JP5461877B2 - Chair backrest structure - Google Patents

Description

  The present invention relates to a backrest structure of a chair, in which a back frame is provided with a cushion body and elastic expansion / contraction means that can bend the cushion body in the front-rear direction.

  As the backrest structure of such a chair, a plurality of upper and lower S-shaped springs are stretched at the center of the frame-shaped back frame, and the front surface of the S-shaped spring and both sides and the upper portion of the back frame are cushioned. Some are covered with a body (see, for example, Patent Documents 1 and 2).

Japanese Utility Model Publication No. 58-24257 Japanese Utility Model Publication No. 64-49144

In the backrest structures described in Patent Documents 1 and 2, since the back frame has a frame shape in which the opposing surfaces of the upper end portions of the left and right side frames are connected by a support. The strength of the back frame is great.
However, if the back frame has a frame shape and the opposing surfaces of the upper ends of the side frames are connected by a support, the cushion attached to the front surface of the back frame can be greatly bent backward. Since only the portion of the S-shaped spring below is provided and the upper part of the cushion body is difficult to bend backward, a comfortable backrest feeling cannot be obtained.
Moreover, since the front surface of the back frame is a substantially flat surface, the positioning of the cushion body is troublesome and cannot be mounted stably.

  The present invention has been made in view of the above problems, and by ensuring that the upper portion of the cushion body is easily bent rearward while ensuring the strength of the back frame, a comfortable backrest feeling can be obtained and the back can be obtained. An object of the present invention is to provide a chair backrest structure in which a cushion body can be positioned and stably mounted on a frame.

According to the present invention, the above-mentioned problems are solved as follows.
(1) In a backrest structure of a chair that supports a cushion body by a back frame that stands up from a rear end portion of a seat body, the back frame is divided into a lower frame that faces in the left-right direction, and both side end portions of the lower frame A pair of left and right side frames erected on the upper surface, and a back plate connected to the lower opposing surface of the upper surface of the lower frame and the left and right side frames above the back plate of the side frames. The front and rear surfaces of the left and right side frames are substantially concave, and elastic expansion / contraction means are provided between the opposite surfaces of the left and right side frames, and at least the elastic expansion / contraction means and the back plate are provided. Cover with cushion body.

  With such a configuration, the back frame includes a lower frame facing in the left-right direction, a pair of left and right side frames erected on the upper surfaces of both end portions of the lower frame, an upper surface of the lower frame, and left and right side portions. The back plate connected to the lower facing surface of the frame has a substantially concave shape when viewed from the front, so that the strength of the lower portion of the back frame is large, and the space between the upper and lower facing surfaces of the left and right side frames is between Since it is released and elastic expansion and contraction means are provided on this part, when the back is put on the cushion body, the upper part effectively bends backward than the back plate in the backrest, so a comfortable backrest feeling can get.

(2) In the above item (1), the upper portions of the left and right side frames are curved in an arc shape obliquely upward and rearward, and at least two places below the curved portion and between the opposing surfaces of the side frames. An elastic expansion / contraction means is provided.

  With such a configuration, when the back is put on the cushion body, the upper half of the backrest can be bent rearward and obliquely rearwardly downward, so that a more comfortable backrest feeling can be obtained.

(3) In the above item (1) or (2), the front and rear dimensions and the left and right dimensions of the left and right side frames are gradually increased toward the lower side.

  With such a configuration, the rigidity of the lower half of the back frame is increased, the vicinity of the waist of the seated person is stably supported, and the back part is comfortably supported by the bending effect of the upper half, Sitting comfort is improved.

(4) In any one of the above items (1) to (3), by connecting the back plate to the lower frame and the rear end portions of the both side frames, the cushion is placed on the upper surface of the lower frame in front of the back plate. A recessed step is formed into which the lower part of the body is fitted.

  With such a configuration, the cushion body can be positioned on the back frame in the vertical and horizontal directions and stably mounted by fitting the lower portion of the cushion body into the recessed stepped portion.

