JP2005152087A - Chair and backrest thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chair superior in a fitness to the upper half of the body of seated person and comfortable to sit in. <P>SOLUTION: A backrest 3 is provided with an inner plate 21 made of a synthetic resin and front and back cushion layers 22 and 23, and an upper part of the inner plate 21 is mounted to a back frame 12. A lumber support 15 is arranged between the backrest 3 and the back frame 12 in such a way that its height is freely adjusted. The inner plate 21 is in a plate-like form bendable and deflectable in shape in its overall surface, and a part in contact with the lumbar support 15 serves as an easily deflectable main deflection tolerant area 25. An intermediate deflection tolerant area 26 and an auxiliary deflection tolerant area 27 continue above the main deflection tolerant area 25. Since the upper part of the inner plate 21 can be bent and deflected in shape while maintaining a protruding function by the lumbar support 15, it is possible to achieve a substantially high fitting property capable of highly smoothly following the physique of a seater and posture changes. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a chair and a backrest thereof.

  The chair back has various structures, but in the case of a swivel chair often used for office work, for example, an inner board made of synthetic resin (may be called a back board or a board) having a function as a strength member, Many have a laminated structure with a cushioning material stretched on the front.

  On the other hand, when a person sits on a chair, if the lumbar vertebra is accurately supported from behind, the burden on the lumbar vertebra and spine is reduced (that is, the posture is correct and unreasonable) and it is difficult to get tired. Therefore, a lumbar support for mainly supporting the lumbar spine is provided on the backrest.

  As an example, for example, in Patent Document 1, when the backrest has a structure in which a cushion material is stretched on the front surface of the synthetic resin inner plate, a slit is formed in a portion corresponding to the waist of the seated person on the inner plate. As a result, a deformation allowing portion that can partially protrude forward is formed on the inner plate, and a lumbar support (referred to as a protruding member in the publication) is disposed on the back side of the deformation allowing portion. It is described that the height can be adjusted with a scissors.

  In addition, in the patent document 2, the applicant of the present application forms a large number of slit groups in the inner plate in a chair with a lumbar support, so that the side cross-sectional shape and the flat cross-sectional shape are flexibly deformed. Disclosed backrest.

Improving sitting comfort in a chair is the most important issue. Supporting the backrest from behind with a lumbar support is intended to improve seating comfort by improving fit to the seated person. As another approach for enhancing the seating comfort, in a rocking chair, the seating person's waist is projected with the backrest when rocking. As an example, Patent Document 3 discloses a horizontal shape at the bottom of the inner plate. It is described that the inner plate is formed so as to bend around its lower part when it is locked by forming the slit.
Japanese Patent No. 3038174 JP 2003-164354 A JP 2003-275054 A

  As described above, improvement of sitting comfort is the most important issue in a chair, and for that purpose, it is important that the backrest fits the body of the seated person.

  However, in the case where the inner plate is only partially protruded by the lumbar support as in Patent Document 1, since the seated person's waist is partially protruded, the fit may be inferior. It was. It can be said that this point is the same in Patent Document 3.

  Further, for example, in Patent Document 3, since the backrest tends to bend in a side view, when it leans against the backrest, the seated person's shoulders and face will be warped upwards, so the upper body May become unstable and become unnatural. For example, if the user tries to face down to see the display of a personal computer in the locked state, the seated person has to put power on the shoulder and neck, so that the sitting comfort is not always good.

  On the other hand, according to the configuration of Patent Document 2, the backrest has excellent fit to the body of the seated person, and a comfortable sitting comfort can be obtained.

  This invention makes it a subject to develop the structure of patent document 2 further, and to obtain higher fitting property and sitting comfort.

  By the way, the physique of the person using the chair is various, and the posture when leaning on the backrest is also various. For example, the waistline and shoulder width vary from person to person, and the person may lean against the backrest in a posture in which the upper body is twisted or a posture in which the upper body is tilted to the left or right.

  In order to obtain high fit while leaning against the backrest, even if the physique and posture are mixed, it is necessary to apply as much pressure as possible to the seated person's body. It is required that the backrest bends and deforms following the differences in physique and posture.

  However, it can be said that the inner plates of Patent Document 1 and Patent Document 3 are merely deformed so as to be bent in a side view, and the conformability to the difference in physique and posture is low, so that the fit is not sufficient. On the other hand, in the structure of patent document 2, since the part which forms the slit group among inner plates can also deform | transform into the state twisted by planar view, the followable | trackability to the difference in a physique and a posture change is high. It can be said that it has excellent fit.

  The inventors of the present application have repeated research and experiments based on such knowledge, and have completed the present invention.

  The invention according to claim 1 is a backrest having a flexible structure as a whole so that substantially the whole can be bent and deformed by the leaning of the seated person, and the range including the portion where the waist of the seated person touches is most easily bent and deformed. The main deformation allowable area is formed, and the range above the main deformation allowable area is an auxiliary deformation allowable area that is less likely to bend and deform than the main deformation area.

  According to a second aspect of the present invention, in the first aspect, the main deformation permissible area and the auxiliary deformation permissible area are intermediate deformation permissible in that the ease of bending deformation is smaller than the main deformation permissible area and larger than the auxiliary deformation permissible area. It is continuous through the area.

  In the invention of claim 3, in claim 1 or 2, the backrest includes an inner plate made of synthetic resin and a cushion layer stretched at least on the front surface of the inner plate, and forms a slit group in the inner plate. To form a main deformation allowable area.

  According to a fourth aspect of the present invention, in the third aspect, the main deformation permissible area includes a center area extending along the longitudinal center line of the inner plate, and sides located on both left and right sides of the center area with a hollow hole extending vertically. And a slit group is formed in each of the center area and the left and right side areas.

