JP4486465B2 - Chair backrest mounting structure - Google Patents

Description

  The present invention relates to a backrest mounting structure for a chair in which a back frame constituting a backrest and backrest support frames provided on both sides of the backrest are connected by connecting bolts.

  Conventionally, this type of chair backrest mounting structure has a backrest with a net member stretched over a downward U-shaped back frame, and a lower frame facing in the left-right direction with the left and right lower ends of the back frame fitted together. And a pair of left and right seat frames that support the seat, the lower frame is disposed between both seat frames, and the groove-shaped receiving portions formed on the left and right end surfaces of the lower frame are Cover the head frame to cover the bolt head after fitting the bolt into the female screw hole that penetrates the seat frame and reaches the groove-shaped receiving portion, and connects the seat frame to the back frame. There exists what fitted the member to the seat part frame (for example, refer to patent documents 1).

Such a chair backrest mounting structure has an advantage that the bolt can be tightened using a wide space on both the left and right sides of the chair, so that it can be easily operated in an easy posture.
JP 2003-135194 A

  However, in the chair backrest mounting structure as described above, a cover member is required to prevent the bolt head from being exposed, so the number of parts increases and the cover member protrudes from the seat frame. May be damaged. Further, when tightening the bolts, it is necessary to align the female screw holes of the seat frame and the back frame while holding the backrest and moving the bolt up and down, which causes a problem in work efficiency.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to improve the appearance without increasing the number of parts by preventing the connection bolts and female screw holes from being exposed to the outside as much as possible. An object of the present invention is to provide a chair backrest mounting structure capable of improving the workability.

According to the present invention, the above problem is solved as follows.
(1) A backrest support frame is provided on the right and left outer sides of the backrest, which is stretched with an elastic tension material, on the front surface of the backframe, and both the backrest support frame and the back frame are fastened with connecting bolts to each other. In the chair backrest mounting structure,
The opposite left and right inner surfaces of the upper part of the left and right back support frames are widened upward to form a pair of left and right upward inclined support surfaces, and to the left and right directions that open only to the both upward inclined support surfaces. A female screw hole is formed in the back support frame, and left and right outer surfaces of the lower part of the back frame are formed as a pair of left and right downward inclined supported surfaces that can be fitted to the pair of upward inclined support surfaces from above. Forming a through-hole in the left-right direction that penetrates the lower part of the back frame and communicates with the female screw hole in the lower part of both back frames, and allows a connecting bolt to be inserted into the through-hole from the inner surface of the lower part of the back frame. The backrest support frame and the back frame are connected to each other by being screwed into the female screw hole.

  (2) In the above item (1), the fitting protrusion is fitted to one of the upward inclined support surface and the downward inclined supported surface of the back frame, and the other is fitted to the fitting protrusion. A fitting groove that can be mated is provided.

  (3) In the above item (2), the fitting protrusion is provided on the upward inclined support surface of the backrest support frame, and the fitting groove is provided on the downward inclined supported surface of the back frame. One end is opened at the top of the fitting protrusion, and the through hole is opened at the bottom of the fitting groove.

  (4) In the above item (3), the fitting protrusion is provided in the middle part in the front-rear direction of the upward inclined support surface in the back support frame.

  (5) In any one of the above items (1) to (4), a recess is formed on the inner surface of the lower part of the back frame, and a through hole for inserting a connecting bolt is opened on the bottom surface of the recess. The height of the head of the connecting bolt to be inserted and the depth of the recess are set to be approximately equal.

According to the present invention, the following effects can be achieved.
(1) According to the first aspect of the present invention, the opposite left and right inner surfaces of the left and right backrest support frames are formed on the left and right pairs of upward inclined support surfaces, and the left and right outer surfaces of the lower portion of the back frame are Since a pair of left and right inclined supported surfaces that can be fitted to a pair of upward inclined support surfaces from above is formed, the back frame is attached to the left and right back support frames when mounting the back support frame and the back frame. Bolts can be tightened simply by fitting them from above, and it is not necessary to align the screw openings by moving up and down while holding the back frame as in the prior art. Since the backrest support frame and the back frame are connected to each other by screwing the connection bolt into the female screw hole from the inner surface of the lower part of the frame, the connection bolt and the female screw hole are not exposed to the outer surface of the back frame. Does not need a cover material such as for concealing al, therefore the appearance can be improved without increasing the number of components.

