JP6972232B2 - Chair - Google Patents

Description

The present invention relates to a chair with a backrest.

As a chair provided with a backrest in the above technical field, for example, the chairs described in the following Patent Documents 1 and 2 are known. These chairs are configured so that the shape of the backrest in contact with the seated person can be changed.

The chair described in Patent Document 1 has a movable / locking mechanism that changes the shape of the backrest by flexibly deforming a part of the backrest shell of the backrest. This movable / lock mechanism has a mounting portion attached to the central portion in the width direction of the backrest shell and a movable portion that is rotatable with respect to the mounting portion and bends both ends (auxiliary support portions) in the width direction of the backrest shell. And have.

The chair described in Patent Document 2 has a bending adjusting mechanism that changes the shape of the backrest by separating both ends of the annular frame stretched with resin fibers in the width direction from the left and right. .. This curvature adjusting mechanism has a tightening bolt that adjusts the amount of tightening in the width direction between the annular frame and the pair of legs vertically formed on the back surface thereof.

Japanese Patent No. 4185992 Jikkensho 46-35018 Gazette

However, the above-mentioned prior art has the following problems.
In the chair described in Patent Document 1, it is a single part of the backrest shell that secures the strength of the backrest. The central part of the backrest shell in the width direction is equipped with a movable / lock mechanism mounting part and receives a load from the seated person, so that the rigidity is high. Therefore, what is deformed by the movable / locking mechanism is a small range of both ends (auxiliary support portions) in the width direction of the backrest shell with reduced rigidity. In addition, it takes time and effort to mold the backrest shell so that the rigidity of the central portion and both ends in the width direction is different.
Further, the chair described in Patent Document 2 is stretched on the annular frame because the bending adjusting mechanism moves the tightening bolts to the left and right to change the distance between both ends in the width direction of the annular frame. The tension of the resin fiber decreases, and the force to support the seated person decreases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a chair capable of significantly changing the curved shape of the backrest and suppressing a decrease in the force for supporting the seated person.

In the chair according to the present invention, the following configuration was adopted in order to solve the above problems.
Chair according to the present invention, a backrest having a receiving surface component for receiving a load in contact with the seated person, and backrest support member supporting the backrest from behind, the back rest the back rest support member to the center portion of the a fixing portion to be fixed to the backrest and the operation member which is movably supported on one of the backrest carrier, provided on the backrest, more the the operating force inputted to said operating member It is characterized by having a moving end portion that can be moved back and forth by elastic deformation of the backrest with the fixed portion as a fulcrum.

Further, in the chair according to the present invention, the fixing portion is characterized in that the upper end portion of the central portion of the backrest is fixed to the backrest support member.

Further, in the chair according to the present invention, the moving end portions are provided at both ends in the width direction of the backrest .

According to the present invention, it is possible to obtain a chair in which the curved shape of the backrest can be greatly changed and the decrease in the force for supporting the seated person can be suppressed.

It is a side view of the chair of 1st Embodiment of this invention. It is a top view of the chair of 1st Embodiment of this invention. It is a rear view of the chair of the 1st Embodiment of this invention. It is a back side perspective view of the chair of 1st Embodiment of this invention. It is a block diagram of the curved shape changing means of 1st Embodiment of this invention. It is a rear view of the backrest provided with the engaging groove of the bending shape changing means of 1st Embodiment of this invention. FIG. 6 is a cross-sectional view taken along the line AA in FIG. It is a front view of the backrest plate of the backrest of the 2nd Embodiment of this invention. It is a top view of the backrest plate of the backrest of the 3rd Embodiment of this invention. It is a front view of the fixing part of the backrest and the backrest support member of the 4th Embodiment of this invention. FIG. 10 is a cross-sectional view taken along the line BB in FIG. It is a front view explaining the combination method of the backrest and the backrest support member of the 4th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the direction pointed by the arrow FR in the figure facing the front of the person sitting in the chair in the normal posture is referred to as "front", and the direction opposite to it is referred to as "rear". For "up", "down", "left", and "right", the direction indicated by the arrow UP in the figure above the person sitting in the chair in the normal posture is "up", and the opposite direction is "up". It is called "down", and the direction indicated by the arrow LH in the figure on the left side of the person sitting in the chair in the normal posture is called "left", and the direction opposite to it is called "right".

