Dual seatback elastic swing mechanism

Abstract

The utility model discloses a kind of double waist rest elastic swing mechanism, including waist rest component, and the waist rest component includes support and two left and right symmetrical arrangement on support's waist rest, each waist rest is equipped with rotating seat and fixed seat respectively on support;Between fixed seat and rotating seat, set up inclined plane linkage mechanism and elastic swing structure, the process of the waist rest assembly is simplified into simple rotating shaft process and screw locking process, simultaneously make the compression spring as elastic return element completely hidden in central hole;Under the premise of forming elastic supporting force to waist rest, ensure that the appearance of waist rest mechanism is simple and beautiful, simultaneously improve the waist rest assembly efficiency.

Description

Technical Field

[0001] This utility model relates to the field of seating, and in particular to a double lumbar support elastic swing mechanism. Background Technology

[0002] Some office chairs or ergonomic chairs are equipped with a double lumbar support mechanism for lumbar support. The double lumbar support mechanism includes a support frame and lumbar supports arranged on the left and right sides of the support frame. The lumbar supports can rotate relative to the support frame. When the waist is leaning against the two lumbar supports, the inner parts of the two lumbar supports rotate backward and provide a lumbar support effect. There is an elastic element between each lumbar support and the support frame. The elastic element deforms elastically when the lumbar support rotates backward, providing elastic support for the waist. When the waist leaves the lumbar support, the elastic element returns to its original position and the two lumbar supports return to their initial position.

[0003] For example, in the chair back assembly patent with publication number CN116211088, two lumbar pillows are connected to the bracket. Each lumbar pillow includes a pillow body, an elastic element, and a support frame. The elastic element is any one of a spring, a sheet spring, a leaf spring, and a rubber block. One end of the elastic element is fixed to the pillow body, and the other end is fixed to the support frame. When the two pillow bodies are subjected to force, the elastic element can elastically deform and provide elastic support for the pillow bodies. However, in this design, the elastic element is exposed between the pillow body and the support frame, which is not simple and aesthetically pleasing in appearance.

[0004] For example, in the chair patent with publication number CN119969768, as shown in Figures 23-24 of the patent, the lower left and right backrests (equivalent to left and right lumbar supports) have two vertically spaced connecting seats. The corresponding ends of the bracket are located between the two connecting seats and are rotatably connected by a connecting shaft. A torsion spring is sleeved on the connecting shaft. The left and right backrests and the bracket have torsion spring positioning grooves to place the ends of the torsion springs (i.e., torsion spring elastic arms). The torsion springs are almost hidden in appearance, but when using torsion springs as elastic elements, it is necessary to forcibly pull the elastic arms to deform them and make them act on the lumbar supports and the brackets during assembly. The operation is time-consuming and laborious, which will have a significant impact on assembly efficiency. Summary of the Invention

[0005] This utility model provides a double lumbar support elastic swing mechanism. By setting an inclined guide mechanism and an elastic swing structure between the fixed seat and the rotating seat, the assembly process of the lumbar support is simplified to a simple process of inserting the rotating shaft and tightening the screw. At the same time, the compression spring, which is an elastic reset component, is completely hidden in the central hole. Under the premise of forming an elastic support force for the lumbar support, the lumbar support mechanism is kept simple and beautiful in appearance and easy to assemble.

[0006] The technical solution of this utility model is implemented as follows: A double-lumbar support elastic swing mechanism includes: The lumbar support assembly includes a bracket and two lumbar supports arranged symmetrically on the bracket. Each lumbar support and the bracket are respectively provided with a rotating seat and a fixed seat. The elastic swing structure includes a rotating seat and a fixed seat, one of which has a central hole that runs through it along the longitudinal direction. A rotating shaft passes through the central hole and a compression spring is sleeved on the rotating shaft. A first boss and a second boss are respectively provided on the outer circumference of the rotating shaft and the inner wall of the central hole. The two ends of the compression spring abut against the first boss and the second boss respectively. An inclined plane linkage structure is provided between a rotating seat and a fixed seat, including a guide inclined plane provided on one of the rotating seat and the fixed seat, and a mating protrusion on the other rotating seat and the fixed seat corresponding to the guide inclined plane; The rotating seat and the fixed seat are fixedly connected to the rotating shaft by screws, so that the mating protrusion contacts the guide slope; when the two waists rotate backward, each mating protrusion slides along the corresponding guide slope, so that the waists rotate circumferentially and move axially at the same time, and cause the compression spring in the center hole to deform elastically.

