A linkage tilt seat

Abstract

The utility model relates to a linkage type reclining chair, including main body frame, chair back, seat and handrail frame, the handrail frame is equipped with linkage mechanism, contains pedestal plate, chair back swing frame and seat swing frame, the chair back swing frame rotatable installation is in the pedestal plate, and is locked multiple reclining angles through angle locking mechanism, the chair back connects the chair back swing frame, the pedestal plate is equipped with arc track, and the seat swing frame can slide on it, and the seat connects the seat swing frame, the chair back swing frame is connected with the seat swing frame through linkage connecting piece, and the chair back rotation drives the seat swing frame to slide, realizes synchronous linkage, the scheme simple structure, convenient operation supports multiple gear adjustment and synchronous linkage.

Description

Technical Field

[0001] This utility model relates to the field of seat design, and in particular to a linked tilting seat. Background Technology

[0002] In the field of seating design, especially for chairs used for extended periods such as office chairs and lounge chairs, providing users with backrest and reclining functions has become a basic requirement. Traditional reclining chairs often employ simple backrest flipping structures or rely on complex springs, air pumps, and other elastic components to achieve reclining and return to their original position. While these structures are common, they often struggle to simultaneously adjust the seat angle and position. When a user reclines, the backrest flipping alters the contact relationship between the body and the seat. If the seat remains stationary, it can easily lead to pressure on the thighs and body slippage, making it impossible to maintain a comfortable and stable sitting posture. Therefore, designs that link the seat and backrest have emerged on the market, using a mechanical connection to ensure that reclining the backrest triggers a corresponding movement in the seat.

[0003] However, many existing linkage mechanisms are complex in structure and have numerous parts, resulting in high production costs. Furthermore, the locking and adjustment of tilt angles are often inconvenient to operate or lack precise positioning, impacting the user experience. Specifically, existing angle locking mechanisms typically use a single fixed point for locking, failing to achieve precise multi-level adjustments, and the unlocking operation is cumbersome. Linkage mechanisms often employ rigid connections, lacking optimized design for seat movement trajectories, leading to insufficient comfort during operation. In addition, the armrest frame structure of existing linked seats is often designed separately from the linkage mechanism, resulting in a loose overall structure and poor stability.

[0004] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0005] To address the aforementioned problems, the purpose of this utility model is to provide a linkage tilting seat, which has the advantages of simple structure, convenient operation, multi-level tilting angle adjustment, and synchronous linkage between the backrest and seat.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This application provides a linkage-type tilting seat, the technical solution of which is as follows: It includes a main frame, a backrest, and a seat. Armrests are provided on both sides of the main frame, and a linkage mechanism is provided on the armrests. The linkage mechanism includes a base plate fixed to the armrests, and a backrest swing frame and a seat swing frame disposed on the base plate. The backrest swing frame is rotatably mounted on the base plate. An angle locking mechanism is provided between the backrest swing frame and the base plate to lock the backrest swing frame at multiple different tilt angles. The backrest is connected to the backrest swing frame. An arc-shaped track is provided on the base plate, and the seat swing frame is slidably disposed on the arc-shaped track. The seat is connected to the seat swing frame. The backrest swing frame and the seat swing frame are connected by a linkage connector, so that the rotation of the backrest drives the seat swing frame to slide along the arc-shaped track through the linkage connector, thereby achieving synchronous linkage between the backrest and the seat.

[0008] Furthermore, this application also proposes that the angle locking mechanism includes a positioning part disposed on the chair back swing frame and a locking assembly disposed on the base plate; the locking assembly includes a retractable locking pin and a driving part for driving the locking pin to move; the driving part controls the engagement or disengagement of the locking pin and the positioning part to achieve locking or releasing of the chair back swing frame.

[0009] Furthermore, this application also proposes that the positioning part consists of a plurality of positioning holes arranged circumferentially along the rotation axis of the chair back frame, and the locking pin is a pin that can be inserted into the positioning hole.

[0010] Furthermore, this application also proposes that the driving part is a rotary handwheel, which is provided with a gradient section. The gradient section has an axial gradient along the circumferential direction, and the pin is pressed against the gradient section by a spring. When the rotary handwheel rotates, the gradient section acts on the pin, driving the pin to move axially, thereby controlling its insertion or withdrawal from the positioning hole.

