Seat back linkage for a chair

Abstract

The application discloses a seat-back linkage device of a chair, which mainly comprises a seat body and a seat base, and a seat cushion assembly plate is arranged above the seat body and the seat base. The seat cushion assembly plate is pivotally connected with the seat body. When a user sits on the seat cushion arranged on the seat cushion assembly plate, the seat cushion assembly plate uses the pivotally connected part with the seat body as a fulcrum. When the front side of the seat cushion assembly plate is displaced downward, the front side of the seat cushion assembly plate is slowly lowered to a required forward inclination angle by using the seat cushion spring sheet connected with the rear side of the seat cushion assembly plate. In addition, when the user leans on the chair back arranged on the rear side of the seat body, the rear side of the seat body is displaced backward using the pivotally connected part of the seat body and the seat base as a fulcrum. The pivotally connected part of the seat body and the seat cushion assembly plate forms a support to support the seat cushion assembly plate, so that the chair back and the seat are synchronously inclined, and the riding comfort is improved.

Description

Technical Field

[0001] This invention relates to the technical field of chairs, and more particularly to a seat-back linkage device for a chair. Background Technology

[0002] Office chairs and other similar furniture typically have a reclining adjustment function on the backrest. When a user sits on the chair and leans back against the backrest, the backrest can swing elastically to achieve a cushioning effect. However, since there is no connection between the backrest and the seat of such office chairs, the seat cannot adjust properly as the user leans back, thus affecting the comfort of the chair.

[0003] Therefore, those skilled in the art have invented chairs that allow the seat and backrest to move in tandem. Please refer to the Taiwan patent TWM599751U "Seating and Backrest Linkage Mechanism" and the Chinese utility model patent CN215271602U "A Chair That Can Tilt Forward and Backward". When a user sits on such a chair and leans back, the backrest can tilt, and the seat can tilt in tandem to achieve a more comfortable sitting posture. However, the linkage mechanism between the seat and backrest of the existing chairs is too complex in structure, has many parts, is relatively expensive to manufacture, and takes up a lot of space, which affects the overall aesthetics of the chair.

[0004] Therefore, considering that existing chairs that allow the seat and back to move together still have the above-mentioned shortcomings in manufacturing and use, the inventor, based on his many years of manufacturing and design experience and knowledge in related fields, and through various conceptualizations, created this invention. Summary of the Invention

[0005] The present invention provides a seat-back linkage device for a chair, the purpose of which is to provide a seat-back linkage device for a chair that enables the backrest to move synchronously with the seat, and has a simple structure, low manufacturing cost, and allows for a flat design.

[0006] To achieve the above-mentioned objectives, the inventors have invented a seat-back linkage device for a chair, comprising:

[0007] A chair seat body, wherein a base assembly is provided on the front side of the chair seat body and a backrest assembly is provided on the rear side of the chair seat body, and a spring piece assembly groove is provided between the base assembly and the backrest assembly, wherein the rear wall of the spring piece assembly groove is adjacent to the backrest assembly.

[0008] A chair base is provided at the base assembly of the chair body and is pivotally connected to the chair body by at least one first pivot. The front side of the chair base is assembled with the rear end of a support spring, which extends forward from the chair base. At least one backrest spring is provided in the spring assembly groove of the chair body. The front end of the backrest spring is assembled with the rear side of the chair base. A latching part is provided on the rear wall of the spring assembly groove opposite to the backrest spring. The rear end of the backrest spring is locked and positioned by the latching part on the rear wall of the spring assembly groove.

[0009] A seat cushion assembly plate is provided, located above the chair body and the chair base, and passing through the seat cushion assembly plate and the chair body with at least one second pivot, thereby pivotally connecting the seat cushion assembly plate and the chair body. The pivot point between the seat cushion assembly plate and the chair body is located in front of the pivot point between the chair body and the chair base, and the front end of the support spring of the chair base abuts against the front side of the seat cushion assembly plate.