[0007] Preferably, the central hole is longitudinally through the fixed seat, and the rotating shaft is fixedly connected to the rotating seat; the guide slope is located at one end of the fixed seat facing the rotating seat, and is provided on the rotating seat in conjunction with the protrusion.

[0008] Preferably, the guide ramp is disposed on the end face of the fixed seat facing the rotating seat; the rotating seat includes a rotating seat body and a mating protrusion, wherein the mating protrusion is disposed on the end face of the rotating seat body facing the fixed seat.

[0009] Preferably, the mating protrusion is provided with a mating inclined surface, which fits tightly with the guide inclined surface; this ensures that the mating protrusion can slide smoothly relative to the mating inclined surface, and also makes the structure between the rotating seat and the fixed seat more compact.

[0010] Preferably, the rotating base has a through hole extending longitudinally, and the end of the rotating shaft facing the rotating base has a screw hole. The screw passes through the through hole and is locked into the screw hole, so that the rotating shaft is fixedly connected to the rotating base.

[0011] Preferably, the rotating shaft includes a non-circular cross-sectional section, and the rotating seat has a plug hole facing the plug section and communicating with the through hole. The cross-sectional shape of the plug hole matches that of the plug section. The plug section is inserted into the plug hole. This facilitates the positioning of the screw when it is fixedly connected to the rotating shaft and the rotating seat, and also restricts the circumferential loosening of the rotating shaft relative to the screw.

[0012] Preferably, the bracket includes a base and two symmetrically connected arms on the base, with a fixed seat connected to the arms; the arms have integrally formed side stops; the side stops cover the outside of the fixed seat and the rotating seat.

[0013] Preferably, at least one of the first boss and the second boss is annular, forming a sufficient contact area with both ends of the compression spring.

[0014] Preferably, the guide ramp is disposed on the end face of the fixed seat facing the rotating seat; the rotating seat includes a rotating seat body and a mating protrusion, wherein the mating protrusion is disposed on the side wall of the rotating seat body and contacts the guide ramp.

[0015] Preferably, the mating protrusion is a single one; or, there are multiple mating protrusions, which are evenly distributed circumferentially on the side wall of the rotating seat body.

[0016] The beneficial effects of this utility model, which adopts the above technical solution, are as follows: This invention features a ramp linkage structure between a rotating seat and a fixed seat, consisting of a mating protrusion and a guide ramp. Taking the center hole on the fixed seat as an example, when the rotating seat rotates circumferentially, the mating protrusion also rotates and slides along the guide ramp, causing the rotating seat to displace axially. This allows the rotating shaft connected to the rotating seat to move axially and compress the compression spring. This design creatively utilizes the compression spring as an elastic reset component and uses the ramp linkage structure to convert the axial elastic force generated by the compression spring into a circumferential elastic force on the lumbar support. In actual assembly, it is only necessary to insert the rotating shaft with the compression spring into the center hole and lock the rotating seat and the rotating shaft together with screws, effectively improving the assembly efficiency of the lumbar support. After assembly, the compression spring, as an elastic reset component, is completely hidden in the center hole and not exposed, while also ensuring a simple and aesthetically pleasing appearance after the lumbar support and bracket are assembled.

[0017] The mating protrusion has a mating inclined surface that fits against the guide inclined surface. When the mating protrusion slides relative to the guide inclined surface, the mating inclined surface makes the contact between the mating protrusion and the guide inclined surface a surface contact, making the sliding process of the mating protrusion smoother. At the same time, the tightly fitting mating inclined surface and the guide inclined surface also make the connection structure between the rotating seat and the fixed seat more compact.

