JP2008302061A - Chair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chair permitting easy assembly of a backrest without detachment of a back panel. <P>SOLUTION: The backrest 6 includes a backrest frame 14 and a backrest inner shell 15. The backrest frame 14 has a vertically longitudinal side member 20, and engagement holes 38 and 40 are formed in the front panel 20a of the side member 20. The back panel 15 has engagement pawls 41 and 42 fitted into the engagement holes 38 and 40, and an auxiliary engagement pawl 40 holding the upper end of the side member 20. The auxiliary engagement pawl 40 is held by an upper side panel 16b" of a rear cover 16 in such a way as immovable upward. When the rear cover 16 is fixed to the backrest frame 14, the back panel 15 is held in such a way as immovable upward. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a chair characterized by the structure of the backrest.

  There are various types of backrest structures in a chair, but one type has a back frame made of metal as a strength member and a back support body such as a back plate with a cushion attached thereto.

  An example of a structure for attaching the back plate to the back frame is disclosed in the patent literature. That is, in Patent Document 1, the back frame has a configuration in which left and right vertical hooks are connected by left and right laterally long connecting hooks, and an engaging projection with a head projects forward from the upper part of the vertical hook, The lower part has a hook-shaped bearing that projects upward in a side view, while the back plate has an engagement hole into which the engagement protrusion of the vertical hook part fits and a bearing of the vertical hook part from above And a horizontal axis.

In the patent document, the engagement hole of the back plate is formed in a dharma shape in which a large-diameter portion large enough to fit and remove the head of the engagement projection and an upward slit into which only the neck portion of the engagement projection fits. The back plate is held so as not to be disengaged from the back frame by fitting the horizontal axis of the back plate into the bearing of the back frame while keeping the engagement projection fitted in the slit.
JP 2001-128789 A

  Patent Document 1 adopts a catch method that is an engagement between an engaging claw and an engaging hole as a means for attaching a back plate, and if such a catch method is adopted, there is an advantage that the backrest can be easily assembled. is there.

  In Patent Document 1, by increasing the vertical length of the slit of the engagement hole, the state in which the engagement protrusion is fitted in the engagement hole while the horizontal shaft is fitted in the bearing is secured. In the neutral state in which no load is applied to the backrest, the engaging protrusion is located in the middle of the slit in the engaging hole, and when the backrest is loaded and elastically deformed so that the backrest extends, the engaging hole For this reason, for example, there is a concern that the engaging protrusion may come out of the engaging hole due to an impact when a seated person leans against the backrest vigorously. Since the upper part of the board moves upward, a relative slip occurs with the back of the person who is seated, and the phenomenon of so-called “backshift” and “shirt dripping” easily occurs.

  Further, in Patent Document 1, the back frame is described as being made of metal or resin. In this case, it is understood that the resin frame is an injection-molded product, while the metal case is not clearly shown. Referring to the drawing, it is understood that the molded product is a die-cast. Therefore, the molded product has a problem that the analysis of the stress distribution is troublesome as compared with the sheet metal processed product, and the design is troublesome.

  The present invention has been made to improve the current situation.

  The chair of the present invention includes a seat and a backrest, and the backrest includes a resin back inner shell with a cushion stretched on the front surface, and a metal back frame disposed on the back side of the back inner shell. In the invention of claim 1, the back inner shell is moved to the back surface and the back frame by moving the back inner shell backward so as to overlap the back frame and then moving downward. Engagement means is provided to hold the shell so that it cannot move forward and left and right, and the back frame is positioned above a part of the back inner shell so that the back inner shell faces upward from the back frame. Stopper means is attached to hold it so that it cannot be detached.

  According to a second aspect of the present invention, in the first aspect, the back frame is made of a metal plate, and is formed in a substantially quadrangular shape when viewed from the front by a vertically long left and right side member, a right and left horizontally long upper member, and a lower member. Each of the left and right side members has a groove shape that has a front plate and is open to the rear. A plurality of engagement grooves are formed on the front plate of the side member so as to be separated from each other. An engaging claw that fits into the fitting hole is formed, the engaging hole and the engaging claw constitute the engaging means, and the back frame has a back cover that covers the back frame from behind. A stopper is formed on the back cover.