(5) In any one of the above items (1) to (4), the fitting protrusion is protruded downward on the lower surface of the lower frame, and the fitting protrusion is provided at the rear end of the seat body. The back frame is supported by the rear end portion of the seat body by fitting into the joint hole.

  With such a configuration, the lower end portion of the back frame whose strength at the lower portion is increased can be firmly and well supported by the rear end portion of the seat body.

  According to the present invention, when the back is put on the cushion body, the upper half of the backrest effectively bends backward, so that a comfortable backrest feeling can be obtained.

It is a front view of the connection chair to which the present invention is applied. Similarly, it is a side view. Similarly, it is a partially cutaway enlarged front view. It is the IV-IV line vertical side view of FIG. Similarly, it is a VV line expansion vertical side view. It is a perspective view before connection of a backrest attachment member and a back frame. Similarly, it is a front view. Similarly, it is a side view. It is the perspective view which looked at the back frame from back.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front view of a chaise lounge installed in a waiting room or the like to which the present invention is applied. FIG. 2 is a side view of the chaise lounge. The left and right ends of the leg 1 are fixed to a square reed 2, the same four-legged chair 3 attached to the upper surface thereof, and the lower end of the reed 2 on both sides of each chair 3. Are provided with a plurality of armrests 4 fixed thereto.

  As shown in FIG. 3 which is a partially cutaway enlarged front view and FIG. 4 which is a cross-sectional view taken along line IV-IV in FIG. 3 (the same structure is shown, only the chair on the right end side is shown). A seat body 5 and a backrest 6 are provided. The seat body 5 has a rectangular seat frame 7 made of plywood or synthetic resin, and a right and left dimension fixed to the upper surface of the rear end portion thereof is substantially equal to that of the seat frame 7. The backrest mounting member 8 made of synthetic resin and the cushion body 9 fixed to the upper surfaces of the seat frame 7 and the backrest mounting member 8 so as to cover the entire surface except for the lower surfaces thereof. .

The seat frame 7 is secured to the upper ends of a pair of left and right brackets 10 and 10 facing the front and rear direction welded to the horizontal flange 2 by being embedded in the bolts 11 and the seat frame 7 to be prevented from rotating. It is fixed by a female screw cylinder 12.
As shown in FIG. 5, the both sides on the front side of the backrest mounting member 8 are bolts fitted from above into a stepped hole 14, which will be described later, embedded in a female screw cylinder 12 embedded in the rear portion of the seat frame 7 and prevented from rotating. 11 is fixed by screwing together. Similarly, both side portions on the rear side are fixed to a rear end portion of the seat frame 7 together with a back frame 21 described later (details will be described later).

  As shown in FIGS. 6 to 8, the backrest mounting member 8 has a substantially triangular side surface and a rear end portion of the cushion body 9 at the center of the front inclined surface 8 a inclined obliquely forward and downward. A recess 13 into which the bolt 11 is inserted is formed, and stepped holes 14, 14 into which the bolts 11 are fitted are formed in the front inclined surfaces 8 a on both sides sandwiching the recess 13. A bifurcated locking piece 15 for locking a retracting member (not shown) for fixing a part of the upper surface on the rear side of the cushion body 9 downward is provided on the upper surface of the front end portion of the recess 13. A plurality of left and right protrusions are provided.

  The rear inclined surface 8b inclined obliquely rearward and downward of the backrest mounting member 8 has a forward-facing U-shape in plan view comprising a rear standing piece 16a facing in the left-right direction and left and right side standing pieces 16b, 16b facing in the front-rear direction. An upward fitting portion 16 is vertically formed, and the inner space of the upward fitting portion 16 is partitioned by partition pieces 17 and 17 that are separated from each other in the left and right directions. A pair of left and right rectangular fitting holes 18, 18 that are long and open upward are formed. On both sides of the rear inclined surface 8 b facing the left and right fitting holes 18, 18, bottomed fitting holes 19, 19 having the same shape as the fitting hole 18 communicate with both the fitting holes 18. (See FIG. 5). Note that the front and rear dimensions of the rear inclined surface 8b are larger than the front and rear dimensions of the fitting holes 18 and 19 so as to be in contact with the lower surface of the back frame 21 described later.

