JP2014004470A - Backrest of chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent backrest of a chair that does not give a sense of discomfort to a human body.SOLUTION: A backrest board 16 includes a body; many vertical projections 37 are formed at the front of the body; and both ends of waist pads 16a area are fixed to a back frame 18 in the way the back frame 18 supports both ends. The surface of the body is exposed between the adjacent projections 37. The board thickness of the projection 37 is smaller than the space between the adjacent projections 37. The backrest board 16 comprises a rubbery resin material, having such elasticity (flexibility) that allows a human to press and bend easily by holding with hands if it is not fixed to the back frame. Because it is rubbery, it properly deforms along a human body, which can give a user a comfortable lean-back experience.

Description

  The present invention relates to a chair backrest.

  A number of improvements have been proposed to improve the comfort and comfort of a seated person in a chair with a backrest. As an example, Patent Document 1 discloses that a chair having a backrest plate and a seat plate made of a thin flexible material can be fitted to a human body by forming a large number of longitudinal slit groups on the back plate and the seat plate. An improved chair is disclosed.

  On the other hand, the back of an office chair has a structure in which a resin inner shell is attached to a resin outer shell and a cushion material is stretched on the front surface of the inner shoulder. In Document 2, by forming a horizontal group of slits on the left and right side portions of the inner shell (inner plate), it is possible to allow the left and right side portions of the inner shell to be greatly bent and deformed backward, and the inner shell A chair has been disclosed in which the upper and lower parts of the board are attached to the back frame and the left and right sides are in a free end state, thereby greatly improving the ease of deformation.

Japanese Patent No. 2969290 Japanese Patent Laying-Open No. 2005-152087

  By the way, the conventional inner shell (inner plate) of the backrest is designed so that the front surface thereof is a smooth surface without unevenness. This is due to the fact that the inner shell is made of a resin that feels soft to the touch even though it is bent (bent), such as polypropylene, and avoids the user from feeling pushed up and uncomfortable. Therefore, it can be said that the front surface of the inner shell is smooth.

  On the other hand, the distribution of nerves on the surface of the human body is not uniform, and there are sensitive and insensitive parts. In addition, the smoothness of the front surface of the inner shell of the backrest does not necessarily improve the fit, and the inner shell may partially hit the person's back and feel uncomfortable. In addition, the backrest fit and cushioning are greatly influenced by the material that hits the person's back.

  The backrest disclosed in Patent Document 2 is based on a flat inner shell and devised the mounting structure and the shape of the slit group, and can provide much higher fit and cushioning than conventional products. did it. The main object of the invention of the present application is to provide a backrest that does not feel pushed up to a human body from a viewpoint different from Patent Document 2.

  For example, in the case of an inner shell (back plate) of a chair, the form and material are major factors as factors that provide a comfortable seating comfort for the seated person. Conventionally, the surface of the inner shell is smoothed to ensure softness to the human body, and the inner shell is made of a material having relatively high rigidity such as polypropylene from the viewpoint of form retention. It can be said that resin was used. The inventor of the present application has completed the present invention by studying both the form and the material of the body support plate such as the inner shell for the backrest from the viewpoint different from the prior art.

  The present invention includes the invention described in each claim. Of these, the invention of claim 1 includes a resin back plate, and the back plate includes a main body that forms an outer shape of the back plate, and a group of protrusions or protrusions are formed on the front surface of the main body. Is formed with the surface of the main body exposed between adjacent ridges or protrusions, and the body of the seated person directly supports the front surface of the ridge group or protrusion group. It has come to be.

  The invention of claim 2 is a preferred example of claim 1, and in this invention, a large number of upper and lower ridges are integrally formed on the front surface of the main body, and the thicknesses of the ridges are adjacent to each other. It is smaller than the interval between the ridges.

  A third aspect of the present invention is the method according to the first or second aspect, wherein the main body is bent in a side view so that a waist resting portion located at a height located at a waist portion of a seated person is located in the forefront. On the front surface, a group of a plurality of vertically elongated ridges are integrally formed in a state where the height is highest at the waist pad portion.

