202c is rotated. Is deformed in the thickness direction and its free end 202d is an inward claw
Move to a position where it cannot touch the 302. At that moment,
The inward claws 302 are deflected to raise the chin in accordance with the deformation of the outer shell 3, and come off from the engagement holes 202.

The outer shell 3 is detachably attached to the inner shell 2 as described above.
As shown in FIGS. 1, 2 and 4, a fixed shell 6 is arranged at a position where the opening 33 is closed. The fixed shell 6 includes a bottom wall 62 integrally including a cylindrical cover 61 surrounding the pillar 12, and a front wall connected to the front end of the bottom wall 62.
63, a rear wall 64 continuous to the rear end of the bottom wall 62, and this rear wall 6
4, a bottom wall 62 and a front wall 63 having side walls 65 integrally provided on both left and right edges of the boat, and the shape of the boat is a rectangle corresponding to the opening 33 in plan view. And the opening
The left and right side edges 33a, the front edge 33b, and the rear edge 33c of 33 are brought close to the side wall 65, the front wall 63, and the rear wall 64 of the fixed shell 6, respectively. In this embodiment, as will be described later, when the backrest 5 is tilted from the reference position shown by the solid line in FIG. 2 to the rest position shown by the imaginary line, the seat 4 looks outward from its front part. The lifting rear portion is moved forward while slightly sinking, and the front edge 33b and the rear edge 33c of the opening 33 of the outer shell 3 substantially follow the movement. Therefore, the front portion 6a and the rear portion 6b of the fixed shell 6 are molded by approximating the loci of the front edge 33b and the rear edge 33c of the opening 33, and the front edge
The 33b and the trailing edge 33c can be kept close to the stationary stationary shell 6. Specifically, the fixed shell 6
Shaft 1 with front wall 63 of front link member 106 attached to the upper pivot point of front link member 106
Almost corresponding to the movement of 08, the rear wall 64 is inclined so as to gradually rise toward the front, and the rear wall 64 is moved to the rear link member 10.
Almost corresponding to the movement of the shaft 111 attached to the upper pivot point of 7, it is inclined and curved so as to gradually descend toward the front. The fixed shell 6 is detachably attached to the lower surface of the support base 13 of the support unit 1 by using the bolt 66.

Further, in this chair, when the corner portion 33d at one longitudinal end of the opening 33 of the outer shell 3 is positioned near the center of the base 11 constituting the support unit 1 and the leg blades 11b are relatively rotated, The openings 33 are formed so that the tips of all the leg blades 11b can pass near the diagonal positions 33e of the openings 33.
And the dimensions of the leg blades 11b are set. Specifically, from the outer periphery of the central boss portion 11a of the base 11 (the root portion B of the two leg blades 11b) to the tip C of the leg blade 11b located on the opposite side thereof.
Is shorter than the diagonal length of the opening 33. Then, first, as shown in FIG. 12 (a), the corner 33d at one longitudinal end of the opening 33 is brought close to the outer periphery of the base end of the pedestal 12 standing upright at the center of the base 11, and When 11b is rotated relative to the outer shell 3, its corners
The tip of the first leg blade 11b passes through the diagonal position of 33d,
The leg blades 11b are located on the inner surface side of the outer shell 3. Next, as shown in FIG. 12 (b), when the leg blades 11b are relatively rotated with the vicinity of the corner 33d of the opening 33 being brought into contact with or close to the outer periphery of the central boss 11a of the base 11, The tips of the second leg blade 11b and the third leg blade 11b sequentially pass near the diagonal position 33e with respect to the corner portion 33d. After that, while gradually separating the corner portion 33d from the central boss portion 11a, the leg blades 11b are further rotated relative to each other to open the fourth and fifth leg blades 11b.
The outer shell 3 can be completely separated from the support unit 1. When mounting the outer shell 3, the above operation may be performed in reverse.

Further, in this chair, the manual operation part 120 is provided on the inner shell 2, and the seat height adjustment mechanism part 121 operated by the manual operation part 120 is provided on the support base 13 of the support unit 1. The manual operation part 120 includes a slider 122 in which concave grooves 122a provided on both sides are slidably fitted to a plate-shaped rail 123 integrally provided in the inner shell 2, and a handle 124 protruding from the lower surface of the slider 122. And the handle 124 is projected to the outside through the transparent window 125 provided in the outer shell 3. On the other hand, the mechanism portion 121 includes a rotating arm 126 having an intermediate portion rotatably supported by the shaft 114, and one rotating end 12 of the rotating arm 126.
6a is connected to the slider 122, and a transmission wire 127 is provided, and the other rotating end 126 of the rotating arm 126 is provided.
b is exposed to the upper end of the operating rod 12e of the gas spring 12a. Then, the handle 124 is operated to slide the slider 122 in the direction of the arrow X, and one of the rotating ends 126a of the rotating arm 126 is pulled by the transmission wire 127, whereby the rotating arm 126 rotates, and The operating rod 12e of the gas spring 12a can be pressed by the rotating end 126b. Then, this manual operation part
The outer shell 3 and the fixed shell 6 are 120 and the mechanical part 121.
Has a connection relation of any kind, and even if the outer shell 3 and the fixed shell 6 are removed, the full function can be exerted.