  On the lower surface of the rear end portion of the backrest mounting member 8, a projecting piece 20 having a vertical dimension substantially equal to the plate thickness of the seat frame 7 is projected downward, and the front surface of the projecting piece 20 is in contact with the rear end of the seat frame 7. By making contact, the backrest mounting member 8 can be positioned in the front-rear direction with respect to the seat frame 7 (see FIGS. 5 and 6).

As shown in FIGS. 3 to 5, the backrest 6 is covered with a skin material 22 a that is covered from above so as to cover the entire surface except the back frame 21 made of synthetic resin and the lower end portion thereof. And a bag-like cushion body 22.
As shown in FIGS. 6 to 8, the back frame 21 is composed of a lower frame 23 that has a lateral dimension slightly smaller than that of the backrest mounting member 8 and faces in the left-right direction, and upper surfaces of both side portions of the lower frame 23. A pair of left and right side frames 24, 24 that stand more vertically and a lower half space between both side frames 24 are closed so as to be integrally connected to the opposing surface and the upper surface of the lower frame 23. The front frame of the lower frame 23 and the left and right side frames 24 has a substantially upward U-shape, and the entire shape of the back frame 21 is substantially the same as the front view with the upper half part released. As a concave shape.

As shown in FIGS. 6 to 9, the lower frame 23 includes a vertical rear surface plate 23 a that faces in the left-right direction and left and right side plates 23 b, 23 b that face in the diagonally up-down direction. It is inclined in the same direction as the rear inclined surface 8b.
The left and right dimensions and the front and rear dimensions of the lower frame 23 are slightly larger than the dimensions between the outer surfaces of the left and right side frames 24 and 24 and the front and rear dimensions of the lower ends of the both side frames 24, respectively. On the upper surface of the peripheral edge portion, a step surface 23c is formed so that the lower end of the cushion body 22 excluding the skin material 22a contacts and is positioned (see FIG. 5). Further, the front-rear dimension of the lower frame 23 is larger than the front-rear dimension of the fitting protrusion 27 described later.

  In the interior surrounded by the rear plate 23a and the left and right side plates 23b, an upward fitting recess 26 is formed that can be fitted to the upper fitting portion 16 of the backrest mounting member 8 from above. A pair of left and right fitting holes 18 formed in the upward fitting portion 16 and the rear inclined surface 8b of the backrest mounting member 8 are formed in the center of the lower surface of the lower frame 23 in the front-rear direction inside the concave portion 26. , 19, which are complementary to them and have a rectangular shaft-shaped fitting protrusion 27, 27 that is complementary to them.

As shown in FIG. 5, between the opposing surfaces of the fitting protrusion 27 and the rear plate 23a, an upward concave hole into which the rear standing piece 16a in the upward fitting portion 16 of the backrest mounting member 8 is fitted. 28 is formed.
Further, the end of the skin material 22a of the cushion body 22 is fitted to the lower surface of the peripheral edge of the lower frame 23, that is, the lower surface of the front end portion of the lower frame 23, and the lower end surfaces of the rear surface plate 23a and the side surface plates 23b. The locking groove 29 for engaging with each other is formed continuously (see FIGS. 5 and 7).

  The upper portions of the left and right side frames 24, 24 are curved in an arc shape so as to face obliquely upward, and the front and rear dimensions on the lower side from the curved portion are gradually increased toward the lower side. In addition, by curving the lower opposing surfaces in an arc toward the inside, the left and right dimensions of the lower half of both side frames 24 are gradually increased downward. Because of such a structure, the rigidity of the lower half of the side frames 24, that is, the bending strength in the front-rear and left-right directions is increased, and the strength of the entire back frame 21 can be increased.

