Backrest support mechanism and linkage support mechanism of a seat cushion backrest

Abstract

The application discloses a backrest supporting mechanism and a linkage supporting mechanism of a seat cushion backrest, wherein the backrest supporting mechanism comprises a backrest support, a backrest, a first guide assembly and a first connecting rod, the first guide assembly comprises a first moving piece, the first connecting rod is rotatably connected to the backrest support and movably connected to a lower part of the backrest, and the first moving piece can drive the first connecting rod to rotate in the vertical direction when moving in the vertical direction, and can drive the lower part of the backrest to move in the horizontal direction. The backrest supporting mechanism can dynamically adjust the backrest posture during the reclining of the user, continuously provide back support, and significantly improve the riding comfort. In particular, the waist support part is optimized: when the user reclines and the backrest is inclined backward, the waist support part can move synchronously toward the user direction, effectively avoiding the suspension of the waist, and enhancing the fitting feeling and the support effect.

Description

Technical Field

[0001] This application relates to a seat back support mechanism and a linkage support mechanism for the seat cushion backrest. Background Technology

[0002] Existing chair backrests generally suffer from poor lumbar support. Most chairs use fixed or limited-adjustment lumbar support structures, often designed based on static human body models, making it difficult to adapt to the dynamic sitting postures that users frequently change in actual use. When a user transitions from a forward-leaning working posture to a backward-leaning resting posture, the physiological curvature and stress points of the spine change significantly. Traditional fixed or single-point adjustable lumbar supports cannot shift and adjust synchronously, causing the lumbar support point to shift and resulting in the lower back being unsupported. Long-term use will affect the user's spinal health and the comfort of prolonged sitting. Summary of the Invention

[0003] This application provides a seat back support mechanism and a linkage support mechanism for the seat cushion backrest, which is used to solve at least one technical problem in the prior art.

[0004] The first aspect of this application provides a backrest support mechanism applied to a seat, the seat including a base, comprising: Backrest support; The backrest has an upper part and a lower part on the side facing the backrest support; A first guide assembly, disposed on the backrest support, includes a first moving member capable of selective vertical movement and rotatably connected to the upper part of the backrest; and A first link is disposed below the first moving member and rotatably connected to the backrest support; the first link has a first end and a second end along its length direction, the first end of the first link faces the backrest support, and the second end of the first link faces the backrest and is movably connected to the lower part of the backrest. The first moving component is connected to the first connecting rod. When the first moving component moves vertically, it can drive the first connecting rod to rotate vertically and cause the lower part of the backrest to move horizontally relative to the backrest support.

[0005] In some embodiments, the first guiding component further includes a first guide member that defines a movement range for the first moving member, enabling the first moving member to move between the top and bottom ends of the movement range.

[0006] In some implementations, the first guide member is a strip-shaped structure, and the first moving member is slidably connected to the first guide member.

[0007] In some embodiments, the first guide component further includes an elastic element that acts on the first moving member to hold the first moving member in a preset position and to apply a restoring force to the first moving member when it deviates from the preset position.

[0008] In some embodiments, the first link is provided with a guide structure extending along its length, and the first moving member is limited to a sliding or rolling connection with the guide structure; or, The first moving member is connected to the first connecting rod via a second connecting rod; wherein, the first end of the second connecting rod is hinged to the first moving member, and the second end of the second connecting rod is hinged to the first connecting rod.

[0009] In some embodiments, the backrest support is rotatably connected to the middle of the first link and divides the first link into two segments; the first moving member is connected to the segment of the first link near its first end.

[0010] In some embodiments, a second guide assembly is also included, which includes a second moving member and a second guide member. The second guide member is disposed at the lower part of the backrest and extends toward the upper part of the backrest. The second moving member is limitedly connected to the second guide member and can move along the extension direction of the second guide member. The second end of the first connecting rod is connected to the second moving part.

[0011] In some embodiments, the second guide includes a linear guide structure, and the second moving member is limited to a sliding or rolling connection with the linear guide structure.

