Biform tray and multifunctional seat

Abstract

The double-form tray comprises an upper tray body and a lower tray body which are vertically spliced, the upper tray body is configured to be connected with a chair seat assembly, the lower tray body is configured to be connected with a chair back assembly, a first hinge part is arranged at the front end of the upper tray body, a second hinge part is arranged at the front end of the lower tray body, and the first hinge part is hinged to the second hinge part; the first hinge part is provided with a first locking hole in a hollowed-out mode in the left-right direction, and the second hinge part is provided with a second locking hole in a hollowed-out mode in the left-right direction. The double-form tray further comprises a locking mechanism, and the locking mechanism comprises a clamping pin connected to the first locking hole and the second locking hole in a sliding mode. The biform tray has a locking state and an unlocking state, in the locking state, the first locking hole is communicated with the second locking hole, the bayonet lock slides to be clamped in the first locking hole and the second locking hole at the same time, and the upper tray and the lower tray are relatively fixed; and in an unlocking state, the bayonet lock slides to avoid the first locking hole or the second locking hole, and the lower tray can rotate relative to the upper tray again.

Description

Technical Field

[0001] The invention relates to the technical field of seating, and in particular to a dual-form tray and a multifunctional seat. Background Art

[0002] As we all know, office workers need to spend most of their time in office chairs. Sitting for long periods of time can easily cause waist fatigue and even health problems such as lumbar muscle strain. In order to solve the above problems, existing office chairs on the market usually have a pitch adjustment function. The backrest of the office chair can be adjusted backward at a large angle relative to the seat, so that the user can adjust the backrest to lean back until he can lie on the office chair to rest during rest time, thereby effectively relieving fatigue.

[0003] The pitch adjustment of existing office chairs is usually completed with the help of a tray. For example, an adjustment control mechanism for a seat tray provided by an existing patent (application number: CN201721778285.7) includes a fixed plate and a movable plate rotatably connected to the fixed plate. The movable plate is connected to the backrest on the office chair, and the fixed plate is connected to the telescopic member on the office chair, so that the movable plate can drive the backrest to rotate forward and backward. A locking hole is provided on the side wall of the movable plate, and a plurality of locking holes are provided along the rotation trajectory of the movable plate. A locking member is axially slidably connected to the locking hole on the fixed plate. A guide rail for limiting the sliding direction of the locking member is provided on the fixed plate. The guide rail and the fixed plate are axially fixed along the guide rail. A driving mechanism for driving the locking member to leave and insert into the locking hole is provided at the outward end of the locking member. When the backrest is rotated to a suitable tilt angle, the locking member is driven by the driving mechanism to move along its axial direction and inserted into the locking hole, so that the movable plate and the fixed plate are fixed, and then the tilt angle of the backrest is fixed.

[0004] However, as users' demands continue to deepen, current users are not only satisfied with the pitch adjustment of the backrest. For example, there is a seat with a back-tracking function on the market. The backrest of this type of seat can slide forward and backward relative to the seat. While adjusting the seat depth, the backrest can always keep in close contact with the user's back during the adjustment process, making it more portable and comfortable to use.

[0005] If the pitch adjustment function and the back-climbing function are integrated into the tray mechanism, the following problem will arise: when the backrest is moving forward and back-climbing, in order to ensure that the backrest can always keep in close contact with the user's back posture, the backrest cannot change its tilt angle, that is, when using the back-climbing function, the moving plate and the fixed plate need to be relatively fixed to lock the pitch adjustment function. Therefore, how to make the tray have multiple switchable forms and switch the functions of the seat has become the main problem that needs to be solved at present. Summary of the invention

[0006] In view of the above-mentioned defects or shortcomings in the prior art, it is desired to provide a dual-form tray and a multifunctional seat, wherein the dual-system tray is composed of an upper tray and a lower tray that are rotatably connected to each other, and has a switchable locked state and unlocked state. In the unlocked state, the lower tray can be rotated downward relative to the upper tray, thereby driving the seat back assembly connected to the lower tray to rotate downward together, thereby realizing the pitch adjustment of the seat back assembly; in the locked state, the lower tray and the upper tray are relatively fixed, so that the seat back assembly can maintain its original posture during the backrest adjustment process and will not pitch and change the inclination angle; thus, by switching the dual-system tray between the locked state and the unlocked state, the function of the seat will also be switched accordingly, and the practicality is good; and, the dual-form tray can be adjusted to switch between the locked state and the unlocked state only by sliding the latch pin so that the latch pin simultaneously engages the first locking hole and the second locking hole or avoids one of the two, and the adjustment operation is relatively simple.

[0007] The effect of the present invention is achieved in this way: In a first aspect, the present application provides a dual-form tray, comprising an upper tray and a lower tray spliced ​​together, the upper tray being configured to connect to a seat assembly, the lower tray being configured to connect to a seat back assembly, a first hinge being provided at a front end of the upper tray, a second hinge being provided at a front end of the lower tray, the first hinge being hinged to the second hinge, so that the lower tray can rotate up and down relative to the upper tray; a first locking hole is hollowed out on an upper edge of the first hinge and arranged in a left-right direction, and a second locking hole is hollowed out on an upper edge of the second hinge; the dual-form tray further comprises a locking mechanism, the locking mechanism comprising a bayonet, the bayonet being slidably connected to the first locking hole and the second locking hole; the dual-form tray has a switchable locking state and an unlocking state, in the locking state, the first locking hole is connected to the second locking hole, the bayonet slides to be simultaneously engaged in the first locking hole and the second locking hole, so that the second hinge cannot rotate relative to the first hinge, and the upper tray and the lower tray are relatively fixed; in the unlocking state, the bayonet slides to avoid the first locking hole or the second locking hole, and the lower tray can rotate relative to the upper tray again.

[0008] Furthermore, the rotation angle of the lower tray relative to the upper tray is 0-20 degrees. The lower tray drives the chair back assembly to pitch, and the lower tray has a large rotation angle, so that when the chair back assembly needs to be pitched, the chair back assembly has a sufficiently large pitch angle to ensure that the user can rest in a comfortable supine position, which is more practical.

[0009] Furthermore, the front end of the lower tray is provided with two second hinged parts that are symmetrical on the left and right sides, and the two second hinged parts are hinged to the left and right sides of the first hinged part, and the second locking holes on the left and right sides are slidably connected with a bayonet. By providing two second hinged parts that are symmetrical on the left and right sides and rotating with the first hinged part, and connecting the two second hinged parts with the first hinged part through the bayonet, the forces on both sides of the first hinged part are balanced, which not only enhances the connection strength between the upper tray and the lower tray, but also makes the rotation process between the lower tray and the upper tray smoother.

[0010] Furthermore, a first elastic reset member is provided between the upper tray and the lower tray, and the two ends of the first elastic reset member act on the upper tray and the lower tray respectively, so that the lower tray always has a tendency to rotate toward the upper tray. When the dual system trays are unlocked, the lower tray will automatically rotate upward under the elastic force of the first elastic reset member, and then when the seat back assembly does not need to be adjusted in pitch, the upper seat back assembly will be driven by the lower tray to reset to a critical state, thereby making the seat adjustment operation more rapid and simple.