An exterior material 8 is stretched on the front side of the inner shell 2 with a cushion material 7 interposed therebetween. The peripheral portion of the exterior material 8 is guided to the back surface side of the inner shell 2 and fixed by a tacker or the like (not shown).

 Next, the operation of this chair will be described.

In the reference position shown by the solid line in FIGS. 1 and 2,
The backrest 5 is upright, and the seat 4 is held in the most retracted position. This reference posture is suitable for performing work and the like. When the user presses the backrest 5 backward from the reference posture, the balance member 101 rotates backward with the backrest 5 about the axis 102 serving 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 seat receiving 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 with the rotation of the balance member 101 is set to be greater than the degree to which 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 lowering the rear end, and reaches a resting posture indicated by imaginary lines in FIG.

At this time, the inner shell 2 and the outer shell 3 are both deformed, but a boundary portion 28 between the seat corresponding portion 21 and the backrest corresponding portion 22 of the inner shell 2 and a seat corresponding portion 31 and the backrest corresponding portion of the outer shell 3 are formed. Boundary 34 with 32
The left and right side edges 28a, 34a are set so that the degree of curvature in the forward direction is substantially zero, and the portions 28, 34 are close to each other. Therefore, the inner shell 2
The outer shell 3 is deformed relatively easily at the boundary portions 28 and 34 thereof while accommodating the elastic repulsive force and smoothly follows the tilting of the backrest 5. On the other hand, the backrest-corresponding portion 22 of the inner shell 2 and the backrest-corresponding portion 32 of the outer shell 3 are curved in the direction in which the left and right side edges 22a, 32a are forward, and moreover, the degree of curvature of the outer shell 3 is It is made larger than the bending degree of the inner shell 2.
Therefore, the inner shell 2 and the outer shell 3 form a three-dimensional hollow columnar shell structure,
With respect to a normal backrest load, the shells are appropriately deformed rearward mainly due to the vertical displacement of the shells within the allowable range.

Thus, in this chair with a backrest, the seat-corresponding part 2
The three-dimensional shell structure of the inner shell 2 and the outer shell 3 in which the parts 1 and 31 and the backrest corresponding parts 22 and 32 are respectively integrated is configured to bear the shape-retaining strength of the seat 4 and the backrest 5 as a whole. By appropriately selecting the degree of curvature of 2, 3 and the allowable sliding range between the shells 2 and 3, or the degree of proximity between the shells 2 and 3, the strength and easiness of deformation of each part can be set within a wide range. Can be set.

In addition, if the outer shell 3 is of an integral structure,
The outer shell 3 follows the movement of the seat 4, but since the fixed shell 6 attached to the support unit 1 is located in the opening 33 of the outer shell 3, the fixed shell 6 and the outer shell 3 If the positional relationship with the shell 3 is known, the gap can be reduced as much as possible.
Then, this clearance management is performed by the shell 6 fixed on one side.
Therefore, it is relatively easy, and as described above, the fixed shell 6 is approximated to the loci of the front edge 33b and the rear edge 33c of the opening 33 when the outer shell 3 operates with respect to the support unit 1. If the front portion 6a and the rear portion 6b of the above are molded, the gap between the shells 3 and 6 can be kept small at all times.

It should be noted that the present invention is not limited to the above-described embodiments, and the seat simply swings up and down with respect to the support unit, and the back support rod is pivotally attached to the support base of the support unit. The present invention can also be applied to a chair that has just been opened or a chair that does not have a back support rod.

[Effects of the Invention] As described in detail above, the present invention configures a three-dimensional structure for bearing the strength of the seat and the backrest by combining the integrally molded inner shell and the integrally molded outer shell. Therefore, it becomes easier to optimally set the rigidity and strength of each part, as compared with the conventional product in which the strength of the seat and the backrest is mainly supported only by the inner shell. That is, instead of providing a large number of complicated ribs or cutouts, the degree of curvature between the inner shell and the outer shell, the distance between the shells, or the relative misalignment range for mutual shells can be selected as appropriate. The strength and easiness of deformation can be variously set over a wide range. Therefore, it is possible to greatly expand the degree of freedom in design, and it is possible to obtain an effect that comfort in use such as cushioning property and durability can be reasonably improved.

In addition, since the moving shells are prevented from adjoining each other with a gap therebetween, a gap is formed only between the outer shell that may move and the fixed shell that is always stationary. It is easy to manage and the size of the gap can be minimized. In particular, in the case where the seat moves while tilting back and forth, and when the opening has a rectangular shape or a shape close to that, the seat of the fixed shell is approximated to the trajectory of the front edge and the rear edge of the opening of the outer shell. If the front part and the rear part are molded, the gap can be kept extremely small at all times.

