KR101111580B1 - A combination apparatus for the back of the chair - Google Patents

Abstract

The present invention relates to a fastening device for a chair back, and more particularly, a user such as an office worker or a student living in a chair for a long time supports the spine and lumbar spine when sitting on a chair, and at the same time reduces fatigue even when sitting in a chair for a long time. The present invention relates to a fastening device for a chair back having improved durability of the back.

The present invention for achieving the above object is a first fastening portion fastened and fixed to the backrest of the chair, the first fastening portion is fixed and connected to the first fastening portion, the first connection portion is fixed to the backrest support of the chair, the first fastening portion And a flow unit configured to be connected and fixed to both sides by the first connection unit.

Chair, backrest, backrest support

Description

Fastening device for chair back {A combination apparatus for the back of the chair}

The present invention relates to a fastening device for a chair back, and more particularly, a user living in a chair for a long time supports the spine and lumbar spine when sitting on a chair, thereby reducing fatigue and improving durability of the backrest. It relates to a fastening device for the chair back.

In general, the chair is configured to include a seat plate for supporting the buttocks to support the buttocks and the backrest for supporting the back, and the seat plate and the backrest are supported in such a way that the seat plate and the back support are movably coupled within an appropriate angle range. It is composed of a configuration that can be tilted (tilting) is installed on the top of the vertical column.

At this time, the backrest is fixed with bolts or hinges to the backrest support that is fastened and fastened to the support device connecting the seat plate and the leg to each other.

As is well known, the backrest of a chair which is commonly used is simply configured to support the back including the waist.

In the conventional chair, when the user leans on the backrest while sitting on the seatboard, the backrest is tilted by the elastic action of the backrest support that is fastened and fixed to the support device provided at the bottom of the seatplate.

This causes the user to be injured because the load is concentrated on the support device provided on the lower part of the seat by the tilting action when leaning on the backrest and falls down when it is severely tilted backwards.

In addition, the conventional backrest is hinged to the backrest support to support the user's back while the backrest is reciprocating rotation within a predetermined range around the hinge, it does not support the user's lumbar spine and back properly posture is disturbed When the chair is used for a long time in this state, there is a problem such as deformation of the lower back or spine.

The present invention has been made to solve the conventional problems, and is provided with a first connecting portion fastened and fixed to the backrest support, and is provided with a fixing member fixed to the backrest is mounted to the first connection portion, the fixing member is first By lifting and rotating around the fastening part, the user's back and lumbar spine seated safely on the chair can be used to relieve fatigue of people who sit in the chair for a long time.

In addition, the first connector and the first fastening portion is connected to each other by a flow unit that rotates to a predetermined radius, the first long hole is formed in the first fastening portion, the first connector is hinged fixed to the first long hole By the reciprocating rotation operation, the center of the backrest in the flow operation is concentrated in the backrest fastening device is to prevent the chair from falling even if the user leans on the backrest.

In addition, the backrest performs the interlocking motion by the first connection part and the first fastening part fastened to the backrest support, thereby safely supporting the user's waist and lumbar spine, reducing fatigue even when living in a chair for a long time, and deformation of the spine, etc. Its purpose is to prevent it from happening.

The present invention for achieving the above object is a first fastening portion fastened and fixed to the backrest of the chair, the first fastening portion is fixed and connected to the first fastening portion, the first connection portion is fixed to the backrest support of the chair, the first fastening portion And a flow unit which is connected to both sides of the first connection unit and is fixed to flow.

Here, the first fastening portion is provided with a first body consisting of a first side plate and a cover member, the first side plate formed on both sides of the first body is formed with a first fastening hole in the upper end, the bottom of the second fastening hole is formed It is characterized by.

The first connecting portion has second side plates formed on both sides thereof, and a first connection member having an installation hole formed between the second side plates, and an upper end portion of the second side plate has a fitting hole formed therein, and the lower portion of the fitting hole is provided. The first fastening hole is formed in the first fastening portion and the second fastening hole is formed, characterized in that the lower portion of the first connecting member is formed with a fixing hole for fixing the back support.

Here, the first long hole is characterized in that the upper side is formed to be inclined inward.

Further, the first washer is characterized in that the guide washer is fastened fixed.