[0011] Furthermore, the lower tray includes an extension portion formed by extending backward from the rear end and a pitch adjustment member connected to the extension portion in a front-to-back sliding manner. The pitch adjustment member is configured to connect to the seat back assembly and drive the seat back assembly to rotate forward and backward by sliding the pitch adjustment member forward and backward. Therefore, when the seat back assembly is adjusted in pitch, the seat back assembly can be further tilted backward by sliding the pitch adjustment member, thereby increasing the pitch adjustment range of the seat back assembly, ensuring that the user can lie on the seat in a more comfortable posture, which is more practical.

[0012] Furthermore, a transmission member is connected between the upper tray and the pitch adjustment member, the front end of the transmission member is hinged to the rear end of the upper tray, and the rear end of the transmission member is hinged to the pitch adjustment member; when the pitch adjustment member slides forward relative to the extension portion, the rear end of the transmission member is driven to slide forward and push the lower tray downward, so that the lower tray is driven by the transmission member to rotate downward relative to the upper tray. The upper tray, the lower tray, the pitch adjustment member and the transmission member are combined to form a structure similar to a three-link and one-slot structure, so that the pitch adjustment member and the lower tray can synchronously adjust the pitch angle of the seat back assembly, making the pitch adjustment process of the seat more stable and smooth.

[0013] Furthermore, a positioning piece is fixedly connected to the extension part, and a gear adjustment mechanism is arranged between the pitch adjustment piece and the positioning piece, and the gear adjustment mechanism includes a clamping head and a plurality of clamping slots, the clamping head is arranged in one of the pitch adjustment piece and the positioning piece, and the plurality of clamping slots are arranged in the other of the pitch adjustment piece and the positioning piece; when the pitch adjustment piece slides forward and backward relative to the positioning piece, the clamping head is engaged with the plurality of clamping slots in sequence. The chair back assembly can adjust and fix the pitch angle with the aid of the gear adjustment mechanism, and is more convenient to use.

[0014] Furthermore, the clamping head is movably connected to the positioning member, and a plurality of clamping slots are correspondingly arranged on the pitch adjustment member. The gear adjustment mechanism has a switchable gear fixing state and gear adjustment state. In the gear fixing state, the clamping head slides outward to be clamped in the clamping slot, so that the pitch adjustment member and the positioning member are relatively fixed; in the gear adjustment state, the clamping head slides inward to be retracted into the positioning member and avoids the clamping slot, so that the pitch adjustment member can slide relative to the positioning member again. By movably setting the clamping head on the positioning member and clamping or avoiding the clamping slot by means of the movement of the clamping head, the movement or fixation between the pitch adjustment member and the extension part is achieved, which is convenient for manipulation and makes the gear adjustment operation relatively simple.

[0015] Furthermore, the positioning member is a hollow structure, including an internal cavity, one end of the clamp passes through the side wall of the positioning member and extends into the cavity, a torsion spring is arranged in the cavity, one side arm of the torsion spring is respectively connected to the clamps on both sides, and the other side arm of the torsion spring is connected to the sliding member; the sliding member can slide in the cavity and drive the torsion spring to pull inward or push the clamp outward, thereby driving the gear adjustment mechanism to switch between the gear fixed state and the gear adjustment state. Only by sliding the adjustment sliding member, the torsion spring can be driven to push or pull the clamp, thereby switching the gear adjustment mechanism between the gear fixed state and the gear adjustment state, thereby making the gear adjustment operation of the tray relatively simple.

[0016] Furthermore, the pitch adjustment member is a plate-shaped structure, a first slide groove extending in the front-back direction is hollowed out on the pitch adjustment member, a positioning member is slidably connected to the pitch adjustment member, a connecting portion is protruded on the positioning member, the connecting portion passes through the first slide groove and is connected to the extension portion, so that the pitch adjustment member is clamped between the extension portion and the positioning member, and the pitch adjustment member slides forward and backward relative to the connecting portion through the first slide groove. Not only does this make the connection strength between the pitch adjustment member and the extension portion higher, but it also makes the sliding process of the pitch adjustment member more stable and smooth.

[0017] In a second aspect, the present application also provides a multifunctional chair, including a chair back assembly and a dual-form tray, the chair back assembly including a chair body, a front bracket and a rear bracket, the top end of the front bracket is hinged to the front end of the chair body, the bottom ends of the two front brackets are hinged to the first hinge part or the second hinge part, the top end of the rear bracket is hinged to the rear end of the chair body, and the bottom end of the rear bracket is hinged to the rear end of the lower tray; the automatic locking mechanism also includes a pushing part, which is arranged on the side of the bottom of the front bracket close to the tray; the multifunctional seat has a switchable chasing state, a critical state and a pitching state. In the critical state, the chair body remains upright and is located at a relatively rearward position; when the multifunctional seat enters the chasing state from the critical state, the front bracket swings forward and the top bracket swings forward. The push part rotates and pushes the latch inward, so that the latch slides inward until it is simultaneously engaged with the first locking hole and the second locking hole, and the locking mechanism enters the locked state. The upper tray and the lower tray are relatively fixed, and the rear bracket responds to the front bracket and swings forward synchronously, thereby driving the upper side of the chair body to move forward and push out; when the multifunctional seat enters the pitching state from the critical state, the front bracket swings backward, and the push part rotates to avoid the latch, so that the latch slides outward to disengage from the first locking hole or the second locking hole, and the locking mechanism enters the unlocked state, so that the lower tray can rotate downward relative to the upper tray again, and the chair body responds to the lower tray and swings downward synchronously, and the rear bracket responds to the front bracket and swings backward synchronously, thereby causing the chair body to tilt backward as a whole. The chair body, the front bracket, the rear bracket and the lower tray are hinged to each other to form a parallel four-bar structure, and the structure is stable. By switching the locking state and the unlocking state with the help of the dual-form tray, the switching operation between the critical state, the back-chasing state and the reclining state can be realized, and the adjustment operation is relatively simple; and the adaptive lumbar support state and the self-loaded reclining state do not interfere with each other, so that the stability of the multifunctional seat is better. Moreover, by arranging a pushing portion on the front bracket, the pushing portion performs circular motion as the front bracket rotates and pushes or avoids the latch pin, so that when the multi-function seat switches from a critical state to a reclining state or a tilting state, the dual system tray can automatically switch to a locked state or an unlocked state as the front bracket rotates, thereby effectively improving the convenience of the multi-function seat state switching operation.

[0018] Furthermore, a second elastic reset member is provided in the second locking hole, and the second elastic reset member acts on the bayonet pin, and makes the bayonet pin always have a tendency to move in a direction away from the first hinged portion. When the dual-system seat is directly switched from the critical state to the self-loaded reclining state, the bayonet pin can automatically pop outward with the elastic force of the second elastic reset member, so that the dual-system tray can automatically switch to the unlocked state, and the multifunctional seat can automatically enter the back-catching state, further improving the simplicity of the dual-system seat state switching operation.

[0019] Furthermore, the end surface of the pushing portion close to the bayonet and / or the end surface of the bayonet close to the pushing portion are arranged to be inclined, so that when the front bracket drives the pushing portion to make a circular motion and pushes the bayonet, the bayonet can slide toward the first hinge portion along the inclined direction of the end surface. The structure is simple, and the circular rotation of the pushing portion can be converted into the sliding of the bayonet in the horizontal direction.