  According to a fifth aspect of the present invention, in the third or fourth aspect, a resin cushion layer is integrally formed on the front surface and the back surface of the inner plate by an insert molding method, and the front and back cushion layers are formed in a bag shape. It is covered with the skin material formed.

  According to a sixth aspect of the present invention, in any one of the third to fifth aspects, a rib for attaching the inner plate to the back frame is provided below the auxiliary deformation permissible area of the back surface of the inner plate. It is provided integrally so as to extend over substantially the entire length on the left and right or a length close to it and to be connected to the inner plate only at both the left and right ends.

  The invention of claim 7 is a chair provided with the backrest according to any one of claims 1 to 6, wherein a lumbar support that pushes the main deformation permissible area from the rear is high on the back side of the main deformation permissible area. It is arranged to be adjustable.

  According to an eighth aspect of the present invention, in the seventh aspect, the inner plate is configured as in the sixth aspect, and the rib of the inner plate is fixed to the back frame.

  According to a ninth aspect of the present invention, in the chair according to the seventh or eighth aspect, the backrest is configured as in the fourth aspect, and the lumbar support can come into contact with the cushion layer through the hollow hole. .

  According to the present invention, since the entire backrest can be bent and deformed by the seated person's backrest, the backrest's deformation following the difference in the physique of the seated person and the change in posture is highly followable, and flexed so as to adapt to the body of the seated person. Can be deformed.

  By the way, if the entire backrest is bent and deformed in a uniform state (that is, the elastic strength is uniform throughout the entire backrest), the backrest will be excessively bent and deformed and the support of the body will become unstable, and the sitting comfort will be reduced. There is a possibility that it cannot be improved.

  On the other hand, in the present invention, since the range where the seated person's waist hits is the main deformation allowance area, the waist (lumbar vertebrae) is accurately determined according to the difference in physique when supported by the lumbar support as in claim 7. In addition, since the upper part of the backrest is an auxiliary deformation allowable area, the entire backrest can bend and deform so as to fit the body of the seated person while stably supporting the seated person's back. . For this reason, according to the present invention, it is possible to ensure high fit and stability in supporting the upper body of the seated person, thereby improving the sitting comfort.

  If comprised like Claim 2, since an elastic force can be gradually changed toward the auxiliary | assistant deformation | transformation permission area from a main deformation | transformation permission area, there exists an advantage which can improve the fit property of the backrest to a body more.

  In general, the backrest often has a laminated structure of an inner plate and a cushion layer, and in this case, as a method of varying the elastic force of the backrest, for example, the thickness of the inner plate can be changed. If the elastic force is changed by forming a slit group in the inner plate as in 3, there is an advantage that the inner plate can be reliably deformed and manufactured easily.

  When the inventors of the present application have repeated experiments, as a form of the main deformation permissible area, the main deformation permissible area is configured in a plan view and a side cross-section by a combination of a hollow and a slit group. It can be bent and deformed greatly in view, and can also be deformed to be twisted. As a result, the fit of the seated person, particularly the waist, can be remarkably improved, which is suitable.

  By the way, when a cushion layer is stretched on the inner plate, the cushion layer not only acts as a cushion but also acts as an elastic body that suppresses deformation of the inner plate. That is, the inner plate functions as a main elastic body, and the cushion layer functions as an auxiliary elastic body.

  And when configured as in claim 5, the front cushion layer and the back cushion are connected together through slit groups and cutout holes, and the inner plate is restrained from elastic deformation by the front and back cushion layers, Since it does not bend into an angular state and smoothly deforms with a gentle curvature as a whole, the fit to the seated person can be further improved. Further, since the cushion layer is also present on the back side of the inner plate, the skin material can be held in a taut state, and it has a soft appearance and an excellent aesthetic appearance.

  If the inner plate and the cushion layer are made of different resins, such as the inner plate is made of polypropylene resin and the cushion layer is made of foamable urethane resin, even if the cushion layer is insert molded, the mutual adhesion is extremely low. Therefore, the cushion layer can be easily peeled off during disposal and recycling, and the front and back cushion layers are separated from the inner plate in use by the anchor effect that the cushion materials on the front and back are connected to each other through slits and cutout holes. There will be no peeling. That is, it is possible to secure a holding function during use without impairing the ease of removal after disposal.

  As a method of attaching the inner plate to the back frame, for example, the inner plate can be screwed to the back frame. However, if the inner plate is formed with left and right longitudinal ribs and the back frame is fixed to this, the attachment work is easy. In addition, there is an advantage that the mounting strength of the inner plate can be increased. However, simply projecting a horizontally long rib makes it difficult for the inner plate to bend and deform due to the presence of the rib, making it difficult to obtain fit.

  In this respect, when configured as in claims 6 and 8, there is a gap between the rib plate except for the left and right ends and the inner plate, so that the deformation of the inner plate is hindered. There is almost nothing. Therefore, it is possible to secure the fit to the seated person while maintaining the ease of assembling the chair and securing the mounting strength.

  According to the ninth aspect of the present invention, it is preferable that an appropriate pressing feeling can be imparted to the seated person as compared with the case where the lumbar support is used to support the seated person through the inner plate.

  Next, an embodiment of the present invention will be described with reference to the drawings.

(1). Outline First, the outline will be explained. FIG. 1 is a side view of a chair. As shown in FIG. 1, the chair includes a leg 1 with a caster, a seat 2, a backrest 3, and an armrest device 4. The leg 1 is provided with a leg support 5 that is freely extendable and rotatable, and a support base 6 is fixed to the upper end of the leg support 5.

