US20110204694A1 - Chair backrest - Google Patents
Chair backrest Download PDFInfo
- Publication number
- US20110204694A1 US20110204694A1 US13/126,731 US200913126731A US2011204694A1 US 20110204694 A1 US20110204694 A1 US 20110204694A1 US 200913126731 A US200913126731 A US 200913126731A US 2011204694 A1 US2011204694 A1 US 2011204694A1
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- United States
- Prior art keywords
- frame
- frames
- backrest
- upholstering material
- upholstering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47C—CHAIRS; SOFAS; BEDS
- A47C7/00—Parts, details, or accessories of chairs or stools
- A47C7/36—Support for the head or the back
- A47C7/40—Support for the head or the back for the back
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- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47C—CHAIRS; SOFAS; BEDS
- A47C7/00—Parts, details, or accessories of chairs or stools
- A47C7/36—Support for the head or the back
- A47C7/40—Support for the head or the back for the back
- A47C7/44—Support for the head or the back for the back with elastically-mounted back-rest or backrest-seat unit in the base frame
- A47C7/446—Support for the head or the back for the back with elastically-mounted back-rest or backrest-seat unit in the base frame with fluid springs
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- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47C—CHAIRS; SOFAS; BEDS
- A47C7/00—Parts, details, or accessories of chairs or stools
- A47C7/36—Support for the head or the back
- A47C7/40—Support for the head or the back for the back
- A47C7/46—Support for the head or the back for the back with special, e.g. adjustable, lumbar region support profile; "Ackerblom" profile chairs
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- Chair Legs, Seat Parts, And Backrests (AREA)
Abstract
A chair backrest in which a frame-like back frame is covered with a bag-like upholstering material having an open lower end in a state of tension, the back frame being formed by connecting a pair of left and right side portion frames, which extend in an up and down direction, together at upper ends and lower ends thereof by an upper frame and a lower frame which extend in the left and right direction, wherein intermediate portions in the left and right direction of the upper frame and the lower frame are connected to each other by an intermediate frame which is situated behind the both side portion frames and is extended in the up and down direction, thereby causing an intermediate portion of a rear surface portion of the upholstering material to project rearward. According to such a backrest, when a person sitting on the chair leans against the backrest, the reaction force of the upholstering material does not vary to an extreme extent during the leaning action, and a rearward recess amount of the upholstering material of the backrest in response to a load can be sufficiently secured, thereby obtaining a comfortable sitting sensation.
Description
- The present invention relates to a chair backrest. This application claims priorities based on Japanese Patent Application Nos. 2008-277530 filed in Japan on Oct. 29, 2008, and 2009-54129 filed in Japan on Mar. 6, 2009, the contents of which are incorporated herein by reference.
- In a chair backrest of the related art, there is one in which a frame-like back frame is covered and upholstered with a bag-like upholstering material having an open lower end in a tension state (for example, see Patent Document 1).
- Patent Document 1: Specification of European Patent Application, First Publication No. 0922419
- In the chair backrest described in
Patent Document 1, a front surface portion and a rear surface portion of an upholstering material covering a back frame are in close proximity to each other. For that reason, when a person sitting on the chair leans against the backrest, initially, only the front surface portion of the upholstering material sinks rearward, then the front surface portion of the upholstering material comes into contact with the rear surface portion thereof, and then both of the front surface portion and the rear surface portion bend rearward to receive the weight of the back of a person sitting on the chair. As a consequence, a reaction force relative to the back of a person sitting in the chair is changed in two stages of an early stage when leaning against the backrest and a subsequent stage, which is uncomfortable for the person sitting in the chair. - Furthermore, when a person sitting in the chair leans against the backrest, in order to obtain a comfortable sitting sensation, there is a need to increase a rearward recess amount of the upholstering material when a load is applied to the upholstering material of the backrest. However, in the chair backrest described in
Patent Document 1, except for the beginning when leaning against the backrest, since both of the front surface portion and the rear surface portion of the upholstering material are integrally bent and the reaction force thereof is increased, it is difficult to increase the recess amount. - In view of the above problems of the related art, an object of the present invention is to provide a chair backrest in which, when a person sitting on the chair leans against the backrest, a reaction force of the upholstering material does not vary to an extreme extent during the leaning action and a rearward recess amount of the upholstering material of the backrest in response to a load is sufficiently secured, thereby obtaining a comfortable sitting sensation.
- According to the present invention, the above problem is solved by the following means:
- (1) A chair backrest in which a frame-like back frame is covered with a bag-like upholstering material having an open lower end in a state of tension, the back frame being formed by connecting a pair of left and right side portion frames, which extend in an up and down direction, together at upper ends and lower ends thereof by an upper frame and a lower frame which extend in the left and right direction, wherein intermediate portions in the left and right direction of the upper frame and the lower frame are connected to each other by an intermediate frame which is situated behind the both side portion frames and is extended in the up and down direction, thereby causing an intermediate portion of a rear surface portion of the upholstering material to project rearward.