In addition, it characterized in that the fixing bolt for fastening and fixing the backrest support inserted into the fixing hole.

In addition, the flow unit is provided with a first fastening member fixed to the first fastening hole and the first bolt of the first fastening portion, a second spaced apart from the first fastening member at a predetermined interval and the second coupling portion is coupled to the fitting hole of the first connection portion A binding member is provided, and the plate which connects the second binding member and the second binding member is provided.

And, it is provided between the connecting portion and the flow portion is characterized in that it is provided with an elastic member for returning the flow portion.

Here, the elastic member is fixed to the second binding member, one end is fixed to the first connection member of the first connecting portion, the other end is characterized in that the fixing jaw formed on the plate of the flow portion.

In addition, the elastic member is characterized in that a pair is provided to be fastened and fixed to each side of the second binding member.

On the other hand, the second fastening portion fastened and fixed to the backrest of the chair, the second fastening portion is fixed to the second fastening portion, the second connection portion fastened and fixed to the backrest support of the chair, and connecting the second fastening portion and the second connection portion It is characterized by consisting of a buffer.

Here, the second fastening portion is provided with a third side plate on both sides, a second body having a seating hole formed therein, a second long hole inclined to face the lower end of the third side plate is formed, A third fastening hole is formed to be spaced apart from the second chapter hole.

In addition, an inclined surface is formed at an upper end of the second body so as to face the outer side, and a first seating hole in which the buffer part is mounted is formed at an inner side of the inclined surface.

In addition, the second connection portion has a fourth side plate is formed on both sides, the second connection member having an installation hole formed between the fourth side plate is provided, the upper end of the fourth side plate is fitted into the second long hole of the second fastening portion A fourth fastening hole is formed to bind the third bolt, and a third long hole is formed at the lower portion of the fourth fastening hole to fasten the fourth bolt to be fitted into the third fastening hole of the second fastening portion. The lower portion of the back support is characterized in that the fixing hole is fixed fastened.

Here, the inclined surface is formed to correspond to the inclined surface of the body 2 fastening portion to the outer side of the upper end of the second connecting member, the inner side of the inclined surface is characterized in that the second seating hole is formed to bind the buffer.

In addition, the support member is seated in the first seating hole of the second fastening portion, a protrusion is formed on the rear surface of the support member, and the lifting member is seated in the second seating hole of the second connector, but the second connector The adjustment member is fastened and fixed from the outside of the inclined surface, characterized in that the elastic member is provided between the support member and the lifting member.

The present invention configured as described above is provided with a first connecting portion fastened and fixed to the backrest support, and is provided with a fixing member mounted to the first connecting portion and fixed to the backrest, and the fixing member moves up and down about the first fastening portion. By doing so, it securely supports the user's back and lumbar spine seated on the chair has the effect of reducing the fatigue of people living in the chair for a long time.

In addition, the first connector and the first fastening portion is connected to each other by a flow unit that rotates to a predetermined radius, the first long hole is formed in the first fastening portion, the first connector is hinged fixed to the first long hole By reciprocating rotation operation, the center of the flow movement of the backrest is concentrated in the backrest fastening device so that the chair does not fall even if the user leans on the backrest.

In addition, the backrest performs the interlocking motion by the first connection part and the first fastening part fastened to the backrest support, thereby safely supporting the user's waist and lumbar spine, reducing fatigue even when living in a chair for a long time, and deformation of the spine, etc. There is an effect to prevent the occurrence.

Hereinafter, with reference to the accompanying drawings for the chair back fastening device according to the present invention will be described in detail as follows.

[First Embodiment]

Figure 1 is an exploded perspective view showing a fastening device for a chair back according to the present invention, Figure 2 is a perspective view showing a separated state of the present invention, Figure 3 is a coupling showing a fastening device for a chair back according to the present invention Status section.

As shown in Figures 1 to 3, the fastening device 100 for a chair back according to the present invention is a seat portion, a backrest, a leg portion fastened and fixed by the support device of the seat portion, a backrest fastened and fixed to the support device A chair composed of supports 102 is provided.

Here, the fastening device 100 for fastening and fixing the backrest 104 is provided with a first fastening portion 110 to be fastened and fixed to the back of the backrest 104.