[0010] As described above, the seat-back linkage device of the chair includes at least one seat cushion spring and a pin in the spring plate assembly groove of the main seat body. The front end of the seat cushion spring is located at the rear side of the seat base, and the rear end of the seat cushion spring has a through hole. The pin passes through the through hole of the seat cushion spring. The bottom end of the pin has a stop portion that abuts against the bottom surface of the seat cushion spring. The upper end of the pin is located at the rear side of the seat cushion assembly plate. A connecting plate is provided between the front side of the seat cushion assembly plate and the front end of the support spring of the seat base. The upper and lower ends of the connecting plate are respectively connected to the seat cushion assembly plate and the support spring.

[0011] In the chair backrest linkage device described above, the connecting plate is inclined from the upper rear to the lower front, and an angle is formed between the connecting plate and the seat cushion assembly plate.

[0012] In the chair backrest linkage device described above, the included angle between the connecting plate and the seat cushion assembly plate is 6 degrees.

[0013] In the chair back linkage device described above, the seat cushion assembly plate has a groove on its front bottom surface, and the connecting plate is correspondingly accommodated in the groove.

[0014] In the seat-back linkage device of the chair described above, the supporting spring plate has a gradually upward curved shape from its rear end to its front end.

[0015] As described above, in the seat-back linkage device of the chair, the seat cushion assembly upright plate has a pivot lug formed on the left and right sides of its bottom surface, and the chair body has a pivot part at the opposite position on the left and right sides. The two pivot parts are pivotally connected to the two pivot lugs on the sides of the seat cushion assembly upright plate through a second pivot.

[0016] In the chair back linkage device described above, the chair seat body is provided with a sound-absorbing plate at the bottom of the spring plate assembly groove and below the chair back spring plate.

[0017] The seat-back linkage device of the chair described above further includes a backrest control unit. The backrest control unit includes a latch, which is disposed in the spring plate assembly groove of the seat body. The spring plate assembly groove has at least one groove in the middle of its rear side groove wall. The groove corresponds to and engages with the latch. A first control plate is provided on one side of the seat cushion assembly plate, and the first control plate is connected to the latch.

[0018] As described above, the seat-back linkage device of the chair further includes a lifting control unit. The lifting control unit includes a second control plate, which is disposed on one side of the seat cushion assembly upright plate. It also includes a drive handle, which is connected to the second control plate. A hollow portion is formed inside the seat base. The drive handle is disposed inside the hollow portion of the seat base and is pivotally connected to the seat base. A lifting rod is disposed at the bottom center of the seat base. An actuation button is provided at the upper end of the lifting rod. The upper end of the lifting rod is located inside the hollow portion of the seat base. The front end of the drive handle contacts the actuation button at the upper end of the lifting rod.

[0019] Compared with the prior art, the present invention has the following features and advantages:

[0020] When a user sits on the seat cushion on the seat cushion assembly stand, the seat cushion assembly stand uses the pivot point with the main body of the chair as a fulcrum. When the front side of the seat cushion assembly stand moves downward, the seat cushion spring connected to the rear side of the seat cushion assembly stand can be used to slowly lower the front side of the seat cushion assembly stand to the desired forward tilt angle. When the user lies back against the rear side of the main body of the chair and the chair back is assembled, the pivot point between the main body of the chair and the chair base is used as a fulcrum, causing the rear side of the main body of the chair to move backward. The pivot point between the main body of the chair and the seat cushion assembly stand forms a top support to raise the seat cushion assembly stand, so that the chair back and the chair tilt synchronously, thereby improving riding comfort. Attached Figure Description

[0021] Figure 1 : A perspective view of the present invention;

[0022] Figure 2 A cross-sectional view of the present invention;

[0023] Figure 3 Another cross-sectional view of the present invention;

[0024] Figure 4 A partially enlarged cross-sectional view of the present invention;

[0025] Figure 5 Another partially enlarged cross-sectional view of the present invention;

[0026] Figure 6 : A partially enlarged cross-sectional view of the chair seat in the sitting state of the present invention;

[0027] Figure 7 : A cross-sectional view of the chair back in the reclining state according to the present invention;

[0028] Figure 8 : A partially enlarged cross-sectional view of the chair back in the latched state according to the present invention;

[0029] Figure 9 : A partially enlarged cross-sectional view of the lifting rod in the driving state of the present invention.