- According to such a configuration, when a person sitting on the chair leans against the backrest, since the front surface portion of the upholstering material does not come into contact with the rear surface portion thereof and the resistance force of the upholstering material does not vary to an extreme extent during the leaning action. Furthermore, in conjunction with the elongation of the front surface portion of the upholstering material, the rear surface portion is also elongated, whereby the elongation of the rear surface portion causes an increase in the rearward recess ratio of the front surface portion, thus making it possible to obtain a comfortable sitting sensation.
- (2) In the above (1), the upper and lower frames have a curved shape in which the intermediate portions are situated behind the both side portion frames when viewed in a planar view.
- According to such a configuration, the intermediate frames can be greatly separated rearward from the both side portion frames. As a consequence, the effect of the above (1) can be further enhanced, and the thickness of the backrest in the front and rear direction can be thickly formed, which can give the backrest a high quality sensation.
- (3) In the above (1) or (2), the lower portions of both side portion frames and the intermediate frame have an arced curved shape in which a curvature center is situated in the front when the lower portions of both side portion framed and the intermediate frame are viewed from the lateral view.
- According to such a configuration, it is possible to cause the side surface shape of the backrest to imitate a side surface shape of the buttocks of a person sitting on the chair, which can reliably support the buttocks to the back of a person sitting on the chair.
- (4) In any one of the above (1) to (3), rearward displacement amounts of the intermediate frame relative to both side portion frames are in parts different from each other in the up and down direction.
- According to such a configuration, it is possible to make the tension of an upholstering material upon being mounted on the back frame different in the up and down direction, without changing in parts the material, the shape, or the like of the bag-like upholstering material in the up and down direction.
- Thus, by increasing or decreasing the displacement amount of a portion of the backrest having a desired height of the backrest in compliance with demand, the tension of the upholstering material of that portion can be strengthened or weakened.
- (5) In any one of the above (1) to (4), the intermediate frame is formed by an elastic material, such that the intermediate frame can be elastically deformed forward when a load is applied to the front surface portion of the upholstering material.
- According to such a configuration, the elasticity of the intermediate frame complements the tension of the upholstering material, whereby it is possible to further increase the rearward recess ratio of the front surface portion of the upholstering material according to this synergistic action.
- (6) In any one of the above (1) to (5), in the upper ends of both side portion frames in the back frame, upward-facing extension frames, which are curved such that intermediate portions are situated ahead of the upper and lower portions when viewed from the side surface, are consecutively provided. Furthermore, upper ends of both extension frames are connected to each other by a top portion frame which extends in the left and right direction, whereby a headrest frame is formed by the extension frames and the top portion frame.
- According to such a configuration, it is possible to integrally form a headrest having a characteristic shape with the back frame in a simple manner.
- According to the present invention, it is possible to provide a chair backrest in which, when a person sitting on the chair leans against the backrest, the reaction force of the upholstering material does not vary to an extreme extent during the leaning action, and a rearward recess amount of the upholstering material of the backrest in response to a load can be sufficiently secured, thereby obtaining a comfortable sitting sensation.
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FIG. 1 is a side view of a stand-by state of a chair that includes a first embodiment of a backrest of the present invention. -
FIG. 2 is a side view of a sitting state of the chair shown inFIG. 1 . -
FIG. 3 is a side view of a reclining state of the chair shown inFIG. 1 . -
FIG. 4 is a perspective view that shows a state before a back frame is covered with an upholstering material when viewed from an inclined rear part of the backrest. -
FIG. 5 is a side view of a chair that includes a backrest device of a second embodiment in the present invention. -
FIG. 6 is a partially enlarged front view that cuts away a part of the upholstering material of a front surface in a chair backrest and shows the upholstering material of a front surface and the upholstering material of a rear surface. -
FIG. 7 is an enlarged longitudinal cross-sectional view of major parts of the backrest taken along lines VII-VII ofFIG. 6 . -
FIG. 8A is a diagram that shows an example of a moirépattern due to a change (%) in the size of a hole portion of a stretched material of a front surface relative to a long material of a rear surface, and shows a shape of a case where the hole portion of the long material of the front surface has a size which is 95% of that of the long material of the rear surface. -
FIG. 8B is a diagram that shows an example of a pattern having a moirépattern due to a change (%) in the size of a hole portion of a long material of a front surface relative to a long material of a rear surface, and shows a shape of a case where the hole portion of the long material of the front surface has a size which is 90% of that of the long material of the rear surface. -
FIG. 8C is a diagram that shows an example of a pattern having a moirépattern due to a change (%) in the size of a hole portion of a long material of a front surface relative to a long material of a rear surface, and shows a shape of a case where the hole portion of the long material of the front surface has a size which is 80% of that of the long material of the rear surface. -
FIG. 9A is a diagram that shows another example of a pattern having a moirépattern due to a change (%) in the size of a hole portion of a long material of a front surface relative to a long material of a rear surface, and shows a shape of a case where the hole portion of the long material of the front surface has a size which is 95% of that of the long material of the rear surface. -
FIG. 9B is a diagram that shows another example of a pattern having a moirépattern due to a change (%) in the size of a hole portion of a long material of a front surface relative to a long material of a rear surface, and shows a shape of a case where the hole portion of the long material of the front surface has a size which is 90% of that of the long material of the rear surface. -
FIG. 9C is a diagram that shows another example of a pattern having a moirépattern due to a change (%) in the size of a hole portion of a long material of a front surface relative to a long material of a rear surface, and shows a shape of a case where the hole portion of the long material of the front surface has a size which is 80% of that of the long material of the rear surface. - Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings.
