Seat back assembly

Abstract

The present application relates to a seat back assembly comprising first and second backrests which are pivotable to one another to vary between first and third relative positions, passing through a second relative position, the seat back assembly further comprising a lock assembly having a lock tongue which is changeable between an extended and a retracted condition, in the extended condition the first and second backrests are lockable by the lock tongue, in the retracted condition the first and second backrests are not lockable by the lock tongue, in the first relative position the first and second backrests are locked by the lock tongue, the lock tongue being in the extended condition; in the second relative position the first and second backrests are unlocked, the first backrest is positioned rearward of the second backrest, and a first angle is formed between the first and second backrests, the lock tongue being in the retracted condition; in the third relative position the first backrest is positioned rearward of the second backrest, and a second angle greater than the first angle is formed between the first and second backrests; during the transition from the second to the third relative position the lock tongue remains in the retracted condition.

Description

Technical Field

[0001] This application generally relates to the field of vehicles, and more specifically, to a seat back assembly. Background Technology

[0002] With the development of vehicle technology, the personalized functions of vehicles are constantly evolving and improving. Vehicle seats are an important component of vehicles, and to meet various personalized needs and adapt to different application scenarios, the flexibility and rationality of vehicle seat adjustments are also constantly being improved and perfected.

[0003] In existing technology, for multiple seat backs arranged side-by-side, a function is provided to lock and unlock adjacent seat backs together using a locking assembly. The unfolding and retracting of the latch in the locking assembly can be correlated with the rotational movement of the two seat backs relative to each other. This allows the latch to retract as the two seat backs rotate apart and unfold as they rotate closer together. This achieves locking when the two seat backs are close together while preventing collisions with occupants, luggage, or other objects caused by the latch protruding from the seat backs when they are separated, thus ensuring a comfortable ride. Furthermore, it is desirable that, with the latch already retracted, further rotation of the two seat backs relative to each other be unimpeded, enabling a wider range and more flexible adjustment of the vehicle seats. Summary of the Invention

[0004] In the sense of this application, the term "vehicle" can be generally understood as a means of transport, such as a land vehicle, a water vehicle (or a ship) or an air vehicle (or an aircraft), especially a motor vehicle such as a passenger car or a truck.

[0005] The applicant of this invention discovered during the research and development of the product that, in vehicle seats known in the prior art, when the latch is already in a folded state, further rotation of two adjacent seat backs relative to each other is hindered.

[0006] Therefore, a first aspect of the present invention relates to a seat back assembly including a first backrest and a second backrest, the first and second backrests being pivotable relative to each other and changing between a first relative position and a third relative position, passing through a second relative position. The seat back assembly further includes a locking assembly disposed between the first and second backrests, the locking assembly having a latch disposed on one of the first and second backrests and being movable between an extended state and a folded state. When the latch is in the extended state, the first and second backrests can be locked together by the locking assembly; when the latch is in the folded state, the first and second backrests cannot be locked together by the locking assembly.

[0007] In the first relative position, the first backrest and the second backrest are locked together by a locking assembly, wherein the latch is in the extended state;

[0008] In the second relative position, the first backrest is located behind the second backrest, and a first angle is formed between the first backrest and the second backrest, wherein the latch moves to a folded state;

[0009] In the third relative position, the first backrest is located behind the second backrest, and a second angle greater than the first angle is formed between the first backrest and the second backrest; during the process from the second relative position to the third relative position, the latch remains in a folded state.

[0010] According to the seat back assembly of the present invention, the locking tongue can be changed from an unfolded state to a folded state as the angle between the first backrest and the second backrest increases, and the angle between the first backrest and the second backrest can be freely increased further after the locking tongue is changed to the folded state, thereby helping to improve the flexibility of vehicle seat adjustment and providing users with a better riding experience.

[0011] In some embodiments, the lock assembly includes: a first elastic member that applies a force to the bolt to change it toward a folded state; and a bolt stop that prevents the bolt from continuing to move after it has moved from an unfolded state to a folded state, thereby restricting it to the folded state.

[0012] In some embodiments, the lock assembly includes a housing that includes the bolt stop, and the first resilient member is configured to be connected to both the housing and the bolt.

[0013] In some embodiments, the seat back assembly includes:

[0014] A first rotating disk is mounted coaxially with a first backrest and a second backrest, and is configured to rotate relative to the first backrest or the second backrest during changes in a first relative position and a third relative position relative to each other.

[0015] A cable, one end of which is connected to the first rotating disk and can be wound and unwound on the first rotating disk, and the other end of which is connected to the latch and can drive the latch from a folded state to an unfolded state.

[0016] In some embodiments, the seat back assembly further includes a limiting mechanism cooperating with the first rotating disk, the limiting mechanism and the first rotating disk being configured such that: when the first backrest and the second backrest are in a first relative position and a second relative position, the first rotating disk applies a force along a first direction to the limiting mechanism; when the first backrest and the second backrest are in a second relative position and a third relative position, the latch remains folded, and the first rotating disk does not apply the force along the first direction to the limiting mechanism, wherein the first direction corresponds to the direction in which the first rotating disk rotates forward, and the force along the first direction is at least partially provided by the first elastic member.

[0017] In some embodiments, the limiting mechanism is configured as a second rotating disk coaxially mounted with the first rotating disk, and the first rotating disk can overcome the force applied to the first rotating disk by the first elastic member by abutting against the second rotating disk.

[0018] In some embodiments, the limiting mechanism is configured as a protrusion fixedly connected to the other of the first backrest and the second backrest, and the first rotating disk can overcome the force applied to the first rotating disk by the first elastic member by abutting against the protrusion.

[0019] In some embodiments, the first backrest and the second backrest pivot relative to each other between a first relative position and a second relative position, passing through a fourth relative position in which the latch is still extended, the first backrest is located behind the second backrest, and a third angle smaller than the first angle is formed between the first backrest and the second backrest.

[0020] In some embodiments, the seat back assembly includes a compensation device configured such that the latch remains deployed when the first backrest and the second backrest are in a first relative position and a fourth relative position.

[0021] In some embodiments, the first backrest and the second backrest pivot relative to each other between a first relative position and a second relative position, passing through a fourth relative position in which the latch is still extended, the first backrest is located behind the second backrest, and a third angle smaller than the first angle is formed between the first backrest and the second backrest.

[0022] The seat back assembly includes a compensation device configured such that the latch remains in an extended state when the first backrest and the second backrest are in a first relative position and a fourth relative position.