Further, when the support unit includes a base having five general leg blades, the corner portion of the rectangular opening on the one end side in the longitudinal direction is positioned near the center of the base to move the leg blades. If the dimensions of the opening and leg blades are set so that the tips of all leg blades can pass near the diagonal position of the opening by rotating, the outer shell will have a relatively small opening. Although only provided, only the outer shell can be completely removed without disassembling the support unit. Therefore, it becomes possible to easily perform maintenance and inspection of the inside.

In addition, if the manual operation part and the mechanism part are provided on the inner shell and the support unit side and are separated from the outer shell and the fixed shell, the manual operation part can be operated even when the outer shell and the fixed shell are removed. The mechanical section can be operated in a state similar to that in use, and the operating state can be directly observed. Therefore, not only can the outer shell and the fixed shell be easily attached and detached, but also the function can be confirmed by actually operating the mechanism section with the outer shell and the fixed shell removed. Therefore, the adjustment of the mechanism portion can be easily performed, and the assembling and maintenance work can be simplified.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a partially cutaway side view, FIG. 2 is a side sectional view showing the inside, and FIG. 3 is a partially cutaway plan sectional view, FIG. FIG. 5 is an exploded perspective view, FIG. 6 is a partial front view showing a portion near the upper edge of the inner shell,
FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6, FIG. 8 is an explanatory view of the action corresponding to FIG. 7, FIG. 9 is a partial front view showing a portion near the side edge of the inner shell, and FIG. FIG. 9 is a sectional view taken along the line XX in FIG. 9, FIG. 11 is an operation explanatory view corresponding to FIG. 10, and FIGS. 12 (a) and 12 (b) are operation explanatory views when the outer shell is detached. 1 ... Support unit, 2 ... Inner shell 3 ... Outer shell, 4 ... Seat 5 ... Backrest, 6 ... Fixed shell 6a ... Front part, 6b ... Rear part 11 ... Base, 11a ... Center Boss 11b …… Leg blade, 12 …… Pedicle 13 …… Support base, 21 …… Seat corresponding part 22 …… Backrest corresponding part 31 …… Seat corresponding part 32 …… Backrest corresponding part 33 …… Opening part, 33b …… Leading edge 33c …… Trailing edge, 33d …… Corner part 33e …… Diagonal position, 120 …… Manual operation part 121 …… Mechanical part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masamitsu Miyashita, 137, Miyata-mura, Kamiina-gun, Nagano Prefecture Takano Co., Ltd. ) Inventor Yoshiyoshi Katagiri, 137 Miyata-mura, Kamiina-gun, Nagano Prefecture Takano Co., Ltd. (56) References Japanese Patent Publication 59-24805 (JP, B2) Japanese Patent Publication 60-33483 (JP, B2)

Claims (6)

[Claims] 1. An L-shaped inner shell formed by integrally molding a seat-corresponding portion and a backrest-corresponding portion, and a side view L formed by integrally molding a seat-corresponding portion having an opening and a backrest-corresponding portion. It comprises a character-shaped outer shell and a fixed shell which is fixed to a support unit which supports the seat and is arranged at a position that closes the opening of the outer shell, and makes the outer shell closely adhere to the inner shell. A chair with a backrest, which is characterized by being attached without any effort. 2. A chair with a backrest according to claim 1,
A chair with a backrest, characterized in that the front and rear portions of the fixed shell are formed so as to approximate the loci of the front edge and the rear edge of the opening when the outer shell operates with respect to the support unit. 3. The chair with a backrest according to claim 1, wherein at least upper half portions of the backrest corresponding portions of the inner shell and the outer shell are curved in a direction in which both left and right side edges are forwardly projected. Make the degree of bending larger than the degree of bending of the inner shell,
A chair with a backrest, characterized in that the inner shell and the outer shell are connected to the backrest corresponding portions in the vicinity of both side edges so as to be relatively movable in the vertical direction by a predetermined distance. 4. The chair with a backrest according to claim 3,
The inner shell and the outer shell are each formed with a non-curved portion having a degree of curvature of substantially zero near the base end of the backrest corresponding portion, and the inner shell and the outer shell are brought close to each other near the non-curved portion. A chair with a backrest. 5. The chair with a backrest according to claim 1, 2, 3 or 4, wherein the outer shell is removably attached to the inner shell, and the support unit is provided with five leg blades radially. The outer base is provided with a base, a pedestal standing upright in the center of the base, and a support base portion provided at an upper end of the pedestal and accommodated between an inner shell and an outer shell. When the openings of the shell are rectangular and the corners on one end side in the longitudinal direction of the openings are located near the center of the base and the leg blades are rotated, the tips of all the leg blades are the opening portions. A chair with a backrest characterized in that the dimensions of the opening and leg blades are set so that the chair can pass near the diagonal position. 6. A chair with a backrest according to claim 1,
The outer shell is detachably attached to the inner shell, the fixed shell is detachably fixed to the support unit, and the manual operation part and the mechanism part operated by the manual operation part are attached to the inner shell and the support unit side. A chair with a backrest, which is provided separately from the outer shell and the fixed shell.