[0020] Furthermore, the multifunctional chair also includes a seat, which is configured to support the user to sit; the front bracket includes a seat connecting rod and a chair body connecting rod that are inclined to each other and always remain relatively fixed, the lower ends of the seat connecting rod and the chair body connecting rod intersect and connect at a tray connecting portion, and the front bracket is hinged to the upper tray through the tray connecting portion, so that the front bracket as a whole can rotate synchronously around the tray connecting portion; the upper end of the chair body connecting rod is hinged to the chair body, and the upper end of the seat connecting rod is hinged to the seat, and the seat can slide up and down relative to the upper tray, and drive the seat connecting rod to rotate forward and backward around the tray connecting portion. By linking the seat and the front bracket, in the back-chasing state, the chair body can respond to the seat sinking to achieve automatic back-chasing, and the back-chasing adjustment operation is simpler; in the reclining state, the seat moves up in response to the reclining of the chair body, so that the overall posture of the seat can be closer to the posture of the human body when it is pitching, and the use experience is more comfortable.

[0021] Furthermore, a third elastic reset member is provided between the seat and the upper tray. In the critical state, the third elastic reset member does not apply elastic force to the seat and the upper tray; in the back-climbing state, the third elastic reset member applies a thrust to the seat and the upper tray, so that the seat has a tendency to move away from the upper tray; in the pitching state, the third elastic reset member applies a pulling force to the seat and the upper tray, so that the seat has a tendency to move toward the upper tray. When the user does not need to use the seat or needs to switch the state again, the dual-system seat automatically resets to the initial state with the elastic force of the third elastic reset member, further improving the convenience of the dual-system seat state switching operation.

[0022] The dual-mode tray and multifunctional seat provided by the present application, the dual-system tray is composed of an upper tray and a lower tray connected to each other in rotation, and the dual-mode tray has a switchable locking state and unlocking state. When the seat needs to pitch and adjust the seat back assembly, the dual-mode tray is switched to the unlocking state, so that the lower tray can rotate downward relative to the upper tray, thereby driving the seat back assembly connected to the lower tray to rotate downward together; when the seat needs to translate the seat back assembly forward and backward for chasing the back, the dual-mode tray is switched to the locking state, so that the lower tray and the upper tray are relatively fixed, and when the seat back assembly is affected by external force, the lower tray remains fixed, so that the seat back assembly can maintain its original posture and will not pitch and change the inclination angle; thus, by switching the dual-system tray between the locking state and the unlocking state, the function of the seat will also be switched accordingly, and the practicality is good; and, only by sliding the latch pin, so that the latch pin is simultaneously engaged with the first locking hole and the second locking hole or avoids one of the two, the dual-mode tray can be adjusted to switch between the locking state and the unlocking state, and the adjustment operation is relatively simple.

[0023] In addition, the chair body, front bracket, rear bracket and lower tray are hinged to form a parallel four-link structure, which is stable. By switching the locking and unlocking states of the dual-mode tray, the multifunctional seat can be switched between the critical state, the back-chasing state and the reclining state, and the adjustment operation is relatively simple; and the adaptive lumbar support state and the self-weight reclining state do not interfere with each other, making the multifunctional seat more stable.

[0024] Moreover, by arranging a pushing part on the front bracket, the pushing part performs a circular motion with the rotation of the front bracket and pushes or avoids the latch, so that when the multi-function seat is switched from the critical state to the rear-chasing state or the reclining state, the dual system tray can automatically switch to the locked state or the unlocked state with the rotation of the front bracket, thereby effectively improving the simplicity of the multi-function seat state switching operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 A schematic diagram of the three-dimensional structure of a dual-form tray in a locked state provided in an embodiment of the present application; Figure 2 A schematic diagram of the three-dimensional structure of a dual-form tray in an unlocked state provided in an embodiment of the present application; Figure 3 A schematic diagram of the change process of the dual-mode tray when switching from a locked state to an unlocked state provided in an embodiment of the present application; Figure 4 A schematic diagram of the connection structure between the upper tray and the lower tray provided in an embodiment of the present application; Figure 5 A schematic diagram of the connection structure between the tray and the gear adjustment mechanism provided in an embodiment of the present application; Figure 6 A schematic cross-sectional view of a dual-form tray in a locked state provided in an embodiment of the present application; Figure 7 A schematic cross-sectional view of a dual-mode tray in an unlocked state provided in an embodiment of the present application; Figure 8 A schematic diagram of the internal structure of a positioning member provided in an embodiment of the present application; Fig. 9 A schematic diagram of the connection structure between the positioning member and the pitch adjustment member in a gear-fixed state provided in an embodiment of the present application; Fig.10 A schematic diagram of the connection structure between the positioning member and the pitch adjustment member in the gear adjustment state provided in an embodiment of the present application; Fig.11 A schematic diagram of the connection structure between the dual-form tray and the seat back assembly provided in an embodiment of the present application; Fig.12 A schematic diagram of the three-dimensional structure of a multifunctional seat provided in an embodiment of the present application; Fig.13 A schematic diagram of the side structure of a multifunctional seat in a critical state provided by an embodiment of the present application; Fig.14 A schematic diagram of the side structure of a multifunctional seat in the rear-chasing state provided by an embodiment of the present application; Fig.15 A schematic diagram of the side structure of a multifunctional seat in a reclining state provided by an embodiment of the present application; Fig.16 A schematic diagram of the connection structure between the front bracket and the dual-form tray provided in an embodiment of the present application; Fig.17 A schematic diagram of the connection structure between the seat and the dual-form tray provided in an embodiment of the present application; Fig.18 A schematic cross-sectional structure diagram of the multifunctional seat provided in an embodiment of the present application.

[0026] The reference numerals are: 1-upper tray, 110-first hinge part, 111-first locking hole, 120-transmission member, 2-lower tray, 201-pin, 202-first elastic reset member, 203-second elastic reset member, 210-second hinge part, 211-second locking hole, 220-extension part, 230-pitch adjustment member, 231-slot, 232-first slide slot, 233-second slide slot 240-positioning member, 241-clip head, 242 -cavity, 243-torsion spring, 244-sliding member, 245-connecting part, 246-fourth elastic reset member, 3-chair body, 4-front bracket, 401-pushing part, 410-seat connecting rod, 420-chair body connecting rod, 430-tray connecting part, 5-rear bracket, 6-seat, 610-third elastic reset member, 620-tray connecting part, 621-guide groove, 621a-back-chasing guide part, 621b-tilt guide part, 630-adjustment switch. DETAILED DESCRIPTION

[0027] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0028] Please refer to the attached Figure 1-18 The embodiment of the present application provides a dual-form pallet, comprising an upper pallet 1 and a lower pallet 2 spliced ​​together, the upper pallet 1 being configured to connect to a seat assembly, the lower pallet 2 being configured to connect to a seat back assembly, a first hinge portion 110 being provided at the front end of the upper pallet 1, a second hinge portion 210 being provided at the front end of the lower pallet 2, the first hinge portion 110 being hinged to the second hinge portion 210, so that the lower pallet 2 can rotate up and down relative to the upper pallet 1; a first locking hole 111 is provided at the upper edge of the first hinge portion 110 in a hollow configuration in a left-right direction, and a second locking hole 211 is provided at the upper edge of the second hinge portion 210 in a hollow configuration in a left-right direction; the dual-form pallet also includes a locking mechanism, The locking mechanism includes a pin 201, which is slidably connected to the first locking hole 111 and the second locking hole 211; the dual-form tray has a switchable locking state and an unlocking state. In the locked state, the first locking hole 111 is connected to the second locking hole 211, and the pin 201 slides to be simultaneously engaged in the first locking hole 111 and the second locking hole 211, so that the second hinge part 210 cannot rotate relative to the first hinge part 110, and the upper tray 1 and the lower tray 2 are relatively fixed; in the unlocked state, the pin 201 slides to avoid the first locking hole 111 or the second locking hole 211, and the lower tray 2 can be rotated relative to the upper tray 1 again.