[0023] The compensation device includes a positioning part disposed on the second rotating disk, a slide groove disposed on the other of the first backrest and the second backrest, and a second elastic member. The second elastic member applies an elastic force to the positioning part toward the end of the slide groove. As the first backrest and the second backrest change between a first relative position and a fourth relative position, the positioning part can correspondingly change relative to the slide groove between a position spaced apart from the end of the slide groove and a position contacting the end of the slide groove, thereby maintaining the cable in a position that allows the latch to unfold.

[0024] In some embodiments, the second elastic member is configured as a coil spring, one end of which is connected to the other of the first backrest and the second backrest, and the other end is connected to the positioning portion.

[0025] In some embodiments, the first backrest and the second backrest pivot relative to each other between a first relative position and a second relative position, passing through a fourth relative position in which the latch is still extended, the first backrest is located behind the second backrest, and a third angle smaller than the first angle is formed between the first backrest and the second backrest.

[0026] The seat back assembly includes a compensation device configured such that the latch remains in an extended state when the first backrest and the second backrest are in a first relative position and a fourth relative position.

[0027] The compensation device includes an elastic compensator connected to the cable. One end of the elastic compensator is connected to the upper half of the cable, and the other end of the elastic compensator is connected to the lower half of the cable. When the first backrest and the second backrest are in a first relative position, the elastic compensator is compressed. As the first backrest and the second backrest change from the first relative position to a fourth relative position, the elastic potential energy of the elastic compensator is gradually released, and the cable is maintained in a position that allows the latch to unfold.

[0028] In some embodiments, the second relative position includes: relative to the first relative position, the first backrest remains stationary, and the second backrest is flipped forward to a position at a first angle relative to the first backrest; relative to the first relative position, the second backrest remains stationary, and the first backrest is flipped backward to a position at a first angle relative to the second backrest; or the second backrest is in a forward-flattened position, and the first backrest is flipped forward to a position at a first angle relative to the second backrest.

[0029] In some embodiments, the third relative position includes: relative to the first relative position, the first backrest remains stationary and the second backrest is in a forward-folded-flat position; relative to the first relative position, the second backrest remains stationary and the first backrest is in a backward-folded-flat position; or the second backrest is in a forward-folded-flat position and the first backrest is in a backward-folded-flat position.

[0030] In some embodiments, the first backrest is configured as an armrest frame backrest, and the second backrest is configured as a side seat backrest adjacent to the armrest frame backrest.

[0031] The technical features mentioned above, those to be mentioned below, and those shown individually in the accompanying drawings can be combined arbitrarily, provided that the combined technical features are not contradictory. All feasible combinations of features are the technical content explicitly described herein. Any one of the multiple sub-features contained in the same statement can be applied independently, without necessarily being applied together with other sub-features. Attached Figure Description

[0032] FIG. 1 A schematic diagram of a seat back assembly according to some embodiments of this application is shown.

[0033] FIG. 2 It shows FIG. 1 An exploded view of the seat back assembly.

[0034] FIG. 3A It shows what can be used for FIG. 1 A schematic diagram of the latch assembly of the locking component in the seat back assembly, wherein the latch is in the deployed state.

[0035] FIG. 3B It shows FIG. 3A The diagram shows the latch assembly, where the latch is in a folded state.

[0036] FIG. 3C It shows FIG. 3A The diagram shows an exploded view of the latch assembly.

[0037] FIG. 4A It shows what can be used for FIG. 1 A schematic diagram showing the connection between one end of the cable of the cable drive assembly in the seat back assembly and the latch assembly.

[0038] FIG. 4B It shows what can be used for FIG. 1 A schematic diagram illustrating the connection between the other end of the cable of the cable drive assembly in the seat back assembly and the first rotating disk.

[0039] FIG. 5A to FIG. 5CIt shows what can be used for FIG. 1 The diagram shows the lock body assembly of the seat backrest component in the locked position, the middle position, and the unlocked position.

[0040] FIG. 6A It shows FIG. 1 An exploded view of the portion of the seat back assembly near the backrest rotation axis, where cables are omitted.

[0041] FIG. 6B It shows FIG. 6A A schematic diagram of the part when viewed from a direction roughly parallel to the axis of rotation of the backrest.

[0042] FIG. 7A It shows FIG. 1 A schematic diagram of the state of the first backrest and the second backrest of the seat back assembly when they are in a first relative position.

[0043] FIG. 7B This shows the situation when the seat back assembly is in FIG. 7A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from one side.

[0044] FIG. 7C This shows the situation when the seat back assembly is in FIG. 7A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from the other side.

[0045] FIG. 7D This shows the situation when the seat back assembly is in FIG. 7A The diagram shows the state of the latch during operation.

[0046] FIG. 8A It shows FIG. 1 A schematic diagram of the state of the first backrest and the second backrest of the seat back assembly when they are in a second relative position.

[0047] FIG. 8B This shows the situation when the seat back assembly is in FIG. 8A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from one side.

[0048] FIG. 8C This shows the situation when the seat back assembly is in FIG. 8A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from the other side.

[0049] FIG. 8D This shows the situation when the seat back assembly is in FIG. 8A The diagram shows the state of the latch during operation.

[0050] FIG. 9A It shows FIG. 1 A schematic diagram of the state in which the first backrest and the second backrest of the seat back assembly are in a second relative position and a third relative position, or in a third relative position.

[0051] FIG. 9B This shows the situation when the seat back assembly is in FIG. 9A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from one side.

[0052] FIG. 9C This shows the situation when the seat back assembly is in FIG. 9A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from the other side.

[0053] FIG. 9D This shows the situation when the seat back assembly is in FIG. 9A The diagram shows the state of the latch during operation.

[0054] FIG. 10A This shows the position of the seat back assembly. FIG. 9D The state begins with the first possible change state that the first backrest can achieve.

[0055] FIG. 10B This shows the position of the seat back assembly. FIG. 9D Starting from the state in the middle, the second change state that the first backrest can achieve.

[0056] FIG. 11A and FIG. 11B It shows FIG. 5A to FIG. 5C The diagram shows the locking components when viewed from the other side, with the locking components in the locked and unlocked positions respectively.

[0057] FIG. 12A It shows FIG. 1 A schematic diagram of the state of the first backrest and the second backrest of the seat back assembly when they are in a fourth relative position.

[0058] FIG. 12B This shows the situation when the seat back assembly is in FIG. 12A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from one side.

[0059] FIG. 12C This shows the situation when the seat back assembly is in FIG. 12A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from the other side.

[0060] FIG. 12DThis shows the situation when the seat back assembly is in FIG. 7A The diagram shows the elastic compensator of the seat back assembly in the current state.

[0061] FIG. 12E This shows the situation when the seat back assembly is in FIG. 12A The diagram shows the elastic compensator of the seat back assembly in the current state.

[0062] FIG. 13 A schematic diagram of a seat back assembly according to some other embodiments of this application is shown.