  As described above, the inner shell of the backrest in the conventional chair has a smooth surface, but when the present inventor applied to the inner shell of the backrest, the support plate as in claim 1 of the present invention. Even if a ridge group or a projection group is formed on the surface of the film, it does not feel a particular sense of incongruity, but rather it can be expected that the contact with the body can be suppressed. And when the slit group is formed as in Patent Document 1, since the slits are open on both the front and back sides of the support plate, it tends to widen the interval between the adjacent slits due to human body pressure and deforms excessively. However, if the ridge group or the projection group is formed as in claim 1 of the present application, the backrest plate can suppress the spread of the curve excessively and ensure the support stability to the human body. it can.

  In the case of claim 1, the direction of the ridge is not limited. However, if the ridge is formed so as to extend long in the vertical direction long in the height direction of the person as in claim 2, it is preferable that there is no sense of incongruity.

  In addition, for example, when a person's body is directly received by a backrest board, the vertical sliding of the body becomes extremely good, and there is an advantage that so-called shirt drooping can be prevented.

It is a schematic perspective view of the chair which concerns on 1st Embodiment. (A) is a schematic right side view of the chair, and (B) is a cross-sectional view taken along the line BB of (A). It is a schematic rear view of a chair. It is a mechanism figure which shows the interlocking relationship between a seat and a backrest. (A) Schematic rear view, (B) is a side view of the backrest, (C) is a sectional view taken along the line CC of (A), and (D) is a sectional view taken along the line DD of (A). FIG. 6 is a sectional view taken along line VI-VI in FIG. 3. FIG. 7 is a sectional view taken along line VII-VII in FIG. 3. FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 3. It is a figure which shows other embodiment. It is a figure which shows other embodiment.

  Next, an embodiment of the present invention will be described with reference to the drawings. 1-8 has shown 1st Embodiment applied to the backrest board of a chair (office revolving chair).

(1). Outline of Chair FIG. 1 is a schematic perspective view of a chair, FIG. 2 (A) is a schematic right side view of the chair, (B) is a sectional view taken along line BB of (A), and FIG. FIG. First, an outline of the chair will be described based on these drawings.

  The chair includes a leg 1, a seat 2, and a backrest 3. The leg 1 includes a group of branch legs 4 extending horizontally and a leg column (gas cylinder) 5, and a base 6 having an upward opening is attached to the upper end of the leg column 5. The seat 2 includes a seat receiving frame 7 and a seat plate (not clearly shown) attached to the upper surface thereof, and a cushion is stretched on the seat plate.

  On both the left and right sides of the base 6, there are disposed swing frames 8 whose rear portions are back struts 8a. The swing frame 8 has a left and right longitudinal direction on the base 6 so as to tilt backward with its front end as the center. The first support shaft 9 is attached. The front portion of the seat receiving frame 7 and the base 6 are connected by two left and right front support links 10, and the rear portion of the seat receiving frame 7 and the left and right swing frames 8 are connected by two rear support links 11. It is connected. As shown in FIG. 3, the left and right back struts 8 a are connected to each other with a reinforcing material 8 c at the upper part thereof.

  The front support link 10 is connected to the base 6 by a left and right longitudinal second support shaft 10 ′, and is rotatably connected to the seat receiving frame 7 by a third support shaft 12. The link 11 is pivotally connected to the swing frame 8 by a fourth support shaft 13 and is also rotatably connected to the seat receiving frame 7 by a fifth support shaft 14. The front and rear support links 10 and 11 are tilted backward in a side view when no person is seated. For this reason, when a person is seated, the front and rear support links 10 and 11 tilt backward. The hole formed in the base 6 so that the second support shaft 10 ′ is fitted is a long hole extending substantially front and rear in a side view.

  As simply shown in FIG. 2A, a compression coil spring 15 that elastically supports the backward movement of the second support shaft 15 is disposed inside the base 6. The compression coil spring 15 is an example of a spring means that elastically supports the rearward tilting of the backrest 3, so that the compression coil spring 15 is not contracted or deformed at all when the person is seated, and is contracted and deformed when the person leans against the backrest 3. Strength is set. As can be easily understood from FIG. 2, in the chair of the present embodiment, the second support shaft 10 ′ slides along the long hole so that the seat 2 moves backward and backward in conjunction with the back tilt of the backrest 3. Needless to say, it may be a type that only the backrest 3 tilts backward.