  In addition, the “metal plate” of claim 2 includes both a case where a processed product such as a pipe or a grooved steel is used and a case where a sheet metal is processed by a press or the like using a strip as a material. Therefore, the upper member and the lower member include a groove-shaped member and a pipe-shaped member that are opened rearward as in the case of the side member.

  According to a third aspect of the present invention, in the second aspect of the invention, the back inner shell is formed with an auxiliary engagement claw having a hook shape in side view that holds the upper end of the front plate of the side member in the back frame from above. Therefore, the front plate of the side member and the auxiliary engagement claw of the back inner shell also constitute the engagement means, and the back cover is formed with an upper plate that covers the upper member of the back frame from above. By positioning the left and right end portions of the upper plate above the auxiliary engagement claws of the back inner shell, the left and right end portions of the upper plate in the back cover constitute the stopper portion.

  In the present invention, the attachment of the back plate to the back frame is performed by fitting engagement means formed on the back frame and the back plate. Therefore, the backrest can be assembled efficiently. In addition, since the back plate is held so as not to move upward by the stopper means provided on the back frame, the back plate is not detached from the back frame due to an impact or the like during locking.

  In claim 2, the back frame is made of a metal plate. However, since the metal plate such as a steel plate is known for its strength and durability and has high reliability, it is easy to analyze the stress distribution and reduce the design effort. There are advantages you can do. In the invention of claim 2, the engagement hole is formed in the side member made of a metal plate. The engagement hole can be processed very easily by punching, but the engagement claw of the back plate is also troublesome by integral molding. Can be processed without. For this reason, in Claim 2, the backrest excellent in intensity | strength can be manufactured easily.

  Further, in claim 2, since a part of the back cover that covers the back frame is also used as the stopper means, the number of members can be reduced and the structure can be simplified and the cost can be reduced. This is the excellent effect of the second aspect.

  According to the third aspect of the present invention, since the back plate is held so as not to move forward even by the auxiliary engagement claws, the mounting strength of the back plate is further increased, and the back plate moves upward at the upper part thereof. When the back plate is stretched and deformed in the vertical direction due to a load during locking, the back plate is allowed to be deformed by extension when the lower part escapes downward. Alternatively, there is an advantage that shirt turning can be prevented or suppressed.

  In the present invention, the stopper means may be a member different from the back cover. In this case, if the upper portion of the back plate is restrained by the stopper means, back slipping or shirt twisting is prevented as in the third aspect. Or it can be suppressed.

  Next, an embodiment of the present invention will be described with reference to the drawings. The present embodiment is applied to a chair used by a child / student as a set with a learning desk, but of course, it can also be used for an adult chair such as an office chair.

(1). Outline of Chair First, an outline will be described with reference to FIGS. 1 is a perspective view of a chair as viewed from the front, FIG. 2A is a front view, FIG. 4B is a side view, FIG. 4 is a perspective view of a tilting frame and a back frame, and FIG. 5 is a part of a locking mechanism. FIG.

  The chair includes, as main elements, a leg 1 with casters, a base 2 fixed to the upper end of the leg 1, a seat 3 disposed above the base 2, and a backrest 4 disposed behind and above the seat 3. And an armrest device 5 as an optional product. The leg 1 is provided with a leg column (gas cylinder) 6 that is freely extendable and rotatable, and a base 2 is fixed to the upper end of the leg column 6.

  Further, the leg 1 includes five branch legs 7 extending radially, and a step plate 8 having an arc shape in plan view is fixed to three adjacent branch legs 7. On the outside of the base 2, there are a handle 9 for adjusting the elasticity of the locking spring, a lifting lever 10 for releasing the lock of the leg column 6 when adjusting the height of the seat 3, and a lock for adjusting the front and rear position of the seat 3. The front / rear lever 11 for releasing is exposed.