[0063] FIG. 14 It shows FIG. 13 An exploded view of the seat back assembly.

[0064] FIG. 15A It shows FIG. 13 A schematic diagram of the portion of the seat back assembly near the backrest rotation axis, in which the cables are omitted.

[0065] FIG. 15B It shows FIG. 15A A partial exploded diagram.

[0066] FIG. 15C It shows FIG. 15A A schematic diagram of the part when viewed from a direction roughly parallel to the axis of rotation of the backrest.

[0067] FIG. 16A It shows FIG. 13 A schematic diagram of the state of the first backrest and the second backrest of the seat back assembly when they are in a first relative position.

[0068] FIG. 16B This shows the situation when the seat back assembly is in FIG. 16A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from one side.

[0069] FIG. 16C This shows the situation when the seat back assembly is in FIG. 16A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from the other side.

[0070] FIG. 17A It shows FIG. 14 A schematic diagram of the state of the first backrest and the second backrest of the seat back assembly when they are in a fourth relative position.

[0071] FIG. 17B This shows the situation when the seat back assembly is in FIG. 17A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from one side.

[0072] FIG. 17C This shows the situation when the seat back assembly is in FIG. 17A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from the other side.

[0073] FIG. 18A It shows FIG. 13 A schematic diagram of the state of the first backrest and the second backrest of the seat back assembly when they are in a second relative position.

[0074] FIG. 18B This shows the situation when the seat back assembly is in FIG. 18A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from one side.

[0075] FIG. 18C This shows the situation when the seat back assembly is in FIG. 18A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from the other side.

[0076] FIG. 19A It shows FIG. 13 A schematic diagram of the state in which the first backrest and the second backrest of the seat back assembly are in a second relative position and a third relative position, or in a third relative position.

[0077] FIG. 19B This shows the situation when the seat back assembly is in FIG. 19A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from one side.

[0078] FIG. 19C This shows the situation when the seat back assembly is in FIG. 19A This is a schematic diagram of the portion of the seat back assembly near the backrest rotation axis when viewed from the other side. Detailed Implementation

[0079] Exemplary embodiments of this application will now be described with reference to the accompanying drawings. However, it should be understood that this application can be presented in many different ways and is not limited to the embodiments described below. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments. Throughout the drawings, the same reference numerals denote the same or functionally identical elements.

[0080] In the context of this application, unless otherwise specified, the expression "front" or "forward" refers to the direction in which the vehicle seat faces the occupant sitting on it, and the expression "rear" or "behind" refers to the opposite direction.

[0081] like FIG. 1 and FIG. 2 As shown, according to some embodiments of the present invention, the seat back assembly 1 may include a first backrest 2 and a second backrest 3. The second backrest 3 may be connected to the first backrest 2 via a bolt 4 and a pivot nut 5, thereby enabling the first backrest 2 and the second backrest 3 to be pivotally connected relative to each other. The first backrest 2 may be configured as an armrest frame backrest in a vehicle seat, for example, and the second backrest 3 may be configured as a side seat backrest adjacent to the armrest frame backrest.

[0082] The seat back assembly 1 may also include a locking assembly 6 disposed between the first backrest 2 and the second backrest 3. This locking assembly 6 is capable of locking the first backrest 2 and the second backrest 3 together under certain conditions and unlocking under correspondingly changed conditions, allowing the first backrest 2 and the second backrest 3 to separate from each other. The unlocking and locking of the locking assembly 6 will be described in detail below.

[0083] like FIG. 2 As shown, the lock assembly 6 may include a lock body assembly 7, a bolt assembly 8, a mounting housing 9, etc. The lock body assembly 7 can be mounted to the second backrest 3, for example, using a first mounting screw 31. The bolt assembly 8 and the mounting housing 9 can be mounted to the first backrest 2, for example, using a second mounting screw 10. It should be understood that the mounting positions of the lock body assembly 7 and the bolt assembly 8 are merely exemplary, and their mounting positions can be interchanged. That is, the lock body assembly 7 can be mounted to the first backrest 2, and the bolt assembly 8 can be mounted to the second backrest 3, as long as the mounting positions of the corresponding other parts fixed to the corresponding backrests are also interchanged.

[0084] Below, in conjunction with FIG. 3A to FIG. 4B The description can be used for seat back assembly according to the invention, for example FIG. 1 The locking tongue assembly 8 of the locking assembly 6 in the seat back assembly 1, and the seat back assembly that can be used according to the invention, for example FIG. 1 The cable drive assembly 22 in the seat back assembly 1 can be used to drive the latch 11 in the latch assembly 8.

[0085] like FIG. 3A to FIG. 3C As shown, the latch assembly 8 may include, for example, a latch 11, a spring 12, a housing 13, etc. The latch 11 may be configured to be able to... FIG. 3A The unfolded state shown and as FIG. 3B The spring 12 can be connected at one end to the latch 11 and at the other end to the housing 13 (e.g., connected to a groove 32 in the housing 13, as shown). FIG. 3B (as shown), and can be configured to apply a biasing force to the latch 11 to change it toward a retracted state. For example...FIG. 3B As shown, the housing 13 may include a latch stop 14, which can be configured to prevent the latch 11 from continuing to move after it has moved from the extended state to the retracted state, thereby restricting it to the retracted state. It should be understood that the latch stop 14 is not necessarily located on the housing 13, but may also be located on other components of the lock assembly 6 that are fixed to the first backrest 2, which will not be described in detail here. When the latch 11 is in the retracted state, the spring 12 may be configured to continue applying a biasing force to the latch 11, or it may be configured not to apply a biasing force to the latch 11.

[0086] like FIG. 3C As shown, the cable drive assembly 22 may include a cable 15 configured to apply force to the latch 11, and the force applied to the latch 11 by the cable 15 can resist the biasing force applied to the latch 11 by the spring 12, thereby enabling the latch 11 to move from such a position as shown in the diagram. FIG. 3B The folded state shown in the figure transforms into as follows FIG. 3A The unfolded state is shown in the image. For example, as shown in the image. FIG. 3C As shown, the latch assembly 8 may include a sleeve 16, which may include a hole 33 configured to mate with the shape of the shank 17 of the latch 11, thereby allowing for coaxial and torsion-resistant mounting on the latch 11. One end of a cable 15 may be mounted to the sleeve 16 offset relative to the axis of rotation of the sleeve 16, such that the tension applied to the sleeve 16 by the cable 15 can drive the latch 11 to rotate in the unfolding direction against the biasing force of the spring 12. FIG. 4A The diagram further illustrates how one end of the cable 15 is mounted to the sleeve 16. For example, one end of the cable 15 may include a first insertion portion 34, and the sleeve 16 may include a first receiving portion 35 that mates with the shape of the first insertion portion 34. It should be understood that the latch assembly 8 may also exclude the sleeve 16, and the cable 15 may be mounted directly to the lever 17, offset from the axis of rotation of the lever 17 relative to the latch 11.