  The backrest 3 is mainly composed of a backrest plate 16 to which the present invention is applied. In the drawing, the back plate 16 is exposed in front of it. The backrest plate 16 inclines backward as a whole in a state in which no person is leaning on, and is curved in a concave shape as a whole in plan view. In addition, an appropriate vertical range centering on a portion of the lower portion that corresponds to the waist of a seated person is curved in a forwardly convex shape in a side view (this portion is referred to as a waist rest portion and is indicated by reference numeral 16a). Furthermore, the upper part is a shoulder pad 16b curved in a forward convex shape. Of course, it is also possible to make the upper part a simple rearward tilted posture without providing the shoulder pad 16b, and instead of or in addition to providing the shoulder pad 16b, a headrest is provided integrally. Is also possible.

  The back portion of the shoulder rest portion 16b of the backrest plate 16 is attached to the back column 8a via a left and right upper frame 17. The left and right end portions of the backrest plate 16 of the backrest plate 16 are attached to the forward tilting frame 20 via the lower frame 18 and the sixth shaft 19, and the left and right ends of the backrest plate 16 are further fixed. The lower end of the intermediate portion (and hence the lower end of the left and right intermediate portion of the waist pad portion 16a) is connected to the bracket 22 of the forward tilt frame 20 via the seventh support shaft 21 (the forward tilt frame 20 will be described later). .)

(2) Automatic backrest advancement mechanism By the way, when a person sits down on a chair, he does not always sit deeply and often sits shallowly. In this case, the posture of the person may become unstable if the backrest does not hit the person's waist. Therefore, in this embodiment, when a person is seated, the lower part of the backrest plate 16 (in other words, the lower part of the backrest 3) is moved forward, so that the person's waist is supported by the waist rest 16a of the backrest board 16 even if the person sits shallowly. In addition, when a person sits deeply, the waist resting portion 16a of the backrest plate 16 is retracted against the spring means so that the person is not prevented from sitting deeply. This point will be described with reference to FIG.

  The aforementioned front and rear support links 10 and 11 are elements of interlocking means (automatic advance mechanism) for advancing the lower part of the backrest 3 when a person is seated, and the front and rear support links 10 and 11 are inclined rearward in a side view. Accordingly, the seat 2 is moved downward while being tilted by a person sitting, and the backward tilting and lowering motion of the seat 2 is caused by the forward movement of the waistrest portion 16a of the backrest plate 16 by the interlocking means shown in the skeleton diagram of FIG. Is converted to This will be described below.

  As a part of the interlocking means, the forward tilt frame 20 is connected to the rear part of the left and right swing frames 8 by a left and right eighth support shaft 24. The rear part of the forward tilting frame 20 is an upright part 20a extending upward in a side view, and the lower frame 18 is rotatably connected to the upright part 20a by an eighth support shaft 24. The lower end of the backrest plate 16 is connected to the bracket 22 formed on the portion 20 a by the sixth support shaft 19.

  Accordingly, when the forward tilting frame 20 moves forward, the waist rest 16a of the backrest plate 16 moves forward. In this case, the upper frame 17 to which the upper portion of the backrest plate 16 is attached can be moved up and down with respect to the back column 8a. By attaching it, it is easy to make the hip rest 16a of the backrest plate 16 move forward greatly. The structure in which the upper frame 17 is moved up and down with respect to the back column 8a is shown in FIG.

  That is, as shown in FIG. 2B, the hollow body 26 is connected to the upper frame 17 with two upper and lower horizontal pins 25, and the hollow body 26 is provided at the upper end of the back column 8a. The guide tube 27 is slidably fitted up and down. The upper frame 17 is urged upward by a spring 28 built in the guide tube 27. Although the upper end of the spring 28 is supported by the lower horizontally long pin 25, other support structures may be adopted. Needless to say, various structures can be adopted as the mechanism for supporting the upper portion of the backrest plate 16 so as to be movable up and down.

