A type of seat

Abstract

This utility model discloses a seat, including a support frame, on which a backrest is rotatably mounted. The backrest rotates around a left-right axis, and its upper end can move in the front-back direction. The seat has two states: folding and tilting. In the folding state, the backrest can switch between a roughly vertical upright posture and a roughly horizontal forward-folding posture. In the tilting state, it can switch between an upright posture and a backward-tilting posture. The seat backrest has a greater range of rotation than existing folding seats, and can simultaneously achieve folding and tilting functions. Moreover, the backrest is directly connected to the support frame, and its rotation does not rely on a seat tray, greatly simplifying the tray structure, reducing production costs, and improving assembly efficiency.

Description

Technical Field

[0001] This utility model relates to the field of furniture, and in particular to a chair. Background Technology

[0002] In everyday use, people's needs for chairs are becoming more and more diverse. Sometimes they want chairs to be foldable for easy storage or transport, such as when space is limited at home, folding can save space, or when they need to take the chair outdoors, foldable chairs are more portable. But sometimes they want chairs to be reclined so they can relax their bodies when sitting for a long time, such as when working or resting, as the reclining function can improve the comfort of the chair.

[0003] However, most chairs on the market today cannot meet both of these needs at the same time; many chairs are fixed and cannot be folded, which not only makes them difficult to move and store, but also makes it difficult to reduce packaging and transportation costs; the few chairs that can be folded do not have a reclining function, so you can only maintain an upright posture when sitting, which can easily lead to fatigue after sitting for a long time.

[0004] There are also a very few seats that can be folded and reclined. The way they achieve the reclining function is also complicated. They are usually like traditional seats, relying on a tray structure at the bottom of the seat to achieve this, and the reclining of the backrest is controlled by a mechanical structure in the tray. However, the tray itself makes the structure of the seat more complicated. With more parts, not only is production and assembly more troublesome, but the cost is also higher.

[0005] Therefore, there is an urgent need for a seat that can be easily folded and can be easily tilted. Summary of the Invention

[0006] To address the aforementioned technical problems, this utility model provides a seat, including a support frame with a rotatable backrest. The backrest rotates around a left-right axis, and its upper end can move in the front-back direction. The seat has two states: folded and tilted. In the folded state, the backrest can switch between a roughly vertical upright posture and a roughly horizontal forward-folding posture. In the tilted state, it can switch between an upright posture and a backward-tilting posture. The seat backrest has a greater range of rotation than existing folding seats, and can simultaneously achieve folding and tilting functions. Furthermore, the backrest is directly connected to the support frame, and its rotation does not rely on a seat tray, greatly simplifying the tray structure, reducing production costs, and improving assembly efficiency.

[0007] The technical solution of this utility model is implemented as follows: A seat includes a frame with a backrest rotatably mounted on the frame. The backrest rotates about a left-right axis, allowing its upper end to rotate in the front-back direction. The seat has a folded-down state and a reclining state. In the folded-down state, the backrest can switch between an upright posture and a forward-folding posture. In the reclining state, the backrest can switch between an upright posture and a backward-tilting posture. The backrest remains approximately vertical in the upright posture. When the backrest switches from the upright posture to the forward-folding posture, the upper end of the backrest rotates forward until the backrest is approximately horizontal. When the backrest switches from the upright posture to the backward-tilting posture, the upper end of the backrest rotates backward.

[0008] Compared to existing folding chairs, the chair back has a greater range of rotation on the support, allowing it to fold and unfold between upright and forward-folding postures, as well as tilt between upright and backward-tilting postures. This enables simultaneous folding and tilting functions. Furthermore, the chair back is directly connected to the support, so the rotation of the chair back is only related to the support and is no longer related to the seat tray. This greatly simplifies the tray structure, reduces production costs, and increases assembly efficiency.

[0009] Preferably, the support has a rotating base, and the chair back has a rotating part, which is rotatably mounted on the rotating base and rotates about an axis in the left-right direction.