[0087] like FIG. 4B As shown, the other end of the cable 15 can be mounted onto the first rotating disk 18 through the cooperation between the second insertion part 36 and the second receiving part 37, and can be wound and unwound on the first rotating disk 18. This allows the cable 15 to tighten on the first rotating disk 18, increasing the force exerted by the cable 15 on the locking tongue 11, while unwinding the cable 15 on the first rotating disk 18 allows the cable 15 to loosen, decreasing the force exerted by the cable 15 on the locking tongue 11. The first rotating disk 18 can be mounted coaxially with the first backrest 2 and the second backrest 3, and can be configured to rotate relative to either the first backrest 2 or the second backrest 3, for example, during relative movement between the first backrest 2 and the second backrest 3. Further operational details of the cable drive assembly 22 will be described later.

[0088] like FIG. 5A to FIG. 5C As shown, it can be used FIG. 1 The lock assembly 7 of the lock assembly 6 of the seat back assembly 1 may include, for example, a body 19, a button 20, a latch member 21, etc., wherein the latch member 21 can be used to engage the latch 11 (not in the seat back assembly 1). FIG. 5A to FIG. 5C (As shown in the diagram) it is locked between the latch member 21 and the body 19. When the lock body assembly 7 is in the position as shown... FIG. 5A In the locked position shown, by along FIG. 5B and FIG. 5C Press button 20 in the direction indicated by the arrow in the image, so that button 20 passes through the direction shown by the arrow in the image. FIG. 5B The location shown and eventually reached as indicated FIG. 5C The latch component 21 can be retracted at the position shown, thereby allowing the bolt 11 to be removed from the lock body assembly 7 to unlock the lock component 6.

[0089] FIG. 6A and FIG. 6B It shows FIG. 1 The portion of the seat back assembly 1 near the axis of rotation of the backrest is shown, wherein the cable is omitted from the diagram. As described above, the second backrest 3 can be connected to the pivot nut 5 on the first backrest 2, for example, by means of a bolt 4, thereby allowing the first backrest 2 and the second backrest 3 to be pivotally connected relative to each other. The cable drive assembly 22 may include a first rotating disk 18 and a cable 15 (not shown in the diagram) wound thereon. FIG. 6A and FIG. 6B As shown in the diagram, the first rotating disk 18 can be mounted about the rotation axis of the bolt 4 and the pivot nut 5 (i.e., the rotation axis of the backrest), thereby enabling the first rotating disk 18 to pivot relative to the first backrest 2 and the third backrest 3. FIG. 6A and FIG. 6B As shown, the seat back assembly 1 may further include a protrusion 23 fixedly disposed on the second back 3. This protrusion 23 may be configured to overcome the force exerted by the first rotating disk 18 along a first direction, thereby serving as a limiting mechanism to restrict the rotation of the first rotating disk 18 along the first direction, where the first direction corresponds to the direction in which the cable 15 is wound onto the first rotating disk 18. As described above, the mounting positions of the lock body assembly 7 and the latch assembly 8 can be interchanged. Therefore, it should be understood that when the lock body assembly 7 is mounted on the first back 2 and the latch assembly 8 is mounted on the second back 3, the protrusion 23 can be fixedly disposed on the first back 2.

[0090] Below, in conjunction with FIG. 7A , FIG. 8A , FIG. 9A The seat back assembly 1 will be further described by considering the relative positions of the first backrest 2 and the second backrest 3.

[0091] like FIG. 7A As shown, the first backrest 2 and the second backrest 3 are in a first relative position, at which the latch 11 is in the extended state, as... FIG. 7D As shown, the first backrest 2 and the second backrest 3 can be locked together by the latch 11. As described above, the latch 11 being in the extended state means that the force applied to the latch 11 by the cable 15 resists the biasing force applied to the latch 11 by the spring 12, and therefore the cable 15 is in a taut state.

[0092] like FIG. 7C As clearly shown, at this relative position, the protrusion 23 and the first rotating disk 18 abut against each other, and because the cable 15 is taut, the first rotating disk 18 applies a force to the protrusion 23 in the aforementioned first direction. Simultaneously, the protrusion 23 prevents the first rotating disk 18 from moving in the direction that causes the cable 15 to unwind (i.e.,...). FIG. 7C The cable 15 is kept taut by rotating counterclockwise (in the direction of rotation) to keep the latch in the extended position. In this state, the force exerted by the first rotating disc 18 on the protrusion 23 can be provided entirely by the spring 12 in the latch assembly 8, or partially by the spring 12 (for example, when there are other components that act directly or indirectly on the cable 15).

[0093] like FIG. 8A As shown, the first backrest 2 and the second backrest 3 are in a second relative position. In this relative position, the first backrest 2 and the second backrest 3 are unlocked. The first backrest 2 is located behind the second backrest 3, and a first angle is formed between the first backrest 2 and the second backrest 3. The locking tongue 11 is in a folded state, as shown... FIG. 8D As shown. From... FIG. 7A The first relative position shown is as follows: FIG. 8A The transformation of the second relative position shown can be achieved by flipping the second backrest 3 forward relative to the first backrest 2, as follows: FIG. 8B The arrow on the second backrest 3, marked in a clockwise direction, is shown in the diagram. It should be understood that this implementation is merely exemplary, and may vary from other implementations. FIG. 7A The first relative position shown is as follows: FIG. 8AThe change in the second relative position shown can also be achieved by flipping the first backrest 2 backward relative to the second backrest 3, or by simultaneously flipping the first backrest 2 backward and the second backrest 3 forward, as long as at least one of the first backrest 2 and the second backrest 3 is flipped so that the first backrest 2 is behind the second backrest 3 and the two form a first angle. When the first backrest 2 and the second backrest 3 are in the second relative position, for example, the first backrest 2 can remain stationary relative to the first relative position and the second backrest 3 can be flipped forward to form a first angle relative to the first backrest 2; or, for example, the second backrest 3 can be in a forward-flattened position and the first backrest 2 can be flipped forward to form a first angle relative to the second backrest 3.

