JPH0771533B2 - Chair with backrest - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a chair with a backrest in which a seat and a backrest are integrally formed by using an inner shell.

[Prior Art] Conventionally, as this type of chair with a backrest, a seat and a backrest are integrally configured by using an L-shaped inner shell in a side view formed by integrally molding a seat-corresponding portion and a backrest-corresponding portion,
The back support rod extended from the support unit and the horizontal bracket fixed to the upper bridge of this back support rod are placed on the back side of the backrest corresponding portion of the inner shell, and the backrest corresponding portion is fixed to the horizontal bracket. What is worn is known.

By the way, in such a chair, in order to improve the feeling of holding to the back and to secure the rigidity of the backrest, the backrest corresponding portion of the inner shell and the lateral brackets are arranged such that the left and right edges of the backrest are in front of the central portion. It is curved in the direction that it goes out. In the conventional case, both the side edge portion and the central portion of the backrest corresponding portion are fixed to the lateral bracket.

[Problems to be Solved by the Invention] However, the backrest-corresponding portion of the inner shell curved in such a direction exhibits particularly high rigidity against warp deformation in a direction in which the upper end side is tilted backward. It will be. That is, this inner shell deforms following the tilting motion of the back support rod mainly due to the deformation of the boundary portion between the seat-corresponding portion and the backrest-corresponding portion, and it is difficult to impart elasticity to the backrest itself. . For this reason, even if the backrest is tilted backwards and an exercise is performed such that the back is further warped, the backrest is not deformed. Therefore, there is a problem that the resting posture is in a limited range.

The present invention aims to solve such problems.

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

That is, as shown in FIGS. 1 and 2, the chair with a backrest according to the present invention has an L-shaped side view inner shell formed by integrally molding a seat-corresponding portion (21) and a backrest-corresponding portion (22). Seat (4) and backrest (5) using (2)
And a back support rod (104) extending from the support unit (1) and a laterally long bracket (119) fixed to the upper end of the back support rod (104), and the inner shell (2) The backrest corresponding part (22) of the inner shell (2), which is arranged on the back side of the backrest corresponding part (22).
Is curved so that both left and right edges (22a) are located in front of the center, and a slit (29) intersecting with the horizontally long bracket (119) is provided near the center,
The inner shell (2) is characterized in that only the portions (22d) near both side edges are fastened to the horizontally long bracket (119) via the fasteners (27).

[Operation] According to such a configuration, when the rearward load is not applied to the inner shell (2), as shown in FIG. 2 (a), the backrest corresponding portion (22) is originally formed. It maintains its curved shape. On the other hand, when a rearward pressing force is applied to a portion of the backrest corresponding portion (22) located above the horizontal bracket (119), the backrest corresponding portion (22) is shown in FIG. 2 (b). As shown in, the left and right side edges (22a) are deformed so that the degree of bending in the forward direction is reduced, and the upper half portions thereof are warped rearward. That is, in the backrest corresponding portion (22), only the side edge vicinity portion (22d) is fixed to the horizontally long bracket (119), and the intermediate portion is released from the horizontally long bracket (119). Therefore, when a rearward load is applied to the upper portion, the middle portion of the upper portion is deformed away from the horizontally long bracket (119), and the rigid shape due to the bending is broken, and the rearward portion is relatively easily warped. In addition, the backrest corresponding portion (22) of the inner shell (2) can smoothly change the degree of curvature of the backrest corresponding portion (22) by providing a slit (29) intersecting with the horizontal bracket (119). This is because the slit (29) can absorb the compression of the member when the degree of bending decreases, and the presence of this slit (29) makes the backrest corresponding part (22) act as a so-called surface spring. To do. Therefore, it becomes easy to give appropriate elasticity to the backrest (5) itself as a chair.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 3 to 13.

The chair with a backrest according to this embodiment is, as shown in FIG.
On the support unit 1, a seat 4 and a backrest 5 that are integrally formed by using an inner shell 2 and an outer shell 3 are arranged.