  Although not shown, the seat 3 includes a resin seat inner shell (seat plate) and a seat cushion stretched on the upper surface thereof, and the seat cushion is covered with a cloth from above. The seat 3 is fixed to, for example, a seat outer shell (seat receiving member) 12 shown in FIG. The seat outer shell 12 is supported by an intermediate fitting (not shown) so that the front / rear position can be adjusted, and the intermediate fitting is covered from the left and right outer sides with a cover denoted by reference numeral 13 in FIG.

  As can be understood from FIG. 4, the backrest 4 includes a back frame 14 formed of a metal plate as a material in a square shape in a rear view (or a front view). The back frame 14 serves as a strength member of the backrest 4. A resin back inner shell (back plate) 15 is attached to the front surface of the back frame 14, and a resin back surface is attached to the back surface of the back frame 14. A cover 16 is attached. A back cushion 17 is placed on the front surface of the back inner shell 15, and the back cushion 17 and the back inner shell 15 are covered with a bag-like cloth 18.

  The back frame 14 is formed in a substantially rectangular shape in front view by left and right upper and lower left and right side members 20 and left and right upper members 21 and a lower member 22, and the lower member 22 faces forward from the lower member 22. A pair of left and right tilting frames 23 that extend is fixed by welding. A horizontally long second shaft 24 is fixed between the front ends of the left and right tilt frames 23, and a plate-like bridge member 25 is fixed between the front and rear middle portions of the tilt frames 23.

  As shown in FIG. 3C, the back inner shell 15 is formed with a large number of slits 19 for facilitating bending deformation and longitudinal deformation. As shown in a partially broken view in FIG. 1, in the backrest 4, the outer periphery of the back cushion 17 is made of a shape-retaining material 17 a that is elastic but hard to lose its shape, thereby sharpening the outer periphery. The square shape is maintained (this is the same for the seat 3).

  The backrest 4 tilts backward, and the seat 3 tilts backward while retracting in conjunction with the backward tilting of the backrest 4. A few points about this point. As shown in FIG. 5, the base 2 is formed in a box shape with an upward opening, and the left and right side plates 2a are formed with a slit groove 26 that opens forward. The provided left and right laterally long first shafts are slidably mounted in the slit groove 26 through the bush. The backward movement of the first shaft is elastically supported by a locking spring (not shown) built in the base 2.

  The tilt frame 23 uses metal pipes (steel pipes) having an oval cross section, and is arranged on both the left and right sides of the base 2. The second shaft 24 fixed to the front end portion of the left / right tilt frame 23 is sandwiched from above and below by the upper center bush 28 and the lower center bush 29, and the upper and lower center bushes 28, 29 are interposed via the center metal fitting 30. The base 2 is fixed to the lower surface. The upper center bush 28 is fitted to the base 2 so as not to move left and right.

  Although details are omitted, a rearwardly elongated third shaft is provided at the rear portion of the above-described intermediate bracket, and the third shaft is connected to a bridge member 25 that is disposed across the left and right tilt frame 23 and a rear bush and a rear bracket. It is connected with. Therefore, the base 2, the intermediate metal fitting, and the tilting frame 23 form a kind of link mechanism. When the backrest 4 is locked (backward tilted), the seat 3 tilts backward while being retracted in conjunction with the rearward tilting of the backrest 4. . As shown in FIG. 5, a back gas cylinder 31 that can hold the backrest 4 at an arbitrary rearward tilt angle is disposed between the rear end of the base 2 and the lower end of the back frame 14. The back gas cylinder 31 is connected to the base 2 and the back frame 14 so as to be relatively rotatable. The back tilt of the backrest 4 and the synchro movement of the seat 3 are elastically supported by the locking spring and the back gas cylinder 31.

  A connecting projection 32 for connecting the back gas cylinder 31 protrudes from the left and right middle portions of the lower portion of the back frame 14, and a receiving member 33 is fixed to the rear portion of the left tilt frame 23. The receiving member 33 is provided with a lever (not shown) for switching the back gas cylinder 31 between a locked state and a free state.