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FIGS. 1 to 3 show a chair that includes a first embodiment of a backrest of the present invention. - The chair includes a lower portion
constituent body 4 in which aleg column 2 is vertically provided in the center of abase 1 of a disk and asupport base 3 is attached to an upper end of theleg column 2. - The
leg column 2 may be configured such that the height thereof can be controlled by a gas spring (not shown). - The
support base 3 has a shape that is expanded from the upper end of theleg column 2 toward the front in a nearly triangular shape in a planar view and the side surface. - In the front end portion of the
support base 3, a front lower portion of aseat 5 is supported via abase shaft 6 extending in the left and right direction, and theseat 5 can be rotated around thebase shaft 6 between a stand-by position inclining rearward and upward as shown inFIG. 1 and a horizontal or a slightly rearward and downwardly inclined use position as shown inFIGS. 2 and 3 . - In both side rear portions of the
seat 5, a pair of left andright armrests - The
respective armrests seat 5. Furthermore, the rear portions of therespective armrests pivot support portion 7 a having acurved surface 8 which is protruded rearward centered on asupport shaft 11 of thebackrest 9 described later and has a semicircular arc shape or a fan shape when viewed from the side surface, and anarm support portion 7 b that is extended forward from the upper portion of the backrestpivot support portion 7 a and has an upward arc shape, and the entire shape forms an approximately forward triangular shape when viewed from the side surface that converges toward the front upper part. - The size of the
arm support portion 7 b in the front and rear direction is set such that the front end portion thereof is in the stand-by position shown inFIG. 1 and is located further forward from a vertical line V passing through the center of thebase shaft 6 that is an attachment shaft of theseat 5. Furthermore, as shown inFIG. 2 , the size is set such that, when theseat 5 is in the use position, the front end portion of thearm support portion 7 b is situated behind the vertical line V, that is, slightly behind thebase shaft 6. - On the outer side surface slightly toward the front of the backrest
pivot support portion 7 a in the left andright armrests front side piece 10 extending forward from both lower portions of thebackrest 9 is supported via thesupport shaft 11 extended approximately in the left and right direction. Thebackrest 9 can be rotated centering on thesupport shaft 11 between a standing position shown inFIG. 2 and a rearward slope position shown inFIG. 3 with respect to theseat 5 and thearmrest 7. In addition, the outer surface of the backrestpivot support portion 7 a is protruded outward such that the attachment part of thefront side piece 10 is situated in the outermost side such that the inner surface of thefront side piece 10 does not widely come into contact with the outer surface of the backrestpivot support portion 7 a. - Portions of both side lower portions of the
backrest 9 facing the rear surface of the backrestpivot support portion 7 a become a circular arc-shaped concavecurved surface 12 which forms a shape approximately corresponding to thecurved surface 8 of the rear surface of the backrestpivot support portion 7 a, and thebackrest 9 can be rotated around thesupport shaft 11 in a state in which the mutually opposed surfaces come close to each other. Between a center portion in the left and right direction of alower frame 20 described later in thebackrest 9 and a front end portion upper surface of thesupport base 3, there is provided first biasing means 13 formed of a gas spring which biases thebackrest 9 in the standing direction, a compression spring or the like. - Moreover, in the
base 3, there is provided second biasing means 14 that can assist the standing of a person sitting on the chair by biasing theseat 5 toward the stand-by position. - The second biasing means 14 includes a
rubber torsion unit 15 that has an axis for example which extends in the left and right direction; a rearward-facingfirst link 16 that is connected to therubber torsion unit 15 and is biased in a counterclockwise direction when viewed from the side surface inFIG. 1 ; and an obliquely rearward upward-facingsecond link 17 that is supported on the front end portion of thefirst link 16 at a lower end portion thereof via a shaft extending in the left and right direction and is supported on the lower surface of an intermediate portion of theseat 5 in the front and rear direction at an upper end portion thereof via the shaft extending in the left and right direction. - Since the
armrest 7 is formed integrally with theseat 5, even when theseat 5 is rotated between the stand-by position and the use position or thebackrest 9 slopes, the relative position of thearmrest 7 relative to theseat 5 is not changed. For that reason, the elbows of a person can be placed on thearmrest 7 in a natural state between the stand-by position and the use position, whereby the usability of the chair is improved. - Furthermore, when the
seat 5 is in the stand-by position, the front end portion of thearm support portion 7 b in thearmrest 7 is situated in front of a vertical line V passing through the center of thebase shaft 6 with theseat 5 attached thereto. Thus, when a person sits on the chair with his hands placed on the front end portion of thearm support portion 7 b in the stand-by position, there is no possibility that theseat 5 will be rotated to the lower portion due to the weight thereof, and he or she can sit in the chair at ease. - In addition, the front end portion of the