As shown in FIG. 3, the support unit 1 includes a base 11 formed by radially projecting leg blades, a pedestal 12 standing upright at the center of the base 11, and a top end of the pedestal 12 connected to each other. The support base 13 is provided. The balance members 101 are axially attached to both sides of the support base 13. Balance member 101
As shown in FIGS. 4 and 5, is an elongated plate-like member extending in the front-rear direction, and an intermediate portion thereof is pivotally attached to the support base 13 via a shaft 102. Then, the rear ends of the left and right balance members 101 are rigidly attached to each other by a connecting fitting 103,
The back support rod 104 extends rearward and upward from the connecting portion. A seat receiving frame 105 is arranged on the support base 13. The front end of the seat receiving frame 05 is connected to the front end of the support base 13 via the front link member 106, and the rear end thereof is connected to the rear end of the both balance members 101 via the rear link member 107. is doing. That is, the upper pivoting ends of the left and right front link members 106 are pivotally attached to the front end portions of the seat receiving frames 105 via the shafts 108, and the lower pivoting ends of the front link members 106 are pivotally attached to the support base portion 13. It is pivoted through 109. Further, the upper pivoting ends of the left and right rear link members 107 are pivotally attached to the rear end portion of the seat receiving frame 105 via shafts 111, and the lower pivoting ends of the rear link members 107 are attached to the rear of the balance member 101. It is pivotally attached to the end through a shaft 112. Then, a long hole 1 extending in the front-rear direction is provided at the front end portion of the both balance members 101.
13 are provided respectively, and the long holes 113 are provided in the front link member 1
A shaft 110 provided at the rear pivot point of 06 is slidably connected to the shaft 110. 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 of the auxiliary spring 116 can be adjusted by changing the locking position.

Then, as shown in FIG. 4, FIG. 5 and FIG. 7, horizontal brackets 118 and 119 are fixedly mounted on the front end of the seat receiving frame 105 and the upper end of the back support rod 104, respectively. , 119 are attached to the inner shell 2. The horizontally long bracket 119 fixed to the upper end of the back support rod 104 is curved in a direction in which the left and right ends 119a are located in front of the central portion 119b.

As shown in FIGS. 4 to 7, the inner shell 2 is an L-shaped side view formed by integrally forming a seat-corresponding portion 21 and a backrest-corresponding portion 22, and is elastically deformable such as polypropylene. Made of synthetic resin. Seat corresponding part 21
Has a shape in which the left and right side edges 21b and the central portion are slightly raised, and a nut 23 is fixed to the front portion of the side edge vicinity portion 21s. Then, the horizontal bracket 118
The inner shell 2 is attached to the seat receiving frame 105 by means of bolts 24 that are passed through the vicinity of both ends and screwed into the nut 23. It should be noted that the inner shell 2 of this embodiment is
A nut 25 is also fixed to the front portion of the central portion of the inner shell 2, and the mounting strength of the inner shell 2 is enhanced by an auxiliary bolt (not shown) which penetrates the front end portion of the seat receiving frame 105 and is screwed to the nut 25. As shown in FIG. 4, the backrest-corresponding portion 22 has a shape in which the left and right side edges 22a are curved in the forward direction, and the nuts 26 are provided in the side edge neighboring portions 22d at the substantially same height position as the so-called backrest point. Is fixed. Then, the inner shell 2 is connected to the back support rod 104 by screwing a bolt 27, which is a fastening tool penetrating the vicinity of both ends of the horizontal bracket 119, to the nut 26. 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 in the forward direction set to substantially zero, and has a semicircular arc shape in side view. However, it is curved so that it bulges backward.
Then, the boundary portion 28 is provided with two parallel slits 29 extending vertically. The lower end 29 of these slits 29
The a side extends to the rear of the seat-corresponding portion 21,
The upper end 29b side extends to a position higher than the backrest point of the backrest corresponding portion 22, and the portion 22b located between these slits 29 is projected forward. Thus, these slits 29 are provided so as to intersect with the horizontally long bracket 119.

The cushion material 7 is provided on the upper surface 2a side of the inner shell 2.
The exterior material 8 is stretched through the. The cushion material 7 is
For example, it is a molded product made of urethane resin or the like, and the exterior material 8
Is made by attaching a urethane sheet or the like to the inner surface of the cloth. The cushion material 7 is directly attached to the inner shell 2. The peripheral portion of the exterior material 8 is guided to the lower surface 2b and the back surface 2c side of the inner shell 2, and is fixed to the inner shell 2 with a large number of tackers while a predetermined tension is applied to the entire exterior material 8. I'm wearing it.

On the other hand, 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, as shown in FIGS. Made of possible synthetic resin. The seat-corresponding portion 31 has a spherical shape that bulges downward, and has a rectangular opening 33 that extends in the front-rear direction in the center thereof.
The backrest-corresponding portion 32 has a shape in which the left and right side edges 32a are curved in a forward direction, and the degree of curvature is set to increase as the backrest point is approached from the upper edge 32b. The degree of curvature of the outer shell 3 near the backrest point is made larger than the degree of curvature of the inner shell 2 at the same cross-section position. In addition,
A boundary portion 34 of the seat-corresponding portion 31 and the backrest-corresponding portion 32 of the outer shell 3 has a degree of bending in a direction in which the left and right side edges 34a are forwardly set to substantially zero, and has a semi-arcuate shape in a side view. It is curved so that it bulges backward. Then, a portion of the outer shell 3 near the base end of the backrest corresponding portion 32, that is, the upper portion of the boundary portion 34 is placed on a portion of the inner shell 2 near the base end of the backrest corresponding portion 22, that is, the upper portion of the boundary portion 28. Are approaching.