  The seat 2 is attached to a seat receiving bracket 8 via an outer shell 7, and the front end portion of the seat receiving bracket 8 is attached to the front end portion of the support base 6 so as to be able to tilt and retract backward by a first shaft 9. ing.

  Further, the front end portion of the metal plate tilting frame 10 is connected to the lower surface of the support base 6 near the rear portion by a second shaft 11 so that the tilting frame 10 can be tilted rearward, and the rear portion of the tilting frame 10 is made of a metal back frame 12. The backrest 3 is attached to the back frame 12.

  A portion of the tilting frame 10 that is behind the second shaft 11 and the rear portion of the seat frame 8 are connected to each other by a third shaft 13 so as to be relatively rotatable. For this reason, when the backrest 3 tilts backward, the seat 2 also moves backward while tilting back together. The back frame 12 is covered with a back cover 14, and a lumbar support 15 is disposed between the back frame 12 and the backrest 3.

  The members constituting the support mechanism such as the support base 6 are shown in the separated perspective view of FIG.

(2). Outline of the back part The back part 3 and the back frame 12 are configured with the lumbar support 15 as a main member. Next, the outline of the back portion will be described with reference to FIGS. 3 is a rear view, FIG. 4 is a rear view with a part omitted, FIG. 5 is a partially separated perspective view, FIG. 6A is a perspective view of the upper portion of the back cover 14, and FIG. Is a rear view of the back frame 12, and (C) is a cross-sectional view taken along the line CC of (B).

  6B, the back frame 12 is fixed to two center members (posts) 12a extending vertically on both sides of the longitudinal center line of the backrest 3 and the upper end thereof. The left and right upper members 12b are formed in a substantially T shape, and the lower part of the center member 12a is fixed to the tilting frame 10.

  As shown in FIG. 5, the tilting frame 10 is separated into left and right, and an intermediate bracket 16 extending so as to straddle the left and right tilting frames 10 is fixed by welding. The intermediate bracket 16 has a function of supporting the third shaft 13 and a function of attaching the armrest 4.

  The center member 12a of the back frame 12 is formed of a round pipe, and the upper member 12b has a groove shape with a cross-sectional rearward opening. The lower parts of the left and right upper members 12 are integrally fixed via a lower connecting bracket 17a, and the upper and lower mid-height portions are integrally connected via an intermediate connecting bracket 17b. Since the upper end of the center member 12a is welded to the upper member 12b, the intermediate coupling fitting 17b may be omitted.

  The back cover 14 is formed so as to cover the rear part of the tilting frame 10, and thus the back cover 14 has a substantially horizontal H-shape when viewed from the back. The lumbar support 15 is formed in a horizontally long shape so as to protrude from the left and right outer sides of the vertically long portion of the back cover 14.

  As shown in FIG. 5, a locking gas cylinder 18 extending in the front-rear direction is disposed at a portion between the left and right tilt frames 10. The locking gas cylinder 18 is used to switch the backrest 3 between a free state in which the backrest 3 can freely tilt and a locked state in which the backrest 3 cannot be tilted, and to fix the backrest 3 at an arbitrary rearward tilt angle. The tip is attached to the bearing bracket 19 with a pin 20. The bearing fitting 19 is fixed to the lower connecting fitting 17a in the back frame 12.

(3). Structure of the backrest Next, the main structure of the backrest 3 will be described mainly with reference to FIGS. 7 is a partially broken rear view of the backrest 3, FIG. 8 is a rear view of the inner plate 21 constituting the backrest 3, FIG. 9 is a rear view of the backrest 3, FIG. 10 is a perspective view of the inner plate 21, and FIG. 12A is a vertical side view of the backrest 3 with the lumbar support 15 and the cushion omitted, and FIG. 12B is a vertical side view showing the cushion and the back cover 14. 13A is a sectional view taken along line XIIIA-XIIIA in FIG. 12, and FIG. 13B is a sectional view taken along line XIIIB-XIIIB in FIG. In FIG. 12B, the lumbar support 15 is simply displayed.

  For example, as can be understood from FIGS. 7 and 12A, the backrest 3 includes a synthetic resin inner plate 21, a front side cushion layer 22 stretched on the front surface, and a back surface stretched on the back surface of the inner plate 21. It is comprised by the side cushion layer 23 and the bag-shaped skin material 24 which covers the cushion layers 22 and 23 of the front and back. The inner plate 21 is made of, for example, a synthetic resin such as polypropylene, and is gently curved in a concave shape in a plan view.

  The cushion layers 22 and 23 on the front and back sides are made of, for example, foamed urethane resin, and are integrally formed on the inner plate 21 by an insert molding method in which the inner plate 21 is fixed in the cavity of the mold and then molded by injecting material resin. Has been.

  As shown in FIG. 8, the inner plate 21 includes a main deformation allowance area 25 that mainly constitutes a range in which the lumbar support 15 moves up and down (mainly a portion corresponding to the waist of the seated person), and intermediate deformations that are continuously connected to the upper end thereof. The allowable area 26, the intermediate deformation allowable area 26, and a series of auxiliary deformation allowable areas 27 are formed.

  The backrest 3 of the present embodiment is set to a height up to a portion slightly below the scapula when a general adult is seated, and the main deformation allowable area 25 is slightly wider than the lower half. The ratio of each area differs depending on the height of the backrest 3.

  The main deformation allowance area 25 includes a center area 25a extending along the vertically long center line 28 and left and right side areas 25b disposed on both sides thereof, and the center area 25a and the side area 25b are arranged vertically. A cutout hole 29 extending in the direction is formed. The lower portions of the center area 25a and the side area 25b are connected together.

  In the center area 25a, groups of center slits 30 extending in the left-right direction are formed in multiple stages. The center slits 30 are alternately arranged in a closed type and communicated with the hollow holes 29 (of course, other forms may be used).