  The back plate 25 is connected to the rear end portion of the lower frame 23 and the left and right side frames 24. As shown in FIGS. 4 and 6, the back plate 25 is disposed in front of the back plate 25 and on the upper surface of the lower frame 23. A recessed step portion 30 is formed for positioning the body 22 in the vertical and horizontal directions and mounting it stably. Note that a plurality of ribs 31 facing in the vertical direction are provided on the rear surface of the upper half of the back plate 25 so as to protrude in the left-right direction, thereby increasing the strength of the back plate 25.

  S-shaped springs 32 and 32 as elastic expansion / contraction means are provided between the upper ends of the arcuate curved portions of the left and right side frames 24 and the slightly upper facing surfaces of the back plate 25, and both ends thereof are disposed on both sides. The upper and lower locking members 33 and 33 projecting inwardly on the inner surface of the part frame 24 are stretched so as to bend in the front-rear direction.

Next, a procedure for connecting the backrest 6 to the seat body 5 will be described.
First, as shown in FIG. 4, the back frame 21 is covered with a cushion body 22 from above, and as shown in the enlarged view of FIG. 5, the end portion of the skin material 22 a is formed on the lower surface of the peripheral portion of the lower frame 23. It is inserted into the engaging groove 29 and engaged. At this time, since the recessed step portion 30 and the step surface 23c are formed on the upper surface of the lower frame 23 in front of the back plate 25 and the peripheral edge portion of the lower frame 23, the cushion body 22 is It can be easily positioned in the vertical and horizontal directions and can be mounted stably.

  Next, as shown in FIGS. 5 and 6, the lower frame 23 of the back frame 21 is inserted into the pair of left and right fitting holes 18 and 19 of the backrest mounting member 8 whose front end is fixed to the rear upper surface of the seat frame 7. A pair of left and right fitting projections 27, 27 projecting downward are fitted from above. At this time, the rear standing piece 16a of the upward fitting portion 16 is also fitted into the concave hole 28 formed between the opposing surfaces of the fitting protrusion 27 and the rear plate 23a.

  Next, both the left and right side portions of the rear end portion of the seat frame 7, the bottom walls of the left and right fitting hole 19 forming portions of the backrest mounting member 8, and the left and right fitting projections 27 are provided in the vertical direction. A long bolt 35 that faces in the up-down direction is inserted into the bolt insertion hole 34 from below, and the upper end of the bolt 35 protrudes into the rear opening 36 formed in the lower end of the side frame 24. Then, a metal plate 37 press-fitted into the lightening hole 36 is passed through and screwed into a nut 38 welded to the upper surface of the metal plate 37 and tightened.

  Thereby, the lower end part of the back frame 21 and the backrest attachment member 8 are fastened together and firmly connected to the rear end part of the seat frame 7. In particular, a relatively long fitting protrusion 27 protruding from the back frame 21 is fitted into the fitting holes 18 and 19 of the backrest mounting member 8 and protruded from the upper surface of the backrest mounting member 8. In the upward fitting portion 16, the rear standing piece 16a facing in the opposite direction to the fitting projection 27 is fitted into the concave hole 28 between the facing surfaces of the fitting projection 27 and the rear plate 23a. Since the bolts 35 and the nuts 38 are fastened, the connection strength of the lower end portion of the back frame 21 with respect to the backrest mounting member 8 becomes extremely large. In addition, when tightening, the lower surface of the lower frame 23 of the back frame 21 is in close contact with the upper surface of the rear inclined surface 8b of the backrest mounting member 8 in a wide area, so that the back frame 21 is prevented from wobbling in the front-rear direction. .

  In addition, the left and right fitting protrusions 27 are penetrated by long bolts 35 that face in the vertical direction, and the left and right bolts 35 function as a core material that reinforces the fitting protrusions 27. The bending strength in the front-rear direction of the connecting portion in the frame 21 is increased.

  Furthermore, when the above-described insertion-type connecting structure is used, the backrest mounting member 8 and the back frame 21 have a sense of unity, and the connecting portions are not exposed. The connecting operation with the drooping 6 is also facilitated.

  When the bolt 35 and the nut 38 are tightened, the lower end of the skin material 22 is pressed against the upper surface of the back mounting member 8, so that the terminal portion of the skin material 22 is prevented from being detached from the locking groove 29.