The attachment structure of the outer shell 3 to the inner shell 2 is as follows. First, the front edge portion 31f and the side edge neighboring portion 31s of the seat corresponding portion 31 of the outer shell 3 are screwed to the front edge portion 21f and the side edge neighboring portion 21s of 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 8 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 by a claw. Specifically, as shown in FIGS. 6 and 8 to 13, a side view L is formed on the side edge vicinity portion 32c of the outer shell 3.
An upward claw 301 that bends in a letter shape, 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 arranged at predetermined intervals from the bottom. In addition to projecting, a downward claw 304 having an undercut portion on the lower side is integrally projected at the upper edge vicinity portion 32d. Also, the claws 301, 302, 30 of the inner shell 2
Engagement holes 201, 202, 203, 204 are formed in the portions corresponding to 3, 304. Then, the upward claws 301 are engaged with the upper edge portions of the corresponding engaging holes 201 so as to be movable in the vertical direction by a required amount, and the inward claws 302 and 303 are engaged with the corresponding engaging holes 20.
2, 203 are engaged with the inner edge portions 202a, 203a of the opening edge, and the downward claw 304 is engaged with the lower edge portion 204a of the opening edge of the corresponding engaging hole 204 by utilizing elastic deformation of the members. . In addition,
The first inward claw 302 is a straight wall-shaped member that extends in the vertical direction, and corresponds to the opening edge inner portion 202a of the engagement hole 202.
Is formed in a straight line, and the inward claw 302 can slide vertically with respect to the engagement hole 202 even in the engaged state. Then, a tongue piece 202c deformable in the thickness direction is integrally projected from the opening edge outer side portion 202b of the engagement hole 202, and the free end 202d of the tongue piece 202c is engaged with the opening edge inner side portion 202a. The inward claw 302 is brought into contact with the outer surface of the inward claw 302. The second inward claw 303 has a half-moon shape similar to the downward claw 304, but the second inward claw 303 is also in the engagement hole 203 so that the second inward claw 303 can move slightly in the vertical direction in the engaged state. The dimensions of are set. The engaging depth and engaging direction of these claws 301, 302, 303, 304 and the corresponding engaging holes 201, 202, 203, 204 are set so as not to come off under normal use conditions. However, the engagement state can be released by applying a releasing operation from the outside. That is, first, regarding the downward claw 304 and the second inward claw 303, as shown in FIG. 10, the rod D having rigidity such as a screwdriver is attached to the upper edge 22 of the inner shell 2.
c or side edge 22a and upper edge 32b or side edge 32a of outer shell 3
When it is inserted between the outer shell 3 and the outer edge of the outer shell 3 and elastically deformed by twisting the upper edge 32b or the side edge 32a backward, the corresponding downward claw 304 or inward claw 303 raises the jaw. It is deflected and disengaged from the engagement holes 204, 203. On the other hand, for the first inward claw 302, as shown in FIG. 13, a rod D having rigidity 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. Then, the tip is brought into contact with the vicinity of the tip of the tongue piece 202c. In this state, when the rod D is rotated rearward with the side edge 22a of the outer shell 3 as a fulcrum, the tip of the rod D pushes the tongue piece 202c forward, and this tongue piece 202c Is deformed in the thickness direction and its free end 202d is an inward claw
Move to a position where it cannot touch 302. At that moment,
The inward claw 302 is deflected so as to raise the jaw according to the deformation of the outer shell 3 and disengages from the engagement hole 202.

As described above, the inner shell 2 and the outer shell 3
A fixed shell 6 is provided at a position where the opening 33 of the outer shell 3 is closed, as shown in FIGS. 3, 4, and 6. The fixed shell 6 is detachably attached to the lower surface of the support base 13 of the support unit 1 using bolts.

Next, the operation of this chair will be described.

In the reference posture shown by the solid line in FIGS. 3 and 4, the backrest 5 stands up and the seat 4 is held in the rearmost retracted position. This standard posture is suitable for performing work and the like. When the user presses the backrest 5 rearward with his / her back from this reference posture, the balance member 101 pivots rearward with the backrest 5 around the shaft 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 larger than the degree to which the shaft 111 at the upper pivot point thereof rises due to the rotation of the rear link member 107. Therefore, the seat 4 apparently moves forward while gradually retracting the rear end, and reaches the resting position shown by the imaginary line in FIG.