[0029] In this embodiment, the dual-system tray is composed of an upper tray 1 and a lower tray 2 that are rotatably connected to each other, and the dual-mode tray has a switchable locked state and unlocked state. When the seat needs to pitch and adjust the seat back assembly, the dual-mode tray is switched to the unlocked state, so that the lower tray 2 can rotate downward relative to the upper tray 1, thereby driving the seat back assembly connected to the lower tray 2 to rotate downward together; when the seat needs to translate the seat back assembly forward and backward for chasing, the dual-mode tray is switched to the locked state, so that the lower tray 2 and the upper tray 1 are relatively fixed, and when the seat back assembly 1 is affected by external force, the lower tray 2 remains fixed, so that the seat back assembly can maintain its original posture and will not pitch and change the inclination angle; thus, by switching the dual-system tray between the locked state and the unlocked state, the function of the seat will also be switched accordingly, and the practicality is good; and, only by sliding the latch 201, so that the latch 201 is simultaneously engaged with the first locking hole 111 and the second locking hole 211 or avoids one of the two, the dual-mode tray can be adjusted to switch between the locked state and the unlocked state, and the adjustment operation is relatively simple.

[0030] Please refer to the attached Figure 1-3 In some embodiments of the present application, the rotation angle of the lower tray 2 relative to the upper tray 1 is 0-20°. The lower tray 2 drives the chair back assembly to pitch, and the lower tray 2 has a large rotation angle, so that when the chair back assembly needs to be pitched, the chair back assembly has a sufficiently large pitch angle to ensure that the user can rest in a comfortable supine position, which is more practical.

[0031] Among them, the lower tray 2 and the upper tray 1 are both semi-open box-like structures. In the locked state, the upper tray 1 and the lower tray 2 are closed to each other to form a complete tray, making the structure of the tray more compact, and the lower tray 2 can rotate at a larger angle relative to the upper tray 1.

[0032] Please refer to the attached Figure 4 In some embodiments of the present application, the front end of the lower tray 2 is provided with two second hinged parts 210 that are symmetrical on both sides, and the two second hinged parts 210 are hinged to the left and right sides of the first hinged part 110, and the second locking holes 211 on both sides are slidably connected with the bayonet 201. By providing two second hinged parts 210 that are symmetrical on both sides and rotate with the first hinged part 110, and the two second hinged parts 210 and the first hinged part 110 are connected by the bayonet 201, the forces on both sides of the first hinged part 110 are balanced, which not only enhances the connection strength between the upper tray 1 and the lower tray 2, but also makes the rotation process between the lower tray 2 and the upper tray 1 more stable and smooth.

[0033] Preferably, the first hinged portion 110 and the second hinged portion 210 are both cylindrical structures, and the first hinged portion 110 and the second hinged portion 210 are hingedly connected via a transversely arranged rotating shaft, and the connection structure is relatively simple.

[0034] Of course, in other embodiments of the present application, the front end of the lower tray 2 may also be provided with only one second hinge portion 210, and the first hinge portion 110 and the second hinge portion 210 are connected to each other on the left and right and are hinged by a transversely arranged rotating shaft.

[0035] Please refer to the attached Figure 4 In some embodiments of the present application, a first elastic reset member 202 is provided between the upper tray 1 and the lower tray 2, and the two ends of the first elastic reset member 202 act on the upper tray 1 and the lower tray 2 respectively, so that the lower tray 2 always has a tendency to rotate toward the upper tray 1. When the dual system tray is unlocked, the lower tray 2 will automatically rotate upward under the elastic force of the first elastic reset member 202, and then when the seat back assembly does not need to be pitched, the upper seat back assembly will be reset to the critical state driven by the lower tray 2, so that the seat adjustment operation is more rapid and simple.

[0036] Preferably, the first elastic reset member 202 is a spring, and the upper tray 1 and the lower tray 2 are connected by two groups of first elastic reset members 202 that are symmetrically arranged on the left and right, so that there is sufficient elastic force between the upper tray 1 and the lower tray 2 for reset. Of course, in other embodiments of the present application, the first elastic reset member 202 can also be a gas spring, an electric telescopic rod, etc.

[0037] Please refer to the attached Figure 4-5 In some embodiments of the present application, the lower tray 2 includes an extension portion 220 formed by extending backward from the rear end and a pitch adjustment member 230 slidably connected to the extension portion 220 in the front-rear direction. The pitch adjustment member 230 is configured to connect the seat back assembly and drive the seat back assembly to rotate forward and backward by sliding the pitch adjustment member 230 forward and backward. Therefore, when the seat back assembly is adjusted in pitch, the seat back assembly can be further tilted backward by sliding the pitch adjustment member 230, thereby increasing the pitch adjustment range of the seat back assembly, ensuring that the user can lie on the seat in a more comfortable posture, and having better practicality.

[0038] Among them, the extension part 220 is tilted, and the tilting direction is from front to back and from low to high, so that when the seat back assembly applies pressure to the pitch adjustment member 230, it can slide downward along the tilting direction of the extension part 220, thereby making the pitch adjustment process of the seat smoother.

[0039] Please refer to the attached Figure 1-3In some embodiments of the present application, a transmission member 120 is also connected between the upper tray 1 and the pitch adjustment member 230, the front end of the transmission member 120 is hinged to the rear end of the upper tray 1, and the rear end of the transmission member 120 is hinged to the pitch adjustment member 230; when the pitch adjustment member 230 slides forward relative to the extension portion 220, the rear end of the transmission member 120 is driven to slide forward and push the lower tray 2 downward, so that the lower tray 2 is driven by the transmission member 120 to rotate downward relative to the upper tray 1.

[0040] In this embodiment, the upper tray 1, the lower tray 2, the pitch adjustment member 230 and the transmission member 120 are combined to form a structure similar to a three-link and one slide slot. When the backrest assembly applies pressure to the pitch adjustment member, the pitch adjustment member 230 slides forward and drives the transmission member 120 to push the lower tray 2 downward to rotate, and the backrest assembly tilts backward; conversely, when the backrest assembly needs to be reset, the lower tray 2 automatically rotates upward under the elastic force of the first elastic reset member 202, and drives the transmission member 120 to push the pitch adjustment member 230 backward to rotate, and the backrest assembly rotates forward to reset. Therefore, by setting the transmission member 120, the pitch adjustment member 230 and the lower tray 2 can synchronously adjust the pitch angle of the backrest assembly, making the pitch adjustment process of the seat more stable and smooth.