[0030] Explanation of icon numbers:

[0031] 1. Seat body; 11. Base assembly; 12. Spring clip assembly groove; 121. Buckle; 122. Clip groove; 13. Backrest assembly; 14. Pivot; 2. Seat base; 21. First pivot; 22. Support spring; 23. Seat cushion spring; 231. Through hole; 24. Backrest spring; 25. Pin; 251. Stop; 26. Sound damping plate; 27. Hollow part; 3. Seat cushion assembly plate; 31. Seat cushion 32. Pivot lug; 33. Second pivot; 34. Connecting plate; 35. Groove; 36. Lock hole; 4. Backrest control unit; 41. Locking tenon; 42. First elastic element; 43. First control board; 44. Locking component; 45. First pull cord; 5. Lifting control unit; 51. Second control board; 52. Second elastic element; 53. Drive handle; 54. Second pull cord; 6. Backrest; 7. Lifting rod; 71. Actuation button. Detailed Implementation

[0032] To provide a more complete and clear description of the technical means and effects of the present invention, please refer to the accompanying drawings and reference numerals. The detailed description is as follows:

[0033] First, please refer to Figure 1 The seat-back linkage device of the chair of the present invention mainly includes:

[0034] A chair seat body 1, with a base assembly part 11 at the front side of the chair seat body 1 and a backrest assembly part 13 at the rear side of the chair seat body 1. A spring piece assembly groove 12 is provided between the base assembly part 11 and the backrest assembly part 13. The rear wall of the spring piece assembly groove 12 is adjacent to the backrest assembly part 13. A backrest 6 is assembled in the backrest assembly part 13.

[0035] Please refer to the chair base 2 as well. Figure 2 and Figure 3 The chair base 2 is located at the base assembly 11 of the chair body 1, and is pivotally connected to the chair base 2 and the base assembly 11 of the chair body 1 by at least one first pivot 21. The front side of the chair base 2 is assembled with the rear end of a support spring 22, and the support spring 22 extends forward from the chair base 2, and the support spring 22 curves upward from its rear end to its front end. The chair seat body 1 is arc-shaped, and at least one seat cushion spring 23, at least one backrest spring 24, and a pin 25 are provided in the spring assembly groove 12. In the main embodiment of the present invention, the seat cushion spring 23 is provided in multiple pieces, and the multiple seat cushion springs 23 are stacked on top of each other. In addition, the backrest spring 24 is provided in multiple pieces, and the multiple backrest springs 24 are stacked on top of each other. The front end of the seat cushion spring 23 and the front end of the backrest spring 24 are aligned with the rear side of the chair seat base 2. The seat cushion spring 23 is configured such that a through hole 231 is provided at the rear end of the seat cushion spring 23, and the pin 25 passes through the through hole 231 of the seat cushion spring 23. A stop part 251 is provided at the bottom end of the pin 25, and the stop part 251 abuts against the bottom surface of the seat cushion spring 23. In addition, a latching part 121 is provided on the rear side wall of the spring assembly groove 12 opposite to the backrest spring 24. The rear end of the backrest spring 24 and the rear side wall of the spring assembly groove 12 are provided with a latching part 121. The buckle part 121 is positioned by a corresponding latch. A sound-absorbing piece 26 is provided at the bottom of the groove 12 of the spring assembly and below the seat cushion spring 23 and the backrest spring 24 to reduce the noise generated when the seat cushion spring 23 and the backrest spring 24 move. A lifting rod 7 is provided at the middle of the bottom of the chair base 2. The lifting rod 7 can be a pneumatic rod. An actuation button 71 is provided at the upper end of the lifting rod 7. The actuation button 71 is located in the hollow part 27 of the chair base 2.