[0010] Preferably, the rotating part is located in the middle or below the middle of the chair back.

[0011] Preferably, the rotating part is located near the lower end of the chair back. This design effectively prevents interference between the lower end of the chair back and the seat when the chair back rotates.

[0012] Preferably, a state-switching structure is provided between the rotating part and the rotating seat. This structure includes a shift block, a first shift slot, and a second shift slot. The shift block is located on one of the rotating part or the rotating seat, while the first and second shift slots are located on the other. When the seat is in a folded-down state and the backrest rotates, the shift block moves in the first shift slot. When the seat is in a reclining state and the backrest rotates, the shift block moves in the second shift slot. When the seat switches from a folded-down state to a reclining state, the shift block moves from the first shift slot into the second shift slot. This state-switching structure achieves the switching between the folded-down and reclining states of the seat. Specifically, it only requires a shift block to switch between two shift slots with different structures, resulting in a simple and ingenious structure.

[0013] Preferably, the first and second position slots are spaced apart circumferentially. This is mainly to prevent the seat from automatically switching from a reclining state to a folding state during normal use, that is, to prevent the seat back from turning into a forward-folding posture for folding during normal use.

[0014] Preferably, the first gear slot has a forward-folding section and a rotating section, with the rotating section closer to the second gear slot than the forward-folding section, and the bottom surface of the forward-folding section is flat. From the forward-folding section to the second gear slot, the rotating section has an inclined surface whose depth gradually decreases. When the gear block is in the first gear slot, the chair back cannot continue to rotate forward towards the seat. However, the chair back can rotate backward and upward via the rotating section, while the inclined surface lifts the gear block, allowing it to automatically disengage from the first gear slot and enter the second gear slot. In other words, the chair back can directly flip from a forward-folding position to an upright position without the need for unlocking via a switch or other mechanism, maintaining a simple structure while simplifying operation.

[0015] Preferably, the bottom surface of the second gear slot is flat, and the gear block is slidably disposed relative to the rotating part and the rotating seat, and the gear block slides away from the second gear slot. When the gear block enters the first gear slot from the second gear slot, after the gear block slides away from the second gear slot, the chair back rotates forward to align the gear block with the first gear slot, and finally the gear block slides back into the first gear slot.

[0016] Preferably, the lengths of both the first and second gear slots are greater than the length of the gear block. This allows the gear block to move within both the first and second gear slots, thereby ensuring the smooth transition of the chair back from a forward-leaning to an upright position, as well as the transition between an upright and a reclining position.

[0017] Preferably, the chair back rotates around the same axis in both the folded and reclining positions. This ensures structural uniformity and simplicity, with the chair back movement achieved solely through the same set of structures and the same axis.

[0018] Preferably, the chair also includes a seat, with the backrest located above the seat. When the backrest is folded forward, it lies roughly horizontally on top of the seat, thus achieving the folding function of the chair.

[0019] Preferably, the lower end of the bracket is connected to the lower surface of the seat, and the bracket extends upward to the side of the backrest; a tray is also connected to the bottom of the seat, and the backrest is only connected to the bracket, with the connection point between the backrest and the bracket located above the seat.

[0020] Preferably, there are two supports, which are arranged side to side; the supports include an arm support at the upper end, which is arranged horizontally, and the supports are configured as the armrests of the seat.

[0021] Preferably, an elastic element is provided between the chair back and the support frame. One end of the elastic element is stationary relative to the support frame, and the other end is connected to the chair back. The elastic element is configured to provide a spring force for the chair back to flip forward. When the chair back switches from an upright position to a forward-flipping position, the elastic element provides an auxiliary flipping spring force for the chair back; when the chair back switches from an upright position to a reclining position, it provides a tilting spring force for the chair back; and when the chair back switches from a reclining position back to an upright position, it provides a restoring spring force for the chair back. The elastic element can be directly fixed to the support frame or indirectly stationary relative to the support frame by being fixed to other locations.