[0011] Furthermore, this application also proposes that the rear side of the chair back frame bends to form a chair back connecting part, which is fixedly connected to the rear side of the chair back.

[0012] Furthermore, this application also proposes that the lower end of the chair frame is bent to form a chair seat connecting part, which is fixedly connected to both sides of the lower end surface of the chair seat.

[0013] Furthermore, this application also proposes that the arc track includes a front arc track and a rear arc track, and the distance between the front arc track and the rear arc track gradually increases from back to front.

[0014] Furthermore, this application also proposes that the linkage connector is a connecting rod, with both ends of the connecting rod hinged to the backrest frame and the seat frame respectively; or, the front end of the backrest frame extends out and is provided with a connecting part, which is hinged to the seat frame.

[0015] As can be seen from the above, the linkage tilting seat and its angle locking mechanism provided in this application realize multi-level adjustment of the backrest tilt angle and synchronous sliding of the seat through the cooperation of the linkage mechanism and the angle locking mechanism. It solves the problems of complex linkage structure and cumbersome locking operation of traditional seats, and has the advantages of compact structure, precise adjustment and high comfort. Attached Figure Description

[0016] Figure 1 A schematic diagram of a first embodiment of a linkage tilting seat provided in this application.

[0017] Figure 2 The first structural diagram of the linkage mechanism is provided for this application.

[0018] Figure 3 The first structural breakdown diagram of the linkage mechanism is provided for this application.

[0019] Figure 4 A schematic diagram of a second embodiment of a linkage tilting seat provided in this application.

[0020] Figure 5 The schematic diagram provided for this application is a second structural representation of the linkage mechanism.

[0021] Figure 6 The provided diagram for this application is a second structural breakdown of the linkage mechanism.

[0022] Figure 7 This is a schematic diagram of the driving structure for the locking component. Detailed Implementation

[0023] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0024] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.

[0026] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] In existing technologies, the chair industry has long faced the problem of the seat not adjusting synchronously when the backrest is reclined. Traditional reclining mechanisms rely on elastic elements to achieve reset, but the fixed seat position leads to thigh compression. While existing linkage designs can adjust synchronously, their complex structure and inconvenient angle adjustment negatively impact the user experience. For example, in office settings, when users recline to rest, a fixed seat can easily cause the body to slide down, requiring frequent adjustments to posture.

[0029] To address these issues, designers observed that the shift in the user's center of gravity required adjustments to the seat position when the chair back reclines. Analysis of ergonomic data revealed that moving the seat forward could counteract the uneven pressure distribution caused by reclining. Based on this, the designers considered converting the backrest's rotational motion into a sliding motion of the seat, while simultaneously simplifying the mechanical structure and introducing a multi-position locking function. After numerous prototype tests, a base plate integrated linkage mechanism was ultimately chosen, transmitting motion through rigid connectors.

[0030] like Figure 1-7As shown, this application proposes a linked tilting seat, including a main frame 1, a backrest 2, and a seat 3. Armrests 4 are provided on both sides of the main frame 1, and a linkage mechanism 5 is installed on the armrests 4. The linkage mechanism 5 includes a base plate 6 fixed to the armrests 4. A rotatable backrest swing frame 7 and a slidable seat swing frame 8 are mounted on the base plate 6. An angle locking mechanism is provided between the backrest swing frame 7 and the base plate 6. The base plate 6 has an arc-shaped track for the seat swing frame 8 to slide. The backrest swing frame 7 and the seat swing frame 8 are connected by a linkage connector, so that when the backrest 2 rotates, it drives the seat swing frame 8 to slide along the track.

[0031] The base plate 6 is a rigid support platform fixed to the armrest frame 4, which can be made of stamped steel plate and is used to support the components of the linkage mechanism 5. The chair back swing frame 7 is a rotating bracket connecting the chair back 2, which can be made of L-shaped steel components and installed on the base plate 6 through a pivot to achieve rotation around the axis. The arc track is a guide groove with a specific curvature, which can be made of laser-cut curved grooves, and its radius of curvature is calculated and determined according to the trajectory of human sitting posture changes. The linkage connector is a rigid component that transmits motion relationships, which can be a hinged connecting rod or a one-piece metal connecting arm.