  Returning to FIG. 4, the description of the interlocking means will be continued. The eighth support shaft 24 that couples the forward tilting frame 20 to the swing frame 8 is inserted into the left and right first interlocking links 29 arranged on the left and right outer sides of the forward tilting frame 20, and is connected to the first interlocking link. The rear end of the link 29 and the forward tilt frame 20 are connected by a ninth support shaft 30. Accordingly, the forward tilting frame 20 and the first interlocking link 29 rotate together around the eighth support shaft 24. The first interlocking link 29 has a forward projecting portion 29 a that extends forward from the eighth support shaft 24.

  A second interlocking link 31 extending forward from the eighth support shaft 24 is disposed on the left and right outer sides of the first interlocking link 29, and the eighth support shaft 24 passes through the rear end of the second interlocking link 31. . Therefore, the front end portion of the forward tilting frame 20, the first interlocking link 29, and the rear end of the second interlocking link 31 are connected by the eighth support shaft 24. The second interlocking link 31 is rotatable about the eighth support shaft 24, and a long hole 31a for allowing relative rotation of both members 31 and 11 is formed at the front end portion thereof. The fifth support shaft 14 connecting the rear support link 11 and the seat receiving frame 7 passes through the elongated hole 31a.

  The left and right second interlocking links 31 are connected by a left and right longitudinal rear auxiliary bar 32, and a forward protruding portion 29 a of the first interlocking link 29 hits the rear auxiliary bar 32 from above. In addition, a rear torsion spring 33 is fitted on the eighth support shaft 24 as an example of a backrest advance spring means, and the rearward end portion 33a of the rear torsion spring 33 is connected to the ninth support shaft 30 (or the first interlocking member). The forward end 33b is applied to the link 29) from below, and the forward end 33b is applied to the rear auxiliary bar 32 (which may be applied to the second interlocking link 31) from below. Accordingly, the first interlocking link 29 and the forward tilting frame 20 are biased by the rear torsion spring 33 in a direction tilting forward about the eighth support shaft 24. In other words, the waist pad portion 16 a of the backrest plate 16 is urged by the rear torsion spring 33 in the advancing direction.

  On the other hand, the left and right rear support links 11 are integrally connected by a front bar 34, and a front torsion spring 35, which is an example of a spring means, is fitted onto the fourth support shaft 13, and one end 35a thereof is connected to the front part. The lower end 35b of the front torsion spring 35 is applied to the auxiliary bar 34 (or the rear support link 11) from below, for example, the rear surface of the base 6 (or the lower surface of the swing frame 8). Accordingly, the rear support link 11 is urged forward by the front torsion spring 35. The front and rear support links 10 and 11 are held in a forward rotation posture by stopper means. As the stopper means, for example, the rear support link 11 may be applied to the lower surface of the seat receiving frame 7. Further, as a stopper means for restricting the backward tilting posture of the front and rear support links 10, 11, the fifth support shaft 14 may be applied to the swing frame 8 from above.

  When a person is seated, the seat 2 is moved downward and tilted against the front torsion spring 35, and the second interlocking link 31 is tilted forward, whereby the front auxiliary bar 34 is lowered. Then, since the restriction by the front auxiliary bar 34 for the first interlocking link 29 is lost, the forward tilt frame 20 is tilted forward by the rear torsion spring 33. Thereby, the waist pad 16a of the backrest plate 16 moves forward. As a result, even if a person sits shallow, the person's waist is supported by the waist rest 16a. Further, even if the second interlocking link 31 is tilted forward, the forward projecting portion 29a of the first interlocking link 29 is allowed to tilt backward against the rear torsion spring 33. The backrest 16a of the backrest plate 16 does not move forward. The spring force of the front torsion spring 35 is set larger than the spring force of the rear torsion spring 33.

  Other mechanisms can be employed as means for advancing the waist rest portion 16a of the backrest plate 16 when a person is seated. It is also possible to advance the entire backrest plate (or backrest) 16 by seating a person. Furthermore, it goes without saying that the chair of the present invention does not require a part or the whole of the backrest plate to move forward when a person is seated.

(3). Form and structure of the backrest plate Next, details of the form of the backrest plate 16 will be described mainly based on the drawings of FIG. 5A is a schematic rear view, FIG. 5B is a side view of the backrest, FIG. 5C is a sectional view taken along the line CC of FIG. 5A, and FIG. 5D is a sectional view taken along the line DD of FIG. 6 is a sectional view taken along line VI-VI in FIG. 3, FIG. 7 is a sectional view taken along line VII-VII in FIG. 3, and FIG. 8 is a sectional view taken along line VIII-VIII in FIG.