[0018] The rotating shaft has a non-circular cross-sectional section for insertion. The insertion section is inserted into the insertion hole on the rotating seat, which facilitates the positioning of the screw hole and through hole when the rotating shaft is fixedly connected to the rotating seat. At the same time, it restricts the relative rotation of the rotating shaft and the rotating seat in the circumferential direction, prevents the screw from loosening, and ensures the connection stability between the rotating seat and the fixed seat. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the double waist support elastic swing mechanism. Figure 2 A sectional view showing the position of the pivot point; Figure 3 An exploded view of the double-waist support elastic swing mechanism; Figure 4 Here is an enlarged view of the structure of each hole on the rotating base; Figure 5 This is a schematic diagram showing that the rotating seat body and the mating protrusion are integrally formed. Figure 6 This is a schematic diagram showing that the second protrusion inside the central hole is annular; Figure 7 A top view of the double-lumbar support elastic swing mechanism; Figure 8 A simplified structural diagram of a double-waist support elastic swing mechanism; Figure 9 A simplified diagram illustrating the further deformation of the elastic support after the elastic guide has deformed to its maximum extent. Figure 10 This is a schematic diagram of embodiment 2, showing the protrusion located on the side wall of the rotating seat body; Figure 11 This is a cross-sectional view of the pivot position in Example 3; The reference numerals in the attached drawings are as follows: 1-bracket, 11-support arm, 11a-side stop, 12-fixed seat, 13-guide ramp, 14-second boss, 15-center hole, 2-lumen rest, 21-guide seat, 22-rotating seat, 221-rotating seat body, 222-fitting protrusion, 23-fitting ramp, 24-through hole, 25-insertion hole, 26-countersunk hole, 3-elastic support, 31-elastic guide, 32-mounting seat, 4-rotating shaft, 41-first boss, 42-screw hole, 43-insertion section, 5-compression spring, 6-screw. Detailed Implementation

[0020] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0022] This utility model has multiple embodiments, and the specific implementation methods are as follows: Example 1: As Figure 1-9 As shown, this embodiment provides a double lumbar support elastic swing mechanism, which is typically installed on the back of a seat and includes: The lumbar support assembly includes a bracket 1 and two lumbar supports 2 symmetrically arranged on the bracket 1. Each lumbar support 2 and the bracket 1 are respectively provided with a rotating seat 22 and a fixed seat 12. Specifically, the bracket 1 includes a base and two support arms 11 symmetrically connected to the base. The rotating seat 22 and the fixed seat 12 are respectively connected to the lumbar support 2 and the corresponding support arm 11. The elastic swing structure includes a rotating seat 22 and a fixed seat 12, one of which has a central hole 15 extending longitudinally. A rotating shaft 4 passes through the central hole 15, and a compression spring 5 is sleeved on the rotating shaft 4. The rotating shaft 4 passes through the central hole 15, so it will not be exposed and affect the appearance of the seat. A first boss 41 and a second boss 14 are respectively provided on the outer circumference of the rotating shaft 4 and the inner wall of the central hole 15. The two ends of the compression spring 5 abut against the first boss 41 and the second boss 14 respectively. The first boss 41 and the second boss 14 provide support points for the deformation of the compression spring 5, and at the same time can prevent the compression spring 5 from disengaging from the central hole 15 or the rotating shaft 4 during deformation. The first boss 41 and the second boss 14 can be integrally formed on the inner wall of the central hole 15 and the outer circumference of the rotating shaft 4, respectively. Alternatively, annular grooves can be opened on the inner wall of the central hole 15 and the outer circumference of the rotating shaft 4, and retaining rings of corresponding specifications can be inserted into the annular grooves to form the first boss 41 and the second boss 14. A ramp linkage structure is provided between the rotating seat 22 and the fixed seat 12. It includes a guide ramp 13 provided on one of the rotating seat 22 and the fixed seat 12, and a mating protrusion 222 corresponding to the guide ramp 13 on the other rotating seat 22 and the fixed seat 12. The guide ramp 13 has a high end and a low end. When the mating protrusion 222 contacts the guide ramp 13 and rotates circumferentially, the mating protrusion 222 will simultaneously change its height position. The range of its height position change is the distance between the high end and the low end. In this embodiment, the central hole 15 is longitudinally through the fixed seat 12, and the rotating shaft 4 is fixedly connected to the rotating seat 22. The guide slope 13 is located at one end of the fixed seat 12 facing the rotating seat 22, and the cooperating protrusion 222 is located on the rotating seat 22 for explanation. When assembling the lumbar support 2, the compression spring 5 is sleeved on the rotating shaft 4 and one end of it abuts against the first protrusion 41. Then, the rotating shaft 4 with the compression spring 5 sleeved is inserted into the central hole 15, and the rotating seat 22 is fixedly connected to the rotating shaft 4 by the screw 6, so that the cooperating protrusion 222 and the guide slope 13 make contact and cooperate, thus completing the installation of a single lumbar support 2. Compared with using a torsion spring as an elastic reset component, this embodiment simplifies the entire assembly process of the lumbar support 2 to a simple compression spring 5 sleeve process and a threaded locking process between the rotating shaft 4 and the rotating seat 22, making the assembly of the lumbar support 2 more time-saving and labor-saving.