First, the first embodiment shown in FIGS. 1 to 7 will be described.
FIG. 1 is a side view of the chair 1 according to the first embodiment of the present invention.
As shown in FIG. 1, the chair 1 of the present embodiment has a leg portion 2 placed on the floor, a box-shaped support base 3 installed at the upper end of the leg portion 2, and a seat on which a seated person sits. The body 4, the seat support member 5 attached to the upper surface of the support base 3 and supporting the seat 4 so as to be slid back and forth, the backrest 6 to support the back of the seated person seated on the seat 4, and the backrest 6 are provided. It has a backrest support member 7 that supports from behind, and a bending shape changing means 8 that changes the bending shape of the receiving surface constituent portion 20 of the backrest 6.

The leg portion 2 has a multi-leg 9 with casters 9a and a pedestal 10 that stands up from the center of the multi-leg 9 and incorporates a gas spring as an elevating mechanism, and has a support base at the upper end of the pedestal 10. 3 is rotatably attached in the horizontal direction. The support base 3 has a built-in elevating adjustment mechanism for the pedestal 10 and a tilt adjusting mechanism for the backrest support member 7. The backrest support member 7 has a substantially L-shaped side view, and the lower end of the front portion thereof is connected to a tilt adjusting mechanism in the support base 3.
In FIG. 1, reference numeral 11 is a pivot shaft of the backrest support member 7 on the support base 3, and reference numeral 12 is an operation knob of the tilt adjusting mechanism projecting from the side surface of the support base 3.

The seat body 4 has a seat plate 13 forming a skeleton portion and a seat body 14 attached to the upper portion of the seat plate 13. Although detailed illustration is omitted, the seat body 14 is a cushion material (not shown) made of a seat frame (not shown) attached to the outer peripheral edge of the seat plate 13 and urethane or the like installed on the upper surface of the seat plate 13. And a seat skin material 15 which is stretched on the seat frame and covers the upper side of the cushion material.

FIG. 2 is a plan view of the chair 1 according to the first embodiment of the present invention. FIG. 3 is a rear view of the chair 1 according to the first embodiment of the present invention. FIG. 4 is a rear perspective view of the chair 1 according to the first embodiment of the present invention.
As shown in FIG. 2, the backrest 6 has a receiving surface component 20 that is in contact with the seated person and receives a load. The receiving surface component 20 has a curved shape that is convex rearward in the plan view shown in FIG. The receiving surface component 20 of the present embodiment is stretched on a resin-molded backrest plate 21 (see FIG. 4), a cushion material (not shown) installed on the front surface of the backrest plate 21, and a backrest plate 21. It is formed by a sheet skin material 22 that is provided and covers the cushion material.

The backrest 6 has a substantially rectangular shape with rounded four corners in the rear view shown in FIG. Further, as shown in FIG. 1, the backrest 6 has a protruding portion 23 that bends forward. The backrest 6 of the present embodiment has a bent shape that is convex forward in the side view shown in FIG. The apex of the protrusion 23 is formed at a position corresponding to the waist of the seated person. That is, the protruding portion 23 has a shape bent at an appropriate position so that a portion slightly above the lower end portion of the backrest 6 protrudes forward in the side view shown in FIG.

As shown in FIG. 1, the backrest support member 7 supports the backrest 6 from behind. The backrest support member 7 has higher rigidity than the backrest 6, and is a strength member that supports the load of the seated person received by the backrest 6. The backrest support member 7 is resin-molded, and is configured to have higher rigidity than the backrest 6 due to its thickness and arrangement of reinforcing ribs. The backrest support member 7 has a frame portion 30 having substantially the same outer shape as the outer shape of the backrest 6 in the rear view shown in FIG. The frame portion 30 has an opening portion 31 having a large opening on the back surface side.