  The backrest plate 16 is made of a resin material having an apparent rubbery property, for example, a resin containing an elastomer. When the backrest plate 16 is not assembled in a chair, a general adult can easily hold it by hand and bend it. Can be deformed. In general, it can be said that in many cases, it has a dull appearance like urethane rubber. If any material is strictly measured, not only resin, it will be elastically deformed against bending, pulling and compression, but the degree of rubbery material is remarkable, and the backrest plate 16 of this embodiment is compressed. It is apparent that it has rubber-like properties to the extent that it can be visually confirmed that it is elastically deformed.

  The backrest plate 16 includes a main body that forms the outer shape of the backrest plate 16, and a large number of vertically long ridges 37 and 38 are formed on both the front and back surfaces (front and rear surfaces) of the main body. In both cases, the flat cross section is uneven. In addition, the code | symbol 16 has shown the part of the main body among the backrest boards.

  The front ridges 37 formed on the surface of the main body of the backrest plate 16 are set so that the height increases toward the left and right end portions of the waist rest portion 16a except for the left and right intermediate portions. . This is because the curvature of the backrest plate 16 can be made to follow the human waist without making it too large. Further, the higher the height of the front protrusion 37, the easier it is to fall and deform, and the contact with the human body becomes softer. However, in this embodiment, the effect of softening the contact with the left and right back portions of the human waist is also exhibited. It can be said that.

  The height of the front ridge 37 is substantially constant at the portions other than the left and right side portions of the waist pad portion 16a. Further, the height of the back ridge 38 is substantially constant throughout. The height of the front ridges 37 and the back ridges 38 with respect to the thickness of the main body of the backrest plate 16 can be set as necessary. The front or back surface of the main body of the backrest plate 16 is exposed between the adjacent ridges 37 and 38, and the plate thickness of the ridges 37 and 38 is smaller than the interval between the adjacent ridges 37 and 38. It has become. The pitch of the adjacent ridges 37 and 38 can be set in consideration of various factors such as the degree of contact with the human body and the design. The density (in other words, pitch) of the ridges 37 and 38 on the front surface, the back surface, or both front and rear surfaces of the main body can be varied depending on the location.

  In this embodiment, the front ridges 37 and the back ridges 38 are arranged so as to overlap the front and rear of the main body, but the front and rear ridges 37, 38 are shifted to the left and right, or the front and rear ridges 37, 38 It is also possible to change the left and right pitch. It is also possible to make the backrest plate 16 a thin transparent or semi-transparent or translucent structure. In such a case, if the front and rear ridges 37 and 38 are formed at the same position, the ridge 37 , 38 are aligned so that the appearance is good. Further, the backrest plate 16 is elastically deformed so that the shape in plan view changes. However, if the positions of the front and rear ridges 37 and 38 are coincident, there is an advantage that such deformation is easily performed.

  As shown in FIGS. 5C and 6, a bearing 39 for attaching to the lower frame 18 protrudes from the back of the left and right ends of the backrest 16 a of the backrest plate 16. 39 is connected to the lower frame 18 by, for example, a bolt (which may be a pin) 40 so as to be relatively rotatable. The lower frame 18 is warped in a concave shape in plan view, and bracket portions 18a provided on both sides sandwiching the left and right intermediate portions are connected to an upright portion 20a of the forward tilting frame 20 by a sixth support shaft 19. .

  Between the lower frame 18 and the waistrest portion of the backrest plate 16, the waistrest portion 16a of the backrest plate 16 is deformed so as to sink backward due to human body pressure (deforms so that the curvature of the forward-facing recess increases). There is enough space to allow that.

  A rearward boss portion 41 is formed at the lower end of the left and right intermediate portion of the backrest plate 16, and this boss portion 41 is connected to the bracket 22 of the forward tilting frame 20 by the seventh support shaft 21 so as to be relatively rotatable. Yes.