front side piece 10 extending forward from both side lower portions of thebackrest 9 is attached to the backrestpivot support portion 7 a standing up from the rear both side portions of theseat 5 via thesupport shaft 11, and the opposed surfaces of the backrestpivot support portion 7 a and the lower portion of thebackrest 9 are a circular arc-shaped or fan-shapedround surface 8 and a circular arc-shaped concavecurved surface 12 around thesupport shaft 11. Thus, it is possible to cause thebackrest 9 to greatly slope rearward without interfering with theseat 5 and thearmrest 7. In addition, since the lower portion of thebackrest 9 is firmly supported on the backrestpivot support portion 7 a of thearmrest 7 formed integrally with theseat 5, thebackrest 9 having a large up and down size can also be supported such that it can be stably and smoothly rotated. - As shown in
FIG. 4 , thebackrest 9 includes aback frame 22 having a front shape of a longitudinal rectangular frame shape that is formed by connecting the upper ends of a pair of left and right side portion frames 18 and 18 extending in the up and down direction by alower frame 20 extending in the left and right direction, connecting the lower ends of both side portion frames 18 and 18 by theupper frame 19 extending in the left and right direction, and connecting the intermediate portions of anupper frame 19 and thelower frame 20 in the left and right direction by anintermediate frame 21 that is situated behind the both side portion frames 18 and 18 and is extended in the up and down direction. - The
back frame 22 is integrally formed by a synthetic resin material having a suitable elasticity. It is desirable that a reinforced fiber such as a glass fiber or a carbon fiber is added to the synthetic resin material. - The lower portions of both side portion frames 18 and 18 and the lower portion of the
intermediate frame 21 have circular arc-shaped curved shapes with a curvature center thereof situated in the front when viewed from the side surface, and theupper frame 19 and thelower frame 20 have curved shapes with an intermediate portion thereof situated behind the both side portions when viewed in a plan view. As a result, the lower portion of thebackrest 9 is separated rearward from the rear end portions of theseat 5 and thearmrest 7, and thebackrest 9 is prevented from interfering with the rear ends of theseat 5 and thearmrest 7 upon being rotated, whereby the rearward rotation range of thebackrest 9 can be enlarged. - It is desirable that the curvature center of the curved shape of the lower portions of both side portion frames 18 and 18 and the lower portion of the
intermediate frame 21 coincides with thesupport shaft 11 of thebackrest 9. - The
intermediate frame 21 is easier to deform elastically than other portions as it is formed to be thinner than other frame constitution members in theback frame 22. For that reason, when a load is applied to the front surface portion of anupholstering material 26 described later, theintermediate frame 21 can be elastically deformed rearward. - The rearward displacement amount of the
intermediate frame 21 relative to both side portion frames 18 and 18 is set to increase as it moves closer to the lower part. - Furthermore, the aforementioned left and right
front side pieces 10 are formed integrally with the lower portions of both side portion frames 18 and 18. - In the upper end of both side portion frames 18 and 18, upward-facing extension frames 23 and 23, which are curved such that intermediate portions thereof are situated ahead of the upper and lower portions when viewed from the side surface, are consecutively provided. Furthermore, a
headrest frame 25 is integrally formed in the upper end of theback frame 22, theheadrest frame 25 being formed by connecting the upper ends of both extension frames 23 and 23 to each other by atop portion frame 24 extended in the left and right direction. - As shown in
FIG. 4 , in theback frame 22 and theheadrest frame 25, the bag-like upholstering material 26 having elasticity with a lower end open and both lower portions open is provided in a state of tension by covering the frames from the upper part. - The
upholstering material 26 includes aheadrest cover portion 27 that covers aheadrest frame 25, and abackrest cover portion 28 that covers theback frame 22, and the fabrics thereof are different from each other. Furthermore, the fabrics of thefront surface portion 27 a and therear surface portion 27 b in theheadrest cover portion 27 and the fabrics of thefront surface portion 28 a and therear surface portion 28 b in thebackrest cover portion 28 are also different from each other. - Both of the fabrics of the
headrest cover portion 27 and thebackrest cover portion 28 are mesh materials, but the fabric of at least thefront surface portion 27 a of theheadrest cover portion 27 is formed by a mesh material having elasticity superior to that of the fabric of at least thefront surface portion 28 a of thebackrest cover portion 28. - Furthermore, the fabric of at least the
front surface portion 27 a of theheadrest cover portion 27 is a mesh material having coarse eyes of a low density, and the fabric of at least thefront surface portion 28 a of thebackrest cover portion 28 is a fine-mesh material which has a high mesh density. - The direction of the texture or the stitches of the mesh material is extended in the left and right direction in the
front surface portion 27 a in theheadrest cover portion 27 and thefront surface portion 28 a in thebackrest cover portion 28, and is extended in the up and down direction in therear surface portion 27 b in theheadrest cover portion 27 and therear surface portion 28 b in thebackrest cover portion 28. That is, such a mesh material is elongated in a transverse direction in thefront surface portions rear surface portions - Furthermore, as mentioned above, the
front surface portion 28 a in thebackrest cover portion 28 is a mesh material having fine eyes of a high density and the surface thereof is a fabric of a mesh material which is flexible and has a low light transmitting property or transparency. Moreover, therear surface portion 28 b in thebackrest cover portion 28 is a mesh material having coarse eyes of a low density and is a fabric of a mesh material having a high light transmitting property or transparency. - As the fabric of the