  (2) According to the invention described in claim 2, the fitting protrusion is provided on one of the upward inclined support surface and the downward inclined supported surface of the back frame, and the fitting protrusion is provided on the other side. Since the fitting groove portions that can be fitted are provided, the back frame does not shift in the front-rear direction even when the back frame is fitted to the backrest support frame or when it is tightened by the connecting bolt. Thus, the workability can be further improved.

  (3) According to the invention of claim 3, the fitting protrusion is provided on the upward inclined support surface of the back support frame and the fitting groove is provided on the downward inclined supported surface of the back frame, respectively, Since one end is opened at the top of the mating projection, the length of the female screw hole is increased by the height of the mating projection even if the left and right widths of the back support frame are reduced to improve the design. Since it can be lengthened, a sufficient fastening force by connecting bolt fastening can be obtained.

  (4) According to the invention described in claim 4, since the fitting protrusion is provided in the front-rear direction intermediate portion of the upward inclined support surface in the backrest support frame, the front and rear surfaces of the backrest support frame, and the back frame There is no vertical groove between the left and right outer surfaces, and the appearance is thus improved.

(5) According to the invention described in claim 5, the concave portion is formed in the inner surface of the lower portion of the back frame, the through hole for inserting the coupling bolt is opened in the bottom surface of the concave portion, and the head portion of the coupling bolt through which the through hole is inserted Therefore, the connecting bolt head and the opening of the through hole are located in the groove, and the appearance is improved.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1-3, the chair provided with one Embodiment of this invention has the leg (3) which has the five leg rods (2) which make | form the radial shape by which the caster (1) was provided in the front-end | tip part. It has. A telescopic leg column (5) having a gas spring (4) is erected at the center of the leg body (3), and a rear portion of the support base (6) is located at the upper end of the leg column (5). It is fixed.

  The support base (6) has a substantially hollow box shape in the shape of a rhombus in plan view in which the upper surface of the front half extending toward the front upper side is opened, and the opening on the upper surface is covered with a removable upper cover (7). ing. A pair of left and right arms on both sides of the front part of the support base (6) that extend obliquely upward toward the left and right sides, and whose top end surface is located above the support base (6) (6a) and (6a) are integrally formed.

  The pivot (8) consisting of a hexagonal shaft facing in the left-right direction passes through the center of the support base (6) in the front-rear direction, and both ends of the pivot (8) projecting on both sides from the support base (6) In the left and right pair of backrest support frames (10) and (10) for supporting the backrest (9), there are formed cylindrical portions (10a) and (10a) facing the left and right formed at the front end of the lower portion facing forward. The pivot (8), the backrest support frame (10), (10), and the backrest (9) are fixed to each other with respect to the support base (6) around the axis of the pivot (8). Can be rotated.

Inside the support base (6), there is a rubber torsion unit (11) (see FIG. 3) for biasing the pivot (8) in the counterclockwise direction in FIG. 2 and its biasing force adjusting means (not shown). In addition, a gas spring unit (12) is provided in the center of the lower surface of the front portion of the support base (6), which is linked to the rubber torsion unit (11) and assists the urging force of the rubber torsion unit (11). As a result, a biasing means for biasing the backrest (9) toward the standing direction is formed.
However, since the rubber torsion unit (11) and the gas spring unit (12) are not directly related to the present invention, detailed illustration and description thereof will be omitted.

  The lower surface of the rubber torsion unit (11) is covered with a pair of left and right lower covers (13) and (13) which are detachably provided on the lower surface of the support base (6).

  A short standing arm (10x) (10x) is projected upward from the pivot (8) of the left and right back support frames (10) and (10). At the upper end, the rear ends of a pair of left and right seat support frames (15) and (15) that support both sides of the seat (14) are connected to the left and right shafts (16), respectively. Has been.