[0012] In some embodiments, the backrest support is configured to be hinged to the base; The backrest support mechanism also includes: The third link is fixed to the backrest bracket, and the third link is provided with a first sliding rod; The fourth link has a slotted hole; the first slide rod passes through the slotted hole and slides in fit. The fifth link, the first end of which is hinged to the first moving member, and the second end of which is hinged to the first end of the fourth link; The second end of the fourth link is configured to be hinged to the base.

[0013] A second aspect of this application provides a linkage support mechanism for a seat cushion backrest, comprising: a base; a backrest bracket rotatably connected to the base; and a seat cushion linkage mechanism, the seat cushion linkage mechanism including a seat cushion, the seat cushion being rotatably connected to the base via a linkage rotation structure; The cushion linkage mechanism further includes a limiting structure, which is used to limit the rear boundary of the linkage rotation structure to rotate backward. The limiting structure is disposed on the backrest support. The limiting structure can move synchronously when the backrest support rotates vertically and redefine the position of the rear boundary. The linkage rotation structure can selectively rotate synchronously with the rear boundary.

[0014] In some embodiments, the linkage rotation structure includes a first support rod and a second support rod arranged laterally, the top of the first support rod and the top of the second support rod being rotatably connected to the seat cushion, and the bottom of the first support rod and the bottom of the second support rod being rotatably connected to the base.

[0015] Compared to existing technologies, this application proposes a seat structure with a backrest support mechanism. This backrest support mechanism, mounted on a backrest bracket, dynamically adjusts the backrest posture as the user leans back, continuously providing back support and significantly improving seating comfort. Particular optimizations have been made to lumbar support: when the user leans back and the backrest tilts backward, the lumbar support moves synchronously towards the user, effectively preventing the lower back from being unsupported and enhancing the fit and support. Furthermore, this application introduces a seat cushion linkage mechanism to achieve coordinated movement between the seat cushion and the backrest bracket. When the backrest bracket tilts backward, the seat cushion moves backward synchronously, thereby maximizing the fit between the user's back and the backrest, further improving overall posture stability and comfort. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. Wherein: Figures 1 to 3 This is a schematic diagram showing different states of the backrest support mechanism in the embodiments of this application; Figure 4 This is a schematic diagram of the backrest bracket and the first backrest support mechanism in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of the first backrest support mechanism in the embodiments of this application; Figure 6 for Figure 5 An explosion diagram; Figure 7A and Figure 7BThis is a schematic diagram of the structure of the first guide component in an embodiment of this application; Figure 8 This is a schematic diagram of the backrest support in the embodiments of this application; Figure 9 for Figure 4 A magnified view of a portion of point A in the middle; Figure 10 for Figure 4 Another perspective illustration; Figure 11 for Figure 10 A magnified view of a portion of point B in the middle; Figure 12 for Figure 10 Another state diagram; Figures 13 to 17 This is a derived structural view of the first backrest support mechanism in the embodiments of this application; Figure 18 for Figure 1 Another perspective illustration; Figure 19 for Figure 18 Cross-sectional view along the CC direction; Figure 20 This is a structural view of the backrest support in an inclined state in an embodiment of this application; Figure 21 for Figure 20 The cross-sectional view, its cross-sectional direction is... Figure 19 same; Figure 22 and Figure 23 This is an exploded view of the seat cushion linkage mechanism in the embodiments of this application; Figure 24 for Figure 19 A magnified view of a portion of point D in the middle; Figure 25 for Figure 24 and Figure 26 A schematic diagram of the intermediate state.