  As described above, the back frame 21 has high rigidity, and the shape of the back frame 21 is substantially concave when viewed from the front with the upper half part released, so that the opposing surfaces of the upper half parts of the left and right side frames 24, 24 Since the S-shaped springs 32 and 32 are stretched between them, when the back is put on the cushion body 22, the upper half part is easily bent backward, and a comfortable backrest feeling is obtained.

In addition, in the said embodiment, although the back frame 21 whole is covered with the cushion body 22, a part on the rear surface side of the lower frame 23 and the backplate 25 may be exposed. The elastic expansion / contraction means may use a rubber belt or the like instead of the S-shaped spring 32.
In the above embodiment, the back plate 25 is connected to the opposing surface of the lower half of the side frame 24, but the connecting position may be lower than the lower half.

  Of course, the present invention can be applied to an ordinary single chair in addition to the above-described connecting chair.

DESCRIPTION OF SYMBOLS 1 Leg 2 Recumbent 3 Chair 4 Armrest 5 Seat body 6 Backrest 7 Seat frame 8 Backrest mounting member 8a Front inclined surface 8b Rear inclined surface 9 Cushion body 10 Bracket 11 Bolt 12 Female screw cylinder 13 Recess 14 Stepped hole 15 Locking piece 16 Upward fitting portion 16a Rear standing piece 16b Side standing piece 17 Partition piece 18 Fitting hole 19 Fitting hole 20 Projection piece 21 Back frame 22 Cushion body 22a Skin material 23 Lower frame 23a Rear plate 23b Side plate 23c Stepped surface 24 Side frame 25 Back plate 26 Fitting recess 27 Fitting protrusion 28 Recess hole 29 Locking groove 30 Recessed step portion 31 Rib 32 S-shaped spring (elastic expansion and contraction means)
33 Locking member 34 Bolt insertion hole 35 Bolt 36 Meat removal hole 37 Metal plate 38 Nut

Claims (4)

In a backrest structure of a chair that supports a cushion body by a back frame that stands up from the rear end of the seat body, the back frame stands on a lower frame that faces in the left-right direction and on the upper surfaces of both side ends of the lower frame. A pair of left and right side frames, and a back plate connected to the upper surface of the lower frame and a lower facing surface of the left and right side frames, and a facing surface above the back plate in the side frames. The space between the left and right side frames is provided with an elastic expansion / contraction means between opposing surfaces above the back plate, and at least the elastic expansion / contraction means and the back plate are cushioned. have covered the further the upper portion of the left and right side frames is curved obliquely rearward and upward in an arc shape, in the curved portion and at least two places of the lower than, between the facing surfaces of the side portions the frame Backrest structure of a chair, characterized in that a resilient and elastic means. In a backrest structure of a chair that supports a cushion body by a back frame that stands up from the rear end of the seat body, the back frame stands on a lower frame that faces in the left-right direction and on the upper surfaces of both side ends of the lower frame. A pair of left and right side frames, and a back plate connected to the upper surface of the lower frame and a lower facing surface of the left and right side frames, and a facing surface above the back plate in the side frames. The space between the left and right side frames is provided with an elastic expansion / contraction means between opposing surfaces above the back plate, and at least the elastic expansion / contraction means and the back plate are cushioned. It has covered the further the back plate, by connecting the rear end portion of the lower frame and the sides frame, on the upper surface of the lower frame at the front of the back plate, the lower cushioning body Backrest structure of a chair, characterized in that the formation of the recessed stepped portion is engaged.   The backrest structure of the chair according to claim 1 or 2, wherein the front and rear dimensions and the left and right dimensions of the left and right side frames are gradually increased downward. On the lower surface of the lower frame, a fitting projection is projected downward, and this fitting projection is fitted into a fitting hole provided in the rear end portion of the seat body, so that the back frame is fitted to the rear end of the seat body. The backrest structure of the chair according to any one of claims 1 to 3 , wherein the chair is supported by a portion.

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