[0094] Taking the transition from the first relative position to the second relative position as an example, which can be achieved by flipping the second backrest 3 forward relative to the first backrest 2, as follows: FIG. 8C As is clearly shown, as the second backrest 3 flips forward relative to the first backrest 2, the protrusion 23 on the second backrest 3 moves along with the second backrest 3 around the aforementioned backrest rotation axis. FIG. 8C The first rotating disk 18 rotates counterclockwise. During this process, the protrusion 23 tends to move away from the first rotating disk 18, while the cable 15 tends to unwind from the first rotating disk 18 due to the force of the spring 12. This causes the first rotating disk 18 to rotate counterclockwise. FIG. 8C The counter-clockwise rotation tendency causes the first rotating disk 18 to rotate with the protrusion 23 and remain in contact with it until the latch 11 reaches the folded position and the spring 12 no longer applies biasing force to the first rotating disk 18 via the cable 15. Therefore, the state of the latch 11 reaching the folded position can correspond to the state of the first backrest 2 and the second backrest 3 reaching the second relative position, or it can correspond to the state of the first rotating disk 18 no longer applying force along the first direction to the protrusion 23.

[0095] For example, when the transition from a first relative position to a second relative position between the first backrest 2 and the second backrest 3 is achieved not by the second backrest 3 flipping forward relative to the first backrest 2, but by the first backrest 2 flipping backward relative to the first backrest 2, during this process, due to the first backrest 2 flipping backward, the cable 15 unwinds from the first rotating disk 18, resulting in a decrease in the biasing force applied to the first rotating disk 18 by the spring 12 via the latch 11 and the cable 15, and a decrease in the force applied to the protrusion 23 by the first rotating disk 18, until the latch 11 reaches a folded state and no longer applies force to the cable 15, and the cable 15 no longer applies force to the protrusion 23 via the first rotating disk 18. During this period, the first rotating disk 18 and the protrusion 23 remain in contact with each other.

[0096] Based on this, during the period when the angle between the first backrest 2 and the second backrest 3 is further increased (i.e., the second backrest 3 is stationary and the first backrest 2 is flipped backward, the first backrest 2 is stationary and the second backrest 3 is flipped forward, or the first backrest 2 is flipped backward and the second backrest 3 is flipped forward) until an angle greater than the first angle is formed between them, the spring 12 no longer applies biasing force to the latch 11, or the biasing force applied by the spring 12 to the latch 11 is unable to make the latch 11 continue to rotate due to the presence of the latch stop 14, so that the latch 11 can no longer provide a force to tighten the cable 15. The state when a second angle (greater than the first angle) is formed between the first backrest 2 and the second backrest 3 can be defined as the third relative position between the first backrest 2 and the second backrest 3. This relative position can be the relative position where the included angle between the first backrest 2 and the second backrest 3 is the largest that can be achieved, and the second angle can be adjusted according to actual needs. For example, the third relative position can be a state in which the first backrest 2 remains stationary relative to the first relative position and the second backrest 3 is in a forward-folded-flat position, or it can be a state in which the first backrest 2 is in a backward-folded-flat or nearly-folded-flat position and the second backrest 3 is in a forward-folded-flat position.

[0097] FIG. 9A This illustrates a scenario where, based on the second relative position reached, the angle between the first backrest 2 and the second backrest 3 further increases, such that, at this relative position, ... FIG. 9D As shown, the latch 11 remains folded and no longer provides a force to tighten the cable 15; that is, the first rotating disc 18 will no longer exert a force on the protrusion 23 in the aforementioned first direction. Therefore, for example, when the first backrest 2 and the second backrest 3 are in a second relative position and the second backrest 3 is flipped forward relative to the first backrest 2 (e.g., flipped until flat), as the protrusion 23 follows the second backrest 3 about the backrest rotation axis as described above... FIG. 9C When rotated counterclockwise, the first rotating disk 18 will no longer follow the protrusion 23, thus gradually separating from the protrusion 23.

[0098] It should be understood that when the angle between the first backrest 2 and the second backrest 3 increases from the second relative position by keeping the second backrest 3 stationary and flipping the first backrest 2 backward, the first rotating disk 18 is not necessarily separated from the protrusion 23. It is only because the flipping of the first backrest 2 causes the cable 15 to unwind from the first rotating disk 18 that the first rotating disk 18 can freely rotate between the position of contacting the protrusion 23 and the position of taut cable 15.

[0099] Therefore, from FIG. 8AStarting from the second relative position shown, the angle between the first backrest 2 and the second backrest 3 can be freely increased to any angle less than or equal to the second angle. The transition from the second relative position to the third relative position of the first backrest 2 and the second backrest 3 can be achieved by flipping the second backrest 3 forward relative to the first backrest 2, or by flipping the first backrest 2 backward relative to the second backrest 3, or by simultaneously flipping the first backrest 2 backward and the second backrest 3 forward, as long as at least one of the first backrest 2 and the second backrest 3 is flipped such that the first backrest 2 is behind the second backrest 3 and the two form the second angle.

[0100] For example, while the first backrest 2 remains stationary (e.g., upright), the second backrest 3 can be adjusted as follows: FIG. 9A That way, it can be folded forward flat. For example, while the second backrest 3 remains stationary relative to the first relative position, the first backrest 2 can be folded backward flat. For example, while the second backrest 3 remains folded forward flat, the first backrest 2 can be folded backward flat. FIG. 10A Flip it backwards like that (for example, flip it until it's flat).

[0101] Of course, it should be understood that starting from a state where the angle between the first backrest 2 and the second backrest 3 is the second angle or any angle smaller than the second angle, it is also possible to freely reduce the angle between the first backrest 2 and the second backrest 3. For example, from FIG. 9A Starting with the first backrest 2 upright and the second backrest 3 folded forward as shown, the first backrest 2 can be moved forward while the second backrest 3 remains folded forward. FIG. 10B That way, it flips forward. As the first backrest 2 from FIG. 9A The state shown is flipped forward so that the first backrest 2 and the second backrest 3 form a first angle (i.e., a second relative position). The cable 15 tends to wind around the first rotating disk 18, causing the first rotating disk 18 to rotate toward the protrusion 23 until it abuts against the protrusion 23. As the angle between the first backrest 2 and the second backrest 3 further decreases from the first angle (e.g., when the first backrest 2 is flipped further forward so that the first backrest 2 and the second backrest 3 reach the first relative position), the cable 15 will gradually wind around the first rotating disk 18 and gradually apply tension to the latch 11 as the protrusion 23 abuts against the first rotating disk 18, preventing the first rotating disk 18 from rotating. As a result, the cable 15 will gradually resist the elastic force of the spring 12 to pull the latch 11 out to the unfolded state and apply a gradually increasing force to the protrusion 23 (as the spring 12 applies a gradually increasing force to the cable 15 as it is gradually tightened).