[0041] Please refer to the attached Figure 5-10 In some embodiments of the present application, a positioning member 240 is fixedly connected to the extension portion 220, and a gear adjustment mechanism is arranged between the pitch adjustment member 230 and the positioning member 240. The gear adjustment mechanism includes a clamping head 241 and a plurality of clamping slots 231. The clamping head 241 is arranged in one of the pitch adjustment member 230 and the positioning member 240, and the plurality of clamping slots 231 are arranged in the other one of the pitch adjustment member 230 and the positioning member 240; when the pitch adjustment member 230 slides back and forth relative to the positioning member 240, the clamping head 241 is engaged with the plurality of clamping slots 231 in sequence.

[0042] In this embodiment, the pitch adjustment member 230 and the positioning member 240 are adjusted in gear through the clamp head 241 and the clamping slot 231, so that the pitch adjustment member 230 can be fixed at any position on the extension part 220, and then the chair back assembly can adjust and fix the pitch angle with the help of the gear adjustment mechanism, which is more convenient to use.

[0043] Please refer to the attached Figure 8-10In some embodiments of the present application, the clamping head 241 is movably connected to the positioning member 240, and a plurality of clamping slots 231 are correspondingly arranged on the pitch adjustment member 230. The gear adjustment mechanism has a switchable gear fixing state and a gear adjustment state. In the gear fixing state, the clamping head 241 slides outward until it is clamped in the clamping slot 231, so that the pitch adjustment member 230 and the positioning member 240 are relatively fixed; in the gear adjustment state, the clamping head 241 slides inward until it is retracted into the positioning member 240 and avoids the clamping slot 231, so that the pitch adjustment member 230 can slide relative to the positioning member 240 again.

[0044] In this embodiment, the clamping head 241 is movably arranged on the positioning member 240, and the clamping head 241 is used to engage or avoid the clamping slot 231, thereby achieving movement or fixation between the pitch adjustment member 230 and the extension portion 220, which is easy to operate and makes the gear adjustment operation simpler.

[0045] Preferably, along the length direction, the pitch adjustment member 230 is provided with four rows of slots 231, so that the gear adjustment mechanism has four adjustable gears, and the adjustment freedom is high. Of course, in other embodiments of the present application, the number of slots 231 on the pitch adjustment member 230 can also be three rows, five rows, six rows, etc.

[0046] Please refer to the attached Figure 8-10 In some embodiments of the present application, the positioning member 240 is a hollow structure, including an internal cavity 242, one end of the clamping head 241 passes through the side wall of the positioning member 240 and extends into the cavity 242, and a torsion spring 243 is arranged in the cavity 242, and the force arm on one side of the torsion spring 243 is respectively connected to the clamping heads 241 on both sides, and the force arm on the other side of the torsion spring 243 is connected to the sliding member 244; the sliding member 244 can slide in the cavity 242, and drive the torsion spring 243 to pull the clamping head 241 inward or push it outward, thereby driving the gear adjustment mechanism to switch between the gear fixing state and the gear adjustment state.

[0047] In this embodiment, only the sliding adjustment sliding member 244 is required to drive the torsion spring 243 to push or pull the clamping head 241, thereby switching the gear adjustment mechanism between the gear fixing state and the gear adjustment state, thereby making the gear adjustment operation of the tray relatively simple.

[0048] The pitch adjustment member 230 is a plate-like structure, the bottom end of the pitch adjustment member 230 is recessed upward to form a second slide groove 233 extending in the length direction, the positioning member 240 is arranged in the second slide groove 233, and the pitch adjustment member 230 slides forward and backward relative to the positioning member 240 through the second slide groove 233, so that the connection strength between the two is better and the sliding process is more stable. The left and right side walls of the second slide groove 233 are provided with a clamping groove 231, the left and right sides of the positioning member 240 are provided with a clamping head 241, and the cavity 242 is provided with two symmetrical torsion springs 243, one side force arm of the two torsion springs 243 is respectively connected to the clamping heads 241 on both sides, and the other side force arms of the two torsion springs 243 are connected to the sliding member 244; the sliding member 244 can slide forward and backward in the cavity 242, and drive the torsion spring 243 to pull or push the clamping head 241 inward.

[0049] The tray is also provided with a wire control mechanism, which includes an adjustment switch 630 and a pull rope, one end of the pull rope is connected to the adjustment switch 630, and the other end passes through the positioning member 240 and is connected to the sliding member 244. When the adjustment switch 630 is turned on, the pull rope pulls the sliding member 244 to slide forward, and drives the torsion spring 243 to pull the clamping head 241 inward, so that the pitch adjustment member 230 can slide relative to the positioning member 240 again; the rear end of the sliding member 244 is also connected to a fourth elastic restoring member. The fourth elastic reset member 246 always pulls the sliding member 244, so that the sliding member 244 always has a tendency to slide backward, and then when the adjustment switch 630 is turned off, the pull rope loosens the sliding member 244, and the sliding member 244 automatically slides backward and resets under the elastic force of the fourth elastic reset member 246, and drives the torsion spring 243 to push the clamping head 241 outward, so that the clamping head 241 is re-engaged in the clamping groove 231, and the pitch adjustment member 230 is re-fixed to the positioning member 240. In this way, the switching state of the gear adjustment mechanism can be controlled by means of the wire control mechanism, and the operation is relatively simple.

[0050] Please refer to the attached Figure 9-10 In some embodiments of the present application, the pitch adjustment member 230 is a plate-like structure, and a first slide groove 232 extending in the front-to-back direction is hollowed out on the pitch adjustment member 230. A positioning member 240 is slidably connected to the pitch adjustment member 230, and a connecting portion 245 is protruded from the positioning member 240. The connecting portion 245 passes through the first slide groove 232 and is connected to the extension portion 220, so that the pitch adjustment member 230 is clamped between the extension portion 220 and the positioning member 240, and the pitch adjustment member 230 slides forward and backward relative to the connecting portion 245 through the first slide groove 232.

[0051] In this embodiment, the pitch adjustment member 230 is clamped by the extension portion 220 and the positioning member 240, and the sliding distance of the pitch adjustment member 230 is limited by the connecting portion 245 and the first sliding groove 232, which not only makes the connection strength between the pitch adjustment member 230 and the extension portion 220 higher, but also makes the sliding process of the pitch adjustment member 230 more stable and smooth.

[0052] Preferably, two connecting parts 245 are formed on the positioning member 240 in a symmetrical manner, and two first sliding grooves 232 are correspondingly hollowed out on the pitch adjustment member 230, so as to further enhance the connection strength between the pitch adjustment member 230 and the positioning member 240. After the connecting part 245 passes through the first sliding groove 232, the positioning member 240 and the extension part 220 are fixed by screw connection, so that the pitch adjustment member 230, the positioning member 240 and the extension part 220 are mutually detachably arranged, so that the installation and removal operations of the chassis are more convenient.