[0017] Figure 26 for Figure 21 A magnified view of a portion of point E in the middle; Figure 27 This is a schematic diagram of the overall support mechanism in Embodiment 2 of this application; Figure 28 This is a schematic diagram of the first partial structure of the support mechanism in Embodiment 2 of this application; Figure 29 This is a schematic diagram of the second partial structure of the support mechanism in Embodiment 2 of this application; Figure 30 This is a first schematic diagram of the support mechanism in the backward tilt state in Embodiment 2 of this application; Figure 31This is a schematic diagram of the first partial structure of the support mechanism in the backward tilting state in Embodiment 2 of this application; Figure Figure 32 This is a schematic diagram of the second partial structure of the support mechanism in the backward tilting state in Embodiment 2 of this application. Figure 33 This is a schematic diagram of the third partial structure of the support mechanism in the backward tilting state in Embodiment 2 of this application; Explanation of reference numerals in the attached figures: 10, 10a, 10b, 10e - First backrest support mechanism; 10c, 10d - Second backrest support mechanism; 101 - Backrest; 1011 - Back support part; 1012 - Waist support part; 102 - First guide assembly; 1021 - First moving part; 1022 - Sliding column; 1023 - First fixed end; 1024 - Second fixed end; 1025 - Compression spring; 103, 103a, 103c, 103d - Second connecting rod; 1031 - First end ; 1032 - Second end; 1033 - First lever; 104, 104b, 104c, 104d - First connecting rod; 1041 - Shaft hole; 1042 - First guide groove; 1043 - Second lever; 1044 - Roller; 105 - Support seat; 1051 - First rotating shaft; 106 - Second guide assembly; 1061 - Guide plate; 1062 - Second guide groove; 1063 - Guide rail; 1064 - Slider; 1065 - Support plate; 107 - Hinge seat; 20-Seat cushion linkage mechanism; 201-Seat cushion; 202-First support rod; 203-Second support rod; 204-Tension spring; 205-Limiting plate; 30 - Base assembly; 301 - Base; 40-Backrest bracket; 401-Mounting slot; 4011-First fixing slot; 4012-Second fixing slot; 402-Hinge end; 403-Second pivot; 404-Torsion spring; 405-Limit block; 60-Base bracket; 501-Third link; 502-First slide bar; 503-Fourth link; 504-Fifth link; 505-Sixth link; 506-First smooth bar; 507-First sliding seat; 508-Second slide bar; 509-Seventh link; 510-Support bracket; 511-Second sliding seat; 512-Second smooth bar; 513-Fulcrum bracket. Detailed Implementation

[0018] The present application will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. In fact, those skilled in the art will recognize that modifications and variations can be made to the present application without departing from the scope or spirit thereof. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the present application encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0019] In the description of this application, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and do not require that this application be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. The terms "connected," "linked," and "set up" used in this application should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0020] The accompanying drawings illustrate one or more examples of this application. The detailed description uses numerical and alphabetic designations to refer to features in the drawings. Similar or analogous designations in the drawings and description have been used to refer to similar or analogous parts of this application. As used herein, the terms “first,” “second,” and “third,” etc., are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of individual components.

[0021] It should be noted that the directional terms such as "horizontal" and "vertical" mentioned in this application are based on Figure 1 The perspective shown is defined, where "horizontal" refers to... Figure 1 The direction indicated by the X-axis, "vertical" refers to... Figure 1 The direction indicated by the Y-axis. It is understood that the above directional terms will change when the attached diagram changes. Therefore, they should not be construed as an absolute limitation on the scope of protection of this application.

[0022] Example 1 like Figure 1 As shown in the figure, this application embodiment proposes a seat, which includes a base assembly 30, a backrest support 40, and a seat cushion 201. The base assembly 30 is provided with a base 301, and the backrest support 40 and the seat cushion 201 are both connected to the base 301. (In conjunction with...) Figures 1 to 3This application also proposes a backrest support mechanism 10, which is disposed on the backrest bracket 40 and can dynamically adjust the posture of the backrest 101 when the user leans back, thereby continuously providing lumbar support for the user and improving riding comfort.

[0023] like Figure 5 and Figure 6 As shown, this application proposes a first backrest support mechanism 10, which includes a backrest 101, a first guide assembly 102, a first connecting rod 104, a second connecting rod 103, a support base 105, and a second guide assembly 106. The backrest 101 has a first side and a second side facing opposite directions, wherein the first side faces the user and the second side faces the backrest support 40. The first side of the backrest 101 includes a back support portion 1011 and a lumbar support portion 1012 in the vertical direction. The second side of the backrest 101 is divided into an upper part and a lower part in the vertical direction, wherein the upper part is provided with a hinge base 107, and the second guide assembly 106 is disposed in the lower part. The first guide assembly 102 and the support base 105 are both disposed on the backrest support 40. The first guide assembly 102 includes a first moving member 1021 that moves vertically, and the first moving member 1021 is hinged to the hinge base 107. The first link 104 is hinged to the support base 105. The first end of the first link 104 is connected to the first moving member 1021 via the second link 103, and the second end is connected to the second guide assembly 106. Applying an external force to the backrest 101 causes the first moving member 1021 of the first guide assembly 102 to move, and drives the lumbar support portion 1012 of the backrest 101 via the second link 103 and the first link 104, causing the lumbar support portion 1012 to move towards the user. For example, when the user leans back in the seat, the lumbar support portion 1012 moves towards the user synchronously during the backward tilting of the backrest 101, preventing the user's waist from being unsupported.