[0102] FIG. 11A and FIG. 11B It shows FIG. 5A to FIG. 5CThe diagram shows the locking component 6 when viewed from the other side, with the locking component 6 in the locked and unlocked positions respectively. FIG. 11A and FIG. 11B As shown, when the lock body assembly 7 unlocks the bolt 11, if the bolt 11 moves from the unfolded position to the folded position during the initial transition of the first backrest 2 and the second backrest 3 from the first relative position to the second relative position, there is a risk that the bolt 11 will interfere with the components of the lock body assembly 7. Therefore, it is more advantageous for the bolt 11 to remain in the unfolded state during the initial transition of the first backrest 2 and the second backrest 3 from the first relative position to the second relative position.

[0103] For example, the first backrest 2 and the second backrest 3 can have the following characteristics: FIG. 12A The fourth relative position is shown, wherein a third angle smaller than the first angle is formed between the two, and the latch 11 remains in the deployed state during the change between the first relative position and the fourth relative position of the first backrest 2 and the second backrest 3. To achieve this, the seat back assembly 1 may include a compensation device configured such that the latch 11 remains in the deployed state when the first backrest 2 and the second backrest 3 are in the first relative position and the fourth relative position. For example, as FIG. 12D and FIG. 12E As shown, the compensation device may include an elastic compensator 24 connected to the cable 15. The elastic compensator 24 may be configured such that it is compressed to store elastic potential energy when the cable 15 has an overstretch, and releases the elastic potential energy accordingly when the overstretch on the cable 15 is eliminated. Specifically, the elastic compensator 24 may be configured to be in a compressed state when the first backrest 2 and the second backrest 3 are in a first relative position (e.g., ...). FIG. 12D (As shown) and has an elongating tendency, as the first backrest 2 and the second backrest 3 change from the first relative position to the fourth relative position, as FIG. 12B and FIG. 12C As shown, the first rotating disk 18 rotates following the protrusion 23 under the elastic force of the elastic compensator 24. The lower half of the cable 15 unwinds from the first rotating disk 18, the overstretch of the cable 15 is gradually eliminated, and the elastic potential energy of the elastic compensator 24 is gradually released and expands (as shown). FIG. 12E (As shown), during this period, cable 15 is maintained in a position that allows the latch 11 to extend.

[0104] It should be understood that, although FIG. 12AThe transition from a first relative position to a fourth relative position between the first backrest 2 and the second backrest 3 is shown to be achieved by flipping the second backrest 3 forward relative to the first backrest 2 while keeping the first backrest 2 stationary. However, this transition can also be achieved by flipping the first backrest 2 backward relative to the second backrest 3 while keeping the second backrest 3 stationary, or by flipping the first backrest 2 backward and the second backrest 3 forward simultaneously, as long as at least one of the first backrest 2 and the second backrest 3 is flipped so that the first backrest 2 is behind the second backrest 3 and the two form a third angle.

[0105] FIG. 13 and FIG. 14 A schematic diagram of a seat back assembly 1' according to some other embodiments of this application is shown. The seat back assembly 1' and the seat back assembly 1 have similar constructions, wherein the same components as in the seat back assembly 1 are indicated by the same reference numerals. The main difference between the seat back assembly 1' and the seat back assembly 1 lies in the construction of the limiting mechanism and the compensation device of the seat back assembly 1'.

[0106] like FIG. 15A to FIG. 15C As shown, the seat back assembly 1' may include a first rotating disk 18 and a second rotating disk 25, and a cable 15 (not shown). FIG. 15A to FIG. 15C (As shown in the diagram) It can be mounted around the first rotating disk 18. The first rotating disk 18 is mounted in the same way as in the seat back assembly 1. The second rotating disk 25 is also mounted around the axis of rotation of the backrest where the bolt 4 and the pivot nut 5 are located, so that the second rotating disk 25 can pivot relative to the first backrest 2 and the third backrest 3 at least within a certain angular range.

[0107] like FIG. 15A to FIG. 15B As clearly shown, the seat back assembly 1' may further include a groove 26 and a coil spring 27 disposed on the second backrest 3, and the second rotating disk 25 may include a positioning portion 28 configured to move along the groove 26. One end of the coil spring 27 is connected to the positioning portion 28 of the second rotating disk 25 and is configured to apply a biasing force toward the end 29 of the groove 26 to the positioning portion 28, wherein the direction toward the end 29 of the groove 26 is opposite to the first direction described above. Thus, the second rotating disk 25 may be configured to resist the force exerted on the second rotating disk 25 by the first rotating disk 18 in the first direction by the biasing force applied to the positioning portion 28 by the coil spring 27, thereby serving as a limiting mechanism to restrict the rotation of the first rotating disk 18 in the first direction. Specifically, as FIG. 15B As shown, the first rotating disk 18 and the second rotating disk 25 can abut against each other through the first abutting part 39 and the second abutting part 30.

[0108] like FIG. 16A to FIG. 16C As shown, the coil spring 27, the second rotating disk 25, and the slide groove 26 can be configured such that when the first backrest 2 and the second backrest 3 are in a first relative position, the positioning portion 28 of the second rotating disk 25 is located in the slide groove 26 at a position spaced apart from the end 29 of the slide groove 26. Specifically, when the first backrest 2 and the second backrest 3 are in the first relative position, the latch 11 is in the extended state. This means that the force applied to the latch 11 by the cable 15 resists the biasing force applied to the latch 11 by the spring 12. Therefore, the cable 15 is in a taut state and applies a biasing force to the second rotating disk 25 via the first rotating disk 18, causing the positioning portion 28 of the second rotating disk 25 to move away from the end 29 of the slide groove 26. On the other hand, the coil spring 27 applies a biasing force to the second rotating disk 25 via the positioning portion 28, causing the positioning portion 28 to move closer to the end 29. Thus, the positioning portion 28 is held in a position spaced apart from the end 29 by the mutually balanced biasing forces from the coil spring 27 and the spring 12.

[0109] As the first backrest 2 and the second backrest 3 move from... FIG. 16A The first relative position shown transforms into as FIG. 17A The fourth relative position shown, for example, is as follows FIG. 17B As clearly shown, the positioning part 28 changes from a position spaced apart from the end 29 to a position in contact with the end 29 relative to the slide 26. During this period, the cable 15 can be maintained in a position that allows the latch 11 to unfold, or in other words, remain stationary relative to the first rotating disk 18. Thus, the positioning part 28, the slide 26, and the coil spring 27 provided on the second rotating disk 25 can be used as a compensation device for the seat back assembly 1'.

[0110] It should be understood that, although FIG. 16A The transition from a first relative position to a fourth relative position between the first backrest 2 and the second backrest 3 is shown to be achieved by flipping the second backrest 3 forward relative to the first backrest 2 while keeping the first backrest 2 stationary. However, this transition can also be achieved by flipping the first backrest 2 backward relative to the second backrest 3 while keeping the second backrest 3 stationary, or by flipping the first backrest 2 backward and the second backrest 3 forward simultaneously, as long as the first backrest 2 is behind the second backrest 3 and a third angle is formed between them.