As shown in FIG. 1, the backrest support member 7 has a protrusion 32 that bends forward at a position corresponding to the protrusion 23 of the backrest 6. That is, the protruding portion 32 has a shape bent at an appropriate position so that a portion slightly above the lower end portion of the frame portion 30 projects forward in the side view shown in FIG. The operating member 50 of the curved shape changing means 8, which will be described later, is arranged on the protruding portion 32. The backrest support member 7 has a connecting portion 33 extending forward from the lower end portion of the frame portion 30. The connecting portion 33 is connected to the tilt adjusting mechanism in the support base 3.

FIG. 5 is a block diagram of the curved shape changing means 8 according to the first embodiment of the present invention. FIG. 6 is a rear view of the backrest 6 provided with the engaging groove 60 of the curved shape changing means 8 according to the first embodiment of the present invention. FIG. 7 is a cross-sectional view taken along the line AA in FIG. In these figures, the cushion material and the seat skin material 22 forming the receiving surface constituent portion 20 are not shown.
As shown in FIG. 5, the curved shape changing means 8 changes the curved shape of the receiving surface constituent portion 20 by relatively moving the central portion 24 and both end portions 25 in the width direction (left-right direction) of the backrest 6 back and forth. It is something to do.

As shown in FIG. 3, the curved shape changing means 8 includes a fixing portion 40 for fixing the central portion 24 of the backrest 6 to the backrest support member 7, and both ends of the backrest 6 as shown in FIGS. 2 and 5. The portion 25 is provided with a moving end portion 41 that can move back and forth with respect to the backrest support member 7. As shown in FIG. 3, the fixing portion 40 is configured to fix the central portion 24 of the backrest 6 to the backrest support member 7 by a plurality of fixing screws 42.

The fixing screw 42 fixes the upper end portion of the central portion 24 of the backrest 6 to the upper end portion of the frame portion 30 of the backrest support member 7, and the lower end portion of the central portion 24 of the backrest support member 7 to the backrest support member. It is fixed to the lower end portion of the frame portion 30 of 7. The upper end of the central portion 24 of the backrest 6 is fixed by the fixing screw 42 at the center of the backrest 6 in the width direction and at three locations on both sides thereof. Further, the lower end portion of the central portion 24 of the backrest 6 is fixed by the fixing screw 42 at one place in the center of the backrest 6 in the width direction.

The moving end portion 41 is a free end of the backrest 6 that is not fixed to the backrest support member 7, and is configured to be movable back and forth with respect to the backrest support member 7. That is, the moving end portion 41 moves back and forth due to the elastic deformation of the backrest 6 (backrest plate 21) with the fixed portion 40 as a fulcrum. The moving end portion 41 is provided at a position corresponding to the protruding portion 23 of the backrest 6. The operating member 50 is arranged at a position corresponding to the protruding portion 23 of the backrest 6, and the moving end portion 41 is configured to move back and forth by pressing the operating member 50.

As shown in FIG. 1, the operation member 50 is movably supported by either one of the backrest 6 and the backrest support member 7 (in the present embodiment, the backrest support member 7). The operation member 50 is for relatively moving the central portion 24 and both end portions 25 of the backrest 6 back and forth, and has a grip portion 51 that can be gripped by the seated person. The grip portion 51 improves the operability of the seated person, and as shown in FIG. 3, has a substantially L shape and protrudes to the side portion of the backrest 6, so that the seated person sits on the seated body 4. It has a structure that can be gripped by.

As shown in FIGS. 4 and 5, the operation member 50 rotates to either one of the facing surfaces 26 and 34 of the backrest 6 and the backrest supporting member 7 facing each other (in the present embodiment, the facing surface 34 side). The base end portion 52 that can be supported and the other side of the facing surfaces 26 and 34 of the backrest 6 and the backrest supporting member 7 that rotate around the base end portion 52 (the facing surface 26 side in this embodiment). Has a tip portion 53 that presses against. Further, as shown in FIGS. 4 to 6, on the other side (opposite surface 26 side in this embodiment) of the facing surfaces 26 and 34 of the backrest 6 and the backrest supporting member 7, the rotation locus of the tip portion 53 Along the line, an engaging groove 60 that can be engaged with the tip portion 53 is formed.