front surface portion 28 a, it is desirable to use a maul-shaped fiber that is formed by twisting a short fiber interposed between a plurality of elastic threads. - In addition, the
front surface portion 27 a and therear surface portion 27 b in theheadrest cover portion 27 and thefront surface portion 28 a and therear surface portion 28 b in thebackrest cover portion 28 are different from each other in color as well as material, thereby the high-quality design can be provided. - The
upholstering material 26 may be formed by covering and providing one formed in a bag shape over theback frame 22 or the like in a state of tension. Alternatively, it may be possible to interpose theheadrest frame 25 and theback frame 22 from the front and back by thefront surface portions rear surface portions upholstering material 26 which is separated into the front and the rear surface portions, and to connect the periphery edge portions of thefront surface portions rear surface portions upholstering material 26 may be formed in a bag shape. - The lower end portion of the
upholstering material 26 is attached to the lower end portion of thelower frame 20 by causing the left and rightfront side pieces front surface portion 28 a and therear surface portion 28 b to each other by a surface fastener, a hook, a fastener, and other joining means (none of which are shown) in the lower part of thelower frame 20 in theback frame 22. - In addition, when the headrest is not necessary, the
headrest cover portion 27 that covers aheadrest frame 25 of theupholstering material 26 may be omitted. - In the
backrest 9 having such a configuration, the intermediate portions of theupper frame 19 and thelower frame 20 are connected by theintermediate frame 21 that is situated behind the both side portion frames 18 and 18 and is extended in the up and down direction, and the intermediate portion of the rear surface portion 26 b of theupholstering material 26 protrudes rearward from theintermediate frame 21. For that reason, when a person sitting on the chair leans against thebackrest 9, thefront surface portion 28 a of theupholstering material 26 does not come into contact with therear surface portion 28 b, and the resistance force of theupholstering material 26 does not vary to an extreme extent during the leaning action. Furthermore, since therear surface portion 28 b is also elongated along with the elongation of thefront surface portion 28 a of theupholstering material 26 and the rearward recess amount of thefront surface portion 28 a is increased by the elongation of therear surface portion 28 b, a comfortable sitting sensation can be obtained. - Furthermore, since the
upper frame 19 and thelower frame 20 have a curved shape in which an intermediate portion is situated behind the both side portions when viewed in a plan view, theintermediate frame 21 can be greatly separated rearward from both side portion frames 18 and 18. For that reason, the aforementioned effect can be further enhanced, and it is possible to give the backrest 9 a high quality sensation by increasing the thickness of thebackrest 9 in the front and rear direction. - In addition, it is possible to simply form the headrest having a characteristic shape integrally with the
back frame 22 by theheadrest frame 25 and by theheadrest cover portion 27 covering theheadrest frame 25 in the bag-like upholstering material 26. - In the
upholstering material 26, the fabrics of thefront surface portions rear surface portions upholstering material 26 to exhibit a suitable deflection amount and to cause the surface of theupholstering material 26 to have the flexibility. In addition, it is possible to obtain a sufficient ventilation property and elasticity in theupholstering material 26 without reducing the light transmitting property or the transparency thereof. - In addition, in the aforementioned embodiment, the rearward displacement amount of the intermediated
frame 21 relative to both side portion frames 18 and 18 increases as it moves closer to the lower part. Thus, simply by covering theback frame 22 with the bag-like upholstering material 26 having the same material, size or the like in any portion of the up and down direction, it is possible to make the initial tension of theupholstering material 22 in the lower portion of thebackrest 9 greater than the initial tension of theupholstering material 26 in the upper portion of thebackrest 9. As a result, when a person sitting on the chair leans against thebackrest 9, the tension of theupholstering material 26 of the upper portion of thebackrest 9 abutting against the upper portion of the back is weak, and theupholstering material 26 is flexibly and deeply recessed rearward. Meanwhile, theupholstering material 26 of the lower portion of thebackrest 9 abutting against the waist and buttocks from the lower portion of the back is strong in tension and strongly supports the body. As a consequence, it is possible to provide a person sitting on the chair with a comfortable sitting sensation. - In this manner, by partially making the rearward displacement amount of the
intermediate frame 21 relative to both side portion frames 18 and 18 different from each other in the up and down direction, it is possible to partially make the tension of theupholstering material 26 upon being mounted on theback frame 22 different from each other in the up and down direction without partially changing the material, the shape or the like of the bag-like upholstering material 26 in the up and down direction. - Thus, by increasing or decreasing the displacement amount of the portion of the backrest having the desired height in compliance with demand, the tension of the
upholstering material 26 of that portion can be strengthened or weakened. - Hereinafter, a second embodiment of the present invention will be described.