  In the side area 25b, a group of side slits 31 extending in a substantially horizontal shape is formed in multiple stages. The groups of side slits 31 are alternately arranged with the ones that are open to the outside of the inner plate 21 and the ones that are open toward the hollow holes 29. For this reason, the side area 25b bends the band in a zigzag shape. It is like a form.

As described above, the main deformation permissible area 25 is obtained by dividing into the center area 25a and the side area 25b through the cut-out holes 29 and forming the groups of slits 30 and 31 in the center area 25a and the side area 25b, respectively. Can be easily bent and deformed so that the plane cross-sectional shape and the vertical cross-sectional shape can be changed individually or sometimes. Therefore, the flat cross-sectional shape and the vertical cross-sectional shape easily protrude forward by pressing by the lumbar support 15, and the body of the seated person When pressure is applied, it can easily bend and deform (that is, it has a flexible structure).
A side slit 31 similar to the side area 25b is formed in the intermediate deformation permissible area 26. Therefore, although not as large as the main deformation permissible area 25, the structure is considerably flexible. Needless to say, the left and right side portions of the intermediate deformation allowance area 26 are easily bent in the front-rear direction, and so to speak, can be elastically deformed while having a core.

  The auxiliary deformation allowable area 27 is not particularly provided with a softening means such as a slit. Therefore, although elastic deformation can be performed by the body pressure of the seated person (pressure acting by leaning), the degree thereof is considerably smaller than the intermediate deformation allowable area 26. Specifically, the elastic strength is set to such an extent that a general adult leans against it.

  A group of through holes 32 is formed in the auxiliary deformation allowable area 27. The main purpose of the through hole 32 is to connect the front and back cushion layers 22 and 23 through resin during insert molding, but it also contributes somewhat to making the auxiliary deformation allowable area 27 easier to bend and deform.

  At the lower end of the auxiliary deformation permissible area 27 (or the boundary between the intermediate deformation permissible area 26 and the auxiliary deformation permissible area 27), a rib 33 that extends over the entire length of the inner plate 21 protrudes rearward.

  The rib 33 is for fixing to the back frame 12, and the back surface thereof is gently curved in a backward convex shape with a smaller curvature than the curved curvature of the inner plate 21 in plan view. Further, as can be understood from FIG. 11, the rib 33 is formed in an L-shaped cross section as a whole. Of course, other forms such as a square cross section may be used. Further, the rib 33 may have a length shorter than the entire length of the inner plate 21 on the left and right.

  The rib 33 is integrated with the inner plate 21 via a connecting portion 33a constituting a certain range of the left and right end portions 33a, and a gap 34 (between the inner plate 21 is provided between the left and right connecting portions 33a. There is a slit in the vertical direction.

  Due to the presence of the gap 34, the reinforcing effect of the rib 33 on the inner plate 21 is remarkably reduced, the bending deformation function of the auxiliary deformation allowable area 27 is ensured, and the intermediate deformation allowable area 26 is directed to the auxiliary deformation allowable area 27. The elastic force gradually decreases.

  By the way, considering only the bending that changes the side cross-sectional shape, slits with front and rear openings may be formed at the upper and lower roots of the ribs 33 in the slit 21, but this cannot be expected to cause elastic deformation that changes the flat cross-sectional shape. . On the other hand, by providing the gap 34 as in the present invention, the auxiliary deformation allowable area 27 is bent and deformed so that both the shape in plan view and the side shape change while maintaining a certain level of waist strength. Can do.

  In order to mold the front and back cushion layers 22 and 23, the inner plate 21 is held in a state of being lifted in a pair of molds by a pin and melted in a cavity formed between the molds in that state. The raw material resin is injected, foamed and then die-cut. In this molding process, the resin fills the slits 30, 31 and the through holes 32. Due to the anchor effect that the resin enters the slits 30, 31, etc., the front and back cushions 22, 23 are connected together and firmly attached to the inner plate 21.

  As shown in FIG. 9, the skin material 24 is formed in a bag shape so as to cover the front and back cushion layers 22 and 23. The skin material 24 has a T-shaped opening on the back side so that most of the ribs 33 can be exposed, and a fastener 26 is provided in the vertically long opening. In addition, since the opening part of the skin material 24 is hidden with the back cover 14, there is no problem of beauty. Moreover, you may close the opening part of the skin material 24 with other closing means, such as a hook.

  Since the rib 33 is formed in the lower end part of the auxiliary deformation permissible area 27 in the inner plate 21, a recess of a rearward opening surrounded by the auxiliary deformation permissible area 27 and the rib 33 is formed. Some processing is necessary from the point.

  In this embodiment, as shown in FIG. 12 (B), the upper surface 23a of the back side cushion layer 23 is filled in the recess surrounded by the auxiliary deformation permissible area 27 and the rib 33, and the back side cushion By setting the back surface of the upper portion 23a of the layer 23 to be smoothly continuous toward the upper end of the inner plate 21, a smooth curved surface is set to be continuous upward from the upper end of the back cover 14. Of course, the back cover 14 may be extended to the upper end of the inner plate 21.

  By the way, in Patent Document 3, the upper part of the inner plate is recessed in a forward-facing concave shape, and a large number of rib groups are formed inside to form a rigid structure, and a cushion layer is overlaid on the end faces of the rib groups. And since the body pressure of the seated person is supported by the end face of the rib group through the cushion layer, when the chair is used for a certain period of time, the pressure on the skin material becomes stronger at the location of the rib, In the material, the pattern of the rib group may appear as a frayed pattern, which may impair the appearance.