(2). Structure of Back Frame Next, the structure of the back frame 14 will be described with reference to FIGS. 7 to 8 in addition to the previous drawings. 6A is a separated perspective view of the back frame 14 and the reinforcing member, FIG. 6B is a perspective view seen from the front of the reinforcing member, and FIG. 7A is a back frame 14 and the back inner shell 15. The perspective view which looked at the stopper engagement claw from the lower part, (C) is the perspective view which looked at the upper engagement claw from the lower part, (D) is the perspective view of the lower engagement claw, 8A is a perspective view of the upper corner portion, FIG. 8B is a rear view of the lower corner portion, FIG. 8C is a sectional view taken along the line VIIIC-VIIIC of FIG. 6A, and FIG. A) VIIID-VIIID sectional view, (E) is an EE sectional view of (B), (F) is an FF sectional view of (B), (G) is G of (B) FIG.

  As described above, the back frame 14 is composed of four vertical left and right side members 20 constituting the side, left and right lateral upper members 21 constituting the upper portion, and left and right laterally lower members 22 constituting the lower portion. Two main members are provided, and reinforcing members 36 are fixed to the left and right lower corner portions 35 by welding. Each member is manufactured by sheet metal processing using a steel plate as a material, and adjacent members are integrated by welding.

  Each member 20, 21, 22 has a flat front plate and a side plate and has a groove shape with a substantially U-shaped cross-section opened rearward. The front side is wide. Further, the side member 20 is curved with a gentle curvature in a forwardly convex shape in a side view so that the position of the seated person's waist is at the front end, while the upper member 21 and the lower member 22 are It is gently curved in a concave shape facing forward in plan view.

  Each member 20, 21, 22 has a front plate and inner and outer side plates and is formed in a U-shaped groove shape (in the following description, only the side member 20 is formed on the front plate and the inner / outer plate). Reference numerals 20a, 20b, and 20c are assigned respectively). Each member 20, 21, 22 is a groove type, but the depth dimension is smaller than the width dimension.

  For example, as can be understood from FIG. 4, the front plate 20a of the side member 20 is inclined at a slight angle so as to recede as it goes inward in a plan view, and the upper member 21 and the lower member 22 are as described above. It is gently curved in a concave shape facing forward in plan view. For this reason, the upper member 21, the lower member 22, and the front surface of the side member 20 are smoothly continuous.

  Further, the front surface of the upper member 21 is slightly tilted rearward with respect to the vertical plane, and the front surface of the lower member 22 is slightly tilted forward with respect to the vertical plane. Therefore, each member 20, 21, 22 is actually in a considerably complicated form. The back inner shell 15 is curved in a forward convex shape in a side view and curved in a forward concave shape in a plan view so as to overlap the front surface of the back frame 14.

  Rear portions 27a of the left and right tilt frames 23 pass through the front plate of the lower member 22, and the rear portions 27a of the tilt frames 23 are fixed to the lower member 22 by welding. Further, upright standing portions 22a are integrally formed at the left and right ends of the lower member 22, and the lower portions of the side members 20 are welded to the standing portions 22a (accordingly, precisely, the left and right sides of the back frame 14). A part of the portion is also constituted by the standing portion 22a of the lower member 22.)

  In this case, the upper half of the upright portion 22a is formed as a narrow width portion 22b stepped down to the left and right inner sides and the rear side by the plate thickness, and the lower portion of the side member 20 is overlapped with the narrow width portion 22b. The width portion 22b and the side member 20 are fixed together by welding.

  And the reinforcement member 36 is inserted from the inner side to the lower corner part 35 comprised by the horizontal part of the lower member 22, and standing part 22a, 22b. The reinforcing member 36 is made of a steel plate and has an L-shape that overlaps the portion of the lower member 22 outside the tilting frame 23 and the upright portion 22a, and has an inner and outer side plate 35a, and has a front-opening flange. It is formed in a shape.