The front part of each seat frame (15) has a box shape whose upper surface is closed and extends downward, and its lower end surface forms an inclined surface (17) inclined downward and downward. (17) A standing wall (18) facing the rear upper side is formed continuously to the rear end.
Each inclined surface (17) is slidably mounted in the front-rear direction on an inclined receiving surface (19) formed on the upper surface of the tip of the arm portion (6a) of the support base (6) and inclined downward. Has been.

  The inclined surface (17) is separated from the inclined receiving surface (19) upward between the tip of the arm (6a) of the support base (6) and the front portion of the seat receiving frame (15). A stop means (20) for blocking is provided. The retaining means (20) includes a long hole (21) facing the front-rear direction (see FIG. 1) provided on the inclined surface (17), a protrusion provided on the inclined receiving surface (19), and the long hole (21). A headed shaft (not shown) having an enlarged head larger than the width of the long hole (21) is slidably fitted.

  The long hole (21) extends rearward from the vicinity of the front end of the inclined surface (17), and the rear end opens rearward from the standing wall (18). The standing wall (18) is provided with an opening that communicates with the long hole (21) and through which the enlarged head of the headed shaft that projects from the inclined receiving surface (19) can pass.

  Accordingly, while introducing the headed shaft from the opening, the inclined surface (17) is slid rearward along the inclined receiving surface (19), and the rear end portion of each seat receiving frame (15) is connected to the shaft (16 ) To each backrest support frame (10), each seat receiving frame (15) can be easily and quickly assembled to the support base (6) and backrest support frame (10).

  After the assembly, the seat back frame (15) and the seat (14) supported by the seat support frame (15) are incliningly received by the inclined surface (17) as the backrest (9) is tilted backward from the standing state. While sliding along the surface (19), it is moved rearward and downward.

The movement of the backrest (9) and the seat (14) at this time causes the angle between the back and the thigh of the seated person and between the thigh and the lower leg to naturally expand, and the lower leg The part tilts slowly with the heel of the foot in contact with the floor as the center, giving the seated person a comfortable and comfortable feeling of movement.
In addition, when the backrest (9) is moved from the rearward tilted state to the standing state, the seat (14) moves in the opposite direction to the above, and at this time, the seated person feels comfortable and comfortable to move. Can be given.

  If the inclined surface (17) and the inclined receiving surface (19) are completely straight when viewed from the side, the seat (14) moves rearward and downward in conjunction with the backward inclination of the backrest (9). The contact surface may change from surface contact to line contact, but the inclined surface (17) and the inclined receiving surface (19) should be gently curved so that they always contact in a wide range. desirable.

  The seat (14) has a stretchable stretch material (for example, a mesh fabric using stretchable fibers, a fabric such as a plain woven fabric, or a synthetic resin film) on a frame (14a) having a substantially rectangular frame shape in plan view. 14b), and when the seated person sits, the upholstery material (14b) expands, and the center part of the seat surface is recessed downward along the seated person's buttocks. Since the central portion of (14b) sinks, a comfortable seating feeling can be given to the seated person.

  In order to allow the center of such a seat (14) to sink when seated, the upper surface of the tip of the pair of left and right arms (6a) (6a) and the backrest support frame (10) With the standing arms (10x) (10x) in (10), the four corners of the seat frame (14a) are lifted and supported higher than the support base (6), so that the lower surface of the central part of the seat (14) and the support base are supported. A space (24) is formed between the upper surface of (6) and the central portion of the lower surface of the seat (14) can bend downward.

  The backrest (9) also has a stretch material (9x) made of the same material as the upholstery material (14b) on the back frame (9a) having a substantially rectangular frame shape in front view, in accordance with the seat (14). It is formed by stretching.

The seat (14) is mounted on the pair of left and right seat receiving frames (15) and (15) so that the front / rear position can be adjusted, but the specific configuration therefor is not directly related to the present invention. Such illustration and description are omitted.
In the case where the front / rear position of the seat (14) is not adjusted, the rear part of the seat (14) is directly supported by the upright arms (10x) (10x) ( 10x) and the front lower surface of the seat (14) may be directly slidable in the front-rear direction on the upper surfaces of the distal ends of the left and right arms (6a) and (6a).

  Each back support frame (10) (10) is provided with an armrest (25), but since this is not directly related to the present invention, detailed illustration and description thereof will be omitted.