[0036] A seat cushion assembly upright plate 3 is located above the main body 1 and the base 2 of the chair seat. A cushion 31 is mounted on the upper surface of the seat cushion assembly upright plate 3. A pivot lug 32 is formed on the left and right sides of the bottom surface of the seat cushion assembly upright plate 3. The main body 1 of the chair seat has a pivot portion 14 at opposite positions on its left and right sides. The pivot portion 14 and the pivot lug 32 on both sides of the seat cushion assembly upright plate 3 are pivotally connected by a second pivot 33. The pivot joint between the upright plate 3 and the main body 1 of the seat is located in front of the pivot joint between the main body 1 of the seat and the base 2 of the seat. The axis of the first pivot 21, which passes through the pivot joint between the main body 1 of the seat and the base 2 of the seat, is higher than the axis of the second pivot 33, which passes through the pivot joint between the upright plate 3 and the main body 1 of the seat. The upright plate 3 of the seat has a locking hole 36 on its rear side. The locking hole 36 is correspondingly locked to the upper end of the pin 25 of the base 2 of the seat. Please refer to the following: Figure 4 A connecting plate 34 is provided between the front side of the seat cushion assembly plate 3 and the front end of the support spring 22 of the seat base plate 2. The upper and lower ends of the connecting plate 34 are pivotally connected to the seat cushion assembly plate 3 and the support spring 22, respectively. The connecting plate 34 is tilted from the upper rear to the lower front, so that the connecting plate 34 and the seat cushion assembly plate 3 form an angle θ of about 6 degrees. The seat cushion assembly plate 3 has a groove 35 on its front bottom surface, in which the connecting plate 34 can be accommodated.

[0037] Please refer to the chair back control unit 4 as well. Figure 5 The seat body 1 includes a tenon 41, which is disposed in the spring plate assembly groove 12 of the seat body 1. The spring plate assembly groove 12 has at least one groove 122 on its rear side groove wall. In the main embodiment of the present invention, the rear side groove wall of the spring plate assembly groove 12 is provided with multiple grooves 122 at intervals from top to bottom. The tenon 41 is engaged with one groove 122 according to the adjustment requirements. A first elastic member 42 is provided between the rear side groove wall of the spring plate assembly groove 12 and the tenon 41. The first elastic member 42 is a tension spring. The seat cushion assembly plate 3 is provided with a first control plate 43 on one of the left and right sides of its bottom. A locking member 44 is provided between the first control plate 43 and the seat cushion assembly plate 3. The first control plate 43 and the tenon 41 are connected by a first pull rope 45.

[0038] A lifting control unit 5 includes a second control plate 51, which is mounted on the bottom of the seat cushion assembly plate 3 on the opposite side of the first control plate 43. The second control plate 51 and the seat cushion assembly plate 3 are connected by a second elastic member 52, which is a tension spring. The unit also includes a drive handle 53, which is disposed in the hollow portion 27 of the seat base 2 and pivotally connected to the seat base 2. The front end of the drive handle 53 contacts the actuation button 71 of the lifting rod 7. The rear end of the second control plate 51 and the drive handle 53 are connected by a second pull rope 54.

[0039] Accordingly, when using the chair described in this invention, when the user sits on the seat cushion 31 of the chair, after bearing the weight of the user, the seat cushion upright plate 3 will use the pivot point of the second pivot 33 provided with the main body of the chair seat 1 as the fulcrum, causing the front side of the seat cushion upright plate 3 to move downward, and at the same time, the rear side of the seat cushion upright plate 3 will move upward. The seat cushion spring plate 23 connected to the pin 25, which is mounted on the rear side of the seat cushion upright plate 3, will be pulled upward. Utilizing the elastic cushioning of the seat cushion spring plate 23, the front side of the seat cushion upright plate 3 can slowly descend until it abuts against the front end of the support spring plate 22 for positioning. Please refer to [further details omitted]. Figure 6 The connecting plate 34 is housed in the groove 35 of the seat cushion assembly plate 3. At this time, the front side of the seat cushion assembly plate 3 is tilted forward at an angle of 6 degrees to achieve the comfort of the user.

[0040] Furthermore, please refer to the following: Figure 7 When the user leans back on the chair back 6, it creates a backward pushing effect on the chair back assembly 13 located at the rear of the chair seat body 1. The elastic cushioning of the chair back spring 24 adjacent to the chair back assembly 13 allows the chair back 6 to produce an elastic swinging effect. As the user's center of gravity gradually shifts backward, the chair seat body 1 uses the pivot point with the first pivot 21 on the chair seat base 2 as a fulcrum, causing the rear of the chair seat body 1, which is connected to the chair back 6, to move backward and downward. At this time, the area between the chair seat body 1 and the chair seat... The seat body 1 and the seat cushion assembly plate 3 at the pivot point in front of the chassis 2 will move upward relative to each other at the pivot point 33. The seat cushion assembly plate 3 is supported upward by the lugs 32 on the left and right sides. In this way, the weight of the user sitting on the seat cushion 31 can be supported by the force of the user lying back on the backrest 6, thereby pushing the user's body upward in sync and achieving the effect of self-support. Through the linkage between the backrest 6 and the seat, the comfort of the user sitting in the chair is improved.