  The upright portion of the reinforcing member 36 is fitted in the upright portion 22a of the lower member 22 so that it cannot be displaced left and right, and the upright portion of the side plate 35a corresponds to the narrow width portion 22b of the upright portion 22a of the lower member 22. Therefore, the upright portion 22a of the reinforcing member 36 exactly overlaps the inner bottom surface of the upright portion 22a of the lower member 22.

  The horizontal portion of the reinforcing member 36 exactly overlaps the horizontal portion of the lower member 22, and the end surface of the horizontal portion of the reinforcing member 36 abuts against the rear end portion 27 a of the tilt frame 23 from the side. The reinforcing member 36 and the horizontal portion and the upright portion of the lower member 22 are fixed by welding, and the reinforcing member 36 and the rear end portion of the tilting frame 23 are fixed by welding.

  A twisting force may act on the back frame 14 as shown by a solid arrow A and a dotted arrow B in FIG. 6 during locking, and this screw force acts on the lower corner portion 35 of the back frame 14 in a concentrated manner. . However, in the present embodiment, since the lower corner portion 35 has a robust structure due to the presence of the reinforcing member 36, high reliability and durability can be ensured.

  A lower engagement hole 37 for attaching a lower portion of the back inner shell 15 is vacated in a portion of the upright portion 22a below the narrow width portion 22b. The lower engagement hole 37 is provided with a downward slit portion 37a located at the left and right intermediate portion thereof, and is substantially T-shaped. An upper engagement hole 38 for attaching the upper portion of the back inner shell 15 is formed in the upper portion of the side member 20. The upper engagement hole 38 also has a downward slit portion 38a and is substantially T-shaped.

  The left and right end surfaces of the front plate and the lower plate of the upper member 21 are in contact with the inner plate 20a of the side member 20, and the contact portions of both the members 21 and 20 are welded. Further, as clearly shown in FIG. 8A, the left and right end portions of the upper plate of the upper member 21 are protruding portions 21a protruding outside the inner plate 20a of the side member 20, and the protruding portions 21a A mounting hole 39 is formed.

(3). Mounting Structure of Back Inner Shell Next, the mounting structure of the back inner shell 15 will be described with reference to FIGS. 9 to 11 in addition to the previous drawings. 9 is an exploded perspective view of the back frame 14 and the back inner shell 15, FIG. 10A is a plan sectional view of the backrest 4, FIG. 9B is a partially enlarged view of FIG. 9 is an XC-XC cross-sectional view of FIG. 9 after assembly, (D) is an XD-XD cross-sectional view of FIG. 9 after assembly, and (A) in FIG. 11 is XIA-XIA of FIG. FIG. 10B is a cross-sectional view taken along the line XIA-XIA in FIG. 10 only at the lower part of the backrest 4 and is a cross-sectional view taken along the line XIB-XIB in FIG. It is XIC-XIC sectional view.

  On the back of the left and right end portions of the back inner shell 15, a side-view type stopper engaging claw 40 disposed near the upper end, an upper engaging claw 41 disposed below, and a lower end edge are disposed. Three pairs of engaging claws with the lower engaging claws 42 are formed. In addition, a center engaging claw 43 protrudes downward from the left and right intermediate portions.

  The stopper engaging claw 40 is shaped like a bowl as viewed from the side, and is fitted to the upper edge of the front plate of the side member 20 in the back frame 14 from above. The upper engaging claw 41 basically has a bowl shape in a side view, but a vertically long wall portion 41 a is formed integrally with the back inner shell 15 at the left and right intermediate portions. The upper engaging claw 41 is fitted into the upper engaging hole 38 formed in the side member 20 from the front and is slid downward. As shown in FIG. The portion is fitted to the wide width portion of the upper engagement claw 41 to hold the back inner shell 15 so as not to move forward, and the wall portion 41a is fitted into the downward slit 38a of the upper engagement hole 38 so that the back inner shell 15 is fitted. The shell 15 is held so as not to move left and right.