  On the other hand, in the present invention, since the front surface of the inner plate 21 is continuous throughout and there is no rib, the surface pattern of the inner plate appears as a frayed pattern on the skin material during use. There is nothing at all, so that the aesthetics do not deteriorate.

  The entire surface of the skin material 24 may be the same color, or the front side and the back side may be different colors (for example, the front side should be a bright color such as blue, green, red, and engine, and the back side should be black or gray. It is also possible to use a subdued color. In addition, the material of the skin material 24 can be changed between the front side and the back side. Of course, it is possible to change both the color and the material. Various materials such as cloth and leather can be used as the material of the skin material 24.

  In general, in a rocking chair whose backrest tilts backward, the back of the back is often composed of a synthetic resin cover, but this often feels cold. In addition, there is a chair in which the entire back portion is covered with leather and the mechanical portion such as the back column is surrounded with leather, but this is poor in change.

  On the other hand, as in the present embodiment, when the back frame 14 and the back cover 14 are arranged on the back side of the backrest 3 while wrapping the entire backrest 3 with the skin material 24, a soft and warm impression is maintained while changing the design. Can be realized.

(4). Attachment of backrest Next, the attachment structure of the backrest 3 to the back frame 12 will be described with reference to FIGS. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 13A, and FIG. 15 is a cross-sectional view taken along line XV-XV in FIG.

  While the upper end portion of the center member 12a in the back frame 12 protrudes upward from the upper member 12b, the upper end portion of the center member 12a is below the rib 33 of the inner plate 21, as shown in FIGS. A cylindrical portion (hole portion) 36 to be fitted is formed.

  Then, as shown in FIG. 15, an enclosure frame portion 14a (see also FIG. 6) formed at the left and right end portions of the back cover 14 and a left and right end portion of the upper member 12b are screwed into a nut 36 and screwed into this. Fastened with (hexagon nut) 37.

  The rib 33 of the inner plate 21 is provided with a nut receiving portion 39 for fitting the nut 38 from the back side and holding it unrotatable. In the present embodiment, the back cover 14 and the upper member 12b are fastened together with screws 37, so that the mounting strength of the back cover 14 is high. In addition, it is also possible to fasten by screwing a self-piercing screw such as a tapping screw into the hole formed in the rib 33 without using the nut 38.

  Since the two center members 12a in the back frame 12 are fitted to the ribs 33 of the inner plate 21, the upper member 12b of the back frame 12 is simply fastened to the ribs 33a of the inner plate 21 with two screws 37 on the left and right. The inner plate 21 is firmly attached to the back frame 12 with a simple configuration.

  As can be understood from FIGS. 9 and 10, by providing a rib 33 protruding rearward on the upper portion of the inner plate 21, the center member 12 a of the back frame 12 and the main deformation allowable area 25 of the inner plate 21 are provided. A certain amount of space (gap) opens. The lumbar support 15 can be arranged in this space.

  The ribs 33 are not formed in a shape extending in the left-right direction, and only two islands project from the left and right end portions of the inner plate 21 and the back frame 12 is fastened to the island-shaped ribs. May be.

(5) Lumber Support Next, the lumbar support 15 will be described mainly with reference to FIGS. 16 is an exploded perspective view, FIG. 17A is a plan sectional view, FIG. 18B is a rear view, FIG. 18 is a perspective view of a member, and FIG. 19 is a sectional view taken along line XIX-XIX in FIG. 20 is a sectional view taken along line XX-XX in FIG.

  As described above, the lumbar support 15 has a horizontally long shape protruding from the vertically long portion of the back cover 14 to the left and right sides, and both left and right end portions are formed in an arc shape when viewed from the back, and the side cross section has a forward convex shape ( It is formed in a backward-facing concave shape.

  As can be understood from FIG. 17A, in this embodiment, the lumbar support 15 has support portions 15 a located on both the left and right sides excluding the intermediate portion thereof, and the back side cushion layer 23 on the main deformation allowing portion 25 of the inner plate 21. It can be contacted by solving. The support portion 15 a of the lumbar support 15 is set so as to overlap with the cutout hole 29 of the inner plate 21. For this reason, the pushing action of the lumbar support 15 can be made to act strongly on the occupant's waist through the cushion layers 22 and 23, and as a result, a comfortable pressing feeling can be given to the occupant.

  The lumbar support 15 can be brought into contact with the inner plate 21 over the entire length of the lumbar support 15 or only the intermediate portion can be brought into contact with the inner plate 21 (in the latter case, from the back cover 14 of the lumbar support 15). The part exposed to the outside is the operation knob). A fly-like support mode in which two portions of the left and right intermediate portions and the left and right end portions hit the main deformation allowing portion 20b of the inner plate 21 can also be adopted.

  The rear surface of the lumbar support 15 is formed with a semicircular upper and lower guide portion 41 that fits in the center member 12a of the back frame 12, and the lumbar support 15 can be smoothly moved up and down. The lumbar support 15 is provided with a slider 42 made of synthetic resin. The slider 42 is fixed to the lumbar support 15 with a screw 44 through a pressing plate 43.

  The slider 42 includes a front receiving plate 42a interposed between the lumbar support 15 and the center member 12a, a rear receiving plate 42b that hits the back surface of the center member 12a, and a spring receiver 42c provided at the upper and lower intermediate portions. A spring 45 that compresses and deforms in the front-rear direction is built in the spring receiver 42 c and is held by a pressing plate 43 so that it cannot be removed. The state in which the center member 12 a is sandwiched by the slider 42 is held by the spring 45, and a frictional resistance is applied to the center member 12. For this reason, the lumbar support 15 does not slide down.