[0023] Furthermore, when the two lumbar supports 2 are subjected to a backward leaning force and rotate backward, each mating protrusion 222 slides along the corresponding guide slope 13. At this time, the rotating shaft 4 and the lumbar supports 2 rotate circumferentially and move axially at the same time, converting the circumferential rotation of the lumbar supports 2 into axial displacement, and causing the compression spring 5 in the central hole 15 to elastically deform between the first protrusion 41 and the second protrusion 41, forming elastic support for the waist. When the waist leaves the two lumbar supports 2, the compression spring 5 resets and the axial elastic force generated then acts in the opposite direction on the rotating seat 22 through the slope linkage structure, forming an elastic reset force, causing the mating protrusion 222 to slide in the opposite direction along the guide slope 13, and driving the lumbar supports 2 to return to the initial position. Therefore, in this embodiment, while ensuring that the lumbar supports 2 are easy to assemble and the compression spring 5 is hidden, the compression spring 5 and the slope linkage structure also indirectly provide elastic support and rebound function for the lumbar supports 2.

[0024] Furthermore, in this embodiment, the guide slope 13 is disposed on the end face of the fixed seat 12 facing the rotating seat 22; the rotating seat 22 includes a rotating seat body 221 and a mating protrusion 222. In this embodiment, the rotating seat body 221 and the mating protrusion 222 are integrally formed; the end of the rotating seat body 221 facing the guide slope 13 is a plane. If this plane is made to directly contact the guide slope 13, it will be difficult to cause the rotating seat 22 and the rotating shaft 4 to move axially. Therefore, the mating protrusion 222 mentioned in this embodiment is disposed on the end face of the rotating seat body 221 facing the fixed seat 12. The protruding mating protrusion 222 can contact the guide slope 13 and drive the rotating shaft 4 to move axially under the guidance of the guide slope 13 when rotating in the circumferential direction, thereby causing the compression spring 5 to deform.

[0025] Furthermore, while the mating protrusion 222 can form a line contact with the guide slope 13, this structure limits the contact area between the mating protrusion 222 and the guide slope 13, making the sliding of the mating protrusion 222 less smooth. Therefore, in this embodiment, the mating protrusion 222 and the guide slope 13 are in surface contact. Specifically, the mating protrusion 222 is provided with a mating slope 23, which fits tightly with the guide slope 13, ensuring that the mating protrusion 222 can slide smoothly relative to the mating slope 23. This also makes the structure between the rotating seat 22 and the fixed seat 12 more compact.

[0026] Furthermore, the threaded connection structure between the rotating shaft 4 and the rotating seat 22 is as follows: the rotating seat 22 is provided with a through hole 24 extending longitudinally, and the end of the rotating shaft 4 facing the rotating seat 22 is provided with a screw hole 42. The screw 6 passes through the through hole 24 and is locked into the screw hole 42, so that the rotating shaft 4 and the rotating seat 22 are fixedly connected; wherein, in order to hide the head of the screw 6, the rotating seat 22 is also provided with a countersunk hole 26 communicating with the through hole 24, and the head of the screw 6 is inside the countersunk hole 26 and does not protrude from the rotating seat 22.