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FIG. 5 is a side view of a chair including a backrest device of a second embodiment in the present invention,FIG. 6 is a partially enlarged front view that partially cuts away upholstering material of a front surface in a chair backrest and shows the upholstering material of a front surface and the upholstering material of a rear surface, andFIG. 7 is a major part enlarged longitudinal cross-sectional view of a backrest taken along lines VII-VII ofFIG. 6 . - In addition, in the following description, the members having the same configuration as those of the first embodiment will be denoted by the same reference numerals as in the first embodiment, and descriptions thereof will be omitted.
- The chair of the present embodiment can be rotated around the
base shaft 6 between an A position of a stand-by state inclining rearward and upward as shown inFIG. 5 , a B position of a nearly horizontal normal use state and a C position of a reclining-use state slightly inclining rearward and downwardly as shown inFIG. 5 by two-dot chain lines. - In the
backrest frame 22 and theheadrest frame 25, a porous sheet-like upholstering material, for example, theupholstering material 26 of a mesh shape having flexibility composed of cloth or the like in a bag shape with a lower end open and both side lower portions open is provided in a state of tension. - As shown in
FIGS. 6 and 7 , amesh 127 in afront surface 26A side of theupholstering material 26 relative to thebackrest frame 22 has the same shape as that of amesh 128 in arear surface 26B thereof. Furthermore, the sizes of themeshes front surface 26A side is fine and that of therear surface 26B side is coarse. - As a result, when viewing the
chair backrest 9 from the front, a clear pattern formed of a plurality of assembly shapes similar to the shapes of themeshes backrest 9. - In this case, when setting the size of the
mesh 128 of therear surface 26B to 100%, it is desirable that the size of themesh 127 of thefront surface 26A in theupholstering material 26 is within the range of 95% to 80% of themesh 128 of therear surface 26B. - That is, as in a case where the size of the
mesh 127 of thefront surface 26A in theupholstering material 26 is equal to or greater than 95% of themesh 128 of therear surface 26B, when there is no great difference in the sizes of themeshes mesh 27 of thefront surface 26A is equal to or less than 80% of that of themesh 128 of therear surface 26B, for example, 50%, there is no interest due to the combination, and in the size equal to or less than 25%, only a shape with insufficient change is obtained in which the shape of themesh 127 of thefront surface 26A and the shape of themesh 128 of therear surface 26B overlap with each other. -
FIGS. 8A to 8C show a pattern of a moiré pattern due to a change (%) in the sizes of the mesh of the upholstering material of the front surface relative to the upholstering material of the rear surface.FIG. 8A is a diagram that shows a shape of a case where the size of the mesh of the upholstering material of the front surface is 95% of that of the upholstering material of the rear surface.FIG. 8B is a diagram that shows a shape of a case where the size of the mesh of the upholstering material of the front surface is 90% of that of the upholstering material of the rear surface.FIG. 8C is a diagram that shows a shape of a case where the size of the mesh of the upholstering material of the front surface is 80% of that of the upholstering material of the rear surface. - As shown in
FIGS. 8A to 8C , when themesh 127 of thefront surface 26A and themesh 128 of the rear surface 28B in theupholstering material 26 have a circular (sphere) shape of the same shape, the clear moiré pattern formed of a plurality of assembly shapes similar to the circular (sphere) shape of themeshes backrest 9 while increasing in number as the size of themesh 127 of theupholstering material 26 of thefront surface 26A becomes smaller than that of themesh 128 of theupholstering material 26 of therear surface 26B. -
FIGS. 9A to 9C show another embodiment of a pattern of a moiré pattern due to a change (%) in the sizes of the mesh of the upholstering material of the front surface relative to the upholstering material of the rear surface.FIG. 9A is a diagram that shows a shape of a case where the size of the mesh of the upholstering material of the front surface is 95% of that of the upholstering material of the rear surface.FIG. 9B is a diagram that shows a shape of a case where the size of the mesh of the upholstering material of the front surface is 90% of that of the upholstering material of the rear surface.FIG. 9C is a diagram that shows a shape of a case where the size of the mesh of the upholstering material of the front surface is 80% of that of the upholstering material of the rear surface. - As shown in
FIGS. 9A to 9C , when themesh 127 of thefront surface 26A and themesh 128 of therear surface 26B in theupholstering material 26 have a longitudinal long square of the same shape, the moiré patterns of a longitudinal stripe shape are regularly arranged in parallel in a transverse direction and clearly emerge over the whole surface of thebackrest 9. - In addition, although, in the aforementioned embodiment, as a porous sheet-like upholstering material, the upholstering material forming a mesh shape formed of a cloth or the like was used, it is also possible to use a punching metal having a plurality of opened hole portions, a wire composed in a mesh shape or the like as the upholstering material.