Further, the first fastening part 110 is in close contact with the back of the backrest 104 is fixed by a bolt (not shown), etc., both sides protrude to the outside to form a seat hole 114 in the first side plate ( A first body 112 is formed, and a first body 112 having a cover member 118 formed integrally with the first side plate 116 and covering the upper portion is provided.

In addition, a first fastening hole 116a is formed at an upper end of the first side plate 116, and a second fastening hole 116b is formed to be spaced apart from the lower end of the first fastening hole 116a.

At this time, the first side plate 116 is further formed with a reinforcement protrusion 120, it is formed at a position where the first fastening hole 116a and the second fastening hole 116b is formed.

In addition, the first connection part 210 is fastened and fixed to the first fastening part 110 to be coupled to the backrest support 102.

Here, the first connection portion 210 is formed on both sides of the second side plate 216 corresponding to the first side plate 116 of the first fastening portion 110 so that the installation hole 214 is formed on both sides of the first connection portion 210 is formed; Between them, a first connection member 212 is provided.

Further, a fitting hole 216a is formed at an upper end of the second side plate 216 of the first connecting portion 210, and a first long hole 216b is formed at a lower end of the position spaced apart from the fitting hole 216a.

At this time, the first long hole 216b is formed to be inclined so that the lower portion is toward the outer side and the upper portion is toward the inner side, and is fastened and fixedly movable by the second fastening hole 116b and the second bolt 132 of the first fastening part. The guide washer 216c is fastened and fixed to the first long hole 216b.

In this case, the second fastening hole 116b may be formed as a protrusion instead of the second bolt 132 so as to be ground in the first long hole 216b of the connection portion 210.

Therefore, the guide washer 216c is fastened and fixed to the first long hole 216b, so that the slide operation can be performed smoothly without frictional resistance during the slide movement of the second bolt 132.

In addition, a lower portion of the first connection member 212 is formed so that the lower portion is open to the fixing hole 220 is inserted into the back support 102 is formed, and penetrates the back support 102 inserted into the fixing hole 220 Fixing bolt 222 is provided to fasten and secure.

  In addition, the first fastening part 110 and the first connection portion 210 is provided with a flow portion 310 which is fastened and fixed to flow while being connected to each other.

Here, the flow portion 310 is formed in communication with the first fastening hole 116a formed in the first side plate 116 of the first fastening portion 110 on the inside, so as to flow by the first bolt 130 A first binding member 312 having a first through hole 312a fitted therein is provided.

In this case, the first fastening hole 116a may be formed as a protrusion instead of the first bolt 130 so as to be caught by the fitting hole 216a of the connection part 120.

Further, the second through-hole provided to be spaced apart from the first binding member 312, the hinge 316 is coupled to the fitting hole (216a) formed in the second side plate 216 of the first connecting portion 210 inside ( A second binding member 314 having 314a formed thereon is provided.

In addition, the plate 318 is provided between the first binding member 312 and the second binding member 314 to connect the first binding member 312 and the second binding member 314 integrally with each other. The plate 318 is provided with a locking jaw 318a.

In addition, the flow part 310 is further provided with an elastic member 320 for returning the first fastening portion 110 rotated when the first fastening portion 110 is rotated.

Here, the elastic member 320 is fixed by the second binding member 314 of the flow portion 310, one side is supported and fixed to the first connecting member 212 of the first connecting portion 210, the other side It is preferable to use a torsion spring that is supported and fixed to the locking step (318a) formed in the plate 318 of the flow portion (310).

Further, the elastic member 320 is provided with a pair to be fitted to both sides of the second binding member 314 of the flow portion 310, respectively.

Referring to the working relationship for the chair back fastener according to the invention configured as described above are as follows.

Figures 4a and 4b is a view showing the working relationship of the chair back fastening device according to the present invention, a view showing the inclined backrest, Figure 5a and 5b is a working relationship of the chair back fastening device according to the present invention As shown, it is a view showing a state in which the backrest is returned to its original state.

As shown in the figure, the chair backrest fastening device 100 according to the present invention is hinged to the first binding member 312 of the flow part 310 when the user leans on the backrest 104 while sitting in a seat part. The first bolt 130 is rotated about the first bolt 130 inserted into the first fastening hole 116a formed in the first side plate 116 of the first fastening part 110.