[0022] Preferably, the elastic element has a first acting arm and a second acting arm. A first receiving groove is provided on the bracket, and a second receiving groove is provided on the backrest. The first acting arm is disposed in the first receiving groove, and the second acting arm is disposed in the second receiving groove. The elastic element has an initial state with no elastic force output and an active state with elastic force. When the backrest is in a forward-folding posture, the elastic element is in the initial state. When the backrest switches from a forward-folding posture to an upright posture, the second receiving groove rotates relative to the first receiving groove, and the second acting arm rotates relative to the first acting arm, causing the elastic element to deform and enter the active state. In this seat, the elastic element does not require pre-tightening installation, reducing the assembly difficulty of the seat and improving assembly efficiency.

[0023] Preferably, the elastic element is a torsion spring or a coil spring.

[0024] The design starting point, concept, and beneficial effects of this utility model, which adopts the above technical solution, are as follows: Compared to existing folding chairs, the chair back has a greater range of rotation on the support, allowing it to fold and unfold between upright and forward-folding postures, as well as tilt between upright and backward-tilting postures. This enables simultaneous folding and tilting functions. Furthermore, the chair back is directly connected to the support, so the rotation of the chair back is only related to the support and is no longer related to the seat tray. This greatly simplifies the tray structure, reduces production costs, and increases assembly efficiency. Attached Figure Description

[0025] Figure 1 This is a three-dimensional structural diagram of the seat with the backrest in an upright position in an embodiment of the present invention; Figure 2 This is a schematic diagram of the three-dimensional structure of the seat in the embodiment of the present invention with the backrest in a forward-folding posture. Figure 1 ; Figure 3 This is a schematic diagram of the three-dimensional structure of the seat in the embodiment of the present invention with the backrest in a forward-folding posture. Figure 2 ; Figure 4 This is a three-dimensional structural diagram of the seat with the backrest in a reclining posture in an embodiment of the present invention. Figure 5 This is a schematic diagram illustrating the movement of the seat in a folded and tilted state in an embodiment of the present invention. Figure 6 The explosion of the flipping structure in the embodiment of this utility model Figure 1 ; Figure 7 The explosion of the flipping structure in the embodiment of this utility model Figure 2 ; Figure 8 This is a cross-sectional view of the flip-up structure in the seat in an embodiment of the present invention; Figure 9 This is a schematic diagram showing that, in an embodiment of the present invention, the two working arms of the elastic member of the chair back are in the two receiving grooves when the chair back is in the forward-folding posture. When the chair back is in the forward-folding posture, the connection between the chair back and the support does not require pre-tightening of the elastic member. Figure 10 This is a schematic diagram showing the position of the second action arm in the second receiving groove when the chair back is in a forward-folding posture in an embodiment of the present invention. Figure 11 This is a schematic diagram of the second action arm contacting the wall of the second receiving groove when the chair back is flipped in an embodiment of the present invention. Figure 12 This is a schematic diagram showing the location of the second action arm and the second receiving groove of the chair back in a backward tilted posture in an embodiment of the present invention. Figure 13 This is a schematic diagram showing the location of the second action arm and the second receiving groove of the chair back in an upright posture in an embodiment of the present invention. Figure 14 This is a three-dimensional structural diagram of the sliding member in an embodiment of the present invention; Figure 15 This is an exploded view of the sliding member in an embodiment of the present invention; Figure 16 This is a three-dimensional structural diagram of the two supports in the embodiment of this utility model; Figure 17 This is a schematic diagram of the first and second gear slots on the rotating part in an embodiment of the present invention; Figure 18 This is a three-dimensional structural diagram of the chair back in an embodiment of the present invention.