[0032] Specifically, when the user leans back and applies force to the backrest 2, the backrest frame 7 rotates around the base plate 6. The angle locking mechanism, through the cooperation of the pin 14 and the positioning hole 12, fixes the backrest frame 7 at a preset angle. The linkage connector converts the rotational motion into linear displacement, pushing the seat frame 8 to slide along the arc track. As the seat 3 moves with the frame, its front end rises and moves forward according to the curvature of the track, simultaneously adjusting the seat cushion tilt angle. Through the above technical solution, this application eliminates the pressure on the front of the thighs when the backrest 2 is leaning back, maintaining the stability of the body's center of gravity. The number of parts in the linkage mechanism 5 is reduced by 40%, reducing assembly complexity. Multi-position angle locking provides precise tilt adjustment and prevents accidental slippage. The seat 3 moves along a predetermined trajectory to ensure that the sitting posture conforms to the human spinal curve, improving comfort during long-term sitting.

[0033] In such Figure 1-6In the specific embodiment shown, the angle locking mechanism includes a positioning part on the chair back frame 7 and a locking assembly on the base plate 6. The locking assembly includes a retractable locking pin and a drive part that drives the locking pin. The drive part controls the engagement or disengagement of the locking pin and the positioning part to lock or release the chair back frame 7. The positioning part refers to a fixed structure on the chair back frame 7 that engages with the locking pin. Specifically, it can be implemented using multiple positioning holes 12 arranged circumferentially along the rotation axis, as described below, forming multiple angle locking reference points through the hole distribution. The locking pin is an axially movable insertion component, specifically a cylindrical pin 14, which restricts the rotation of the chair back frame 7 by inserting into or withdrawing from the positioning hole 12. The drive part is an operating mechanism that controls the movement of the locking pin, specifically a combination of a rotating handwheel 15 and a transition section 16, converting the rotational motion into linear displacement of the locking pin.

[0034] Specifically, when the backrest frame 7 needs to be locked, the drive unit is operated to push the locking pin into the positioning hole 12. At this time, a rigid connection is formed between the backrest frame 7 and the base plate 6, and the rotational freedom is completely restricted. When the backrest frame 7 needs to be released, the drive unit moves in the opposite direction to make the locking pin exit the positioning hole 12, and the backrest frame 7 can rotate freely around the base plate 6. The axial movement path of the locking pin is coaxial with the arrangement direction of the positioning holes 12 to ensure no interference during the insertion process. The number and spacing of the positioning holes 12 are determined according to the preset tilt angle levels, and each hole corresponds to a fixed tilt angle. Through the above technical solution, this application can achieve rapid locking and releasing of the tilt angle. During the operation, only the drive unit needs to be activated to complete the state switching, avoiding the complex multi-step operation in traditional mechanisms. The rigid fit between the locking pin and the positioning hole 12 can accurately maintain the position of the backrest frame 7, ensuring the consistency of the tilt angle after each locking in multi-angle adjustment, and solving the positioning offset problem caused by deformation of elastic elements or frictional wear in the prior art.

[0035] Furthermore, the positioning holes 12 refer to the hole structure evenly distributed along the rotation trajectory of the chair back swing frame 7. Specifically, they can be circular through holes or stepped holes, with each hole corresponding to a locking position when the chair back swing frame 7 rotates to a specific angle. The locking pin is a rigid rod with a cylindrical end, specifically a metal pin or a composite material pin, whose diameter forms a clearance fit with the inner diameter of the positioning hole 12. Specifically, when the chair back swing frame 7 rotates around the base plate 6, the positioning holes 12 move circumferentially to different angular positions along the rotation axis. The locking pin moves axially under the action of the drive unit, and when the end of the locking pin is inserted into the corresponding positioning hole 12, the rotational freedom of the chair back swing frame 7 is completely restricted. Because the positioning holes 12 are evenly distributed circumferentially, the tilt angle corresponding to each hole position of the chair back swing frame 7 has a fixed interval, for example, one hole position is set every 5 degrees. The rigid contact between the locking pin and the positioning hole 12 forms a mechanical interlock, which, compared to the traditional friction locking structure, avoids the problem of wear and loosening caused by long-term use.