  Next, the mounting structure of the backrest (9) and the backrest support frames (10) (10), which is a feature of the present invention, will be described. The back support frame (10) (10) has a forward-facing portion (10b) (10b) extending rearward and obliquely upward from a cylindrical portion (10a) (10a) fixedly fitted to the pivot (8), and forward-facing It is formed of upright portions (10c) and (10c) extending obliquely upward from the rear ends of the portions (10b) and (10b). The spacing in the left-right direction at the upright portions (10c) and (10c) is widened toward the top so that the inner surfaces of the upright portions (10c) and (10c) form upwardly inclined support surfaces (10d) and (10d). It expands upward.

  As shown in FIGS. 4 and 5, fitting protrusions (10 e) and (10 e) are provided at the intermediate portion in the vertical direction of the upward inclined support surfaces (10 d) and (10 d). The fitting ridges (10e) and (10e) are formed in the middle part in the front-rear direction of the upward inclined support surfaces (10d) and (10d), and the top surfaces of the fitting ridges (10e) and (10e) are formed flat. Is desirable. Furthermore, the back support frame (10) (10) has a female screw hole (10f) in the left-right direction in which one end is opened at the top surface of the fitting protrusion (10e) (10e) and the other end is closed. 10f) is formed. The number of the female screw holes (10f) (10f) is not particularly limited, but two are formed in the illustrated example.

  The lower part of the back frame (9a) in the shape of a rectangular frame in the backrest (9) extends rearward and obliquely downward, and the left and right outer surfaces of the lower part of the back frame (9a) are the back support frame (10). The upper inclined support surfaces (10d) and (10d) in (10) are formed on the lower inclined supported surfaces (9b) and (9b) so that they can be fitted from above.

  On both inclined supported surfaces (9b) and (9b), fitting groove portions (9c) and (9c) that can be fitted to the fitting protrusions (10e) and (10e) from above are formed. It is desirable that the bottom surfaces of the fitting groove portions (9c) and (9c) be formed flat so that they can come into contact with the top surfaces of the fitting protrusions (10e) and (10e) with surface contact. The lower part of the back frame (9a) penetrates the lower part of the back frame (9a) at the position communicating with the female screw holes (10f) (10f), and the inner surface of the lower part of the back frame (9a) and the fitting groove (9c). ) (9c) are provided with through-holes (9d) and (9d) in the left-right direction that open on both sides of the bottom surface.

  Furthermore, concave portions (9e) and (9e) are provided on both left and right inner surfaces of the lower portion of the back frame (9a). The recesses (9e) and (9e) are for preventing the head of the connecting bolt (26), which will be described later, from being exposed as much as possible from the viewpoint of improving the appearance, so that they cannot be seen from the outside. 9d) is formed so that one end of the recess (9e) (9e) opens to the bottom of the recess (9e) (9e), and the depth of the recess (9e) (9e) is approximately equal to the height of the head of the connecting bolt (26). . The vertical grooves (27) formed on the left and right outer sides of the back frame (9a) that open to the side are formed on the left and right edges of the upholstery (9x) in the backrest (9). The fixed edge material (28) is fitted and the tension material (9x) is stretched.

  In order to connect the back support frame (10) (10) and the back frame (9a) to each other, the back frame (9a) may be fitted to the back support frame (10) (10) from above. Thus, the fitting groove portions (9c) and (9c) are fitted into the fitting protrusions (10e) and (10e) from above. Next, the connecting bolt (26) may be screwed into the female screw holes (10f) and (10f) from the recesses (9e) and (9e) through the through holes (9d) and (9d).

  In the above, the backrest support frame (10) (10) and the back frame (9a) are provided with fitting protrusions (10e) (10e) and fitting groove portions (9c) (9c), respectively. These may be omitted, or may be formed only at positions corresponding to the female screw holes (10f) and (10f). Contrary to the above, the fitting protrusions (10e) and (10e) may be provided on the back frame (9a), and the fitting grooves (9c) and (9c) may be provided on the back support frame (10) and (10). Is possible.