The engaging groove 60 is provided behind the backrest 6. As shown in FIG. 6, the engaging groove 60 is provided along the outer shape of both end portions 25 of the backrest 6. That is, the engaging groove 60 extends in the height direction (vertical direction). Further, the engaging groove 60 extends so as to vertically straddle the position corresponding to the protruding portion 23 of the backrest 6, and is oriented in the width direction along the inclined shape below the protruding portion 23 of the backrest 6. (Left and right direction) It is formed so as to bend inward.

As shown in FIG. 7, the engaging groove 60 is formed by a liner 61 having a predetermined slidability and a holding portion 64 in the liner support member 63. The liner 61 is in sliding contact with the tip portion 53 of the operating member 50, and has a shape corresponding to the shape of the tip portion 53. The tip portion 53 of the operating member 50 of the present embodiment is formed in a ball shape (spherical shape), and the liner 61 is formed in an arc shape in a cross-sectional view. The liner 61 is configured to be divisible into a first liner member 61a and a second liner member 61b. The first liner member 61a and the second liner member 61b are configured to be able to be combined by the uneven fitting portion 62.

The liner 61 is fixed to the back of the backrest 6 (backrest plate 21) by the liner support member 63. The liner support member 63 has a holding portion 64 for holding the liner 61, and an engaging protrusion 65 that can be engaged with the backrest plate 21. The holding portions 64 are provided in pairs at intervals narrower than the outer diameter of the liner 61. The engagement protrusion 65 is provided so as to project in the width direction (left-right direction) inside the liner support member 63. Although not shown, a plurality of engaging protrusions 65 are provided at appropriate positions on the left and right sides of the liner support member 63. The liner 61 and the liner support member 63 may be integrally formed by means such as two-color molding.

The backrest plate 21 has a mounting groove 66 to which the liner support member 63 can be mounted. A plurality of ribs 67 are erected in the mounting groove 66. The liner 61 is sandwiched and fixed between the liner support member 63 and the plurality of ribs 67. The rib 67 is provided with an engaging hole 68 that engages with the engaging projection 65 of the liner support member 63. The engaging hole 68 is provided through the rib 67 in the width direction (left-right direction). By engaging the engaging protrusion 65 and the engaging hole 68, the liner support member 63 is fixed to the backrest plate 21.

The tip portion 53 of the operation member 50 engages with the engagement groove 60, while the base end portion 52 is rotatably supported by the rotation shaft 69. The rotation shaft 69 extends in the width direction and is provided on the backrest support member 7. The base end portion 52 has a bearing hole 70 through which the rotating shaft 69 is inserted. The diameter of the bearing hole 70 is designed to be larger than the diameter of the rotating shaft 69. That is, the base end portion 52 has play in the direction orthogonal to the axis of the rotation axis 69. The operation member 50 of the present embodiment is capable of moving the tip portion 53 in the width direction (left-right direction) along the engagement groove 60 shown in FIG. 6 due to this backlash.

Subsequently, the operation of changing the shape of the backrest 6 using the curved shape changing means 8 having the above configuration and its action will be described.

The seated person grips the grip portion 51 of the operating member 50 projecting to the left and right of the backrest 6 shown in FIG. 3 while sitting on the seat body 4, and pulls it upward. In the operation member 50, the base end portion 52 is rotatably supported by the backrest support member 7, and the tip end portion 53 rotates upward around the base end portion 52 (see FIG. 1). When the tip portion 53 rotates upward, the operating member 50 stretches between the facing surfaces 26 and 34 of the backrest 6 and the backrest supporting member 7 facing each other, and pushes the distance between the facing surfaces 26 and 34. The backrest support member 7 has higher rigidity than the backrest 6, and the backrest 6 side is elastically deformed.

As shown in FIG. 3, the backrest 6 has a central portion 24 fixed to the backrest support member 7 by a fixing portion 40, and both end portions 25 are movable with respect to the backrest support member 7. Therefore, both end portions 25 of the backrest 6 move forward by pressing the operating member 50 (see FIG. 5). When both end portions 25 of the backrest 6 move forward, the curvature of the receiving surface constituent portion 20 of the backrest 6 increases, and as shown in FIG. 5, the curved shape of the receiving surface constituent portion 20 changes from shape C1 to shape C2. It will be changed.