[0036] like Figure 7 As shown, the driving unit is a rotary handwheel 15, which has a gradient section 16. The gradient section 16 has an axial gradient along the circumferential direction, and the pin 14 is pressed against the gradient section 16 by a spring. When the rotary handwheel 15 rotates, the gradient section 16 acts on the pin 14, driving the pin 14 to move axially, thereby controlling its insertion or withdrawal from the positioning hole 12. The gradient section 16 refers to a continuous curved surface structure on the circumferential surface of the rotary handwheel 15, which can be implemented using a helical cam or an involute profile, with its axial height gradually changing along the rotation direction. This structure can convert rotational motion into linear displacement, pushing the pin 14 to move through the height difference of the curved surface. The spring pressing refers to applying continuous pressure to the pin 14 using an elastic element, which can be implemented using a compression spring or a torsion spring, ensuring that the pin 14 always remains in contact with the gradient section 16. This design prevents components from disengaging and enhances the locking force after the pin 14 is inserted into the positioning hole 12. Axial movement refers to the linear movement of the pin 14 along a direction perpendicular to the axis of the rotating handwheel 15. Specifically, the movement trajectory of the pin 14 can be limited by a guide groove or slide rail structure. This movement method ensures that the pin 14 can be accurately aligned with the positioning hole 12 to achieve locking.

[0037] Specifically, when the handwheel 15 is rotated, the curved contour of the transition section 16 and the contact surface of the pin 14 are relatively displaced. Due to the change in axial height of the transition section 16, the pin 14 is axially displaced along the guide structure under spring pressure. When the low point of the transition section 16 corresponds to the position of the pin 14, the pin 14 exits the positioning hole 12 and is unlocked; when the high point of the transition section 16 pushes the pin 14, the spring pushes the pin 14 into the positioning hole 12 to complete the locking. By controlling the rotation angle of the handwheel, the mating position of the pin 14 with different positioning holes 12 can be precisely selected to achieve multi-level angle adjustment. Through the above technical solution, this application can quickly switch the locking state by single-handed rotation operation, reducing operation steps and lowering the probability of misoperation. The mating between the pin 14 and the positioning hole 12 maintains stable contact under the action of spring preload, preventing shaking or displacement caused by force during seat tilting. The continuous curved surface design of the transition section 16 makes the gear shifting process smooth and without jamming, while providing clear gear tactile feedback.

[0038] like Figure 1-6 As shown, the backrest frame 7 of the linked reclining seat is bent at the rear to form a backrest connection part 19, which is fixedly connected to the rear side of the backrest 2. The backrest frame 7 refers to the rod-shaped component that serves as the supporting skeleton, which can be made by bending metal tubing or profiles. The backrest connection part 19 formed by its bending is directly fixed to the rear side of the backrest 2, reducing the use of separate connecting parts. The backrest connection part 19 refers to the fixed area formed by the bending process, which can be achieved by welding, bolting, or riveting. Its close fit and fixation to the rear side of the backrest 2 ensures even stress distribution and avoids localized stress concentration. Specifically, the backrest frame 7 forms the backrest connection part 19 by bending at the rear, and this connection part is directly fixed to the rear side of the backrest 2, making the backrest 2 and the linkage mechanism 5 an integrated structure. The bending process creates a continuous transition between the backrest frame 7 and the connection part, eliminating the need for additional connecting parts and preventing installation misalignment caused by processing errors in a separate structure. When the backrest connecting part 19 is fixed to the rear side of the backrest 2, the tilting moment of the backrest 2 is transmitted to the base plate 6 through the swing arm, ensuring that the movement path of the backrest 2 and the linkage mechanism 5 are consistent. Since the backrest swing frame 7 and the connecting part are integral structures, no relative displacement will occur during the tilting process, avoiding the shaking or loosening caused by gaps in traditional split hinge structures.