At this time, when rotating around the first bolt 130 of the first fastening hole 116a of the first fastening portion 110, the elastic member 320 fixed by the flow portion 310 is pressed while the first The fastening part 110 is rotated.

And, when the first fastening portion 110 is rotated about the first bolt 130 fitted in the first fastening hole 116a, the second binding fastened to the fitting hole (216a) of the first connection portion 210 The first binding member 312 rotates about the member 314 in the same manner as the first fastening portion 110.

As such, the second fastening member 314 of the flow part 310 is rotated about the first bolt 130 fitted in the first fastening hole 116a of the first fastening part 110. Since the first bolt 130 is rotated about the first bolt 130 fitted in the (116a) at the same time, the first fastening portion 110 by the rotation radius of the second fastening member 314 of the flow portion 310 is the first fastening hole (116a) It is lowered by a rotation radius that rotates about the first bolt 130 fitted in the).

As described above, when the first fastening part 110 descends by the rotation radius of the second fastening member 314 of the flow part 310, the first fastening inserted into the first long hole 216b of the first connection member 212. The second bolt 132 fitted into the second fastening hole 116b of the part 110 slides downward along the first long hole 216b in a state located above the first long hole 216b.

Accordingly, the first fastening part 110 rotates about the first bolt 130 of the first fastening hole 116a and simultaneously slides the second bolt 132 inserted into the second fastening hole 116b. It rotates while descending.

As described above, the first fastening part 110 rotates about the first bolt 130 fitted in the first fastening hole 116a and is inserted into the first long hole 216b of the first connection member 212. As the two bolts 132 slide downward while moving on the first chapter hole 216b, the user may support the user's lumbar spine and waist when the user leans on the backrest 104 to prevent the user's body deformation from occurring. do.

In addition, when the user leans on the backrest 104, the center of gravity is not driven to the bottom of the backrest support 102, and the load is distributed by the flow of the first fastening portion 110 so that the user can safely lean on the backrest 104. do.

On the other hand, when the user releases the pressing force applied to the backrest 104 in a state where the user leans from the backrest 104, the first fastening portion 110 has the backrest 104 perpendicular to the vertical position by the elastic force of the elastic member 320. Will be restored.

 By the repetitive operation as described above, when the user leans on the backrest 104, the chair does not fall and can safely support the user's spine and lumbar spine.

Second Embodiment

Figure 6 is an exploded perspective view showing a fastening device for a chair back according to the second embodiment of the present invention, Figure 7 is a cross-sectional view of the coupling state showing the fastening device for a chair back of the second embodiment according to the present invention.

As shown in Figure 6 and 7 the seat back fastening device 1000 according to the present invention is a seat, back and legs, the seat is fastened and fixed by the support device to the seat and fastened to the support device A chair composed of the backrest support 102 is provided.

Here, the fastening device 1000 for fastening and fixing the backrest 104 is provided with a second fastening part 1100 fastened and fixed to the back of the backrest 104.

Further, the second fastening part 1100 is closely attached to the back of the backrest 104 and is fixed by fixing means such as bolts (not shown), and both sides protrude outward to form a seating hole 1104 inside. A third body 1106 is formed, and a second body 1102 is formed integrally with the third side plate 1106 and has a cover member 1108 covering the upper portion thereof.

In addition, a second long hole 1106a is formed at an upper end of the third side plate 1106 to be inclined downward, and a third fastening hole 1106b is spaced apart from a lower end of the second long hole 1106a.

In addition, a first inclined surface 1110 is formed at an upper end of the second body 1102 so that the backrest 104 is coupled to and fixed to the opposite direction, that is, the outer surface of the second body 1102 is directed to the outside.

In this case, a first seating hole 1112 is formed in the inner seating hole 1104 of the first inclined surface 1110 to protrude outward from the bottom surface.

In addition, a second connection part 2100 is fastened and fixed to the second fastening part 1100 and is coupled to the backrest support 102.

Here, the second connection member 2100 may include a second connection member having a fourth side plate 2106 corresponding to the third side plate 1106 of the second fastening portion 1100 so that the installation hole 2104 is formed therein ( 2102 is provided.