[0041] When the user leans back against the chair back 6, the deformed backrest spring 24, which was caused by the user leaning back against the chair back 6, will return to its original shape, and will also cause the chair back assembly part 13 on the rear side of the chair seat body 1, which is assembled with the chair back 6, to return to its original position. Please refer to the following: Figure 8 Then, the user can manually pull the first control plate 43 of the chair back control unit 4, and pull the connected latch 41 through the first pull rope 45. This causes the latch 41 to be locked in the groove 122 on the rear side of the spring plate assembly groove 12 of the seat body 1. This creates a braking effect on the chair back assembly 13 adjacent to the rear side of the spring plate assembly groove 12, fixing the chair back 6 in place. In this way, the linkage between the chair back 6 and the seat can be released. At this time, the locking component 44 between the first control plate 43 and the seat cushion assembly plate 3 can fix the latch 41 in the locked state with the groove 122. After the locking component 44 is released, the latch 41 will be pulled back by the first elastic element 42 connected to it to disengage from the groove 122.

[0042] When the user leaves the chair, the seat cushion spring 23, which was deformed due to the user sitting on the seat cushion 31 of the seat cushion assembly 3, will return to its original shape and pull the connected pin 25 downward. At this time, the pin 25 will also pull the rear side of the seat cushion assembly 3 downward. With the pivot point between the seat cushion assembly 3 and the main body 1 of the chair as the fulcrum, the front side of the seat cushion assembly 3 will move upward relative to it, so that the seat cushion assembly 3 returns to a flat state.

[0043] Additionally, when the user wants to adjust the seat height, they can move the second control plate 51 of the height control unit 5, causing the second control plate 51 to pull the drive handle 53 via the second pull rope 54. Please refer to [further details]. Figure 9 This causes the front end of the drive handle 53 to press the actuation button 71 of the lifting rod 7, thereby driving the lifting rod 7 to move the seat base 2 and the seat body 1 and other seat parts up and down. When the user releases the lever on the second control panel 51, the elastic return action of the second elastic element 52 provided between the second control panel 51 and the seat cushion assembly plate 3 causes the front end of the drive handle 53 to disengage from the actuation button 71 of the lifting rod 7, thereby fixing the adjusted height of the seat.

[0044] The foregoing embodiments or drawings are not intended to limit the scope of protection of the present invention. The present invention may omit the connecting plate 34 between the seat cushion assembly plate 3 and the support spring 22 of the seat base 2, thereby allowing the front end of the support spring 22 of the seat base 2 to directly contact the front bottom surface of the seat cushion assembly plate 3. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the scope of protection of the present invention.

[0045] As can be seen from the above structure and implementation methods, the present invention has the following advantages:

[0046] The seat-back linkage device of the chair of the present invention has a simple structural design and low manufacturing cost. It also makes effective use of the internal space of the chair seat, which is conducive to the flattening of the seat-back linkage device and has a very beautiful appearance. Therefore, it enhances consumers' willingness to buy and improves the competitiveness of the product of the present invention.

[0047] The seat-back linkage device of the chair of the present invention simultaneously supports the body of the user sitting on the seat when the user lies back against the back of the chair, thereby using the force of the user lying back against the back of the chair to support the body weight of the user on the seat and achieve the effect of self-supporting.

[0048] The seat-back linkage device of the chair of the present invention has a connecting plate between the seat cushion assembly plate and the support spring plate, so that the connecting plate and the seat cushion assembly plate form an angle of about 6 degrees. In this way, when the user sits on the seat cushion, the seat cushion can be tilted forward by 6 degrees to improve the comfort of sitting.