[0024] The first guide assembly 102 further includes a first guide member that vertically defines a movement range for the first moving member 1021, which is movable between the top and bottom ends of the movement range. In some embodiments, the first guide assembly 102 also includes an elastic member, which holds the first moving member 1021 at the top end of the movement range. Applying an external force to the first moving member 1021 causes it to move towards the bottom end of the movement range and causes the elastic member to undergo elastic deformation. When the external force acting on the first moving member 1021 is removed or weakened, the first moving member 1021 can move towards the top end under the action of the elastic member, thus resetting the first moving member 1021.

[0025] like Figure 6 , Figure 7A and Figure 7BAs shown, in some embodiments, the first guide member includes a slide post 1022, and the first moving member 1021 is a block structure with a sliding hole. The slide post 1022 slides with the sliding hole so that the first moving member 1021 can move along the length direction of the slide post 1022. The top of the slide post 1022 is provided with a first fixed end 1023, and the bottom is provided with a second fixed end 1024. The first fixed end 1023 and the second fixed end 1024 restrict the first moving member 1021 on the slide post 1022. The elastic member is a compression spring 1025, which is located between the first moving member 1021 and the second fixed end 1024 and sleeved on the slide post 1022. Figure 7A As shown, under normal circumstances, the compression spring 1025 keeps the first moving member 1021 always at the top of the slide bar 1022. Figure 7B As shown, when an external force is applied to the first moving member 1021 in the direction of the arrow, and the external force is sufficiently large, the first moving member 1021 can move towards the bottom end of the sliding column 1022. Here, "sufficiently large external force" means that the external force needs to be greater than the restoring force of the compression spring 1025. It should be noted that the sliding column 1022 in this embodiment has two columns. This implementation not only improves the strength of the first guide assembly 102 but also restricts the circumferential movement of the first moving member 1021 within the sliding column 1022.

[0026] like Figure 4 and Figure 8 As shown, in some embodiments, the backrest bracket 40 is provided with a mounting groove 401, which extends vertically, and the first guide assembly 102 is fixedly installed in the mounting groove 401. For example, the mounting groove 401 is provided with a first fixing groove 4011 and a second fixing groove 4012 in a vertical direction, wherein the first fixing groove 4011 is located at the top. The first fixing end 1023 of the first guide assembly 102 is installed in the first fixing groove 4011, and the second fixing end 1024 is installed in the second fixing groove 4012.

[0027] like Figures 4 to 6 As shown, the support base 105 is vertically positioned below the sliding block and fixed to the backrest bracket 40. The first link 104 has a first end and a second end along its length. The middle portion of the first link 104 is hinged to the support base 105 and can rotate vertically relative to the support base 105. The second link 103 has a first end 1031 and a second end 1032 along its length. The first end 1031 of the second link 103 is connected to the sliding block, and the second end 1032 of the second link 103 is connected to the first end of the first link 104. Moving the sliding block can drive the first link 104 to rotate vertically via the second link 103.

[0028] like Figure 6 and Figure 9As shown, in some embodiments, the first end 1031 of the second connecting rod 103 is fixed to the sliding block. The first connecting rod 104 has a shaft hole 1041 in its middle portion, and the support base 105 has a first rotating shaft 1051. The first rotating shaft 1051 is rotatably connected to the shaft hole 1041 so that the first connecting rod 104 is rotatably connected to the support base 105. The first end of the first connecting rod 104 has a first guide groove 1042, which extends along the length direction of the first connecting rod 104. The second end 1032 of the second connecting rod 103 has a first lever 1033, which is slidably connected to the first guide groove 1042. The slidably connected connection means that the first lever 1033 can slide within the first guide groove 1042 along its extension direction, and is restricted by the first guide groove 1042 and cannot disengage.