[0026] The reference numerals in the attached drawings are as follows: Rotating seat 1; Rotating part 2; Sliding part 3; First connecting part 31; Conical hole 311; Mounting groove 312; Second connecting part 32; Conical column 321; Mounting block 322; Rotation limiting block 33; Gear block 4; First gear groove 5; Forward tilt section 51; Rotating section 52; Inclined surface 53; Second gear groove 6; Button 7; First receiving groove 8; Return spring 9; Ring seat 10; Second receiving groove 11; Shaft hole 12; Rotation limiting groove 13; Screw 14; Bracket 21; Arm support part 211; Backrest 22; Seat 23; Tray 24; Support base 25; Lifting gas spring 251; Support foot 252; Mounting column 26; Elastic element 27; First actuating arm 271; Second actuating arm 272; First receiving groove 28; Second receiving groove 29; Roller 30. Detailed Implementation

[0027] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0028] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0029] In the description of this utility model, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] The specific embodiments of this utility model are as follows: like Figure 6-8 As shown, this utility model provides a flipping structure, including a base, a moving part rotatably connected to the base, and a sliding part 3 between the base and the moving part. The sliding part 3 is slidably disposed relative to both the base and the moving part. The sliding part 3 is circumferentially fixed to the base, and the moving part rotates relative to both the sliding part 3 and the base, making the base, which is circumferentially fixed to the sliding part 3, a relatively stationary part, and the moving part, which rotates relative to the sliding part 3, a relatively rotating part. A state switching structure is provided between the sliding part 3 and the moving part. The state switching structure includes a gear block 4 and a first gear groove 5 and a second gear groove 6 arranged at intervals. The gear block 4 is disposed on the sliding part 3, and the first and second gear grooves are disposed on the moving part, which is a relatively rotating part. The sliding direction of the sliding part 3 is the same as the groove depth direction of the gear groove. When the sliding part 3 slides, the sliding block leaves or enters the gear groove. When the gear block 4 leaves the gear groove, the relative movement between the moving part and the base is unlocked.

[0031] This flip-up structure is used in a type of seat, such as Figure 1-5 As shown, the seat includes a bracket 21, a backrest 22, a seat 23, a tray 24, and a support base 25. The tray 24 is disposed on the lower surface of the seat 23, and the support base 25 is connected to the tray 24 and located below the tray 24. There are two brackets 21, which are spaced apart from each other on the left and right sides. The lower end of the bracket 21 is connected to the lower surface of the seat 23 and extends upward to the side of the backrest 22. Unlike traditional seats, in this embodiment, the backrest 22 is only connected to the bracket 21, and the connection point of the backrest 22 is located above the seat 23, and does not have a direct connection with the tray 24. The bracket 21 is the same as... It also serves as the armrest of the seat. The support 21 includes an arm support 211 at its upper end, which is arranged horizontally. The support 21 below the arm support 211 is an L-shaped vertical strip. A rotating seat 1 is provided in the middle of the support 21. The backrest 22 has a forward-protruding rotating part 2 at its lower end. There are two rotating parts 2 corresponding to the support 21. The two rotating parts 2 are located at the left and right ends of the backrest 22, respectively. The rotating parts 2 are rotatably connected to the rotating seat 1 and rotate around the axis in the left and right direction. The sliding member 3 is slidably disposed on the rotating parts 2 and the rotating seat 1 and can be used to unlock the rotation of the backrest 22.

[0032] Specifically, the flip structure has two unlocking methods: active unlocking and passive unlocking. Active unlocking is achieved by the user controlling the sliding member 3 to slide, while passive unlocking is achieved by the user rotating the backrest 22 to drive the sliding member 3 to slide. Passive unlocking can only be achieved when the backrest 22 rotates in one direction. If the backrest 22 rotates in the other direction, the backrest 22 is still locked by the stop block 4 and the stop groove.