[0053] Please refer to the attached Figure 11-15 The embodiment of the present application also provides a multifunctional chair, including a chair back assembly and a dual-form tray, the chair back assembly including a chair body 3, a front bracket 4 and a rear bracket 5, the top end of the front bracket 4 is hinged to the front end of the chair body 3, the bottom ends of the two front brackets 4 are hinged to the first hinge part 110 or the second hinge part 210, the top end of the rear bracket 5 is hinged to the rear end of the chair body 3, and the bottom end of the rear bracket 5 is hinged to the rear end of the lower tray 2; the automatic locking mechanism also includes a pushing portion 401, which is arranged on the side of the bottom of the front bracket 4 close to the tray; the multifunctional chair has a switchable chasing state, a critical state and a pitching state, in the critical state, the chair body 3 maintains an upright state and is located at a relatively rearward position; when the multifunctional chair enters the chasing state from the critical state, the front bracket 4 swings forward, and the pushing portion 401 rotates and The latch pin 201 is pushed inward, so that the latch pin 201 slides inward until it is simultaneously engaged with the first locking hole 111 and the second locking hole 211, and the locking mechanism enters a locked state, the upper tray 1 and the lower tray 2 are relatively fixed, and the rear bracket 5 swings forward synchronously in response to the front bracket 4, thereby driving the upper chair body 3 to move forward and be pushed out; when the multifunctional seat enters a pitch state from a critical state, the front bracket 5 swings backward, and the pushing portion 401 rotates accordingly to avoid the latch pin 201, so that the latch pin 201 slides outward to disengage from the first locking hole 111 or the second locking hole 211, and the locking mechanism enters an unlocked state, so that the lower tray 2 can be rotated downward relative to the upper tray 1 again, the chair body 3 swings downward synchronously in response to the lower tray 2, and the rear bracket 5 swings backward synchronously in response to the front bracket 4, thereby causing the chair body 3 to tilt backward as a whole.

[0054] In this embodiment, the chair body 3, the front bracket 4, the rear bracket 5 and the lower tray 2 are hinged to each other to form a parallel four-link structure, which is stable and can meet the user's needs for back-chasing adjustment and pitch adjustment at the same time, and has good practicality. In addition, when the dual-mode tray is in the locked state, the front bracket 4 and the rear bracket 5 can only swing forward and backward, thereby driving the chair body 3 to move forward and backward; when the dual-mode tray is in the unlocked state, the lower tray 2 can rotate downward relative to the upper tray 1, thereby driving the upper chair body 3 to rotate downward together; thus, by switching the locked state and the unlocked state of the dual-mode tray, the multifunctional seat can be switched between the critical state, the back-chasing state and the reclining state, and the adjustment operation is relatively simple; and in the back-chasing state, the chair body 3 cannot be pitched, which will not affect the back-chasing adjustment of the chair body 3; similarly, in the reclining state, the chair body 3 cannot be adjusted forward, thereby not affecting the pitch adjustment of the chair body 3; that is, the adaptive lumbar support state and the self-weighted reclining state do not interfere with each other, so that the stability of the multifunctional seat is good. Moreover, by arranging a pushing portion 401 on the front bracket 4, the pushing portion 401 performs a circular motion with the rotation of the front bracket 4 and pushes or avoids the latch pin 201, so that when the multi-functional seat is switched from a critical state to a rear-chasing state or a reclining state, the dual system tray can automatically switch to a locked state or an unlocked state with the rotation of the front bracket 4, without the need for manual adjustment by the user, thereby effectively improving the simplicity of the multi-functional seat state switching operation.

[0055] Among them, the front end of the lower tray 2 is provided with two left-right symmetrical second hinge parts 210, and the left and right sides of the chair body 3 are also hinged with two left-right symmetrical front brackets 4, which are respectively connected to the second hinge parts 210 on both sides. With the rotation of the front brackets 4 on both sides of the dual-system seat, the two groups of pins 201 are driven to slide at the same time, making the locking or unlocking operation of the dual-system tray smoother.

[0056] Please refer to the attached Figure 6-7 In some embodiments of the present application, a second elastic reset member 203 is provided in the second locking hole 211 , and the second elastic reset member 203 acts on the bayonet 201 and makes the bayonet 201 always have a tendency to move in a direction away from the first hinge portion 110 .

[0057] In this embodiment, when the dual-system seat switches directly from the critical state to the self-loaded reclining state, when the current bracket 4 rotates to the pushing part 401 to avoid the pin 201, the pin 201 can automatically pop outward with the help of the elastic force of the second elastic return member 203 and disengage from the first locking hole 111, so that the dual-system tray can automatically switch to the unlocked state, and the multi-functional seat can automatically enter the chasing state, further improving the simplicity of the dual-system seat state switching operation.

[0058] Among them, preferably, the second elastic return member 203 is a spring, and the overall structure of the bayonet 201 is a T-shaped structure. The wider side of the bayonet 201 is close to the pushing portion 401, and the spring is sleeved on the slender side of the bayonet 201 and squeezes the bayonet 201 outward. The structure is simple and easy to set up.

[0059] Please refer to the attached Figure 13-15 In some embodiments of the present application, the end surface of the pushing portion 401 close to the pin 201 and / or the end surface of the pin 201 close to the pushing portion 401 is inclined, so that when the front bracket 4 drives the pushing portion 401 to make a circular motion and pushes the pin 201, the pin 201 can slide toward the first hinge portion 110 along the inclined direction of the above-mentioned end surface.

[0060] In this embodiment, by tilting the end surfaces of the pushing portion 401 and / or the bayonet 201 that are close to each other, the structure is simple and the circular rotation of the pushing portion 401 can be converted into the sliding of the bayonet 201 in the horizontal direction.

[0061] Preferably, the end surface of the pushing portion 401 close to the bayonet 201 and the end surface of the bayonet 201 close to the pushing portion 401 are both inclined, so that the transmission between the two is more stable and smooth.

[0062] Please refer to the attached Fig.17 In some embodiments of the present application, the multifunctional chair also includes a seat 6, which is configured to support a user to sit; the front bracket 4 includes a seat connecting rod 410 and a chair body connecting rod 420 that are inclined to each other and always remain relatively fixed, and the portion where the lower ends of the seat connecting rod 410 and the chair body connecting rod 420 intersect and connect is a tray connecting portion 430, and the front bracket 4 is hinged to the upper tray 1 through the tray connecting portion 430, so that the front bracket 4 as a whole can rotate synchronously around the tray connecting portion 430; the upper end of the chair body connecting rod 420 is hinged to the chair body 1, and the upper end of the seat connecting rod 410 is hinged to the seat 6, and the seat 6 can slide up and down relative to the upper tray 1, and drive the seat connecting rod 410 to rotate back and forth around the tray connecting portion 430.

[0063] In this embodiment, the seat 6 and the front bracket 4 are linked so that in the chasing state, the seat 6 is subjected to pressure from the user, thereby driving the front bracket 4 to rotate forward, and then driving the chair body 3 to move forward and chase the back, that is, the chair body 3 can respond to the sinking of the seat 6 to achieve automatic chasing, and the chasing adjustment operation is simpler; in the reclining state, the chair body 3 tilts backward due to the reclining, the front bracket 4 swings backward and drives the seat 6 to move upward, so that the overall posture of the chair can be closer to the posture of the human body when pitching, and the user experience is more comfortable.