In the present embodiment, since the back of the backrest 6 is supported by the backrest support member 7, the load of the seated person can be reduced even if the rigidity of the backrest 6 as a whole is reduced by the amount that the strength can be secured by the backrest support member 7. Can receive. Therefore, sufficient elasticity can be given to the backrest 6, and the curved shape of the receiving surface component 20 can be significantly changed as shown in FIGS. 2 and 5. Further, since the backrest 6 relatively moves the central portion 24 and both end portions 25 in the width direction back and forth, the distance between the end portions 25 in the width direction is not significantly changed when the curved shape is changed.

That is, in the conventional form in which the central portion 24 and both end portions 25 of the backrest 6 in the width direction are relatively moved to the left and right, when the receiving surface constituent portion 20 is made of a stretch material or the like, the seated person is caused by bending. Although there is a possibility that the supporting force may decrease, in the present embodiment, since the central portion 24 and both end portions 25 of the backrest 6 in the width direction are relatively moved back and forth, the decrease in the supporting force of the seated person is suppressed. can do.

Further, in the present embodiment, the central portion 24 in the width direction of the backrest 6 is fixed to the backrest support member 7, and the moving end portions 41 provided at both end portions 25 in the width direction of the backrest 6 are connected by the operating member 50. It is designed to be pressed and moved back and forth. The moving end portion 41 is provided at a position corresponding to a protruding portion 23 that bends forward of the backrest 6. Since the protruding portion 23 is a portion that supports the seated person's waist and the like and affects the sitting comfort, the seating feeling of the seated person can be easily changed by moving the position corresponding to the protruding portion 23 back and forth. For example, by changing the curved shape of the backrest 6 so as to hold the waist of the seated person, it is possible to prevent the seated person from shifting laterally.

Further, in the present embodiment, the operating member 50 is operated, the tip portion 53 thereof is rotated around the base end portion 52 thereof, the facing surface 26 side of the backrest 6 is pressed, and the operating member 50 is pressed against the facing surface thereof. By stretching between 26 and 34, the curved shape of the receiving surface component 20 is changed. As shown in FIG. 7, the backrest 6 is provided with an engaging groove 60 along the rotation locus of the tip portion 53. Therefore, the tip portion 53 is engaged with the engaging groove 60 while rotating, and is not disengaged from the backrest 6 to release the pressing. Further, the tip portion 53 is formed in a ball shape, so that the way of hitting the backrest 6 can be kept constant, and the operation feeling does not change even if the operation member 50 is rotated.

As described above, according to the above-described embodiment, the backrest 6 having the receiving surface component 20 that is in contact with the seated person and receives the load, the backrest support member 7 that supports the backrest 6 from behind, and the backrest 6 By adopting a configuration having a curved shape changing means 8 for changing the curved shape of the receiving surface constituent portion 20 by relatively moving the central portion 24 and both end portions 25 in the width direction of the backrest. A chair 1 can be obtained in which the curved shape of 6 can be greatly changed and the decrease in the force for supporting the seated person can be suppressed.

Subsequently, the second embodiment of the present invention will be described with reference to FIGS. 1 to 7 with reference to FIG. In each of the embodiments described below, the same reference numerals are given to the parts common to the above embodiments, and duplicate description will be omitted.
FIG. 8 is a front view of the backrest plate 80 of the backrest 6 according to the second embodiment of the present invention. The chair of this embodiment differs from the first embodiment only in the structure of the backrest 6, and the other parts are the same as those of the first embodiment.

The receiving surface component 20 of the backrest 6 of this embodiment is installed on the backrest plate 80 in which a plurality of openings are formed in the height direction and the width direction by a large number of wire rod portions 82, and on the front surface of the backrest plate 80. A cushion material (not shown), a sheet skin material (not shown) that is stretched on the backrest plate 80 to cover the cushioning material, and a backrest cover (not shown) that covers the back surface of the backrest plate 80. It is formed. The backrest plate 80 is formed by a frame 81 forming an outer edge portion thereof, and a plurality of wire rod portions 82 arranged vertically and horizontally inside the frame 81.