[0033] The active unlocking implementation structure is as follows: like Figure 6-8 As shown in Figures 14 and 15, the slider 3 includes a button 7 located at the end of the slider 3. The button 7 is exposed on the rotating seat 1, which is a relatively stationary component. The button 7 is configured for the user to press to actively control the slider 3 to slide. The button 7 is a disc-shaped end cap. The rotating seat 1 is provided with a first receiving groove 8 corresponding to the button 7, which can accommodate the button 7. When the slider 3 slides, the button 7 will enter or leave the first receiving groove 8. A return spring 9 is provided between the button 7 and the rotating seat 1. The return spring 9 is located in the first receiving groove 8, and its two ends abut against the end faces of the button 7 and the first receiving groove 8, respectively. The return spring 9 is configured to provide a spring force to the button 7, and this spring force causes the gear block 4 to tend to move toward the gear groove. That is, when the user presses the button 7, the slider 3 slides and causes the gear block 4 to leave the gear groove. When the user releases the button 7, under the action of the return spring 9, the slider 3 slides in the direction that the gear block 4 moves toward the gear groove.

[0034] The passive unlocking implementation structure is as follows: like Figure 6-8As shown in Figures 14-18, a ring seat 10 is provided on the slider 3 located at the other end of the button 7. The gear block 4 is disposed on the ring seat 10, which is also a disc-shaped end cap. The rotating part 2 is provided with a second receiving groove 11 that can accommodate the ring seat 10. The first gear groove 5 and the second gear groove 6 are both opened in the second receiving groove 11. The first gear groove 5 and the second gear groove 6 are arranged at intervals along the rotation direction of the chair back 22, that is, at intervals along the circumferential direction. Both the first gear groove 5 and the second gear groove 6 have It has an arc shape; the first gear slot 5 has a forward-flipping section 51 and a rotating section 52, the rotating section 52 is closer to the second gear slot 6 than the forward-flipping section 51; the bottom surface of the forward-flipping section 51 is flat, the rotating section 52 has the above-mentioned passive unlocking structure, and in the direction from the forward-flipping section 51 to the second gear slot 6, the rotating section 52 has an inclined surface 53 whose groove depth gradually becomes shallower; the passive unlocking structure is configured such that when the gear block 4 moves on the passive unlocking structure, it drives the sliding member 3 to slide, and can make the gear block 4 leave the first gear slot 5.

[0035] The active and passive unlocking mechanisms work together to provide different states for the movement of the seat back 22. When the shift block 4 moves from the first shift slot 5 to the second shift slot 6, passive unlocking is sufficient without pressing the button 7. When the shift block 4 moves from the second shift slot 6 to the first shift slot 5, active unlocking is required. This allows the seat to have a folding and reclining state. Specifically: The backrest 22 is rotatably mounted on the bracket 21 around a left-right axis, allowing the upper end of the backrest 22 to rotate in the front-back direction. In the folded state, the backrest 22 can switch between an upright posture and a forward-folding posture; in the reclining state, the backrest 22 can switch between an upright posture and a backward-tilting posture. The backrest 22 remains approximately vertical in the upright posture. When switching from an upright posture to a forward-folding posture, the upper end of the backrest 22 rotates forward until the backrest 22 is approximately horizontal; when switching from an upright posture to a backward-tilting posture, the upper end of the backrest 22 rotates backward. In other words, in the folded state, the seat's folding function is achieved, with the backrest 22 positioned above the seat 23, and the backrest 22 approximately horizontal in the forward-folding posture. The chair is laid flat on top of the seat 23, thus folding the backrest 22 and the seat 23. In the reclining state, the backrest 22 can tilt backward as the user leans back, achieving the tilting function of the backrest 22. The tilting and folding functions are achieved through the same structure. Moreover, the backrest 22 rotates around the same axis in both the folded and reclining states. When the seat is in the folded state and the backrest 22 is rotating, the shift block 4 moves in the first shift groove 5. When the seat is in the reclining state and the backrest 22 is rotating, the shift block 4 moves in the second shift groove 6. When the seat switches from the folded state to the reclining state, the shift block 4 moves from the first shift groove 5 into the second shift groove 6, and vice versa.