[0039] The lower end of the chair frame 8 is bent to form a chair seat connection part 21, which is fixedly connected to both sides of the lower end face of the chair seat 3. The chair frame 8 refers to a rigid rod that supports the chair seat 3 and transmits the linkage force; it can be made by bending metal tubing. The chair seat connection part 21 formed by the bending at its lower end can disperse stress concentration areas. The chair seat connection part 21 is a structure directly fixed to the chair seat 3, which can be achieved by welding or bolting. The symmetrical layout on both sides can balance the lateral forces during tilting. Specifically, by bending the chair frame 8 to form the chair seat connection part 21, the bending stress of the rod is evenly distributed to the bending area when subjected to tilting loads, preventing deformation or breakage of the straight rod structure due to excessive local stress. The chair seat connection part 21 is fixed to both sides of the lower end face of the chair seat 3, ensuring that the chair seat 3 experiences synchronous force on both sides when sliding along the curved track, eliminating tilting or jamming caused by a single-sided connection. When the backrest frame 7 drives the linkage connector, the seat frame 8 absorbs part of the impact load through the bending part, while the fixed points on both sides constrain the lateral displacement of the seat 3, ensuring that the sliding trajectory of the seat 3 is precisely matched with the rotation angle of the backrest 2.

[0040] like Figure 3 and 6 As shown, the arc-shaped track includes a front arc-shaped track 22 and a rear arc-shaped track 23, with the distance between them gradually increasing from back to front. The front arc-shaped track 22 and the rear arc-shaped track 23 are two arc-shaped sliding tracks, respectively positioned at the front and rear of the base plate 6. They can be implemented using bent metal plates or injection-molded plastic tracks, guiding the sliding path of the chair frame 8. The gradually increasing distance from back to front means that the spacing between the two tracks increases along the sliding direction. This can be achieved by adjusting the track installation angle or changing the track curvature radius, thus constraining the chair frame 8 during sliding by the change in the distance between the two tracks.

[0041] Specifically, by setting a front arc-shaped track 22 and a rear arc-shaped track 23, the sliding path of the chair seat frame 8 is restricted to the two tracks. When the chair seat frame 8 slides along the tracks, the gradual change in the distance between the two tracks dynamically adjusts the curvature of the sliding trajectory. As the chair back 2 tilts back, causing the chair seat frame 8 to slide forward, the track distance gradually increases, precisely guiding the sliding direction of the chair seat frame 8, and the front end of the chair seat 3 tilts up to accommodate the tilting motion of the chair back 2. When the chair back 2 returns to its original position, the track distance gradually decreases, guiding the front end of the chair seat frame 8 to lower, thus adapting to the change in the angle of the chair back 2. The dual-track structure disperses sliding resistance by increasing the number of support points, while the gradual change in the track distance ensures that the chair seat frame 8 maintains balanced force at different tilt angles, avoiding jamming or wear caused by local stress concentration. Through the above technical solution, this application solves the problem of insufficient stability or excessive sliding resistance caused by a single trajectory during the sliding process of the chair seat frame 8. The dual-track gradient structure precisely guides the sliding path of the seat frame 8, preventing deviation or wobbling. At the same time, by dynamically adjusting the track spacing, the force distribution is optimized, reducing the jamming phenomenon during the sliding process, and ensuring that the tilting linkage between the seat 3 and the backrest 2 is more stable and reliable.

[0042] like Figure 1-3 In the illustrated scheme, the linkage is a connecting rod 11, with its two ends hinged to the backrest frame 7 and the seat frame 8, respectively. The connecting rod 11 is a rigid rod used to transmit motion; it can be a metal rod or a high-strength plastic rod. The hinged structure at both ends converts rotational motion into push-pull motion. The hinge allows the component to rotate around an axis, and can be achieved using a pin and bushing combination structure to ensure flexible motion transmission. In the first embodiment, the two ends of the connecting rod 11 are connected to the backrest frame 7 and the seat frame 8 via pins. When the backrest frame 7 rotates, the connecting rod 11 converts the rotational motion into a linear push-pull action, driving the seat frame 8 to slide along an arc-shaped track.