Furthermore, a fourth fastening hole 2106a is formed at an upper end of the fourth side plate 2106 of the second connection member 2102, and a third long hole 2106b is disposed at a lower end of the second fastening hole 2106a which is spaced below the fourth fastening hole 2106a. ) Is formed.

At this time, the fourth fastening hole 2106a is fastened to the second long hole 1106a of the second fastening part 1100 by a third bolt 1302, and the third long hole 2106b has a lower back 104. It is formed to be inclined toward the () is coupled to be fixed to flow by the third fastening hole (1106b) and the fourth bolt (1304) of the second fastening portion (1100).

In addition, a second inclined surface 2110 is formed at an upper end of the second connection member 2102 to correspond to the first inclined surface 1110 of the second fastening portion 1100, and a second inclined surface 2110 is formed inside the second inclined surface 2110. The second seating hole 2112 is formed to correspond to the first seating hole 1112 formed in the first inclined surface 1110 of the second fastening part 1100.

In addition, a lower portion of the second connection member 2102 is formed so that the lower portion is opened to form a fixing hole 2120 into which the backrest support 102 is inserted, and penetrates the backrest support 102 inserted into the fixing hole 2120. Fixing bolt 2122 is provided to fasten and secure.

In addition, a buffer unit 3100 is provided between the second fastening unit 1100 and the second connection unit 2100 to provide a buffering function during the operation of the second fastening unit 1100 and to restore the original shape.

Here, the shock absorbing portion 3100 is fixed to the first seating hole 1112 of the second fastening portion 1100, the contact surface in contact with the bottom surface of the first seating hole 1112 of the second fastening portion 1100 The support member 3102 with the protrusion 3104 formed thereon is provided.

In this case, the protrusion 3104 is formed in a circular shape such that the support member 3102 smoothly flows when the second fastening part 1100 flows, and the support member 3102 is smaller than the diameter of the first seating hole 1112. It is preferable to form small.

In addition, the second seating hole 2110 of the second connection member 2102 is provided with a lifting member 3106, the second inclined surface 2110 of the second connecting member 2102 from the outside through the lifting member ( 3106 is provided with an adjustment member 3108 fastened and fixed.

In addition, an elastic member 3110 having an elastic force is provided between the support member 3102 and the elevating member 3106.

Therefore, when the second fastening portion 1100 flows, the shock applied to the second body 1102 is absorbed and relieved by the elastic force of the elastic member 3110 and at the same time by the elastic force of the elastic member 3110. The second body 1102 can be returned to its original state.

Referring to the operational relationship of the fastening device for the chair back of the second embodiment according to the present invention configured as described above are as follows.

8 is a view showing the working relationship of the fastening device for the chair back of the second embodiment according to the present invention.

As shown therein, the chair back fastening device 1000 according to the present invention is formed on the third side plate 1106 of the second fastening part 1100 when the user leans against the backrest 104 while the user is sitting on the seat. The upper portion of the second body 1102 is rotated while being slid according to the guide of the third bolt 1302 inserted into the second long hole 1106a.

At this time, when the second fastening portion 1100 slides according to the guide of the second bolt 1302 fitted in the second long hole 1106a, the second fastening portion 1100 is inserted into the third long hole 216a of the second connection portion 2100. The lower portion of the second fastening portion 1100 rotates in the same manner as the upper portion while the slide operation is performed according to the guide of the four bolts 1304.

Accordingly, the second fastening part 1100 slides with the guide of the third bolt 1300 at the second long hole 1106a and at the same time the third long hole 2106b of the second connection part 2100 is fourth bolt 1304. By performing the slide operation according to the guidance of), the second fastening portion 1100 as a whole relative to the second connecting portion 2100 is rotated at a predetermined angle.

On the other hand, when the second fastening part 1100 performs the rotation operation with respect to the second connection part 2100, the elastic member 3110 of the shock absorbing part 3100 is pressed in the second fastening part 1100. The rotational operation to mitigate the impact generated when the second fastening portion 1100 is rotated by the elastic member 3110 and at the same time when the user falls from the backrest, the elastic force of the elastic member 3110 As a result, the second fastening part 1100 is returned to its original shape.