[0111] As the first backrest 2 and the second backrest 3 move from... FIG. 17A The fourth relative position shown transforms into as FIG. 18A The second relative position shown, for example, is as follows FIG. 18BAs clearly shown, since the end 29 is in contact with the positioning part 28, the forward flipping of the second backrest 3 can cause the positioning part 28, or the second rotating disk 25, to rotate forward (i.e., along the first direction mentioned above). Thus, the second rotating disk 25 tends to move away from the first rotating disk 18. On the other hand, due to the biasing force applied to the first rotating disk 18 by the spring 12 via the cable 15, the first rotating disk 18 rotates along the first direction under the action of this biasing force and remains in contact with the second rotating disk 25, thereby maintaining relative stillness with the second backrest 3 until the latch 11 reaches the folded position and the spring 12 no longer applies biasing force to the first rotating disk 18 via the cable 15. Therefore, the state of the latch 11 reaching the folded position can correspond to the state of the first backrest 2 and the second backrest 3 reaching the second relative position, or it can correspond to the state of the first rotating disk 18 no longer applying a force along the first direction to the second rotating disk 25.

[0112] For example, when the transition from the fourth relative position to the second relative position between the first backrest 2 and the second backrest 3 is achieved not by the second backrest 3 flipping forward relative to the first backrest 2, but by the first backrest 2 flipping backward relative to the first backrest 2, during this process, as the first backrest 2 flips backward, the cable 15 unwinds from the first rotating disk 18, thereby gradually reducing the bias force applied to the first rotating disk 18 by the spring 12, or in other words, the force applied to the second rotating disk 25 by the first rotating disk 18, until the latch 11 reaches the retracted state, and the first rotating disk 18 no longer applies force to the second rotating disk 25. During this period, the first rotating disk 18 and the second rotating disk 25 remain in contact.

[0113] The first backrest 2 and the second backrest 3 reach as FIG. 18A Based on the second relative position shown, during the period when the angle between the first backrest 2 and the second backrest 3 is further increased (i.e., the second backrest 3 is stationary and the first backrest 2 is flipped backward, the first backrest 2 is stationary and the second backrest 3 is flipped forward, or the first backrest 2 is flipped backward and the second backrest 3 is flipped forward) to form a second angle greater than the first angle between them (i.e., the first backrest 2 and the second backrest 3 reach the third relative position), the latch 11 remains in a folded state and no longer provides a force to the cable 15 to tighten the cable 15, that is, the first rotating disk 18 will no longer apply a force along the first direction to the second rotating disk 25.

[0114] FIG. 19AThis illustrates a scenario where, based on the first backrest 2 and the second backrest 3 reaching a second relative position, the angle between the first backrest 2 and the second backrest 3 further increases. At this relative position, the latch 11 remains folded and no longer provides a force to tighten the cable 15; that is, the first rotating disc 18 no longer applies a force along the aforementioned first direction to the second rotating disc 25. Therefore, for example, when the first backrest 2 and the second backrest 3 depart from the second relative position, and the second backrest 3 flips forward relative to the first backrest 2 (e.g., flips until flat), as the second rotating disc 25 follows the second backrest 3 around the backrest rotation axis as described above... FIG. 19C When rotated counterclockwise, the first rotating disk 18 will no longer follow the second rotating disk 25, thus gradually separating from it. It should be understood that when the angle between the first backrest 2 and the second backrest 3 increases from the second relative position by keeping the second backrest 3 stationary and flipping the first backrest 2 backward, the first rotating disk 18 does not necessarily separate from the second rotating disk 25. It is only because the backward flipping of the first backrest 2 causes the cable 15 to unwind from the first rotating disk 18 that the first rotating disk 18 can freely rotate between the position contacting the second rotating disk 25 and the position where the cable 15 is taut.

[0115] Therefore, from FIG. 18A Starting from the second relative position shown, the angle between the first backrest 2 and the second backrest 3 can be further increased freely. Of course, it should be understood that, as described for seat backrest assembly 1, similarly for seat backrest assembly 1', starting from a state where the angle between the first backrest 2 and the second backrest 3 is the second angle or any angle smaller than the second angle, the angle between the first backrest 2 and the second backrest 3 can also be freely decreased, which will not be elaborated here.

[0116] It should be understood that the specific positions of the first backrest 2 and the second backrest 3 described for the various relative positions (i.e., the first relative position, the second relative position, the third relative position, and the fourth relative position) in the first backrest 2 and the second backrest 3 in the seat backrest assembly 1 can also be applied to the first backrest 2 and the second backrest 3 in the seat backrest assembly 1'.

[0117] According to the seat back assembly of the present invention, the locking tongue 11 can be changed from an unfolded state to a folded state as the angle between the first backrest 2 and the second backrest 3 increases. Furthermore, after the locking tongue is changed to the folded state, the angle between the first backrest 2 and the second backrest 3 can be freely increased further, thereby helping to improve the flexibility of vehicle seat adjustment and providing users with a better riding experience.

[0118] It should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit this application. All terms used in this specification, unless otherwise defined, have the meanings commonly understood by those skilled in the art. For the sake of brevity or clarity, well-known functions or structures may not be described in detail.

[0119] Unless otherwise specified, the singular forms “a,” “the,” and “the” used in this specification include the plural forms. The terms “comprising,” “including,” and “containing” used in this specification indicate the presence of the claimed feature but do not exclude the presence of one or more other features. The term “and / or” used in this specification includes any and all combinations of one or more of the relevant listed items.

[0120] In the specification, when an element is described as being "on," "attached," "connected," "coupled," or "in contact" with another element, the element can be directly located on, attached to, connected to, coupled to, or in contact with the other element, or there may be intermediate elements present. Conversely, when an element is described as being "directly" located on, directly attached to, directly connected to, directly coupled to, or directly in contact with another element, no intermediate elements are present. In the specification, the description of a feature being arranged "adjacent" to another feature can mean that a feature has a portion overlapping with the adjacent feature or a portion located above or below the adjacent feature.

[0121] It is understood that although the terms "first," "second," etc., may be used herein to describe different elements, these elements should not be limited by these terms. These terms are merely used to distinguish one element from another. Therefore, a first element may be referred to as a second element without departing from the teachings of this application.

[0122] Finally, it should be noted that the above embodiments are merely for understanding this application and do not constitute a limitation on the scope of protection of this application. Those skilled in the art can make modifications based on the above embodiments, and these modifications will not depart from the scope of protection of this application.