[0043] like Figure 4-6 In the illustrated scheme, a connecting portion 24 extends from the front end of the chair back frame 7, and the connecting portion 24 is hinged to the chair seat frame 8. The connecting portion 24 refers to the structure extending from the front end of the chair back frame 7, which can be manufactured using stamping or welding processes, and is used to directly form a hinge point with the chair seat frame 8. In the second embodiment, the connecting portion 24 extending from the front end of the chair back frame 7 is directly hinged to the chair seat frame 8, and the rotation of the chair back frame 7 is directly transmitted to the chair seat frame 8 through the connecting portion 24, causing them to slide synchronously. Both methods reduce the number of independent components by simplifying the transmission chain, avoiding the problem of gap accumulation caused by multi-stage hinges.

[0044] In summary, the linkage tilting seat and its angle locking mechanism provided in this application, through the cooperation of the linkage mechanism 5 and the angle locking mechanism, realizes multi-level adjustment of the tilting angle of the backrest 2 and synchronous sliding of the seat 3, which solves the problems of complex linkage structure and cumbersome locking operation of traditional seats, and has the advantages of compact structure, precise adjustment and high comfort.

[0045] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0046] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A linkage-type reclining seat, comprising a main frame (1), a backrest (2), and a seat (3), wherein armrests (4) are provided on both sides of the main frame (1), characterized in that: The armrest frame (4) is provided with a linkage mechanism (5), which includes a base plate (6) fixed to the armrest frame (4), and a backrest bracket (7) and a seat bracket (8) provided on the base plate (6); the backrest bracket (7) is rotatably mounted on the base plate (6); an angle locking mechanism is provided between the backrest bracket (7) and the base plate (6) to lock the backrest bracket (7) at multiple different tilt angles; the chair The backrest (2) is connected to the backrest frame (7); the base plate (6) is provided with an arc track, and the seat frame (8) is slidably set on the arc track; the seat (3) is connected to the seat frame (8); the backrest frame (7) and the seat frame (8) are connected by a linkage connector, so that the rotation of the backrest (2) drives the seat frame (8) to slide along the arc track through the linkage connector, thereby realizing the synchronous linkage of the backrest (2) and the seat (3).

2. The linked tilting seat according to claim 1, characterized in that: The angle locking mechanism includes a positioning part on the chair back frame (7) and a locking component on the base plate (6); the locking component includes a retractable locking pin and a driving part for driving the locking pin to move; the driving part controls the engagement or disengagement of the locking pin and the positioning part to lock or release the chair back frame (7).

3. A linkage tilting seat according to claim 2, characterized in that: The positioning part consists of a plurality of positioning holes (12) arranged circumferentially along the rotation axis of the chair back frame (7), and the locking pin is a pin (14) that can be inserted into the positioning hole (12).

4. A linkage tilting seat according to claim 3, characterized in that: The driving unit is a rotating handwheel (15), which is provided with a gradient section (16). The gradient section (16) has an axial gradient along the circumferential direction. The pin (14) is pressed against the gradient section (16) by a spring. When the rotating handwheel (15) rotates, the gradient section (16) acts on the pin (14) to drive the pin (14) to move axially, thereby controlling its insertion or withdrawal from the positioning hole (12).

5. A linkage tilting seat according to claim 1, characterized in that: The backrest bracket (7) is bent at the rear to form a backrest connection part (19), which is fixedly connected to the rear side of the backrest (2).

6. A linkage tilting seat according to claim 1, characterized in that: The lower end of the chair frame (8) is bent to form a chair connection part (21), which is fixedly connected to both sides of the lower end face of the chair (3).

7. A linkage tilting seat according to claim 1, characterized in that: The arc-shaped track includes a front arc-shaped track (22) and a rear arc-shaped track (23), and the distance between the front arc-shaped track (22) and the rear arc-shaped track (23) gradually increases from back to front.

8. A linkage tilting seat according to claim 1, characterized in that: The linkage connector is a connecting rod (11), and the two ends of the connecting rod (11) are respectively hinged to the backrest frame (7) and the seat frame (8); or, the front end of the backrest frame (7) is provided with a connecting part (24), and the connecting part (24) is hinged to the seat frame (8).

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