[0064] Please refer to the attached Fig.17The upper end of the seat connecting rod 410 is hinged to the front end of the seat 6, and the rear end of the seat 6 is provided with two symmetrical tray connecting parts 620, which are attached to the left and right sides of the upper tray 1. The tray connecting parts 620 and the upper tray 1 are connected by a guide mechanism, and the guide mechanism includes a guide groove 621 and a guide pin that slide with each other. The guide groove 621 is provided on the tray connecting part 620, and the guide pin is provided on the upper tray. The seat 6, the seat connecting rod 410, the upper tray 1 and the guide groove 621 form a structure similar to a three-link and a slide groove. With the help of the sliding of the guide pin in the guide groove 621, the seat 6 slides up and down relative to the upper tray 1 and links the seat connecting rod 410 to rotate forward and backward. The structure is simple and the transmission process between the seat 6 and the seat connecting rod 410 is more stable and smooth.

[0065] The guide slot 621 includes a back-climbing guide portion 621a and a reclining guide portion 621b, both of which are tilted from front to back and from low to high, and the back-climbing guide portion 621a is tilted relative to the horizontal plane at a greater angle than the reclining guide portion 621b. By tilting the guide slot 621, the horizontal position of the seat 6 will change when the seat 6 slides up and down, and the tilt of the back-climbing guide portion 621a is greater than the reclining guide portion 621b, so that when the multifunctional chair is in the back-climbing state, the seat 6 changes less in the horizontal direction, thereby avoiding affecting the seat depth adjustment; in the reclining state, the seat 6 will move a longer distance in the horizontal direction, thereby adapting to the position change of the human buttocks when the chair body 3 reclines, and the support experience is more comfortable.

[0066] Please refer to the attached Figure 17-18 In some embodiments of the present application, a third elastic reset member 610 is provided between the seat 6 and the upper tray 1. In the critical state, the third elastic reset member 610 does not apply elastic force to the seat 6 and the upper tray 1; in the back-climbing state, the third elastic reset member 610 applies a thrust to the seat 6 and the upper tray 1, so that the seat 6 has a tendency to move away from the upper tray 1; in the pitching state, the third elastic reset member 610 applies a pulling force to the seat 6 and the upper tray 1, so that the seat 6 has a tendency to move toward the upper tray 1. When the user does not need to use the seat or needs to switch the state again, the seat 6 can automatically reset with the elastic force of the third elastic reset member 610, and the front bracket 4, the lower tray 2, the rear bracket 5 and the chair body 3 are driven by the seat 6 to move, so that the dual-system seat is reset to the initial state without the need for manual reset by the user, further improving the convenience of the dual-system seat state switching operation.

[0067] Preferably, the third elastic reset member 610 is a controllable gas spring, and the seat 6 and the third elastic reset member 610 are connected via a wire control mechanism, which includes an adjustment switch 630 and a pull cord connected between the adjustment switch 630 and the third elastic reset member 610, and the adjustment switch 630 is configured to adjust the pull cord to pull or release the ejector pin of the third elastic reset member 610, so that the third elastic reset member 610 can be fixed at any telescopic length. The third elastic reset member 610 can be adjusted to be telescopic or fixed by only pressing the adjustment switch 630, and the adjustment operation is very simple.

[0068] Among them, the adjustment switch 630 controls not only the third elastic reset member 610, but also the sliding member 244 in the positioning member 240, so that after the adjustment switch 630 is turned on, the third elastic reset member 610 can be retracted and retracted again, the chair body 3 can be translated forward and backward, and the sliding member 244 pulls the torsion spring 243 downward and drives the clamp 241 to retract, the pitch adjustment member 230 can slide forward and backward and drive the chair body 3 to adjust the reclining angle, so that the chair body 3 as a whole can be adjusted movably; when the adjustment switch 630 is closed, the length of the third elastic reset member 610 is fixed, the front and rear position of the chair body 3 is fixed, and the sliding member 244 releases the torsion spring 243 and drives the clamp 241 to pop out, the position of the pitch adjustment member 230 is fixed and the chair body 3 cannot be rotated to adjust the reclining angle, so that the chair body 3 as a whole remains fixed. Therefore, by pressing the adjustment switch 630, the fixation or activity of the entire chair body 3 can be controlled, further improving the simplicity of the dual-system seat adjustment operation.

Claims

1. A dual-form pallet, characterized in that: The dual-form tray comprises an upper tray (1) and a lower tray (2) which are connected in an upper and lower manner, wherein the upper tray (1) is configured to be connected to a seat assembly, and the lower tray (2) is configured to be connected to a seat back assembly, a first hinged portion (110) is provided at a front end of the upper tray (1), and a second hinged portion (210) is provided at a front end of the lower tray (2), the first hinged portion (110) being hinged to the second hinged portion (210), so that the lower tray (2) can rotate up and down relative to the upper tray (1); a first locking hole (111) is hollowed out on an upper edge of the first hinged portion (110) in a left-right direction, and a second locking hole (211) is hollowed out on an upper edge of the second hinged portion (210) in a left-right direction; the dual-form tray further comprises a locking mechanism, wherein the locking mechanism comprises a bayonet (201), the The latch (201) is slidably connected to the first locking hole (111) and the second locking hole (211); the dual-form tray has a switchable locked state and an unlocked state; in the locked state, the first locking hole (111) is connected to the second locking hole (211), and the latch (201) slides to be simultaneously engaged in the first locking hole (111) and the second locking hole (211), so that the second hinge part (210) cannot rotate relative to the first hinge part (110), and the upper tray (1) and the lower tray (2) are relatively fixed; in the unlocked state, the latch (201) slides to avoid the first locking hole (111) or the second locking hole (211), and the lower tray (2) can be rotated relative to the upper tray (1) again.

2. The dual-form pallet according to claim 1, characterized in that: The rotation angle of the lower tray (2) relative to the upper tray (1) is 0-20°.

3. The dual-form pallet according to claim 1, characterized in that: The front end of the lower tray (2) is provided with two second hinged parts (210) which are symmetrical on the left and right sides. The two second hinged parts (210) are hinged to the left and right sides of the first hinged part (110), and the second locking holes (211) on the left and right sides are both slidably connected to the bayonet pins (201).

4. The dual-form pallet according to claim 1, characterized in that: A first elastic return member (202) is provided between the upper tray (1) and the lower tray (2), and two ends of the first elastic return member (202) act on the upper tray (1) and the lower tray (2) respectively, so that the lower tray (2) always has a tendency to rotate towards the upper tray (1).

5. The dual-form pallet according to claim 1, characterized in that: The lower tray (2) comprises an extension portion (220) formed by extending rearward from a rear end, and a pitch adjustment member (230) connected to the extension portion (220) in a slidable manner in a front-rear direction, wherein the pitch adjustment member (230) is configured to be connected to a chair back assembly and to drive the chair back assembly to rotate forward and backward by sliding forward and backward with the help of the pitch adjustment member (230).

6. The dual system seat according to claim 5, characterized in that: A transmission member (120) is further connected between the upper tray (1) and the pitch adjustment member (230); the front end of the transmission member (120) is hinged to the rear end of the upper tray (1), and the rear end of the transmission member (120) is hinged to the pitch adjustment member (230); when the pitch adjustment member (230) slides forward relative to the extension portion (220), the rear end of the transmission member (120) is driven to slide forward and push the lower tray (2) downward, so that the lower tray (2) is driven by the transmission member (120) to rotate downward relative to the upper tray (1).