  The lower engaging claw 42 is formed in a T shape in a plan view. When the lower engaging claw 42 is fitted into the lower engaging hole 37 from the front and is slid downward, as shown in FIG. It is dropped into the slit part 37a. For this reason, the back inner shell 15 is held by the lower engagement claw 42 so that it cannot be displaced laterally and cannot move forward. As shown in FIG. 11B, the lower engagement claw 42 is positioned above the downward slit portion 37 a of the lower engagement hole 37 in a state in which no human body pressure is applied to the backrest 4.

  When a person's body pressure is applied to the backrest 4, the back inner shell 15 is deformed so as to extend toward a flat state, but the lower engagement claw 42 slides downward with the downward slit portion 37a fitted. As a result, the deformation of the back inner shell 15 is allowed to be deformed, and as a result, it is possible to secure a high fit by eliminating the feeling of tension.

  The center engaging claw 43 is an auxiliary one that holds the lower part of the back inner shell 15 so as not to move excessively forward, and the lower end part is a recessed part 43a that is recessed forwardly, and this recessed part 43a is As shown in FIG. 11C, the back gas cylinder 31 is positioned behind the upper connecting shaft 44. The upper connecting shaft 44 is attached to a bracket 45, and the bracket 45 is fixed to a shaft support protrusion 32 provided on the lower member 22 with screws.

(4). Back Cover Mounting Structure Next, the back cover 16 mounting structure will be described with reference to FIGS. 12 and 13 in addition to the previous drawings. 12 is an exploded perspective view of the back frame 14 and the back cover 16, FIG. 13A is a vertical side view of the left and right middle portion of the upper portion of the back frame 14, and FIG. 12B is a lower side view of FIG. It is XIIIB sectional view.

  The back cover 16 is formed in a square frame shape similar to the back frame 14, and is formed in a substantially rectangular shape with side portions 16 a, an upper portion 16 b, and a lower portion 16 c corresponding to each member of the back frame 14. The side portion 16a and the upper portion 16b include forward-facing inner plates 16a 'and 16b' and outer plates 16a "and 16b" that cover the back frame 14 from inside and outside, respectively, while the lower portion 16c includes an inner plate 16c '. However, it does not have an outer plate. This is because the three lower surfaces of the lower member 22 in the back frame 14 do not touch the human eye in normal use (a lower outer plate may be provided).

  As means for fixing the back cover 16 to the back frame 14, the left and right ends of the outer plate 16b ″ of the upper portion 16b are fixed to the upper member 21 of the back frame 14 with screws 46, and the inner plate 16a ″ of the side portion 16b is fixed. Fastening to the inner surface of the side member 20 with a screw 46 and fastening a bracket piece 47 projecting forward on the lower portion 16 c to the lower surface of the lower member 22 with a screw 46 are employed. Of course, other methods such as a catch method using an engaging claw can be employed.

  The outer plate 16b ″ of the upper portion 16b of the back cover 16 can be referred to as the upper plate (or the upper surface plate) of the back cover 16. As described above, the upper plate 16b ″ of the back cover 16 is the upper of the back frame 14. The member 21 is fixed to the member 21 with a screw 46. As can be understood from FIG. 11A, the upper plate 16b ″ of the back cover 16 is fixed to the stopper engaging claw 40 in the back inner shell 15 as a feature of this embodiment. In other words, the end portion of the upper plate 16b ″ of the back cover 16 is a stopper portion that prevents the back plate 15 from moving upward.

  Accordingly, the back inner shell 15 is held so as not to be detached, although the engaging claws 40, 41, 42 are simply fitted into the back frame 14. That is, the back inner shell 15 can be held so as not to be pulled out although it can be easily assembled. As shown in FIGS. 10C and 10D and FIG. 13, the front plate of the back cover 16 is in contact with or close to the back surface of the back frame 19.

(5) Summary In the present embodiment, the left and right tilt frames 23 and the back frame 14 are separately manufactured and then assembled by welding. Moreover, the back frame 14 is also comprised by the four members 20-22, and after each member 20-22 is manufactured separately, it integrates by welding. Accordingly, the back frame 14 has a complicated shape bent three-dimensionally as a whole and has engagement holes 37, 38, etc., but each member 20 to 22 is made of a band plate as a material (for example, a male shape). It can be easily processed by press working using a female mold.