[0027] Furthermore, to prevent the screw 6 from loosening after fixing the shaft 4 to the rotating seat 22, in this embodiment, the shaft 4 includes a non-circular insertion section 43, and the rotating seat 22 has an insertion hole 25 facing the insertion section 43 and communicating with the through hole 24. The cross-sectional shape of the insertion hole 25 matches that of the insertion section 43. When the screw 6 is installed, the insertion section 43 is inserted into the insertion hole 25, so that the through hole 24 and the screw hole 42 are quickly aligned and positioned. At the same time, since the cross-sectional shapes of the insertion section 43 and the insertion hole 25 are both non-circular, the shaft 4 can also be restricted from rotating circumferentially relative to the screw 6, forming an anti-loosening effect, so that the rotating seat 22 and the shaft 4 are stably fixedly connected.

[0028] Furthermore, the shape of the insertion segment 43 is formed by milling a local area on the circumferential sidewall of the rotating shaft 4, thereby forming the insertion segment 43 with a cut surface; this special shape design is simple, efficient, low-cost, and facilitates alignment and insertion during assembly.

[0029] Furthermore, in this embodiment, at least one of the first boss 41 and the second boss 14 is annular; the annular design facilitates the passage of the rotating shaft 4, and also ensures that the first boss 41 and the second boss 14 form sufficient contact area with both ends of the compression spring 5.

[0030] Furthermore, when the two waist supports 2 rotate backward, the rotating seat 22 will also rotate backward and move axially upward. At this time, a large gap will appear between the rotating seat 22 and the fixed seat 12, affecting the appearance of the seat. Therefore, in this embodiment, the support arm 11 is integrally formed with a side baffle 11a. The side baffle 11a covers the outside of the fixed seat 12 and the rotating seat 22, preventing the gap from being seen and ensuring that the seat always has a simple and beautiful appearance.

[0031] Furthermore, since the lumbar support 2 itself has a certain elasticity, and there is an assembly error between the lumbar support 2 and the support 1, when the two lumbar supports 2 are subjected to a backward leaning force and rotate backward, they are prone to swaying and tilting. The lumbar support 2 that deviates from the predetermined direction of swaying can easily cause the mating protrusion 222 to slide relative to the guide inclined surface 13, creating a sense of resistance and affecting the normal deformation of the compression spring 5. In order to avoid the tilting or swaying phenomenon when the two lumbar supports 2 rotate, in this embodiment, each lumbar support 2 is provided with a swing guide structure that is spaced left and right between itself and the support frame 1, so that each lumbar support 2 and the support frame 1 form two connection points spaced left and right. More specifically, the swing guide structure is located inside the elastic swing structure; such as Figure 7-9As shown, the swing guide structure includes an auxiliary elastic element set on the support frame 1 and a guide groove corresponding to each lumbar support 2. The auxiliary elastic element includes an elastic guide part 31 that is slidably connected in the corresponding guide groove. When the two lumbar supports 2 are not subjected to a backward leaning force, the corresponding swing guide structure prevents the two lumbar supports 2 from easily shaking. When the two lumbar supports 2 are subjected to a backward leaning force, the two elastic guide parts 31 undergo elastic deformation and slide in the corresponding guide groove to guide the two lumbar supports 2 to swing backward synchronously, avoiding any swaying phenomenon in either of the two lumbar supports 2, so that the two lumbar supports 2 form a stable and comfortable waist support feeling on the left and right sides of the waist.

[0032] Furthermore, the guide groove can extend in a vertical or horizontal direction, allowing the elastic guide portion to be inserted into the guide groove in either a vertical or horizontal direction. However, to better accommodate and adapt to the swing trajectory of the lumbar support 2, the guide groove in this embodiment preferably extends in a horizontal direction. Specifically, for example... Figure 1 As shown, the lumbar support 2 includes a lumbar support body and a guide seat 21 disposed on the lumbar support body. The guide seat 21 is provided with a guide groove running through it in the left and right direction. The elastic guide part 31 is an elastic sheet that slides through the guide groove. When the waist leans back against the two lumbar supports 2, the lumbar supports 2 swing backward, which triggers the two elastic sheet to deform and slide in the guide groove, thus guiding the two lumbar supports at the same time. Compared with a lumbar support that can swing freely in any direction, the swing guide structure reduces the degree of asynchrony in the rotation of the two lumbar supports 2, and improves the support and comfort of the waist provided by the elastic lumbar support assembly.