In addition, it is possible to adjust the pressing force generated when the second fastening portion 1100 rotates by using the adjusting member 3108 of the buffer portion 3100.

That is, when the elevating member 3106 is advanced by rotating the adjusting member 3108, the elastic member 3110 maintains the pressurized state as the elevating member 3106 is advanced, so that the second fastening portion 1100 At the time of rotation, a stronger force of force is generated.

In addition, when the second fastening part 1100 rotates, the support member 3102 of the buffer part 3100 may always securely support the elastic member 3110 by the protrusion 3104.

As described above, the second fastening part 1100 performs a rotational motion based on the second connection part 2100, thereby supporting the user's lumbar spine and waist when the user leans on the backrest 104 to maintain the user's comfortable posture. It becomes possible.

In addition, when the user leans on the backrest 104, the center of gravity is not driven to the bottom of the backrest support 102, and the load is distributed by the flow of the second fastening portion 1100 so that the user can safely lean on the backrest 104. do.

By this repetitive operation, when the user leans on the backrest 104, the chair does not fall and can safely support the user's spine and lumbar spine.

In the above, a preferred embodiment of the backrest fastening device for a chair according to the present invention has been described, but the present invention is not limited thereto, and various modifications are made within the scope of the claims and the detailed description of the invention and the accompanying drawings. It is possible to implement, which also belongs to the scope of the present invention.

The present invention relates to a fastening device for a chair back, and more particularly, a user such as an office worker or a student living in a chair for a long time supports the spine and lumbar spine when sitting on a chair, and at the same time reduces fatigue even when sitting in a chair for a long time. The present invention relates to a fastening device for a chair back having improved durability of the back.

1 is an exploded perspective view showing a fastening device for the chair back of the first embodiment according to the present invention.

Figure 2 is a perspective view showing a state in which the first fastening portion of the first embodiment according to the present invention is separated.

Figure 3 is a cross-sectional view of the coupling state showing the fastening device for the chair back of the first embodiment according to the present invention.

Figures 4a and 4b is a view showing the working relationship of the fastening device for the backrest of the chair according to the first embodiment of the present invention, a view showing a state in which the backrest is inclined.

Figures 5a and 5b is a view showing the working relationship of the fastening device for the backrest of the chair according to the first embodiment of the present invention, the backrest is showing the original state.

Figure 6 is an exploded perspective view showing a fastening device for the chair back of the second embodiment according to the present invention.

Figure 7 is a cross-sectional view showing a coupling device for the chair back of the second embodiment according to the present invention.

8 is a view showing the working relationship of the fastening device for the chair back of the second embodiment according to the present invention.

[Description of Symbols for Main Parts of Drawing]

100, 1000: fastening device 102: backrest support

104: back 110, 1100: first and second fasteners

112,1102: First and second body 114, 1104: Seating hole

116, 216, 1106, 2106: first and second side plates

116a, 116b, 1106b, 2106a: first, second, third and fourth fasteners

118, 1108: cover member 120: reinforcing member

130, 132, 1302, 1304: 1, 2, 3, 4 volts

210, 2100: First and second connection parts 212, 2102: First and second connection members

214, 2104: mounting hole 216a: fitting hole

216b, 1106a, 2106b: 1st, 2nd, 3rd hole

216c: Guide washer 220, 2120: Fixing hole

222, 2122: fixing bolt 310: flow part

312, 314: First and second binding members 312a, 314a: First and second through holes

316: hinge 318: plate

318a: locking jaw 320, 3110: elastic member

3100: cushioning portion 3102: support member

3104 protrusion 3106 lifting member

3108: adjusting member

Claims (16)