[0029] like Figures 1 to 3 As shown, in some embodiments, the second guide assembly 106 includes a second moving member and a second guide member, wherein the second guide member extends from the lower part of the second side surface towards the upper part, and the second moving member is slidably connected to the second guide member. The second moving member is connected to the second end of the first link 104. Rotating the first link 104 drives the second moving member to move relative to the second guide member, so that the lumbar support portion 1012 of the backrest 101 moves closer to or away from the backrest bracket 40.

[0030] like Figure 6 , Figure 11 and Figure 12 As shown, in some embodiments, the second guide member includes a guide plate 1061, which has a second guide groove 1062 extending upward from the lower part of the second side. The second moving member includes a second lever 1043, which is slidably connected to the second guide groove 1062. The second lever 1043 is disposed at the second end of the first connecting rod 104. It should be noted that the structure shown in the figure includes two guide plates 1061, with the second end of the first connecting rod 104 disposed between the two guide plates 1061. This structure can improve the strength and stability of the second guide assembly 106.

[0031] like Figure 13As shown, in some embodiments, based on the above-described embodiments of the first backrest support mechanism 10a, the connection relationship between the first moving member 1021, the hinge seat 107, the second connecting rod 103a, and the first connecting rod 104 is adjusted. Specifically, the first end 1031 of the second connecting rod 103a is hinged to the hinge seat 107, and the second end 1032 is fixed to the first moving member 1021. The first lever 1033 is disposed on the first moving member 1021 and is slidably connected to the first guide groove 1042 of the first connecting rod 104. The adjustment principle of the backrest 101, especially the movement principle of the lumbar support portion 1012, is described above and will not be repeated here. Based on the above embodiments, it can be seen that the second connecting rod 103a is a part of the first moving member 1021. Alternatively, the first moving member 1021 is hinged to the hinge seat 107 and connected to the second end of the first connecting rod 104.

[0032] like Figure 14 As shown, in some embodiments, the following adjustments are made based on the above-described embodiment of the first backrest support mechanism 10b. The first end of the first connecting rod 104b is hinged to the support base 105 and can rotate vertically relative to the support base 105. A first guide groove 1042 is provided between the first and second ends of the first connecting rod 104b. A first lever 1033 is provided at the second end 1032 of the second connecting rod 103 and is slidably connected to the first guide groove 1042. The adjustment principle of the backrest 101, especially the movement principle of the lumbar support portion 1012, is described above and will not be repeated here.

[0033] like Figure 15 As shown, this application provides a second backrest support mechanism 10c, which has the same support principle as the backrest 101 of the first backrest support mechanism 10. In particular, during the backward tilting of the backrest 101, its lumbar support portion 1012 moves synchronously toward the user, preventing the user's waist from being unsupported. Therefore, the main difference between the two is explained here. In this embodiment, the first end 1031 of the second link 103c is hinged to the first moving member 1021, and the second end 1032 of the second link 103c is hinged to the first end of the first link 104c. In addition, the second guide assembly 106 adopts a sliding guide structure of guide rail 1063 and slider 1064. For example, a ball guide rail 1063 or a roller guide rail 1063 can be selected, which can make the slider 1064 slide more smoothly on the guide rail 1063.

[0034] like Figure 16As shown, in some embodiments, the second backrest support mechanism 10d is adjusted based on the above embodiments as follows: the first end of the first link 104 is hinged to the support base 105, and the second end 1032 of the second link 103d is hinged between the first end and the second end of the first link 104d. The adjustment principle of the backrest 101, especially the movement principle of the lumbar support 1012, is explained above and will not be repeated here.

[0035] like Figure 17 As shown, in some embodiments, the first backrest support mechanism 10e is adjusted based on the above embodiments as follows. The second guide component is simplified to a support plate 1065, and a roller 1044 is provided at the second end of the first connecting rod 104. The first connecting rod 104 is tactilely connected to the support plate 1065. The support plate 1065 may also be part of the backrest 101, without specific limitations. Furthermore, in some embodiments, the support plate 1065 is provided with a guide rail or guide groove extending from the bottom to the top, and the roller 1044 moves along the extension direction of the guide rail or guide groove under the constraint of the guide rail or guide groove.