[0033] Furthermore, in this embodiment, the auxiliary elastic element may only include the elastic guide portion 31, with one end of the elastic guide portion 31 inserted into the guide groove and the other end fixed to the support frame 1. This design can also guide the swing of the lumbar support 2. However, the deformation elasticity generated by the two sheet-like elastic guide portions 31 is limited and it is difficult to form a stable elastic support for the waist. Therefore, in this embodiment, an elastic support portion 3 fixed to the support frame 1 is provided between the two elastic guide portions 31. The elastic support portion 3 is integrally formed with the two elastic guide portions 31. When the two elastic guide portions 31 elastically deform and slide in the corresponding guide groove, the elastic support portion 3 elastically deforms and forms elastic support for the lumbar support 2. Figure 9 As shown, when the waist leans back, the elastic guide part 31 deforms, and the elastic support part 3 also produces a slight elastic deformation. When the waist continues to lean back and the elastic guide part 31 deforms to its maximum, the elastic support part 3 will deform further and form a larger elastic support force on the lumbar support 2. This design conforms to the pressure change on the lumbar support 2 when the waist leans back, providing better elastic support for the waist. At the same time, since the elastic support part 3 and the two elastic guide parts 31 are integrally formed, the synchronicity of the elastic deformation of the two elastic guide parts 31 is also improved, and the guidance of the lumbar support 2 swings more smoothly.

[0034] Furthermore, in this embodiment, the elastic support 3 is an elastic ring fixed on the support frame 1 and integrally formed with the two elastic guides 31. The elastic ring is usually made of elastic plastic. The shape of the elastic ring can be any of the following: circular ring, elliptical ring, or polygonal ring. In this embodiment, only an elliptical ring is shown. The elastic ring can also be replaced with a spring sheet that extends in a wave shape or arc shape. The rear end of the elastic ring is provided with a mounting base 32, which is fixed on the base of the support frame 1. The elastic ring has a simple structure and is lightweight. The ring-shaped structure allows it to store more elastic potential energy, making it easier to deform and generate a larger elastic force when subjected to external force.

[0035] Example 2: As Figure 10 As shown, this embodiment differs from the above embodiment in that the position of the mating protrusion 222 is different. Specifically, the mating protrusion 222 is located on the side wall of the rotating seat body 221 and contacts the guide inclined surface 13. The mating protrusion 222 can be a single one; or, the mating protrusion 222 can be multiple, with multiple mating protrusions 222 evenly distributed circumferentially on the side wall of the rotating seat body 221. The mating protrusion 222 protruding from the side wall of the rotating seat body 221 can slide relative to the guide inclined surface 13 and achieve the same effect as in the above embodiment.

[0036] Example 3: As Figure 11 As shown, this embodiment differs from the previous embodiment in that, in the elastic swing structure of this embodiment, the central hole 15 is longitudinally disposed on the rotating seat 22, and the rotating shaft 4 is fixedly connected to the fixed seat 12; the guide slope 13 is disposed at one end of the rotating seat 22 facing the fixed seat 12, and the mating protrusion 222 is disposed on the fixed seat 12; during assembly, the compression spring 5 is first sleeved on the rotating shaft 4, and then the rotating shaft 4 is inserted into the central hole 15 on the rotating seat 22, so that the rotating shaft 4 and the fixed seat 12 are locked together by the screw 6, and the mating protrusion 222 is in contact with the guide slope 13; this structure can also hide the rotating shaft 4 and the compression spring 5, achieving the same technical effect as in the previous embodiment.

[0037] Furthermore, when the lumbar support 2 is subjected to force and swings backward, the rotating seat 22 rotates circumferentially relative to the fixed seat 12, causing the guide inclined surface 13 and the mating protrusion 222 to slide relative to each other. At this time, during the rotation of the rotating seat 22, the rotating shaft 4 of the central hole 15 inside it moves axially and causes the compression spring 5 to be compressed, thereby achieving the same technical effect as in the above embodiment.