The receiving surface component 20 forms a region T1 that is deformed by the relative movement of the central portion 24 and both end portions 25 by the above-mentioned curved shape changing means 8 and a region T2 that is relatively less deformed than the region T1. It has a boundary portion 83 to be formed. The boundary portion 83 of the present embodiment is formed on the backrest plate 80. The boundary portion 83 has a slit 84 formed in the wire rod portion 82 of the backrest plate 80. The slits 84 are provided at appropriate positions in the wire rod portion 82, and are arranged side by side in the height direction (vertical direction).

The boundary portion 83 reduces the rigidity at a suitable position by the slit 84 formed in the wire rod portion 82, and forms the boundary of deformation. According to this second embodiment, the presence of the boundary portion 83 makes it possible to distinguish between the deformable region T1 and the relatively non-deformable region T2, and the curved shape of the receiving surface constituent portion 20 can be controlled to some extent. That is, since the deformation of the receiving surface component 20 can be directed to some extent in the left-right direction, the action and effect of the first embodiment can be more reliably exhibited, the curved shape of the backrest 6 can be greatly changed, and the curvature can be changed. It is possible to prevent the seating feeling of the seated person from being significantly changed when the shape is changed.

Subsequently, the third embodiment of the present invention will be described with reference to FIGS. 1 to 7 with reference to FIGS. 9. In each of the embodiments described below, the same reference numerals are given to the parts common to the above embodiments, and duplicate description will be omitted.
FIG. 9 is a plan view of the backrest plate 21 of the backrest 6 according to the third embodiment of the present invention. The chair of this embodiment differs from the first embodiment only in the structure of the backrest plate 21, and other parts are the same as those of the first embodiment.

The boundary portion 83 of this embodiment is formed on the backrest plate 21. The boundary portion 83 has a groove 85 formed in the backrest plate 21. The groove 85 is provided at an appropriate position on the backrest plate 21 and extends in the height direction (vertical direction). The boundary portion 83 reduces the thickness (rigidity) at an appropriate position by the groove 85 formed in the backrest plate 21, and forms the boundary of deformation. According to the third embodiment, the presence of the boundary portion 83 makes it possible to distinguish between the deformable region T1 and the relatively non-deformable region T2, and to control the curved shape of the receiving surface constituent portion 20. It is possible to exert the same action and effect as those of the second embodiment.

Subsequently, the fourth embodiment of the present invention will be described with reference to FIGS. 1 to 7 with reference to FIGS. 10 to 12. In each of the embodiments described below, the same reference numerals are given to the parts common to the above embodiments, and duplicate description will be omitted.
FIG. 10 is a front view of the fixing portion 40 between the backrest 6 and the backrest support member 7 according to the fourth embodiment of the present invention. FIG. 11 is a cross-sectional view taken along the line BB in FIG. FIG. 11 is a front view illustrating how to combine the backrest 6 and the backrest support member 7 according to the fourth embodiment of the present invention. The chair of this embodiment differs from the first embodiment only in the structure of the backrest 6, the backrest support member 7, and the fixing portion 40, and the other parts are the same as those of the first embodiment.

As shown in FIG. 10, the receiving surface component 20 of the backrest 6 of this embodiment includes a backrest plate 80 in which a plurality of openings are formed in the height direction and the width direction by a large number of wire rod portions 82, and a backrest plate 80. A cushion material (not shown) installed on the front surface of the backrest plate 80, a sheet skin material (not shown) stretched on the backrest plate 80 to cover the cushion material, and a backrest cover covering the back surface of the backrest plate 80. (Not shown) and. The backrest plate 80 is formed by a frame 81 forming an outer edge portion thereof, and a plurality of wire rod portions 82 arranged vertically and horizontally inside the frame 81.