[0036] like Figure 20 As shown, the backrest bracket 40 is hinged to the base assembly 30 so that the backrest bracket 40 can rotate vertically. In this embodiment, the backrest bracket 40 is provided with a hinge end 402, and the base assembly 30 includes a base 301. The base 301 has a first end and a second end in its lateral direction, and the hinge end 402 is rotatably connected to the second end of the base 301 through a second rotating shaft 403.

[0037] like Figure 8 and Figure 22 As shown, in some embodiments, a torsion spring 404 is sleeved on the second pivot 403. One end of the torsion spring 404 acts on the hinge end 402, and the other end acts on the base 301, so that the backrest support 40 remains upright when there is no external force. The torsion spring 404 can rotate around the second pivot 403 and undergo elastic deformation when the backrest support 40 is subjected to an external force, and drive the backrest support 40 to return to the upright state after the external force is removed or reduced.

[0038] In addition, in some embodiments, the backrest bracket 40 can also lock its tilt angle using a tilt angle limiting device. Since this application does not improve the tilt angle limiting device and existing technology can be used, it will not be described in detail.

[0039] When the backrest support 40 tilts backward, in order to ensure the stability of the user's body posture and continuous support, this application proposes a seat cushion linkage mechanism 20. The seat cushion linkage mechanism 20 enables the seat cushion 201 and the backrest support 40 to move in coordination: as the backrest support 40 tilts backward, the seat cushion 201 moves backward synchronously, thereby maintaining the fit between the user's back and the backrest 101 as much as possible.

[0040] like Figure 22 and Figure 23 As shown, the seat cushion linkage mechanism 20 includes a seat cushion 201, a first support rod 202, and a second support rod 203. The first support rod 202 and the second support rod 203 are located between the seat cushion 201 and the base 301, and are arranged laterally. Specifically, the first support rod 202 is close to the first end 3011 of the base 301, and the second support rod 203 is close to the second end of the base 301. The tops of the first support rod 202 and the second support rod 203 are rotatably connected to the seat cushion 201, and the bottoms of the first support rod 202 and the second support rod 203 are rotatably connected to the base 301. The first support rod 202, the second support rod 203, the seat cushion 201, and the base 301 form a quadrilateral linkage rotation structure, allowing the seat cushion 201 and the base 301 to be rotatably connected laterally. It should be noted that, as... Figure 25 As shown, quadrilateral P refers to the shape formed by the connecting axes between the first support rod 202, the second support rod 203, the seat cushion 201, and the base 301. In this embodiment, the first support rod 202, the second support rod 203, the seat cushion 201, and the base 301 constitute a parallelogram linkage rotation structure, so that the seat cushion 201 can move laterally without rotating itself.

[0041] The seat cushion linkage mechanism 20 is provided with a first limiting member and a second limiting member. The first limiting member is used to limit the front boundary of the linkage rotating structure to rotate forward, and the second limiting member is used to limit the rear boundary of the linkage rotating structure to rotate backward. The linkage rotating structure can rotate between the front boundary and the rear boundary.

[0042] like Figure 22 and Figure 24 As shown, in some embodiments, the first limiting member includes a limiting plate 205, which is located on the forward-facing side of the first support rod 202 and fixed to the base 301. When the first support rod 202 rotates forward to a preset angle, it abuts against the limiting plate 205 to define the front boundary of the linkage rotation structure.

[0043] like Figure 22 and Figure 24 As shown, in some embodiments, the second limiting member includes a limiting block 405, which is located on the rearward side of the second support rod 203 and fixed to the hinge end 402. When the second support rod 203 rotates rearward to a preset angle, it abuts against the limiting block 405 to define the rear boundary of the linkage rotation structure. In this figure, the backrest bracket 40 is in a vertical state, the first support rod 202 abuts against the limiting plate 205, and the second support rod 203 abuts against the limiting block 405; therefore, the lateral movement of the linkage rotation structure is restricted.