A first fastening part fastened and fixed to the back of the chair, A first connection part fixed to the first fastening part and fixed to a back support of a chair; The first fastening portion and the first connection portion is composed of a flow portion which is connected to both sides of the flow to be fixed, The first fastening portion is provided with a first body consisting of a first side plate and a cover member, the first side plate formed on both sides of the first body is formed with a first fastening hole in the upper end, the second fastening hole is formed in the lower portion Fastening device for chair back. delete A first fastening part fastened and fixed to the back of the chair, A first connection part fixed to the first fastening part and fixed to a back support of a chair; The first fastening portion and the first connection portion is composed of a flow portion which is connected to both sides of the flow to be fixed, The first connection portion is provided with a second side plate on both sides, the first connection member having an installation hole is provided between the second side plate, A fitting hole is formed in an upper end of the second side plate, and a lower first hole is formed in the lower portion of the fitting hole, the first hole being engaged with the second fastening hole of the first fastening part. Fastening device for a chair back, characterized in that a fixing hole for fixing the back support is formed in the lower portion of the first connection member. The method of claim 3, wherein The first chapter hole is fastening device for a chair back, characterized in that the upper side is formed to be inclined inward. 5. The method of claim 4, Fastening device for a chair back, characterized in that the guide washer is fastened fixed to the first chapter hole. The method of claim 4, wherein Fastening device for a chair back, characterized in that the fixing bolt for fastening and fixing the backrest support inserted into the fixing hole. The method according to claim 1 or 3, The flow part is provided with a first fastening member fixed to the first fastening hole and the first bolt of the first fastening portion, The second binding member is spaced apart from the first binding member at predetermined intervals and is provided with a second binding member hinged to the fitting hole of the first connection portion. Fastening device for a chair back, characterized in that provided with a plate for connecting the first binding member and the second binding member to each other. A first fastening part fastened and fixed to the back of the chair, A first connection part fixed to the first fastening part and fixed to a back support of a chair; The first fastening portion and the first connection portion is composed of a flow portion which is connected to both sides of the flow to be fixed, Fastening device for a chair back, characterized in that the elastic member is provided between the first connecting portion and the flow portion to return the flow portion. The method of claim 8, The elastic member is fixed to the second binding member, one end is fixed to the first connection member of the first connecting portion, the other end is fastening device for a chair back, characterized in that fixed to the locking jaw formed on the plate of the flow portion. The method of claim 9, The elastic member is a backrest fastening device for a chair, characterized in that a pair is provided to be fastened and fixed to each side of the second binding member. A second fastening part fastened and fixed to the back of the chair, A second connection part fixed to the second fastening part and fastened to the back support of the chair; Consists of the buffer portion for connecting the second fastening portion and the second connection portion, The second fastening part includes a third side plate at both sides, a second body having a seating hole formed therein, a second long hole inclined to face the lower end of the third side plate, and a second bottom plate. Fastening device for a chair back, characterized in that the third fastening hole is formed spaced apart from the long hole. delete The method of claim 11, An inclined surface is formed at an upper end of the second body so as to face the outer side, and an inner side of the inclined surface is provided with a first seating hole in which a buffer part is mounted. A second fastening part fastened and fixed to the back of the chair, A second connection part fixed to the second fastening part and fastened to the back support of the chair; Consists of the buffer portion for connecting the second fastening portion and the second connection portion, Fourth side plate is formed on both sides of the second connection portion is provided with a second connection member is formed between the fourth side plate, A fourth fastening hole is formed in the upper end of the fourth side plate to which the third bolt to be fitted into the second long hole of the second fastening part is formed, and a fourth fastening hole inserted into the third fastening hole of the second fastening part is provided below the fourth fastening hole. The third chapter hole is formed to bind the bolt, Fastening device for a chair back, characterized in that the bottom of the second connecting member is formed with a fixing hole for fastening the back support. The method of claim 14, The inclined surface is formed to correspond to the inclined surface of the body 2 fastening portion to the outer side of the upper end of the second connecting member, the inside of the inclined surface is a fastening device for a chair back, characterized in that the second seating hole is formed to bind the buffer. A second fastening part fastened and fixed to the back of the chair, A second connection part fixed to the second fastening part and fastened to the back support of the chair; Consists of the buffer portion for connecting the second fastening portion and the second connection portion, The buffer part is a support member is seated in the first seating hole of the second fastening portion, a protrusion is formed on the back of the support member, The lifting member is seated in the second seating hole of the second connection part, and an adjustment member fixedly penetrating and fixed from the outside of the inclined surface of the second connection part is provided. Fastening device for a chair back, characterized in that the elastic member is provided between the support member and the lifting member.

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