- The present invention can be carried out in a plurality of modified forms without being limited to only the above embodiments.
- As mentioned above, according to the present invention, it is possible to provide a chair backrest in which, when a person sitting on the chair leans against the backrest, the reaction force of the upholstering material does not vary to an extreme extent during the leaning action, and a rearward recess amount of the upholstering material of the backrest in response to a load can be sufficiently secured, thereby obtaining a comfortable sitting sensation.
-
-
- 1 base, 2 leg column, 3 support base, 4 lower constituent body, 5 seat, 6 base shaft, 7 armrest, 7 a backrest pivot support portion, 7 b arm support portion, 8 curved surface, 9 backrest, 10 front side piece, 11 support shaft, 12 concave curved surface, 13 first biasing means, 14 second biasing means, 15 rubber torsion unit, 16 first link, 17 second link, 18side portion frame, 19 upper frame, 20 lower frame, 21 intermediate frame, 22 back frame, 23 extension frame, 24 top frame, 25 headrest frame, 26 upholstering material, 26A front surface, 26B rear surface, 27 headrest cover portion, 27 a front surface portion, 27 b rear surface portion, 28 backrest cover portion, 28 a front surface portion, 28 b rear surface portion, 127, 128 mesh, V vertical line
Claims (12)
1. A chair backrest in which a frame-like back frame is covered with a bag-like upholstering material having an open lower end in a state of tension, the back frame being formed by connecting a pair of left and right side portion frames, which extend in an up and down direction, together at upper ends and lower ends thereof by an upper frame and a lower frame which extend in the left and right direction,
wherein intermediate portions in the left and right direction of the upper frame and the lower frame are connected to each other by an intermediate frame which is situated behind the both side portion frames and is extended in the up and down direction, thereby causing an intermediate portion of a rear surface portion of the upholstering material to project rearward.
2. The chair backrest according to claim 1 ,
wherein the upper and lower frames have a curved shape in which the intermediate portions are situated behind the both side portion frames in a plan view.
3. The chair backrest according to claim 1 ,
wherein the lower portions of both side portion frames and the intermediate frame have an arced curved shape in which a curvature center is situated in the front when viewed from the side.
4. The chair backrest according to claim 1 ,
wherein rearward displacement amounts of the intermediate frame relative to both side portion frames are in parts different from each other in the up and down direction.
5. The chair backrest according to claim 3 ,
wherein rearward displacement amounts of the intermediate frame relative to both side portion frames are in parts different from each other in the up and down direction.
6. The chair backrest according to claim 1 ,
wherein the intermediate frame is formed by an elastic material, such that the intermediate frame can be elastically deformed forward when a load is applied to a front surface portion of the upholstering material.
7. The chair backrest according to claim 3 ,
wherein the intermediate frame is formed by an elastic material, such that the intermediate frame can be elastically deformed forward when a load is applied to a front surface portion of the upholstering material.
8. The chair backrest according to claim 4 ,
wherein the intermediate frame is formed by an elastic material, such that the intermediate frame can be elastically deformed forward when a load is applied to a front surface portion of the upholstering material.
9. The chair backrest according to claim 1 ,
wherein, in the upper ends of both side portion frames in the back frame, upward-facing extension frames, which are curved such that intermediate portions are situated ahead of the upper and lower portions when viewed from the side surface, are consecutively provided, and upper ends of both extension frames are connected to each other by a top portion frame which extends in the left and right direction, whereby a headrest frame is formed by the extension frames and the top portion frame.
10. The chair backrest according to claim 3 ,
wherein, in the upper ends of both side portion frames in the back frame, upward-facing extension frames, which are curved such that intermediate portions are situated ahead of the upper and lower portions when viewed from the side surface, are consecutively provided, and upper ends of both extension frames are connected to each other by a top portion frame which extends in the left and right direction, whereby a headrest frame is formed by the extension frames and the top portion frame.
11. The chair backrest according to claim 4 ,
wherein, in the upper ends of both side portion frames in the back frame, upward-facing extension frames, which are curved such that intermediate portions are situated ahead of the upper and lower portions when viewed from the side surface, are consecutively provided, and upper ends of both extension frames are connected to each other by a top portion frame which extends in the left and right direction, whereby a headrest frame is formed by the extension frames and the top portion frame.