  As shown in FIG. 20, the slider 42 is provided with an engaging claw 42 c that is caught on the edge of the pressing plate 43. For this reason, the pressing plate 43 is held so as not to drop by simply pressing the pressing plate 43 against the slider 42. For this reason, there is no need to hold the holding plate 43 by hand when screwing the screws 44, and there is an advantage that the lumbar support 15 can be easily attached.

  For example, as shown in FIG. 11, a stopper piece 46 that extends downward at the left and right intermediate portions is integrally formed at the lower end of the inner plate 21. As shown in FIG. 12, the stopper piece 46 is located between the lower connecting bracket 17 a of the back frame 12 and the gas cylinder mounting pin 20. That is, the stopper piece 46 is prevented from moving largely in the front-rear direction by the lower connecting bracket 17a and the gas cylinder mounting pin 20, and is allowed to move in the vertical direction.

  For this reason, the backrest 3 is allowed to be deformed by the lumbar support 15 and does not escape to the lower part of the backrest 3 or backward due to the seated person's backrest. The stopper piece 46 may be manufactured separately and screwed to the inner plate 21.

(6). Other embodiment (FIG. 21)
FIG. 21 shows another embodiment. In this embodiment, the left and right ends of the lumbar support 15 are the main support portion 15a, and the recessed portion between them is the sub-support portion 15b. The gap 48 is formed between the main support portions 15a when not locked. When the seat is opened and the seated person leans against the backrest 3, the backrest 3 is bent and deformed as shown by a dashed line in FIG. In addition, the slit group and the hollow hole of the inner board 21 are abbreviate | omitted.

  In (A), the gap 48 is set to a substantially equal groove width over the entire length, and in (B), the groove width is set to become smaller as it goes to the left and right ends. Therefore, in the form (B), when the seated person leans against the backrest 3, the back surface of the backrest 3 can abut on the entire main support portion 15a and the sub-support portion 15b.

  In this embodiment, the backrest 3 is supported by the lumbar support 15 so as to be supported at both ends, so that an elastic resistance is given to the seated person at the time of locking, and it can be said that the fit and cushioning are excellent. Further, when the backrest 3 is deformed to some extent, the backrest 3 hits the sub-support portion 15b of the lumbar support 15 and is prevented from further deformation, so that it is not excessively deformed and an appropriate cushioning property can be obtained.

(7). Others The present invention can be embodied in various ways other than the above embodiment. For example, the material of the lumbar support can be selected freely such as made of sheet metal or wood, and the shape can be arbitrarily set (for example, a pipe shape or a simple plate shape can be used).

  In addition, it is not always necessary to provide an inner plate made of synthetic resin or the like for the backrest. For example, a material having a certain degree of waist such as a nonwoven fabric or a resin sheet is used as a core material (base material), and a cushion material is bonded to or integrated with this It is also possible to have a molded structure.

  The shape of the back frame can also be set in various ways. When the center member is provided on the back frame as in the illustrated embodiment, only one center member may be provided, and the center member may be made of sheet metal or synthetic resin. It is also possible to eliminate the back cover by using a synthetic resin for the back frame.

(8) Reference Example FIGS. 22 to 30 show reference examples. This point will be described next. 22 is a perspective view of the chair as seen from the rear, FIG. 23 is a rear view of the back with the skin material omitted, FIG. 24 is a vertical side view, FIG. 25 is a vertical side view of the upper portion of the back, and FIG. 25 is a sectional view taken along line XXVI-XXVI in FIG. 25, FIG. 27 is a sectional view taken along line XXVII-XXVII in FIG. 23, FIG. 28 is a sectional view taken along line XXVIII-XXVIII in FIG. FIG. 30 is an explanatory view of the operation.

  In this example, the tilting frame 10 is formed in a substantially U shape in plan view, and the center member 12a of the back frame 12 stands up from the rear part. The lumbar support 15 protrudes from the back cover 14 to the left and right, and this point is common to the first embodiment.

  As shown in FIG. 24, in this example, the cushion layer 22 is stretched only on the front surface of the inner plate 21 (of course, it can also be stretched on the rear surface). Moreover, the bag-shaped skin material 24 is provided. As a feature of this example, the back inner plate 21 is composed of a rigid body portion 21a that occupies about 30% of the upper side thereof, and a deformation allowing portion 20e that occupies a lower portion thereof.

  The rigid body portion 21a is formed in a forward-facing concave shape whose depth becomes shallower toward the upper portion. Therefore, the lower end of the rigid body portion 21a protrudes backward in an overhanging manner relative to the deformation-permitting portion (that is, a stepped shape). It has become). A large number of ribs 50 extending in the horizontal direction and the vertical direction are integrally formed in the rigid body portion 21b in order to reinforce and stably support the cushion material 22.

  The deformation allowing portion 21b has a plate shape, and can be easily bent and deformed by the lumbar support 15 by forming a large number of slits as shown in FIG. In addition, the body can be slightly bent and deformed by the body pressure of the seated person.

  As a specific form of the slit group formed in the deformation allowing portion 21 b, a state in which the main slit 52, which has an upward opening extending substantially symmetrically across the longitudinal center line 51 of the inner plate 21, is connected to the main slit 52. The first auxiliary slit group 53 that extends in the left-right direction, the second auxiliary slit group 54 that is independently formed on the inner side surrounded by the main slit 53, and the inner plate 21 on the left and right outer sides of the main slit 52. A left and right third auxiliary slit group 55 formed so as to open at the end face is formed.

  For example, as shown in FIG. 25 to FIG. 28, in this example, a nut 36 for screwing a cylindrical portion 36 into which the upper end portion of the upper member 12 b is fitted and a screw 37 on the lower end portion of the rigid body portion 21 a of the inner plate 21. A nut receiving portion 39 for holding 38 is formed. In this example, the upper member 12b of the back frame 12 is fastened to the inner plate 21, and the back cover 14 is not fastened together.