[0036] When the shift block 4 is located in the forward-folding section 51 of the first shift slot 5, the backrest 22 is in a forward-folding posture. When the backrest 22 rotates from the forward-folding posture to the upright posture in the flipped state, the shift block 4 slides from the inclined surface 53 until it enters the second shift slot 6. The lengths of both the first shift slot 5 and the second shift slot 6 are greater than the length of the shift block 4, so that when the shift block 4 is in the first shift slot 5, the backrest 22 can be flipped to the upright posture directly without unlocking. When the shift block 4 is in the second shift slot 6, the backrest 22 can also rotate back and forth to tilt the backrest 22.

[0037] The bottom surface of the second gear slot 6 is a plane. The first and last positions of the path of the second gear slot 6 can restrict the gear block 4 from leaving the second gear slot 6. Therefore, it is necessary to press the button 7 to make the slider 3 slide left and right to drive the gear block 4 away from the second gear slot 6. Then, by rotating the chair back 22 forward, the gear block 4 is aligned with the first gear slot 5. Finally, the gear block 4 is released to slide into the first gear slot 5.

[0038] In addition, the support base 25 includes a lifting gas spring 251 and a support foot 252. When the chair back 22 is in the forward-folding position, since the rotating seat 1 is located in the middle of the bracket 21 and is higher than the seat 23, there is a gap between the chair back 22 and the seat 23. At this time, the support base 25 can be removed, and the lifting gas spring 251 and the support foot 252 can be separated. This gap allows the support foot 252 to be placed in it. Since the support foot 252 is generally a five-star foot, the support foot 252 can be placed on the seat 23. The rollers 30 under the support foot 252 are located around the seat 23. This is the packaging and transportation state of the chair. When the consumer receives the chair in this state, he / she only needs to connect the tray 24 and the support foot 252 with the lifting gas spring 251, and then flip the chair back 22 backward and upward to an upright position before use.

[0039] Furthermore, such as Figure 9-13As shown, the side connecting the rotating seat 1 and the rotating part 2 is called the inner side of the rotating seat 1 and the rotating part 2, while the side farther away from the rotating seat 1 and the rotating part 2 is called the outer side of the rotating seat 1 and the rotating part 2. The sliding member 3 passes through the rotating seat 1 and the rotating part 2, and the two ends of the sliding member 3 in the axial direction are exposed on the outer sides of the rotating seat 1 and the rotating part 2, respectively. That is, the button 7 and the ring seat 10 are located on the outer sides of the rotating seat 1 and the rotating part 2, respectively. The first receiving groove 8 is provided on the outer side of the rotating seat 1, and the second receiving groove 11 is provided on the outer side of the rotating part 2. A mounting post 26 protrudes from the inner side of the rotating part 2, and an elastic member 2 is provided on the mounting post 26. 7. The elastic element 27 is a torsion spring or a coil spring. In this embodiment, the elastic element 27 is a torsion spring. One end of the elastic element 27 is stationary relative to the rotating seat 1 of the bracket 21, and the other end of the elastic element 27 is connected to the rotating part 2 of the backrest 22. The elastic element 27 is configured to provide a spring force for the backrest 22 to flip forward. When the backrest 22 switches from an upright state to a forward-flipping state, the elastic element 27 provides an auxiliary flipping spring force for the backrest 22. When the backrest 22 switches from an upright state to a reclining state, the elastic element 27 provides a tilting spring force for the backrest 22. When the backrest 22 switches from a reclining state back to an upright state, the elastic element 27 provides a restoring spring force for the backrest 22.