  As shown in FIG. 8, the upper end of the backrest plate 16 is a horizontal piece 42 protruding rearward, and an upper horizontal rib 43 extending horizontally is formed below the horizontal piece 42. A forward-facing portion 17 a of the upper frame 17 is sandwiched between the horizontally long ribs 43. In addition, the upper frame 17 is curved in a concave shape facing forward in a side cross section, and on the lower back surface of the shoulder rest portion 16b of the backrest plate 16 is formed a thick lower horizontal rib 44 that overlaps the lower portion of the upper frame 17. Yes. For the attachment of the upper frame 17 and the backrest plate 16, an appropriate means such as forced fitting, screwing, or adhesion can be adopted.

  Since there is a space between the upper frame 17 and the shoulder frame 16b, the shoulder pad 16b can be somewhat elastically deformed so as to sink backward. However, the shoulder pad 16b of the backrest plate 16 has high rigidity because of the presence of the upper and lower horizontal ribs 42 and 43, and therefore does not deform greatly. This is because if the backrest plate 16 is excessively deformed, it will be uncomfortable.

  In this embodiment, the back column 8a, the upper frame 17, the lower frame 18, and the forward tilt frame 20 constitute a back frame. Needless to say, the form of the back frame can be set freely. Needless to say, the back strut may be configured separately from the swing frame, and members such as the swing frame may not be a sheet metal product.

(4) Summary As already described, when a person is seated, the seat 2 is lowered and the waist rest portion of the backrest plate 16 moves forward. When the seated person leans against the backrest plate 16, the backrest plate 16 tilts backward. And since the backrest board 16 is elastically deformed greatly in a side view and a plan view, a high fit and cushioning properties can be ensured. Further, even when the person's body is directly received by the backrest plate 16, the front protrusion 37 does not receive a push-up.

  In the case of a material having a rubber-like property, it is excellent in softness and flexibility (elasticity) to the body, but for example, when a group of slits is formed, it is excessively spread and deformed, and the support function to the body is reduced instead. There is a fear. On the other hand, in this embodiment, since the protrusions 37 and 38 are formed on the main body while having rubber-like properties, the backrest plate 16 is not excessively spread and deformed, and the user is comfortable. You can experience leaning comfort.

  By the way, in the rocking chair, when leaning against the backrest, the relative position of the person's buttocks and the seat is constant, whereas the seat and the backrest tend to separate, so-called shirt-spinning phenomenon However, in this embodiment, since the lower frame 18 is in a concave shape in a plan view and the rear portion is connected to the forward tilting frame 20 in a plan view, when a seated person leans against the backrest plate 16, The lower frame 18 has a tendency to tilt forward in a side view, and the backrest plate 16 also has a tendency to descend. This prevents or suppresses an increase in the relative distance between the seat 2 and the backrest plate 16. , There is an advantage that the phenomenon of shirt drowning can be prevented or significantly suppressed.

  In addition, although the backrest plate 16 of this embodiment has the front surface exposed, as shown in FIG. 5C, a thin flexible surface plate 45 is stacked on the front surface of the backrest plate 16, As shown by a two-dot chain line in FIG. 5C, a cushion layer 46 may be provided on the front surface of the backrest plate 16 by an appropriate means such as insert molding. Of course, the surface plate 45 and the cushion layer 46 can be used in combination. The back surface may be left exposed or a cover may be provided.

  The upper part of the backrest plate may be attached to the upper frame 17 only at the left and right intermediate portions. Further, by attaching the backrest plate to the upper frame 17 at a position somewhat below the upper end thereof, a portion above the upper frame 17 is made a free end, and when the person leans, this free end portion becomes its root. It is also possible to configure so as to fall back and deform around the center.

  It is also possible to provide a lumbar support that forcibly pushes the waist rest 16a of the backrest plate 16, and the backrest plate 16 of the present embodiment is easily deformed. Therefore, when applied to a chair having a lumbar support, its value is further increased. Demonstrated.

(5). Other Embodiments FIG. 9 and FIG. 10 show other embodiments. In this embodiment, the backrest plate is denoted by reference numeral 48. In the example shown in FIG. 9A, when the protrusions 49 are formed on the front and back of the main body 48, the height of the protrusions 49 on the back surface is higher than the protrusions 49 on the front surface. In the example shown in FIG. 4, the protrusions 49 are formed only on the front surface.