[0038] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A dual seatback flexibility swing mechanism characterized by, include: The lumbar support assembly includes a bracket (1) and two lumbar supports (2) arranged symmetrically on the bracket (1). Each lumbar support (2) and the bracket (1) are respectively provided with a rotating seat (22) and a fixed seat (12). The elastic swing structure includes a rotating seat (22) and a fixed seat (12), one of which has a central hole (15) that runs through it along the longitudinal direction. A rotating shaft (4) passes through the central hole (15), and a compression spring (5) is sleeved on the rotating shaft (4). A first boss (41) and a second boss (14) are respectively provided on the outer circumference of the rotating shaft (4) and the inner wall of the central hole (15). The two ends of the compression spring (5) abut against the first boss (41) and the second boss (14) respectively. The inclined plane linkage structure is set between the rotating seat (22) and the fixed seat (12), including a guide inclined plane (13) set on one of the rotating seat (22) and the fixed seat (12), and the other of the rotating seat (22) and the fixed seat (12) has a mating protrusion (222) corresponding to the guide inclined plane (13). The other of the rotating seat (22) and the fixed seat (12) is fixedly connected to the rotating shaft (4) by screws (6), so that the mating protrusion (222) contacts and engages with the guide slope (13); when the two waist supports (2) rotate backward, each mating protrusion (222) slides along the corresponding guide slope (13), so that the waist support (2) rotates circumferentially and moves axially at the same time, and causes the compression spring (5) in the center hole (15) to deform elastically.

2. The dual lumbar flexibility swing mechanism of claim 1, wherein: The central hole (15) is longitudinally disposed on the fixed seat (12), and the rotating shaft (4) is fixedly connected to the rotating seat (22); the guide slope (13) is disposed at one end of the fixed seat (12) facing the rotating seat (22), and is disposed on the rotating seat (22) in conjunction with the protrusion (222).

3. The dual seatback flexibility mechanism of claim 2, wherein: The guide slope (13) is provided on the end face of the fixed seat (12) facing the rotating seat (22); the rotating seat (22) includes a rotating seat body (221) and a mating protrusion (222), the mating protrusion (222) being provided on the end face of the rotating seat body (221) facing the fixed seat (12).

4. The dual lumbar flexibility swing mechanism of claim 3, wherein: The protrusion (222) is provided with a mating slope (23), which is in close contact with the guide slope (13).

5. The dual lumbar flexibility swing mechanism of claim 2, wherein: The rotating seat (22) has a through hole (24) extending longitudinally, and the end of the rotating shaft (4) facing the rotating seat (22) has a screw hole (42). The screw (6) passes through the through hole (24) and is locked into the screw hole (42) so that the rotating shaft (4) is fixedly connected to the rotating seat (22).

6. The dual lumbar flexibility swing mechanism of claim 2, wherein: The rotating shaft (4) includes a non-circular cross-sectional section (43), and the rotating seat (22) has a plug hole (25) facing the plug section (43) and communicating with the through hole (24). The cross-sectional shape of the plug hole (25) matches that of the plug section (43); the plug section (43) is inserted into the plug hole (25).

7. The dual lumbar flexibility swing mechanism of claim 1, wherein: The bracket (1) includes a base and two symmetrical support arms (11) connected to the base. A fixed seat (12) is connected to the support arm (11). A side baffle (11a) is integrally formed on the support arm (11). The side baffle (11a) covers the outside of the fixed seat (12) and the rotating seat (22).

8. The dual lumbar flexibility swing mechanism of claim 1, wherein: At least one of the first boss (41) and the second boss (14) is annular.

9. The dual lumbar flexibility swing mechanism of claim 2, wherein: The guide slope (13) is set on the end face of the fixed seat (12) facing the rotating seat (22); the rotating seat (22) includes a rotating seat body (221) and a mating protrusion (222), the mating protrusion (222) is set on the side wall of the rotating seat body (221) and contacts the guide slope (13).

10. The dual lumbar flexibility swing mechanism of claim 9, wherein: The mating protrusion (222) is a single one; or, the mating protrusion (222) is multiple, and the multiple mating protrusions (222) are evenly distributed circumferentially on the side wall of the rotating seat body (221).

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