The frame 81 has a slit 86 that divides the center of the lower end portion thereof. The space formed by the slit 86 communicates with the opening 87 at the center of the lower end portion formed by the wire rod portion 82. Therefore, the backrest plate 80 is bifurcated at the center of the lower end portion.
As shown in FIG. 12, the backrest support member 7 is provided with a plurality of ribs 90 for ensuring rigidity vertically and horizontally inside the frame portion 30. The rib 90 is formed at the lower end portion of the frame portion 30 and the connecting portion 33.

As shown in FIG. 10, the curved shape changing means 8 has a fixing portion 40 for fixing the central portion 24 of the backrest 6 to the backrest support member 7. The fixing portion 40 includes a fixing screw 42 for fixing the upper end portion of the central portion 24 of the backrest 6 to the upper end portion of the frame portion 30 of the backrest support member 7, and the lower end portion and the backrest support of the central portion 24 of the backrest 6. It has an engaging portion 43 that engages with the lower end portion of the member 7. As shown in FIG. 12, the engaging portion 43 is formed of an engaging projection 44 provided on the backrest 6 and an engaging groove 45 provided on the backrest support member 7. The engaging portion 43 regulates the forward movement (disengagement) of the lower end portion of the backrest 6 while allowing the backrest 6 to be deformed in the direction of opening the lower end portion of the backrest plate 80.

The engaging protrusion 44 is integrally formed with the backrest plate 80. The engaging protrusions 44 are rods extending downward from the lower end of the backrest plate 80, and are provided in pairs on both sides of the slit 86. The engaging projection 44 has a tip portion 44a that bulges forward.
On the other hand, the engaging groove 45 is integrally formed with the backrest support member 7. The engaging grooves 45 are grooves formed between the ribs 90 at the lower end of the frame portion 30, and are provided in pairs corresponding to the engaging protrusions 44. The engaging groove 45 is formed so as to extend in the left-right direction.

As shown in the cross-sectional view of FIG. 11, the engaging groove 45 is opened diagonally upward and forward, and the engaging projection 44 is inserted into the opening. The engagement groove 45 has an opening 46 formed on the side surface of the rib 90 forming the front wall. By engaging the tip portion 44a of the engaging protrusion 44 with the opening portion 46, the pull-out of the engaging protrusion 44 is restricted from being slanted upward. As shown in FIG. 10, the opening 46 is formed so as to extend in the left-right direction. Therefore, the engaging protrusion 44 is configured to be movable to the left and right with the tip portion 44a engaged with the opening portion 46.

According to the fourth embodiment of the above configuration, the lower end portion of the central portion 24 of the backrest 6 is not completely fixed, but is in a semi-fixed state in which the movement in the forward direction is restricted while allowing deformation in the left-right direction. Can be done. As described above, the backrest 6 fixes the central portion 24 in the width direction of the backrest 6 to the backrest support member 7, and operates the moving end portions 41 provided at both end portions 25 in the width direction of the backrest 6. It is designed to be pressed by the member 50 and moved back and forth. According to this fourth embodiment, since the lower end portion of the central portion 24 of the backrest 6 is not completely fixed, it can be flexibly deformed in the left-right direction following the front-back movement of the moving end portion 41. As a result, the force required to operate the operating member 50 becomes smaller than that in the first embodiment, and the operability of the operating member 50 can be improved.

Although the preferred embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to the above embodiment. The various shapes and combinations of the constituent members shown in the above-described embodiments are examples, and various changes can be made based on design requirements and the like within a range that does not deviate from the gist of the present invention.

For example, in the above embodiment, the configuration in which the tip end portion of the operating member presses the facing surface side of the backrest has been described, but in the present invention, the tip end portion of the operating member presses the facing surface side of the backrest supporting member. It may be. Further, in this case, it is preferable to adopt a configuration in which an engaging groove is formed on the facing surface side of the backrest.

Further, for example, in the above embodiment, the configuration in which the base end portion of the operating member is supported by inserting the rotating shaft into the bearing hole has been described, but in the present invention, the base end portion of the operating member is supported by a ball joint. It may be configured to be. However, in the case of a ball joint, it moves in response to a load in all directions. Therefore, if the load from the seated person is excessive, the bearing hole is designed to be large as in the above embodiment, and the axis of the rotating shaft is aligned. It is preferable to adopt a robust configuration in which the play is intentionally given in the direction orthogonal to the above.