7. The dual system seat according to claim 5, characterized in that: A positioning member (240) is fixedly connected to the extension portion (220); a gear adjustment mechanism is provided between the pitch adjustment member (230) and the positioning member (240); the gear adjustment mechanism comprises a clamping head (241) and a plurality of clamping slots (231); the clamping head (241) is provided on one of the pitch adjustment member (230) and the positioning member (240); and the plurality of clamping slots (231) are provided on the other of the pitch adjustment member (230) and the positioning member (240); when the pitch adjustment member (230) slides forward and backward relative to the positioning member (240), the clamping head (241) is clamped and matched with the plurality of clamping slots (231) in sequence.

8. The dual system seat according to claim 7, characterized in that: The clamping head (241) is movably connected to the positioning member (240); the pitch adjustment member (230) is correspondingly provided with the plurality of clamping slots (231); the gear adjustment mechanism has a switchable gear fixing state and a gear adjustment state; in the gear fixing state, the clamping head (241) slides outwards until it is clamped in the clamping slot (231), so that the pitch adjustment member (230) and the positioning member (240) are relatively fixed; in the gear adjustment state, the clamping head (241) slides inwards until it is retracted into the positioning member (240) and avoids the clamping slot (231), so that the pitch adjustment member (230) can slide relative to the positioning member (240) again.

9. The dual system seat according to claim 8, characterized in that: The positioning member (240) is a hollow structure, comprising an internal cavity (242); one end of the clamping head (241) passes through the side wall of the positioning member (240) and extends into the cavity (242); a torsion spring (243) is arranged in the cavity (242); a force arm on one side of the torsion spring (243) is respectively connected to the clamping heads (241) on both sides; and a force arm on the other side of the torsion spring (243) is connected to a sliding member (244); the sliding member (244) can slide in the cavity (242) and drive the torsion spring (243) to pull the clamping head (241) inwardly or push it outwardly, thereby driving the gear adjustment mechanism to switch between a gear fixing state and a gear adjustment state.

10. The dual system seat according to claim 5, characterized in that: The pitch adjustment member (230) is a plate-like structure. A first slide groove (232) extending in a front-to-rear direction is hollowed out on the pitch adjustment member (230). A positioning member (240) is slidably connected to the pitch adjustment member (230). A connecting portion (245) is protruded from the positioning member (240). The connecting portion (245) passes through the first slide groove (232) and is connected to the extension portion (220), so that the pitch adjustment member (230) is clamped between the extension portion (220) and the positioning member (240), and the pitch adjustment member (230) slides forward and backward relative to the connecting portion (245) through the first slide groove (232).

11. A multifunctional seat, characterized in that: The invention comprises a chair back assembly and a dual-form tray as claimed in any one of claims 1 to 10, wherein the chair back assembly comprises a chair body (3), a front bracket (4) and a rear bracket (5), wherein the top end of the front bracket (4) is hinged to the front end of the chair body (3), the bottom ends of the two front brackets (4) are hinged to the first hinge part (110) or the second hinge part (210), the top end of the rear bracket (5) is hinged to the rear end of the chair body (3), and the bottom end of the rear bracket (5) is hinged to the lower tray (2). the rear end of the seat; the automatic locking mechanism further comprises a pushing portion (401), the pushing portion (401) being arranged at a side of the bottom of the front bracket (4) close to the tray; the multifunctional seat has a switchable back-catching state, a critical state and a pitching state, in which the seat body (3) remains in an upright state and is located at a relatively rearward position; when the multifunctional seat enters the back-catching state from the critical state, the front bracket (4) swings forward, the pushing portion (401) rotates accordingly and pushes the latch pin (201) inward, so that the latch pin (201) slides inward until it is simultaneously engaged with the first locking hole (111) and the second locking hole (211), the locking mechanism enters a locked state, the upper tray (1) and the lower tray (2) are relatively fixed, the rear bracket (5) swings forward synchronously in response to the front bracket (4), thereby driving the seat body (3) on the upper side to be translated forward and ejected; when the multifunctional seat enters the pitching state from the critical state, the front bracket (5) swings backward, the pushing portion (401) rotates accordingly and pushes the latch pin (201) inward, so that the latch pin (201) slides inward until it is simultaneously engaged with the first locking hole (111) and the second locking hole (211), the locking mechanism enters a locked state, the upper tray (1) and the lower tray (2) are relatively fixed, the rear bracket (5) swings forward synchronously in response to the front bracket (4), and thereby drives the upper side of the seat body (3) to be translated forward and ejected; The portion (401) then rotates to avoid the latch (201), so that the latch (201) slides outward to disengage from the first locking hole (111) or the second locking hole (211), and the locking mechanism enters an unlocked state, so that the lower tray (2) can rotate downward relative to the upper tray (1) again, the chair body (3) responds to the lower tray (2) and swings downward synchronously, and the rear bracket (5) responds to the front bracket (4) and swings backward synchronously, thereby causing the chair body (3) to tilt backward as a whole.

12. The multifunctional seat according to claim 11, characterized in that: A second elastic reset member (203) is disposed in the second locking hole (211), and the second elastic reset member (203) acts on the latch pin (201) to always have a tendency to move in a direction away from the first hinged portion (110).

13. The multifunctional seat according to claim 11, characterized in that: The end surface of the pushing portion (401) close to the latch pin (201) and / or the end surface of the latch pin (201) close to the pushing portion (401) is arranged to be inclined, so that when the front bracket (4) drives the pushing portion (401) to perform a circular motion and push the latch pin (201), the latch pin (201) can slide towards the first hinge portion (110) along the inclined direction of the end surface.

14. The multifunctional seat according to claim 11, characterized in that: The multifunctional chair further comprises a seat (6), wherein the seat (6) is configured to support a user while sitting; the front bracket (4) comprises a seat connecting rod (410) and a chair body connecting rod (420) which are inclined to each other and always remain relatively fixed; the portion where the lower ends of the seat connecting rod (410) and the chair body connecting rod (420) intersect and connect is a tray connecting portion (430); the front bracket (4) is hinged to the upper tray (1) via the tray connecting portion (430), so that the front bracket (4) as a whole can rotate synchronously around the tray connecting portion (430); the upper end of the chair body connecting rod (420) is hinged to the chair body (1), and the upper end of the seat connecting rod (410) is hinged to the seat (6); the seat (6) can slide up and down relative to the upper tray (1), and drive the seat connecting rod (410) to rotate forward and backward around the tray connecting portion (430).

15. The multifunctional seat according to claim 14, characterized in that: A third elastic reset member (610) is provided between the seat (6) and the upper tray (1); in a critical state, the third elastic reset member (610) does not apply elastic force to the seat (6) and the upper tray (1); in a reclining state, the third elastic reset member (610) applies a thrust to the seat (6) and the upper tray (1), so that the seat (6) has a tendency to move in a direction away from the upper tray (1); in a pitching state, the third elastic reset member (610) applies a pulling force to the seat (6) and the upper tray (1), so that the seat (6) has a tendency to move in a direction close to the upper tray (1).

Images