  As can be understood from FIG. 24, a certain amount of space is provided between the center member 12 a of the back frame 12 and the deformation-permitting portion 21 b of the inner plate 21 by providing a rearwardly protruding rigid body portion 21 a on the upper portion of the inner plate 21. (Gap) opens. The lumbar support 15 can be arranged in this space.

  As shown in FIG. 24, as an example of a stopper means for restricting the back and forth movement of the lower part of the backrest 3 at the lower end portion of the inner plate 21 and the back of the left and right intermediate portion, a hook 56 having a hook shape facing downward as viewed from the side is provided with a screw. On the other hand, an engagement bar 57 to which the hook 56 is hooked and engaged is fixed to the back frame 12 at the lower end portion of the center member 12a by welding or the like. The function of the hook 56 is the same as that of the stopper piece 46 of the first embodiment.

  Note that the hook 56 may be integrally formed with the inner plate 21 in the same manner as the stopper piece 46 of the first embodiment. Further, the hook 56 and the stopper piece 46 of the first embodiment can be arranged on the left and right sides with the pair of the center members 12a of the back frame 12 interposed therebetween, but it is easy to twist the backrest 3 in a plan view. In order to be able to deform it, it is preferable to arrange only one in the middle part sandwiched between the left and right center members 14a as in this embodiment.

  In this example, the slider 42 of the lumbar support 15 is vertically separated, and the upper and lower sliders 42 are pressed and held by a single pressing plate 43. Since the lumbar support 15 protrudes from the left and right outer sides of the back cover 18, a person can turn up and down by turning both hands backwards while touching the back-exposed portion of the lumbar support 15. The height of the lumbar support 15 can be easily adjusted while sitting.

  As shown in FIG. 29A, the end portion of the lumbar support 15 may be applied to the skin material 24 in a point contact state in plan view. In this case, the contact area is small, and therefore the lumbar support 15 is frequently moved up and down. When the moving operation is performed, depending on the material of the skin material 24, there is a concern that the skin material 24 may be rubbed to cause shine or fluff.

  On the other hand, as shown in FIG. 29B, when the support portion 15a of the lumbar support 15 is curled in a plan view, and a flat portion is formed and brought into surface contact with the skin material 24, a unit of the skin material 24 is obtained. Since the pressing force per area is reduced, there is no or almost no problem of shine and scuffing, and as a result, there is an advantage that the freedom of material selection can be improved.

  In this example, the upper portion of the back cover 14 is fixed to the upper member 12b of the back frame 12 with screws, and the vertically long portion thereof is fixed to the connecting bracket 58 fixed to the center member 12a of the back frame 12 with screws. ing. Therefore, in this example, the back cover 14 is attached to the back frame 12 in advance. Since the back cover 14 is screwed to the back frame 12, the mounting strength is excellent.

  Next, the advantages of this example will be described with reference to FIG. 30A and 30B show a comparative example (conventional example), and this inner plate 21 'is made of synthetic resin and has a concave shape facing forward in a flat section. In each drawing, cross-sectional display (parallel oblique lines) is omitted.

  An alternate long and short dash line B shows a simplified profile in plan view of the back of the waist of the seated person, and a fat person has a large lateral width and curvature, and thus tends to strongly hit the left and right side portions of the inner plate 21 '. On the other hand, a thin person has a small lateral width and curvature, and tends to hit the middle part of the inner plate 21 'strongly.

  In the conventional lumbar support mechanism, the flat cross-sectional shape of the inner plate 21 ′ does not change so much, so that a fat person feels a bulge at the left and right flank positions, and on the contrary, a thin person has a lumbar spine or spine There is a tendency to receive a sense of tension. For this reason, in any case, the fit is insufficient.

  On the other hand, in the present example, the deformation allowing portion 20e of the inner plate 21 can be greatly deformed in the plane cross-sectional shape due to the presence of the slit groups 52 to 54, and the lumbar support 15 has a concave shape facing forward in plan view. 21 can be deformed in a state in which the curvature in plan view increases or decreases, so that in the case of a fat person, as shown in FIG. In contrast, in the case of a thin person, the deformation-permitting portion 21b tends to bend and deform so that the curvature in a plan view becomes small. The fit is also high.

  That is, the backward body pressure of the seated person is dispersed and supported by the deformation-permitting portion 21b of the inner plate 21, thereby preventing the inner plate 21 and the lumbar support 15 from giving a sense of tension to the seated person. (This point is the same in the present invention).

  As shown in FIG. 30 (E), as in the first embodiment, a back-side cushion layer 23 may be provided on the back surface of the inner plate 21 (or the back surface of only the deformation allowing portion 21b) (of course, the back surface side). The cushion layer 23 is also covered with the skin material 24).

  Further, the seated person sometimes twists the upper body with the arm stretched on the armrest 4, for example. In this case, an external force that twists the inner plate 21 in a plan view acts strongly. Because it can suppress the tension against the upper body, it has excellent fit. In the present invention, since the upper part of the inner plate 21 can be bent and deformed by the twisting action, the fit is further improved.

  In addition, when a person with a wide shoulder width (waist width) leans against the backrest 3, an external force is applied to the inner plate 21 to push the inner plate 21. However, in this case, the back inner plate 20 also has a plan view. Since it is easy to deform so that the curvature becomes small, it has excellent fit.

  Further, since the side cross-sectional shape is easily changed due to the presence of the horizontally long auxiliary slit groups 24b to 24c, the deformation function (extrusion function) by the lumbar support 15 is not hindered. Since the first auxiliary slit group 24b and the second auxiliary slit group 24c are alternately arranged on the inner side surrounded by the main slit 24a, the back inner plate 20 is a portion of the boundary between the auxiliary slit groups 24b and 24c. Therefore, the function of deforming the flat cross-sectional shape is more strongly exhibited.