  In the example shown in (C), when the ridges 49 are formed on the front and back of the main body 48, the thickness of the front ridge (not shown) is defined between the adjacent front ridges. The width is larger than 50. In the example shown in (D), vertical ridges 49 are formed on the surface of the main body 48, and a group of vertical ridges 49 and horizontal ridges 50 are formed on the back surface. In this case, the ease with which the support plate 48 bends is set to change between the vertical direction and the horizontal direction by forming the lateral protrusions 51 on the back surface in a concave shape in plan view. As indicated by the alternate long and short dash line, it is possible to form a horizontally long lateral protrusion 51 on the front surface. In the example shown in (E), narrow and high ridges 49 are formed on the surface of the main body 48, and low and wide ridges 49 are formed on the back surface.

  (F) In the example shown in (G), a group of protrusions such as a circle is formed on the front and back of the support plate ((G) is a cross-sectional view taken along line GG in (F)). The shape of the protrusion 52 can adopt a form of means such as a square. Between the adjacent protrusions 52, the front surface and the back surface of the main body 48 are exposed.

  In the example shown in FIGS. 10A and 10B, vertical and horizontal grid-like ridges 49 are formed on the front surface of the main body 48 ((B) is a cross-sectional view taken along line BB in (A)). In the example shown in (C), oblique grid-like ridges 49 are formed on the front surface of the main body 48. In the example shown to (D), the vertical protrusion 49 is formed in the front surface of a main body, and the horizontally long protrusion 49 is formed in the back surface ((E) is EE view sectional drawing of (D). .) (F) In the example shown in (G), the ridge 49 is formed inside the periphery of the main body 48, and in the example shown in (G), the ridge 49 is formed intermittently.

  Each of the above examples is a case where the backrest plate has an integral structure, but FIGS. 10H and 10I show examples in which a composite structure is formed by an insert molding method, a two-color molding method, adhesion, or the like. . Among these, in the example shown in (H), the flat base layer 48a and the main body 48b having the ridges 49 are integrated. The main body 48b is preferably made of a rubber material or a pure rubber material such as an elastomer. In the example shown in (I), only the protrusions 49 are made of a rubber-like material (thus, the main body 48 is not a rubber-like material).

(6). Others The present invention can be embodied in various ways other than the above embodiment. For example, the outer shape and thickness of the backrest plate (main body) can be variously set.

(7). Advantages of First Embodiment This embodiment includes a unique improvement related to a chair with a backrest. This point will be described next.

  There are various types of chairs, and various improvements are made according to the types. As an example, for example, prior art document 1 (Japanese Patent Publication No. 44-20784) discloses a chair whose seat leans forward when a seated person leans against the backrest, while prior art document 2 (Japanese Examined Patent Publication No. 46- Japanese Patent No. 27517) describes a chair in which when a person is seated, the seat tilts in a side view centering on a substantially middle portion of the seat, and the backrest tilts in conjunction with the rear tilt of the seat. ing. Both patent documents employ a kind of link mechanism as means for interlocking the backrest with the seat.

  In the case of the prior art document 1, there is no change in the posture of both the seat and the back when only a person is seated. It is intended to tilt the seat forward, and its purpose is to ensure a comfortable state by making it easier to stretch the human body in the locked state.

  On the other hand, in the prior art document 2, for example, when a person sits on the front part of the seat, the backrest greatly leans forward and pushes the person forward, and the user feels uncomfortable and shifts the sitting position backward. It will be. That is, in the prior art document 2, when a user sits on the front part of the seat, so-called “chong hanging” (or “choi hanging”), the user feels uncomfortable so that a correct sitting posture is taken. (End of background).

  When a person uses a chair, he does not necessarily sit deeply, but often sits shallowly. Since the use of chairs varies from person to person, the design philosophy of the chair also requires a user-friendly idea to minimize the burden on the user even if the sitting position is different (such as in offices). It is often necessary to sit down shallowly in business, so it is highly necessary to consider such usage conditions.)

  However, the thing of patent document 1 is only assumed that it is in a rocking state, and no consideration is given to what is called a shallow sitting. On the other hand, the thing of patent document 2 is trying to make the user put on the heel which sits down deeply, and it is hard to say that this also considers a user enough.