[0040] The elastic element 27 is fixed to the bracket 21 either directly or indirectly by being fixed to other locations so that it remains relatively stationary relative to the bracket 21. Specifically, the elastic element 27 has a first actuating arm 271 and a second actuating arm 272. The inner side of the rotating seat 1 is provided with a first receiving groove 28, and the inner side of the rotating part 2 is provided with a second receiving groove 29. The first actuating arm 271 is disposed in the first receiving groove 28, and the second actuating arm 272 is disposed in the second receiving groove 29. The size of the first receiving groove 28 corresponds to the diameter of the first actuating arm 271, so that the first actuating arm 271 remains relatively stationary when the chair back 22 rotates. The elastic element 27 has an initial state with no elastic force output and an active state with elastic force. When the chair back 22 is in a forward-folding posture, the elastic element 27 is in the initial state. When the chair back 22 switches from the forward-folding posture to the upright posture, the second receiving groove 29 rotates relative to the first receiving groove 28, and the second actuating arm 272 rotates relative to the first actuating arm 271, causing the elastic element 27 to deform and enter the active state.

[0041] The second receiving groove 29 is larger than the diameter of the second actuating arm 272, and the second receiving groove 29 is fan-shaped. When the backrest 22 is in a forward-folding position, the first actuating arm 271 and the second actuating arm 272 directly enter the first receiving groove 28 and the second receiving groove 29, with the second actuating arm 272 located at the rear of the second receiving groove 29. This eliminates the need for pre-tightening the elastic element 27 during installation, greatly reducing assembly difficulty. When the backrest 22 rotates backward from the forward-folding position, the second actuating arm 272 moves to the front of the second receiving groove 29 until it intersects with the second receiving groove 29. The front end of the second receiving groove 29 abuts against the backrest 22, which continues to rotate, causing the second action arm 272 to rotate relative to the first action arm 271, thereby pre-tightening the elastic element 27. In other words, after the consumer completes the installation of the support base 25, the elastic element 27 is pre-tightened while flipping the backrest 22, thus ensuring that the elastic element 27 can always provide tilting elasticity when the seat is tilted. The gap at the front of the second receiving groove 29 can prevent the elastic element 27 from giving too much elasticity when flipping the backrest 22, which would increase the difficulty of flipping the backrest 22.

[0042] Furthermore, both the rotating base 1 and the rotating part 2 are provided with shaft holes 12, and the sliding member 3 is slidably disposed in the shaft hole 12. The diameters of the ring seat 10 and the button 7 are both larger than the shaft holes 12 on the rotating base 1 and the rotating part 2. Since the diameters of the ring seat 10 and the button 7 are both larger than the shaft holes 12, the sliding member 3 is made by splicing rather than being integrally formed. The sliding member 3 includes a first connecting member 31 and a second connecting member 32. The first connecting member 31 and the second connecting member 32 are inserted into each other along the sliding direction of the sliding member 3 and fixed by screws 14. The button 7 is disposed on the first connecting member 31, and the stop block 4 is disposed on the second connecting member 31. 2. The sliding member 3 is circumferentially fixed to the rotating seat 1 by means of a radially protruding limiting block 33 on the sliding member 3, and a limiting groove 13 is opened in the shaft hole 12 of the rotating seat 1, and the limiting block 33 is slidably disposed in the limiting groove 13; the end of the second connecting member 32 near the first connecting member 31 has a tapered column 321, and two mounting blocks 322 are protruding on both sides of the tapered column 321. The first connecting member 31 is provided with a tapered hole 311 corresponding to the tapered column 321, and two mounting grooves 312 are opened corresponding to the two mounting blocks 322, so as to facilitate the connection between the first connecting member 31 and the second connecting member 32.

[0043] Two sets of gear blocks 4 and gear slots are provided between the sliding member 3 and the rotating part 2 to increase the stability of the gear blocks 4 and gear slots.

[0044] The rotating part 2 can also be located in the middle or lower part of the backrest 22. In this embodiment, the rotating part 2 is located at the lower end of the backrest 22 to ensure that the backrest 22 will not interfere with the seat 23 when it rotates.