12. The chair backrest according to claim 5 ,
wherein, in the upper ends of both side portion frames in the back frame, upward-facing extension frames, which are curved such that intermediate portions are situated ahead of the upper and lower portions when viewed from the side surface, are consecutively provided, and upper ends of both extension frames are connected to each other by a top portion frame which extends in the left and right direction, whereby a headrest frame is formed by the extension frames and the top portion frame.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2008277530A JP5512951B2 (en) | 2008-10-29 | 2008-10-29 | Chair back |
JP2008-277530 | 2008-10-29 | ||
JP2009-054129 | 2009-03-06 | ||
JP2009054129A JP5616585B2 (en) | 2009-03-06 | 2009-03-06 | Chair backrest device |
PCT/JP2009/005705 WO2010050204A1 (en) | 2008-10-29 | 2009-10-28 | Chair backrest |
Publications (1)
Publication Number | Publication Date |
---|---|
US20110204694A1 true US20110204694A1 (en) | 2011-08-25 |
Family
ID=42128575
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/126,731 Abandoned US20110204694A1 (en) | 2008-10-29 | 2009-10-28 | Chair backrest |
Country Status (6)
Country | Link |
---|---|
US (1) | US20110204694A1 (en) |
EP (1) | EP2359717B1 (en) |
KR (1) | KR20110090904A (en) |
CN (1) | CN102202546A (en) |
CA (1) | CA2742008A1 (en) |
WO (1) | WO2010050204A1 (en) |
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US8991931B2 (en) | 2010-06-11 | 2015-03-31 | Okamura Corporation | Furniture cloth and chair |
US8998337B2 (en) | 2010-09-27 | 2015-04-07 | Seizou Miyamoto | Backrest chair, and a sheet material for use thereon |
US10334953B2 (en) | 2014-10-24 | 2019-07-02 | Okamura Corporation | Furniture, load support member for chair, and chair |
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JP5600032B2 (en) * | 2010-06-11 | 2014-10-01 | 株式会社岡村製作所 | Furniture fabric |
JP5571470B2 (en) * | 2010-06-11 | 2014-08-13 | 株式会社岡村製作所 | Chair |
CN103391733A (en) * | 2011-01-27 | 2013-11-13 | 株式会社冈村制作所 | Chair backrest device |
US8998339B2 (en) | 2012-09-20 | 2015-04-07 | Steelcase Inc. | Chair assembly with upholstery covering |
US11304528B2 (en) | 2012-09-20 | 2022-04-19 | Steelcase Inc. | Chair assembly with upholstery covering |
US11229294B2 (en) | 2012-09-20 | 2022-01-25 | Steelcase Inc. | Chair assembly with upholstery covering |
JP6204011B2 (en) * | 2012-10-16 | 2017-09-27 | 株式会社岡村製作所 | The structure of tensioning the tension material on the frame and the backrest of the chair using it |
JP6123239B2 (en) * | 2012-11-06 | 2017-05-10 | コクヨ株式会社 | Chair skin material |
USD704945S1 (en) | 2013-05-16 | 2014-05-20 | Steelcase Inc. | Chair |
USD708466S1 (en) | 2013-05-16 | 2014-07-08 | Steelcase Inc. | Chair |
USD705561S1 (en) | 2013-05-16 | 2014-05-27 | Steelcase Inc. | Chair |
WO2016063973A1 (en) * | 2014-10-24 | 2016-04-28 | 株式会社岡村製作所 | Furniture, load supporting member for chair, and chair |
JP6552083B2 (en) * | 2014-10-24 | 2019-07-31 | 株式会社オカムラ | Chair load bearing member and chair |
CN117860063A (en) * | 2017-12-05 | 2024-04-12 | 斯蒂尔凯斯有限公司 | Compliant backrest |
WO2020172243A1 (en) | 2019-02-21 | 2020-08-27 | Steelcase Inc. | Body support assembly and methods for the use and assembly thereof |
US11357329B2 (en) | 2019-12-13 | 2022-06-14 | Steelcase Inc. | Body support assembly and methods for the use and assembly thereof |
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- 2009-10-28 EP EP09823317.4A patent/EP2359717B1/en not_active Not-in-force
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US8998337B2 (en) | 2010-09-27 | 2015-04-07 | Seizou Miyamoto | Backrest chair, and a sheet material for use thereon |
US10334953B2 (en) | 2014-10-24 | 2019-07-02 | Okamura Corporation | Furniture, load support member for chair, and chair |
Also Published As
Publication number | Publication date |
---|---|
WO2010050204A1 (en) | 2010-05-06 |
EP2359717A4 (en) | 2013-10-16 |
CN102202546A (en) | 2011-09-28 |
EP2359717A1 (en) | 2011-08-24 |
EP2359717B1 (en) | 2014-11-26 |
KR20110090904A (en) | 2011-08-10 |
CA2742008A1 (en) | 2010-05-06 |
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