From this state, when the user further performs an operation of bending the upper body backward, a rearward load is further exerted on the upper end 5a side of the backrest 5, and the backrest corresponding portion 22 of the inner shell 2 moves backward. It will be elastically deformed as it warps. That is, the backrest corresponding portion 22 is a side edge vicinity portion.
Only 22d is fixed to the horizontally long bracket 119, and a portion 22b located inside the slit 29 and a portion 22e near the outside of the slit 29 are opened from the horizontally long bracket 119.
Therefore, when a rearward load is applied to the upper portion thereof, the portions 22b and 22e are deformed to separate from the horizontally long bracket 119 and relatively easily warped rearward, and the slit 29 as described in the section of the action. In combination with the existence of, the backrest corresponding portion 22 exerts a function as a surface spring. By the way, in this embodiment, when the upper portion of the backrest corresponding portion 22 of the inner shell 2 warps backward, the outer shell 3
However, the backrest 5 is further set to cause a positional displacement downward with respect to the inner shell 2. However, when the outer shell 3 reaches the positional displacement limit point, the rigidity of the backrest 5 rapidly increases, and the inner shell beyond The deformation of 2 is suppressed.

In the embodiment described above, the upper portion of the portion 22b located between the slits 29 of the inner shell 2 has a high rigidity, and a portion 119c for backing up this portion 22b is provided at the center of the horizontally long bracket 119. If the backrest-corresponding portion 22 of the inner shell 2 is warped rearward with the horizontally long bracket 119 as a fulcrum, that portion 2 is provided.
Although 2b is made to project relatively to the front, the present invention can be applied to a device which does not have such a device. The number of slits according to the present invention is not limited to two and may be one or three or more.

Further, the fastening device for fastening the inner shell to the horizontally long bracket is not limited to the illustrated embodiment, and for example, a pin may be provided so as to project from the inner shell side and the pin may be passed through the horizontally long bracket. Various modifications can be made without departing from the gist of the present invention, such as mounting a retaining member on the through end.

Furthermore, the present invention can be applied to, for example, a chair in which the seat simply swings with respect to the support unit, a chair in which the back support rod is pivotally attached to the support unit so as to be able to tilt backward, and the like. .

[Effects of the Invention] As described in detail above, the present invention is devised in the fastening position of the inner shell and the horizontally long bracket, and by providing a slit in the backrest corresponding portion of the inner shell, the surface corresponding to the backrest corresponding portion is provided. Since the spring function is exerted, it is possible to give the backrest appropriate elasticity as a chair without complicating the structure. Therefore, when resting by lying down on the backrest, the upper body can be bent and stretched to naturally take a wider variety of resting postures, which can greatly improve comfort during use. Can be provided.

[Brief description of drawings]

1 and 2 are drawings for clarifying the configuration of the present invention, and FIG. 1 is a schematic perspective view, FIG. 2 (a),
(B) is a schematic plan cross-sectional view showing a fastening position of the inner shell and the horizontally long bracket. 3 to 13 show one embodiment of the present invention, FIG. 3 is a partially cutaway side view, FIG. 4 is a side sectional view showing the inside, and FIG. FIGS. 6, 6 and 7 are exploded perspective views, FIG. 8 is a partial front view showing the vicinity of the upper edge of the inner shell, FIG. 9 is a sectional view taken along the line AA in FIG. 8, and FIG. FIG. 11 is a partial front view showing the vicinity of the side edge of the inner shell, FIG. 12 is a sectional view taken along the line BB in FIG. 11,
FIG. 13 is an operation explanatory view corresponding to FIG. 2 ... Inner shell, 4 ... Seat 5 ... Backrest, 21 ... Seat-corresponding portion 22 ... Backrest-corresponding portion 22a ... Side edge, 22d ... Side edge vicinity 27 ... Fastener (bolt) 29 ... Slit, 104 ... Back support rod 119 ... Horizontal bracket

 ─────────────────────────────────────────────────── ─── 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.

Claims (1)

[Claims] 1. A back support rod extending from a support unit in which a seat and a backrest are integrally formed by using an L-shaped inner shell in side view formed by integrally forming a seat corresponding portion and a backrest corresponding portion. A chair with a backrest, in which a horizontally long bracket fixed to the upper end of this back support rod is arranged on the back side of the backrest corresponding portion of the inner shell, and the backrest corresponding portion of the inner shell has the right and left side edges more than the center. It is curved so as to be positioned in the front, and a slit intersecting with the horizontally long bracket is provided near the center thereof, and only the portions near both side edges of this inner shell are fastened to the horizontally long bracket through fasteners. Chair with backrest characterized by being.