  Furthermore, in order to reduce the burden on the body of a person who has been seated, it is important to support the person's waist and make it easier to take a state where the back is stretched. A chair with a lumbar support that supports it in a concentrated manner is widespread, but since the thing of the prior document 2 tilts the entire backrest forward, the user of the chair is pushed by the upper part of the backrest with the backrest. As a result, the spine is not stretched, and therefore the lumbar support function cannot be secured in Patent Document 2.

  Further, in the configuration of the prior permission document 2, there is a problem that when a person sits shallowly, the seat is tilted forward, so that it is difficult for the person to take an upright posture with his upper body extended.

  The backrest support mechanism described in the present embodiment is also intended to improve the current situation, and it is an object to provide a more user-friendly chair. (In the above, the “problem to be solved by the invention” in the disclosure of the invention).

  In the present embodiment, as means for solving the above-described problems, a seat, a backrest on which a seated person's back and waist can hit, and interlocking means for projecting forward at least the lower part of the backrest when the person sits down. However, this interlocking means includes spring means for advancing at least the lower part of the backrest by the seating of a person, and the backrest can be moved backward against the spring means.

  Furthermore, the invention of this embodiment is preferably a. The chair has a swing frame having a back column (the back column may be an integral structure with the swing frame or a separate structure), and the upper part of the backrest is attached to the back column so as to be able to move down. Structure, b. The interlocking means includes a link mechanism, and the spring means for advancing at least the lower part of the backrest by seating is a torsion spring fitted on a shaft connecting the links; c. The interlocking means includes a backrest advance frame having an upright portion, and includes a configuration in which at least a waist rest portion of the backrest is connected to the upright portion of the advance frame so as to be relatively rotatable.

  According to this embodiment, when a person is seated, at least the lower part of the backrest protrudes forward, so that even if the person sits shallowly on the seat, the seated person's waist can be supported from behind by the backrest. That is, the backrest can exert a lumbar support function, and therefore, the burden on the user's body can be remarkably reduced even in a shallow sitting state such as a so-called chest.

  Since the backrest is moved forward by the spring means, for example, when the user sits down deeply, the backrest can be prevented from moving forward, and therefore there is no inconvenience when sitting up deeply. In this case, if a torsion coil spring is used as the spring means, the spring only needs to be wound around a shaft for connecting the links, so that the installation space for the spring is substantially unnecessary, and therefore the interlocking means can be remarkably compact. There are advantages.

  In addition, when a backrest advance frame with an upright part is used, the backrest advance frame can be arranged so as to be hidden under the seat or inside the back column, so that the interlocking means protrudes from the back of the chair or the left and right outside of the seat. This can be further reduced in size. Further, as in the embodiment, downsizing can also be achieved by configuring the interlocking means by a group of links and frames arranged on the left and right below the rear part of the seat. Each link and frame can be set in various cross-sectional shapes such as a plate shape, a pipe shape, and a solid bar shape. Moreover, when the forward-facing concave lower frame 18 is used in a plan view, the links can be gathered into the inner portion sandwiched between the left and right back posts, and therefore the size can be further reduced. (Effects of the invention).

2 seats 3 backrest 8 swing frame 8a back column 16 backrest plate 17 upper frame 18 lower frame 37, 38 ridge

Claims (3)

A backrest plate made of resin, and the backrest plate includes a main body that forms an outer shape of the backrest plate, and a group of convex stripes or a group of protrusions are adjacent to each other on the front surface of the main body. The body surface is exposed between or between the protrusions, and the body of the seated person is directly supported on the front surface of the group of protrusions or protrusions.
The back of the chair. The front surface of the main body is integrally formed with a plurality of vertically elongated ridges, and the thickness of each ridge is smaller than the interval between adjacent ridges,
The chair back according to claim 1. The main body is bent in a side view so that the waist resting portion located at the height located at the waist of the seated person is located at the front, and a group of a plurality of vertically elongated protrusions is formed on the front surface of the main body. , Is integrally formed in a state where the height is the highest at the location of the waist pad,
The chair back according to claim 1 or 2.

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