Claims

1. A seat-back linkage device for a chair, characterized in that, include: A chair seat body, wherein a base assembly is provided on the front side of the chair seat body and a backrest assembly is provided on the rear side of the chair seat body, and a spring piece assembly groove is provided between the base assembly and the backrest assembly, wherein the rear wall of the spring piece assembly groove is adjacent to the backrest assembly. A chair base is provided at the base assembly of the chair body and is pivotally connected to the chair body by at least one first pivot. The front side of the chair base is assembled with the rear end of a support spring, which extends forward from the chair base. At least one backrest spring is provided in the spring assembly groove of the chair body. The front end of the backrest spring is assembled with the rear side of the chair base. A latching part is provided on the rear wall of the spring assembly groove opposite to the backrest spring. The rear end of the backrest spring is locked and positioned by the latching part on the rear wall of the spring assembly groove. A seat cushion assembly plate is provided, located above the chair body and the chair base, and passing through the seat cushion assembly plate and the chair body with at least one second pivot, thereby pivotally connecting the seat cushion assembly plate and the chair body. The pivot point between the seat cushion assembly plate and the chair body is located in front of the pivot point between the chair body and the chair base, and the front end of the support spring of the chair base abuts against the front side of the seat cushion assembly plate.

2. The seat-back linkage device for a chair according to claim 1, characterized in that, At least one seat cushion spring and a pin are further provided in the spring plate mounting groove of the main body of the chair seat. The front end of the seat cushion spring is set at the rear side of the chair seat base. A through hole is provided at the rear end of the seat cushion spring. The pin passes through the through hole of the seat cushion spring. A stop part is provided at the bottom end of the pin. The stop part abuts against the bottom surface of the seat cushion spring. The upper end of the pin is set at the rear side of the seat cushion assembly plate. A connecting plate is provided between the front side of the seat cushion assembly plate and the front end of the support spring of the chair seat base. The upper and lower ends of the connecting plate are respectively connected to the seat cushion assembly plate and the support spring.

3. The seat-back linkage device for a chair according to claim 2, characterized in that, The connecting plate is inclined from the upper rear to the lower front, and an angle is formed between the connecting plate and the seat cushion assembly upright plate.

4. The seat-back linkage device for a chair according to claim 3, characterized in that, The angle between the connecting plate and the seat cushion assembly plate is 6 degrees.

5. The seat-back linkage device for a chair according to claim 2, characterized in that, The seat cushion assembly plate has a groove on its front bottom surface, and the connecting plate is correspondingly accommodated in the groove.

6. The seat-back linkage device for a chair according to claim 1, characterized in that, The supporting spring sheet has a gradually upward curved shape from its rear end to its front end.

7. The seat-back linkage device for a chair according to claim 1, characterized in that, The seat cushion assembly plate has a pivot lug formed on the left and right sides of its bottom surface, and the main body of the chair seat has a pivot part at the opposite position on its left and right sides. The two pivot parts are pivotally connected to the pivot lugs on both sides of the seat cushion assembly plate through a second pivot.

8. The seat-back linkage device for a chair according to claim 1, characterized in that, The main body of the chair seat is provided with a sound-absorbing plate at the bottom of the groove of the spring assembly and below the spring of the chair back.

9. The seat-back linkage device for a chair according to claim 1, characterized in that, The seat-back linkage device of the chair further includes a backrest control unit. The backrest control unit includes a latch, which is disposed in the spring plate assembly groove of the main body of the chair seat. The spring plate assembly groove has at least one groove in the middle of its rear side groove wall. The groove corresponds to and engages with the latch. A first control plate is provided on one side of the seat cushion assembly plate, and the first control plate is connected to the latch.

10. The seat-back linkage device for a chair according to claim 1, characterized in that, The seat-back linkage device of the chair further includes a lifting control unit, which includes a second control board disposed on one side of the seat cushion assembly upright plate, and a drive handle connected to the second control board. A hollow portion is formed inside the seat base, and the drive handle is disposed inside the hollow portion of the seat base and pivotally connected to the seat base. A lifting rod is disposed at the bottom center of the seat base, and an actuation button is provided at the upper end of the lifting rod. The upper end of the lifting rod is located inside the hollow portion of the seat base, and the front end of the drive handle contacts the actuation button at the upper end of the lifting rod.

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