Further, for example, in the above embodiment, the configuration in which the receiving surface constituent portion is formed by the backrest plate and the cushion material arranged on the front surface thereof has been described, but in the present invention, the receiving surface constituent portion is stretched on the frame member. It may be configured to be formed of a stretched material such as a mesh. In this case, it is preferable to adopt a structure in which the frame member is elastically deformable and is pressed in the front-rear direction by the operating member.

Further, for example, in the above embodiment, the configuration in which the central portion in the width direction of the backrest is fixed and both ends in the width direction of the backrest are moved back and forth has been described. Both ends may be fixed and the central portion in the width direction of the backrest may be moved back and forth. In this case, it is preferable to adopt a configuration in which the backrest support member is arranged behind the central portion in the width direction of the backrest and the central portion is pressed by the operating member.

Further, for example, in the above embodiment, the configuration in which the central portion and both end portions in the width direction of the backrest are relatively moved back and forth by the operating member has been described, but the present invention has been described by hand directly without using the operating member. The central portion and both end portions in the width direction of the backrest may be relatively moved back and forth. However, if an operating member is used, the curved shape of the backrest can be changed with a lighter force than by moving it directly by hand.

Further, for example, in the above embodiment, as the fixing portion, the lower end portion of the central portion of the backrest is not completely fixed, but is in a semi-fixed state in which the movement in the forward direction is restricted while allowing deformation in the left-right direction. Although the configuration in which the joint portion is adopted has been described, the present invention is not limited to this configuration. For example, a protrusion-shaped locking portion that regulates the forward movement (detachment) of the lower end portion of the central portion of the backrest is provided, and the lower end portion of the central portion of the backrest is fixed only by the locking portion. A configuration in which the semi-fixed state may be adopted may be adopted.

Further, for example, in the above embodiment, a configuration has been described in which a fixing screw for fixing the upper end portion of the central portion of the backrest to the upper end portion of the frame portion of the backrest support member is adopted as the fixing portion. It is not limited to this configuration. For example, a plurality of engaging protrusions are formed behind the upper end of the central portion of the backrest, and these engaging protrusions engage with the engaging recesses formed in the backrest support to form the central portion of the backrest. A configuration may be adopted in which the upper end portion of the backrest support member is fixed to the upper end portion of the frame portion of the backrest support member. In addition, by providing some play in the dimensions of the engaging recess, the upper end of the central part of the backrest is also semi-fixed, making the backrest easier to move with respect to the backrest support member, and thereby operating. It becomes possible to make the operability of the member lighter.

1 Chair 6 Backrest 7 Backrest support member 8 Curved shape changing means 20 Receiving surface component 23 Protruding part 24 Central part 25 Both ends 26 Facing surface 34 Facing surface 40 Fixed part 41 Moving end part 50 Operating member 52 Base end part 53 Tip 60 Engagement groove 83 Boundary T1 region T2 region

Claims (3)

A backrest with a receiving surface component that is in contact with the seated person and receives a load,
The backrest support member that supports the backrest from behind,
A fixing portion for fixing the central portion of the backrest to the backrest support member, and a fixing portion.
An operating member movably supported by either the backrest or the backrest support member, and
Wherein provided on the backrest, have a, and moving end portion movable back and forth by the back rest of the elastic deformation a fulcrum the fixing portion by the operation force inputted to the operating member,
The fixing portion is a chair characterized in that the upper end portion of the central portion of the backrest is fixed to the backrest support member. The chair according to claim 1 , wherein the moving ends are provided at both ends in the width direction of the backrest. A backrest with a receiving surface component that is in contact with the seated person and receives a load,
The backrest support member that supports the backrest from behind,
A fixing portion for fixing the central portion of the backrest to the backrest support member, and a fixing portion.
An operating member movably supported by either the backrest or the backrest support member, and
It has a moving end portion provided on the backrest and movable back and forth by elastic deformation of the backrest with the fixed portion as a fulcrum by an operating force input to the operating member.
The moving end is a chair provided at both ends in the width direction of the backrest.

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