[0044] like Figure 24 and Figure 26As shown, the limiting block 405 moves synchronously with the backrest support 40 when it rotates, redefining the position of the rear boundary. At this time, a downward force is applied to the seat cushion 201, which rotates backward with the cooperation of the linkage rotating structure until the second support rod 203 abuts against the limiting block 405. In actual use, the above process is usually continuous, or in other words, the user's own weight always acts on the seat cushion 201, and the linkage rotating structure moves synchronously with the backrest support 40 during its tilting process, thereby maintaining the user's back against the backrest 101 as closely as possible. If the user gets up, the backrest support 40 will return to a vertical state under the action of the torsion spring 404, and at the same time drive the second support rod 203 to rotate the linkage rotating structure forward to the front boundary.

[0045] like Figures 24 to 26 As shown, in some embodiments, the seat linkage mechanism 20 is further provided with a tension spring 204. The first end of the tension spring 204 acts on the first support rod 202 or the second support rod 203, and the second end of the tension spring 204 acts on the base 301, providing a forward rotational force for the linkage rotation structure.

[0046] Example 2 like Figure 27-33 As shown, this application provides another backrest support mechanism, with the lower end of the backrest bracket 40 hinged to the base bracket 60. The lower end of the third link 501 is mounted on the backrest bracket 40, and a first slide rod 502 is mounted on the third link 501. A first smooth rod 506 is mounted in a rectangular through hole at the upper part of the backrest bracket 40, and a first sliding seat 507 is slidably mounted on the first smooth rod 506. The upper part of the sixth link 505 is connected to the first sliding seat 507, the upper end of the sixth link 505 is hinged to the upper middle part of the backrest 101, the lower end of the sixth link 505 is hinged to the first end of the fifth link 504, the second end of the fifth link 504 is hinged to the first end of the fourth link 503, the fourth link 503 is provided with a strip hole, the first slide rod 502 slides through the strip hole of the fourth link 503, and the second end of the fourth link 503 is hinged to the backrest bracket 40. The second slide rod 508 is installed through the lower middle part of the sixth connecting rod 505. Two sets of second guide rods 512 are provided, symmetrically installed on both sides of the backrest 101, with a second sliding seat 511 slidably mounted on each set of second guide rods 512.

[0047] The support frame 510 has two second sliding seats 511 rotatably connected to its two ends. Two seventh connecting rods 509 are fixedly connected to the end of the support frame 510 away from the second sliding seats 511. Each seventh connecting rod 509 has a slotted hole, and both seventh connecting rods 509 are slidably connected to a second sliding rod 508 through the slotted hole. The fulcrum frame 513 is fixedly connected to the backrest support 40, and the support frame 510 is hinged to the fulcrum frame 513.

[0048] Working principle: When the user sits on the cushion on the base support 60, the user leans back, and their back presses against the backrest 101. The backrest 101 then transmits the pressure to the backrest support 40, which begins to slowly rotate backward under pressure. During the rotation of the backrest support 40, the third link 501 is pulled downward, which in turn pulls the fourth link 503 downward via the first slide rod 502. The upper end of the fourth link 503 pulls the fifth link 504 downward, which in turn drives the sixth link 505 to move downward. The sixth link 505 drives the first sliding seat 507 to slide downward along the first smooth rod 506, pulling the backrest 101 downward. At the same time, the sixth link 505 drives the second slide rod 508 downward, which slides in the seventh link 509 and pushes the seventh link 509 downward. Because the top of the backrest 101 is hinged to the sixth link 505, it cannot move in the vertical direction of its body, but can only rotate around the hinge point with the sixth link 505. Therefore, when the seventh link 509 is pushed downwards, it will cause the support frame 510 to rotate around the fulcrum frame 513, causing the end of the support frame 510 away from the fulcrum frame 513 to tilt upwards. This, in turn, causes the support frame 510 to drive the second sliding seat 511 to slide upwards on the second guide rod 512. As the support frame 510 drives the second sliding seat 511 upwards, the entire backrest 101 rotates away from the base support 60. The lower part of the backrest 101 is then lifted upwards by the support frame 510 and the second sliding seat 511, resulting in a forward-supporting posture for the user's waist. Figure 30 and 31 As shown, the seat is in a reclined position. The backrest 101 tilts backward in sync with the user's back, providing forward support to the lower back, reducing pressure on the user's lower back, and providing effective support and protection for the user's lower back, lumbar spine, and cervical spine, greatly improving the user's comfort and providing effective protection for the user's lumbar spine and cervical spine.