Claims

1. A seat back assembly comprising a first backrest (2) and a second backrest (3), the first backrest and the second backrest being pivotable relative to each other and changing between a first relative position and a third relative position, passing through a second relative position, the seat back assembly further comprising a locking assembly (6) disposed between the first backrest and the second backrest, the locking assembly comprising a latch (11) and a first elastic member, the latch (11) being disposed on one of the first backrest and the second backrest and being changeable between an extended state and a retracted state, wherein when the latch is in the extended state, the first backrest and the second backrest can be locked together by the locking assembly, and when the latch is in the retracted state, the first backrest and the second backrest cannot be locked together by the locking assembly, the first elastic member applying a force to the latch to change it toward the retracted state, characterized in that, In the first relative position, the first backrest and the second backrest are locked together by a locking assembly, wherein the latch is in the extended state; In the second relative position, the first backrest is located behind the second backrest, and a first angle is formed between the first backrest and the second backrest, wherein the latch moves to a folded state; In the third relative position, the first backrest is located behind the second backrest, and a second angle greater than the first angle is formed between the first backrest and the second backrest; during the process from the second relative position to the third relative position, the latch remains in a folded state; The seat back assembly also includes: A first rotating disk (18) is mounted coaxially with a first backrest and a second backrest, and is configured to rotate relative to the first backrest or the second backrest during changes in a first relative position and a third relative position relative to each other. Cable (15), one end of which is connected to the first rotating disk and can be wound and unwound on the first rotating disk, and the other end of which is connected to the latch and can drive the latch from a folded state to an unfolded state; A limiting mechanism cooperating with the first rotating disk, the limiting mechanism and the first rotating disk being configured such that: when the first backrest and the second backrest are between a first relative position and a second relative position, the first rotating disk applies a force along a first direction to the limiting mechanism; when the first backrest and the second backrest are between a second relative position and a third relative position, the latch remains in a retracted state, and the first rotating disk does not apply the force along the first direction to the limiting mechanism, wherein the first direction corresponds to the direction in which the first rotating disk rotates forward, and the force along the first direction is at least partially provided by a first elastic member.

2. The seat back assembly according to claim 1, characterized in that, The lock assembly includes The latch stop prevents the latch from moving further after it has moved from the extended state to the retracted state, thus restricting it to the retracted state.

3. The seat back assembly according to claim 2, characterized in that, The lock assembly includes a housing (13) which includes the bolt stop, and the first elastic member is configured to be connected to the housing and the bolt respectively.

4. The seat back assembly according to claim 1, characterized in that, The second backrest (3) is connected to the pivot nut (5) on the first backrest (2) by bolts (4), so that the first backrest and the second backrest can be pivotally connected to each other, and the first rotating disk (18) is rotatably mounted on the pivot nut between the first backrest and the second backrest.

5. The seat back assembly according to claim 1, characterized in that, The limiting mechanism is configured to be a second rotating disk (25) coaxially mounted with the first rotating disk, and the first rotating disk can overcome the force applied to the first rotating disk by the first elastic member by abutting against the second rotating disk.

6. The seat back assembly according to claim 1, characterized in that, The limiting mechanism is constructed as a protrusion (23) fixedly connected to the other of the first backrest and the second backrest, and the first rotating disk can overcome the force applied to the first rotating disk by the first elastic member by abutting against the protrusion.

7. The seat back assembly according to claim 1, characterized in that, The first backrest and the second backrest pivot relative to each other between the first and second relative positions, passing through a fourth relative position in which the latch is still extended, the first backrest is located behind the second backrest, and a third angle smaller than the first angle is formed between the first and second backrests.

8. The seat back assembly according to claim 7, characterized in that, The seat back assembly includes a compensation device configured such that the latch remains deployed when the first backrest and the second backrest are in a first relative position and a fourth relative position.

9. The seat back assembly according to claim 5, characterized in that, The first backrest and the second backrest pivot relative to each other between the first and second relative positions and pass through a fourth relative position, in which the latch is still in the extended state, the first backrest is located behind the second backrest, and a third angle smaller than the first angle is formed between the first backrest and the second backrest. The seat back assembly includes a compensation device configured such that the latch remains in an extended state when the first backrest and the second backrest are in a first relative position and a fourth relative position. The compensation device includes a positioning part (28) disposed on the second rotating disk, a slide groove (26) disposed on the other of the first backrest and the second backrest, and a second elastic member, the second elastic member applying an elastic force toward the end (29) of the slide groove to the positioning part. As the first backrest and the second backrest change between a first relative position and a fourth relative position, the positioning part can correspondingly change between a position spaced apart from the end of the slide groove and a position contacting the end of the slide groove relative to the slide groove, and keep the cable in a position that allows the latch to unfold.

10. The seat back assembly according to claim 9, characterized in that, The second elastic member is configured as a coil spring (27), one end of which is connected to the other of the first backrest and the second backrest, and the other end is connected to the positioning part.

11. The seat back assembly according to claim 6, characterized in that, The first backrest and the second backrest pivot relative to each other between the first and second relative positions and pass through a fourth relative position, in which the latch is still in the extended state, the first backrest is located behind the second backrest, and a third angle smaller than the first angle is formed between the first backrest and the second backrest. The seat back assembly includes a compensation device configured such that the latch remains in an extended state when the first backrest and the second backrest are in a first relative position and a fourth relative position. The compensation device includes an elastic compensator (24) connected to the cable. One end of the elastic compensator is connected to the upper half of the cable, and the other end of the elastic compensator is connected to the lower half of the cable. When the first backrest and the second backrest are in a first relative position, the elastic compensator is compressed. As the first backrest and the second backrest change from the first relative position to a fourth relative position, the elastic potential energy of the elastic compensator is gradually released, and the cable is maintained in a position that allows the latch to unfold.

12. The seat back assembly according to any one of claims 1 to 11, characterized in that, The second relative position includes: relative to the first relative position, the first backrest remains stationary, and the second backrest is flipped forward to a position at a first angle relative to the first backrest; relative to the first relative position, the second backrest remains stationary, and the first backrest is flipped backward to a position at a first angle relative to the second backrest; or the second backrest is in a forward-flattened position, and the first backrest is flipped forward to a position at a first angle relative to the second backrest.

13. The seat back assembly according to any one of claims 1 to 11, characterized in that, The third relative position includes: relative to the first relative position, the first backrest remains stationary and the second backrest is in a forward-folded-flat position; relative to the first relative position, the second backrest remains stationary and the first backrest is in a backward-folded-flat position; or the second backrest is in a forward-folded-flat position and the first backrest is in a backward-folded-flat position.

14. The seat back assembly according to any one of claims 1 to 11, characterized in that, The first backrest is configured as an armrest frame backrest, and the second backrest is configured as a side seat backrest adjacent to the armrest frame backrest.

Images