  As is apparent from the above, according to this embodiment, in the backrest mounting structure in which the backrest support frame (10) and the backframe (9a) are fastened to each other with the connecting bolt (26), the backrest support frame (10 The left and right inner surfaces of the upper part of the upper part of the upper support) are formed upward to form an upward inclined support surface (10d), and a female screw hole (10f) that opens only to the upward inclined support surface (10d) is provided on the back support frame (10). ) And the lower outer surface of the back frame (9a) is formed into a downward inclined supported surface (9b) that can be fitted to the upward inclined support surface from above, and a through hole (9d) that penetrates the lower portion of the back frame The back support frame (10) and the back frame (9a) are formed by inserting the connecting bolt (26) through the through hole (9d) from the lower frame inner surface and screwing into the female screw hole (10f). Are connected to each other, it is possible to improve the appearance of the chair and to improve the workability of attaching the backrest support frame and the back frame.

It is a front view of a chair provided with one embodiment of the present invention. Similarly, it is a side view. Similarly, it is an exploded perspective view of a main member. Similarly, it is an expanded vertical front view of the principal part along the IV-IV line of FIG. Similarly, it is sectional drawing which follows the VV line of FIG. Similarly, it is sectional drawing which follows the VI-VI line of FIG. Similarly, it is a side view showing the lower outside surface of the back frame.

Explanation of symbols

(1) Casters
(2) Legs
(3) Leg
(4) Gas spring
(5) pedestal
(6) Support base
(6a) Arm
(7) Top cover
(8) Axis
(9) Backrest
(9a) Back frame
(9b) Downward inclined supported surface
(9c) Mating groove
(9d) Through hole
(9e) Recess
(9x) Upholstery
(10) Back support frame
(10a) Tube part
(10b) Forward part
(10c) Standing part
(10d) Upward inclined support surface
(10e) Mating ridge
(10f) Female screw hole
(10x) Standing arm
(11) Rubber torsion unit
(12) Gas spring unit
(13) Bottom cover
(14) Seat
(14a) Seat frame
(14b) Upholstery material
(15) Seat support frame
(16) axis
(17) Inclined surface
(18) Standing wall
(19) Inclined bearing surface
(20) Stop prevention means
(21) Long hole
(24) Empty space
(25) Armrest
(26) Connecting bolt
(27) Vertical groove
(28) Edge material

Claims (5)

The back frame is provided with a back support frame on the left and right outer sides of the back with an elastic upholstery stretched on the front surface of the back frame, and the back support frame and the back frame are fastened to each other with connecting bolts. In the back mounting structure,
The opposite left and right inner surfaces of the upper part of the left and right back support frames are widened upward to form a pair of left and right upward inclined support surfaces, and to the left and right directions that open only to the both upward inclined support surfaces. A female screw hole is formed in the back support frame, and left and right outer surfaces of the lower part of the back frame are formed as a pair of left and right downward inclined supported surfaces that can be fitted to the pair of upward inclined support surfaces from above. Forming a through-hole in the left-right direction that penetrates the lower part of the back frame and communicates with the female screw hole in the lower part of both back frames, and allows a connecting bolt to be inserted into the through-hole from the inner surface of the lower part of the back frame. A backrest mounting structure for a chair, wherein the backrest support frame and the back frame are connected to each other by being screwed into the female screw hole.   A fitting protrusion is provided on one of the upward inclined support surface and the downward inclined supported surface of the back frame, and a fitting groove that can be fitted on the fitting protrusion is provided on the other. 2. The chair backrest mounting structure according to claim 1, wherein   A fitting protrusion is provided on the upward inclined support surface of the backrest support frame, and a fitting groove is provided on the downward inclined supported surface of the back frame, and one end of the female screw hole is formed on the top of the fitting protrusion. 3. The chair backrest mounting structure according to claim 2, wherein the through holes are opened at the bottom surfaces of the fitting grooves.   4. The chair backrest mounting structure according to claim 3, wherein the fitting protrusion is provided at an intermediate portion in the front-rear direction of the upward inclined support surface of the backrest support frame. A recess is formed on the inner surface of the lower part of the back frame, and a through hole for inserting a connection bolt is opened on the bottom surface of the recess, and the height of the head of the connection bolt that passes through the through hole and the depth of the recess are approximately The chair backrest mounting structure according to any one of claims 1 to 4, wherein the chair backrest mounting structure is set to an equal size.

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