[0049] The above descriptions are merely some embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A backrest support mechanism, applied to a seat, the seat including a base, characterized in that, include: Backrest support; The backrest has an upper part and a lower part on the side facing the backrest support; A first guide assembly is disposed on the backrest support. The first guide assembly includes a first moving member that is selectively movable vertically and rotatably connected to the upper part of the backrest. as well as A first link is disposed below the first moving member and rotatably connected to the backrest support; the first link has a first end and a second end along its length direction, the first end of the first link faces the backrest support, and the second end of the first link faces the backrest and is movably connected to the lower part of the backrest. The first moving component is connected to the first connecting rod. When the first moving component moves vertically, it can drive the first connecting rod to rotate vertically and cause the lower part of the backrest to move horizontally relative to the backrest support.

2. The backrest support mechanism according to claim 1, characterized in that, The first guiding component further includes a first guide member that defines a movement range for the first moving member, enabling the first moving member to move between the top and bottom ends of the movement range.

3. The backrest support mechanism according to claim 2, characterized in that, The first guide member is a strip-shaped structure, and the first moving member is slidably connected to the first guide member for limiting.

4. The backrest support mechanism according to claim 1, characterized in that, The first connecting rod is provided with a guide structure extending along its length, and the first moving member is limited by sliding or rolling connection with the guide structure; or The first moving member is connected to the first connecting rod via a second connecting rod; wherein, the first end of the second connecting rod is hinged to the first moving member, and the second end of the second connecting rod is hinged to the first connecting rod.

5. The backrest support mechanism according to claim 4, characterized in that, The backrest bracket is rotatably connected to the middle of the first link and divides the first link into two sections; the first moving part is connected to the section of the first link near its first end.

6. The backrest support mechanism according to any one of claims 1 to 5, characterized in that, The first guide component further includes an elastic element that acts on the first moving member to keep the first moving member in a preset position and to apply a restoring force to the first moving member when it deviates from the preset position.

7. The backrest support mechanism according to any one of claims 1 to 5, characterized in that, It also includes a second guide assembly, which includes a second moving member and a second guide member. The second guide member is disposed at the lower part of the backrest and extends towards the upper part of the backrest. The second moving member is limitedly connected to the second guide member and can move along the extension direction of the second guide member. The second end of the first connecting rod is connected to the second moving member.

8. The backrest support mechanism according to claim 7, characterized in that, The second guide member includes a linear guide structure, and the second moving member is limited to a sliding or rolling connection with the linear guide structure.

9. The backrest support mechanism according to any one of claims 1 to 5, characterized in that, The backrest support is configured to be hinged to the base; The backrest support mechanism also includes: The third link is fixed to the backrest bracket, and the third link is provided with a first sliding rod; The fourth link, wherein the fourth link is provided with a strip-shaped hole; the first slide rod passes through the strip-shaped hole and is slidably engaged; and The fifth link, the first end of which is hinged to the first moving member, and the second end of which is hinged to the first end of the fourth link; The second end of the fourth link is configured to be hinged to the base.

10. A linkage support mechanism for a seat cushion and backrest, characterized in that, include: Base; The backrest support mechanism according to any one of claims 1 to 9, wherein the backrest bracket is rotatably connected to the base; as well as A seat cushion linkage mechanism, wherein the seat cushion linkage mechanism includes a seat cushion, and the seat cushion is rotatably connected to the base via a linkage rotation structure; The cushion linkage mechanism further includes a limiting structure, which is used to limit the rear boundary of the linkage rotation structure to rotate backward. The limiting structure is disposed on the backrest support. The limiting structure can move synchronously when the backrest support rotates vertically and redefine the position of the rear boundary. The linkage rotation structure can selectively rotate synchronously with the rear boundary.

11. The linkage support mechanism according to claim 10, characterized in that, The linkage rotation structure includes a first support rod and a second support rod arranged laterally. The top of the first support rod and the top of the second support rod are rotatably connected to the seat cushion, and the bottom of the first support rod and the bottom of the second support rod are rotatably connected to the base.

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