  By the way, in the case of patent document 1, the backrest is provided with the back cover which is not shown in figure, and when adjusting a lumbar support up and down, a back cover must be removed.

  However, it is extremely troublesome to remove the back cover each time the lumbar support height is adjusted. In addition, since the lumbar support of Patent Document 1 has a size that overlaps with the back support rod in a front view or a back view, even if the back cover is removed, it is difficult to move the lumbar support up and down without using any tool. This can be said to contribute to the difficulty of height adjustment.

  On the other hand, Japanese Utility Model Publication No. 62-7161 discloses that the lumbar support is moved up and down by rotating the handle. According to this publication, in the case of adjusting the height of the lumbar support by operating the handle (or lever), the height of the lumbar support can be easily adjusted while seated, but there is an advantage that the lumbar support function can be exhibited. There is a problem that the cost for making the structure complicated increases.

  On the other hand, in the present reference example (and the embodiment of the present application), the lumbar support 15 is exposed on the back side of the backrest, so that a person can easily adjust the height position by placing a hand on the lumbar support 15. Can do. In addition, the person adjusts the height by placing his / her hand directly on the lumbar support, and there is no need for handles (or levers) or interlocking mechanisms. The increase in cost can be avoided.

  Furthermore, by making the lumbar support visible to humans, it is possible to ensure novelty that is not found in conventional chairs and to make it excellent in design. In addition, the back of the back of conventional chairs has a variety of forms with little change. However, by adopting the lumbar support 15 as an external component of the back as in this reference example or the embodiment of the present application, the diversity of the design is remarkably increased. It can be said that it can be expanded.

It is a side view of the chair concerning this embodiment. It is a separation perspective view of a member. It is a rear view of a back part. It is a rear view of the back part in the state where a part was omitted. It is a partial separation perspective view. (A) is a perspective view of the upper part of the back cover, (B) is a rear view of the back frame, and (C) is a sectional view taken along the line CC of (B). It is a partially broken rear view of a backrest. It is a rear view of the inner board which comprises a backrest. It is a rear view of a backrest. It is a perspective view of an inner board. It is the isolation | separation perspective view which looked at the back part from back. The vertical side view of the backrest in a state where members are omitted, (B) is a vertical side view. (A) is a sectional view taken along line XIIIA-XIIIA in FIG. 12, and (B) is a sectional view taken along line XIIIB-XIIIB in FIG. It is XIV-XIV sectional view taken on the line of FIG. It is XV-XV sectional view taken on the line of FIG. It is a separation perspective view of a lumbar support mechanism. It is a figure which shows a lumbar support mechanism, (A) is a plane sectional view, (B) is a rear view. It is a perspective view of a slider. It is XIX-XIX sectional view taken on the line of FIG. It is XX-XX sectional view taken on the line of FIG. It is a figure which shows other embodiment. It is the perspective view which looked at the chair of the reference example from back. It is a rear view of the back part of the reference example in the state which omitted the skin material. It is a vertical side view of a reference example. It is a vertical side view of the upper part of the back part of a reference example. It is XXVI-XXVI sectional view taken on the line of FIG. It is XXVII-XXVII sectional view taken on the line of FIG. It is XXVIII-XXVIII sectional view taken on the line of FIG. It is a partial plane sectional view which shows the support state by a lumbar support. It is explanatory drawing of an effect | action.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Leg apparatus 2 Seat body 3 Backrest 10 Tilt frame 12 Back frame 14 Back cover 15 Lumber support 21 Inner board 22, 23 Cushion layer 25 Main deformation | transformation tolerance area 26 Intermediate deformation area 27 Auxiliary deformation tolerance area

Claims (9)

The backrest has a flexible structure so that almost the entire body can be bent and deformed by the leaning of the seated person, and the range including the portion where the waist of the seated person touches is the most easily deformable main deformation area. The upper range is formed as an auxiliary deformation permissible area that is less likely to bend and deform than the main deformation area.
The back of the chair. The main deformation permissible area and the auxiliary deformation permissible area are continuous via an intermediate deformation permissible area where the ease of bending deformation is smaller than the main deformation permissible area and larger than the auxiliary deformation permissible area.
The chair back according to claim 1. It is provided with a synthetic resin inner plate and a cushion layer stretched at least on the front surface of the inner plate, and a main deformation allowable area is formed by forming a slit group on the inner plate.
The chair back according to claim 1 or 2. The main deformation permissible area includes a center area extending along the longitudinal center line of the inner plate, and side areas located on both left and right sides of the center area with a hollow extending vertically. A slit group is formed in each area.
The backrest of the chair according to claim 3. The front and back surfaces of the inner plate are integrally molded with a resin cushion layer by an insert molding method, and the front and back cushion layers are covered with a bag-shaped skin material,
The chair back according to claim 3 or 4. A rib for attaching the inner plate to the back frame is extended to substantially the full length of the left and right of the inner plate or a length close to it at the bottom of the auxiliary deformation permissible area of the back surface of the inner plate. It is provided integrally so as to connect,
The backrest of the chair as described in any one of Claims 3-5. On the back side of the main deformation permissible area, a lumbar support that pushes out the main deformation permissible area from the rear is arranged so that the height can be adjusted.
The chair provided with the backrest in any one of Claims 1-6. The inner plate is configured as in claim 6, and the rib of the inner plate is fixed to the back frame.
The chair according to claim 7. The backrest has the structure of claim 4, and the lumbar support can come into contact with the cushion layer through the cutout hole.
The chair according to claim 7 or 8.

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