  Further, the back inner shell 15 can be attached very simply by dropping the engaging claws 40, 41, 42 into the side members 20 of the back frame 19, and the upper plate 16 b ″ of the back cover 16 faces the back plate 15 upward. Since it functions as a stopper means for preventing movement, the back plate 15 can be easily assembled. However, for example, there is no problem that the back plate 15 is detached from the back frame 14 during use.

  In the present embodiment, only the left and right sides of the back inner shell 15 are restrained by the side members 20, and there is a gap between the back inner shell 15 and the upper member 21 and the lower member 22. Therefore, it is allowed to stretch and deform so as to escape to the back side by the body pressure of the person who is seated, and thus high fit can be obtained.

  In addition, the back plate 15 is deformed so as to extend in a flat state in a longitudinal side view due to the presence of a large number of slits 19. In this case, the back plate 15 is upper end by the upper plate 16 b ″ of the back cover 16. Since the back plate 15 is restrained so as not to move upward, the back plate 15 is allowed to be deformed by escaping so that the lower part of the back plate 15 moves downward. As a result, back slip or shirt wrinkle is prevented or suppressed.

  As the locking is applied, a force pulled inside acts on the back plate 15. In this case, if the upper engaging claw 41 has a simple hook shape, the hook portion hits the inner surface of the upper engaging hole 38. Since the joint pawl 41 is in a cantilever state only in a hook shape, a load accompanying rocking is generated as a large moment, so that a high support strength cannot be ensured. At first, the upper engaging claw 41 cannot be excessively enlarged.

  On the other hand, when the wall 41a is provided on the upper engagement claw 41 as in this embodiment, the wall 41a is continuous with the back plate 15 and can secure high rigidity against bending. No. 41 has an advantage that high strength and durability can be secured without excessively thickening.

  Furthermore, if the lower engaging claw 42 is formed in a T shape over substantially the entire top and bottom as in the present embodiment, there is an advantage that it is possible to reliably absorb the back plate 15 extending and deforming in the vertical direction. Further, when the auxiliary engagement claw 40 is provided as in the present embodiment, not only the mounting strength to the back frame 14 can be further improved, but the upper auxiliary engagement claw 40 is separated from the upper end of the back frame 14 to the near side. Therefore, there is an advantage that the function of holding the back plate 15 immovably upward by the upper plate 16b ″ of the back frame 14 becomes more perfect.

  In the present embodiment, an intermediate engagement hole is provided in a vertical halfway height portion of the left and right side members 20 in the back frame 14 (for example, a vertex portion that protrudes most forward in a side view), and an intermediate engagement claw of the back plate is provided on this. It can also be fitted.

(6). Others The present invention can be embodied in various ways other than the above embodiment. For example, it can be applied to a chair whose backrest does not rock. When applied to a rocking chair, various rocking mechanisms can be employed.

  The back frame may be generally rectangular when viewed from the front, and may be trapezoidal or inverted trapezoidal. For example, the back frame can be formed in a Japanese character shape having an intermediate member between the upper member and the lower member, and when a back cover is provided, the back frame can be configured to cover the entire back plate. is there. Further, the back frame can be processed into a single piece by pressing, for example, using a single steel plate as a material. The tilting frame can also be a single structure.

  It is also possible to configure all or a part of the constituent members of the back frame with square pipes or C-shaped channel members. Furthermore, when each member is formed in a groove shape, it can be opened forward. It is.

  The engagement means is not limited to the combination of the engagement hole and the engagement claw as in the embodiment. For example, the engagement member protrudes outward, inward, or both sides to the side member of the back frame. On the other hand, it is also possible to provide the back plate with a hook-like engagement claw that is fitted onto the locking bar from above.