Claims

1. A seat, characterized by: The chair includes a support frame, on which a backrest is rotatably mounted. The backrest rotates about a left-right axis, allowing the upper end of the backrest to rotate in the front-back direction. The chair has a folded-down state and a reclining state. In the folded-down state, the backrest can switch between an upright posture and a forward-folding posture. In the reclining state, the backrest can switch between an upright posture and a backward-tilting posture. The backrest remains approximately vertical in the upright posture. When the backrest switches from the upright posture to the forward-folding posture, the upper end of the backrest rotates forward until the backrest is approximately horizontal. When the backrest switches from the upright posture to the backward-tilting posture, the upper end of the backrest rotates backward.

2. The seat of claim 1, wherein: The frame has a rotating base, and the chair back has a rotating part. The rotating part is rotatably mounted on the rotating base and rotates around an axis in the left-right direction.

3. The seat of claim 2, wherein: The rotating part is located in the middle or below the middle of the chair back.

4. The seat of claim 2, wherein: The rotating part is located near the lower end of the chair back.

5. The seat of claim 2, wherein: A state switching structure is provided between the rotating part and the rotating seat. The state switching structure includes a gear block, a first gear slot, and a second gear slot. The gear block is disposed on one of the rotating part or the rotating seat, and the first and second gear slots are disposed on the other of the rotating part or the rotating seat. When the seat is in the folded state and the backrest is rotating, the gear block moves in the first gear slot. When the seat is in the reclining state and the backrest is rotating, the gear block moves in the second gear slot. When the seat switches from the folded state to the reclining state, the gear block moves from the first gear slot into the second gear slot.

6. The seat of claim 5, wherein: The first gear slot and the second gear slot are distributed circumferentially.

7. The seat of claim 6, wherein: The first gear slot has a forward tilting section and a rotating section. The rotating section is closer to the second gear slot than the forward tilting section, and the bottom surface of the forward tilting section is a plane. From the forward tilting section to the second gear slot, the rotating section has an inclined surface with a gradually shallower groove depth.

8. The seat of claim 7, wherein: The bottom surface of the second gear slot is a plane. The gear block is slidably positioned relative to the rotating part and the rotating seat, and the gear block moves away from the second gear slot by sliding.

9. The seat of claim 5, wherein: The lengths of both the first and second gear slots are greater than the length of the gear block.

10. The seat of claim 1, wherein: When the seat is folded down or reclined, the backrest rotates around the same axis.

11. The seat of claim 1, wherein: It also includes a seat, with the backrest located above the seat. When the backrest is tilted forward, it lies roughly horizontally above the seat.

12. The seat of claim 11, wherein: The lower end of the bracket is connected to the lower surface of the seat, and the bracket extends upward to the side of the backrest; a tray is also connected to the bottom of the seat, and the backrest is only connected to the bracket, with the connection point between the backrest and the bracket located above the seat.

13. The seat of claim 1, wherein: There are two supports, which are arranged alternately on the left and right sides; the supports include an arm support at the upper end, which is arranged horizontally, and the supports are configured as the armrests of the seat.

14. The seat of claim 1, wherein: An elastic element is also provided between the chair back and the support frame. One end of the elastic element is stationary relative to the support frame, and the other end of the elastic element is connected to the chair back. The elastic element is configured to provide a spring force for the chair back to flip forward.

15. The seat of claim 14, wherein: The elastic element has a first working arm and a second working arm. The bracket is provided with a first receiving groove, and the chair back is provided with a second receiving groove. The first working arm is disposed in the first receiving groove, and the second working arm is disposed in the second receiving groove. The elastic member has an initial state without elastic force output and an action state with elastic force output; when the chair back is in the forward tilting posture, the elastic member is in the initial state; when the chair back is switched from the forward tilting posture to the upright posture, the second accommodating groove rotates relative to the first accommodating groove, the second action arm rotates relative to the first action arm, and the elastic member is deformed to be in the action state.

16. The seat of claim 15, wherein: The elastic member is a torsion spring or a coil spring.

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