  It is also possible to form the side member in a groove shape opened forward and to provide a locking bar inside thereof. Alternatively, it is also possible to form an upward hook-like engagement claw on the front surface of the side member and fit the engagement claw of the back plate into this from above. Alternatively, when the back frame includes an upper member and a lower member, it is possible to form an engaging claw that fits the upper member and the lower member from above on the back plate (in this case, the upper member). And the lower member itself functions as an engagement means.)

  The present invention includes a case where the backrest is not provided with a back cover. In this case, the stopper means is naturally fixed to the back frame with a screw or the like as a dedicated member. Further, in this case, a back-facing stopper portion located below the stopper means may be provided on the back surface of the back plate. The stopper means may be, for example, a screw screwed and fixed to the back frame. The stopper portion (or stopper material) may be attached to the back frame by a fitting method using elastic deformation.

It is the perspective view which looked at the chair which concerns on embodiment of this invention from the front. (A) is a front view, (B) is a side view. It is an isolation | separation perspective view of the location centering on the seat. It is a perspective view which shows the attachment structure of a back frame. It is a separation perspective view of a mechanism part. (A) is the isolation | separation perspective view of a back frame and a reinforcement member, (B) is the perspective view which looked at the reinforcement member from the front. (A) is the isolation | separation perspective view of a back frame and a back inner shell, (B) is a perspective view of an upper engagement nail | claw. It is a figure which shows the structure of a back frame. It is a separation perspective view of a back frame and a back inner shell. (A) is a cross-sectional plan view of the backrest, (B) is a partially enlarged view of (A), (C) and (D) are cross-sectional views taken along the line XC-XC in FIG. 9 (A) after assembly, XD-XD FIG. 10A is a cross-sectional view taken along the line XIA-XIA in FIG. 10 showing only the upper portion of the backrest, and FIG. 10B is a cross-sectional view taken along the line XIA-XIA in FIG. FIG. (C) is a sectional view taken along the line XIC-XIC of FIG. 10 showing only the lower part of the backrest. It is a separation perspective view of a back frame and a back cover. FIG. 11A is a vertical side view of the upper left and right middle portions of the back frame, and FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Leg apparatus 2 Base 3 Seat 4 Backrest 14 Back frame 15 Resin inner shell made of resin as an example of back plate 16 Back cover 16b ″ Upper plate of back cover also serving as stopper means 23 Tilt frame 20 Back frame side member 20a Front plate 20b Inner plate 20c Outer plate 21 Upper member of back frame 22 Lower member of back frame

Claims (3)

A seat and a backrest, the backrest comprising a resin back inner shell with a cushion stretched on the front surface, and a metal back frame disposed on the back side of the back inner shell;
The back inner shell and the back frame are configured to hold the back inner shell so as not to move forward and to the left and right by moving the back inner shell backward so as to overlap the back frame and then moving downward. In addition, the back frame is provided with stopper means for holding the back inner shell so as not to be detached upward from the back frame by being positioned above a part of the back inner shell.
Chair. The back frame is made of a metal plate, and is formed in a substantially quadrangular shape when viewed from the front with left and right side members that are vertically long and left and right upper and lower members, and the left and right side members have a front plate and are opened rearward. A plurality of engagement grooves are formed on the front plate of the side member so as to be separated from each other vertically, and an engagement claw that fits into the engagement hole is formed on the back inner shell. The engagement hole and the engagement claw constitute the engagement means,
Furthermore, a back cover that covers the back frame from behind is attached to the back frame, and a stopper portion is formed on the back cover.
The chair according to claim 1. The back inner shell is formed with an auxiliary engagement claw having a side-view-like shape that holds the upper end portion of the front plate of the side member in the back frame from above, so that the front plate of the side member and the back inner shell are formed. The auxiliary engaging claw of the shell also constitutes the engaging means,
Further, the back cover is formed with an upper plate that covers the upper member of the back frame from above, and the left and right end portions of the upper plate are positioned above the auxiliary engagement claws of the back inner shell. The left and right ends of the upper plate in the cover form the stopper portion,
The chair according to claim 2.

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