Chair backrest and chair structure

Abstract

According to the chair backrest and the chair structure, the backrest mounted on a back frame is divided into a left backrest and a right backrest which are opposite to each other on the left side and the right side, the left backrest and the right backrest are rotatably connected with the back frame through a bracket, and elastic mechanisms are mounted at the connecting ends. When a user sits on the chair and leans against the chair, the left backrest and the right backrest are pressed to rotate, and the elastic mechanism deforms and generates resilience force to drive the left backrest and the right backrest to rotate reversely, so that the left backrest and the right backrest are more tightly attached to the back of the user, an additional supporting effect is provided for the back of the user, a better supporting effect is formed, and the use comfort of the user is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to furniture, especially to a chair and a backrest structure thereon. BACKGROUND

[0002] The conventional chair backrest is a straight plate type fixed structure, but as the human back is curved, the straight plate type backrest is easy to fail to provide effective support due to the inability to closely adhere to the human back, and even causes discomfort to the user. Therefore, the ergonomic chair is often designed as an arc shape to better adhere to the human back. Although this arc-shaped backrest can improve the adhesion between the backrest and the user's back to a certain extent, because the specific shape of the back of different users is not consistent, the existing ergonomic chair cannot be well applied to different people. SUMMARY

[0003] The utility model aims at providing a chair backrest which can better adhere to the human back, and a chair using the backrest, so as to improve the adhesion of the backrest to the human back and improve the use comfort.

[0004] The chair backrest comprises a back frame fixedly arranged, and a backrest mounted on the back frame. The backrest comprises a left backrest and a right backrest opposite to the left and right sides of the human back, and the left backrest and the right backrest are rotatably mounted on the back frame through elastic mechanisms, respectively. The deformation of the elastic mechanisms exerts an acting force on the left backrest and the right backrest to make them rotate.

[0005] The chair structure is provided with the chair backrest as described above.

[0006] The chair backrest and the chair structure are characterized in that the back frame is fixedly arranged on the chair, the backrest comprises a left backrest and a right backrest for supporting the left and right sides of the human back, and the left and right backrests are rotatable. When the user sits on the chair and leans back on the backrest, the left and right sides of the back are pressed on the left and right backrests, respectively, so that the left and right backrests rotate. The elastic mechanisms will be deformed to generate a rebound force during the rotation of the left and right backrests. The acting force will drive the left and right backrests to rotate reversely, so that the left and right backrests more closely adhere to the back of the user and provide additional support to the back of the user, forming a better support effect and improving the use comfort of the user.

[0007] Preferably, a bracket is arranged transversely or obliquely, one end of the bracket is rotatably connected with the left backrest or the right backrest through the elastic mechanism, and the other end of the bracket is rotatably connected with the back frame through the elastic mechanism.

[0008] Preferably, the support comprises a plurality of support rods hingedly connected in sequence, wherein the end of the support rod at one end is hingedly connected to the back frame, and the end of the support rod at the other end is hingedly connected to the left or right backrest, and the adjacent support rods are rotatably connected by elastic mechanisms.

[0009] Preferably, the elastic mechanism is a torsion spring; the left backrest, the right backrest or the back frame is provided with a connecting seat, the connecting seat is provided with a recessed seat groove, the seat groove is provided with a limiting groove, the end of the support is arranged in the seat groove and is hingedly connected to the connecting seat through a rotating shaft, and the end of the support is further provided with a recessed torsion spring mounting groove, and the torsion spring is mounted in the torsion spring mounting groove and one end of the torsion spring is arranged in the limiting groove.

[0010] Preferably, the left backrest, the right backrest or the back frame is provided with a connecting seat, the upper and lower ends of the connecting seat are oppositely provided with connecting plates, and coaxial through holes are formed in the two connecting plates; one end of the support is arranged between the two connecting plates, and the end of the support is provided with a containing cavity for placing the elastic mechanism, and the elastic mechanism is a torsion spring; a connecting shaft passes through the two connecting plates and the containing cavity therebetween in sequence, the torsion spring is sleeved outside the connecting shaft, and the left backrest, the right backrest or the back frame is provided with a torsion spring positioning groove for placing the end of the torsion spring.

[0011] Preferably, the left backrest, the right backrest and the support, and the support and the back frame are provided with turning limiting blocks and turning limiting grooves in the circumferential direction.

[0012] Preferably, the back frame comprises a fixedly arranged base and a lifting seat moving up and down relative to the base, and the left backrest and the right backrest are mounted on the lifting seat.

[0013] Preferably, all the left backrests and the right backrests are mounted on the same lifting seat.

[0014] Preferably, the left backrest, the right backrest and the lifting seat are all provided with two or more left backrests and right backrests at the same horizontal height, and the left backrests and the right backrests at the same horizontal height are mounted on the same lifting seat.

[0015] Preferably, the base is provided with a vertically arranged guide groove, the two sides of the guide groove are provided with a plurality of vertically arranged positioning clamping grooves, and the positioning clamping grooves are inclined upward; the lifting seat is provided with two transversely arranged positioning blocks, one end of the two positioning blocks is rotatably mounted on the lifting seat, the other end of the two positioning blocks is a clamping part, a clamping assembly and a positioning elastic member are respectively arranged between the middle parts of the two positioning blocks and are fixedly clamped with each other, and the positioning elastic member applies a force to the positioning blocks in the direction of the positioning clamping grooves; the top of the guide groove is a clamping guide part for applying a relative moving force to the two positioning blocks and driving the clamping assembly to be fixedly clamped with each other, and the bottom of the guide groove is provided with an unlocking guide block inserted between the two positioning blocks and driving the clamping assembly to be separated from each other.

[0016] Preferably, the engaging assembly comprises a clamping groove part and a clamping block part respectively arranged on the two positioning blocks, the clamping groove part is provided with an inner recessed clamping groove, and the end of the clamping block part can be inserted into and fixed in the clamping groove.

[0017] Preferably, the base is provided with a toothed rack with upwardly inclined teeth, and a clamping plate is further provided, the clamping plate is provided with clamping teeth matched with the toothed rack, the base is provided with a clamping plate mounting groove opposite to the bottom of the toothed rack, the bottom of the clamping plate mounting groove is provided with a clamping plate limiting block capable of blocking the bottom of the clamping plate, the clamping plate is arranged in the clamping plate mounting groove and connected with the clamping plate mounting groove through a clamping plate spring, the base is provided with an upper pressing block above the toothed rack and a lower pressing block below the toothed rack, the clamping plate mounting groove is provided with a gap above and below the clamping plate mounting groove for the upper pressing block or the lower pressing block to pass through, the upper pressing block passes through the gap and abuts against the top of the clamping plate and presses the bottom of the clamping plate into the inner side of the clamping plate limiting block, and the lower pressing block passes through the gap and abuts against the bottom of the clamping plate and pushes the bottom of the clamping plate out of the clamping plate limiting block.

[0018] Preferably, the base is provided with a vertically arranged lifting guide groove, the side wall of the lifting guide groove is provided with a plurality of positioning clamping ports at intervals, the lifting seat is provided with a laterally movable positioning plug, the positioning plug is provided with a positioning part capable of being inserted into the positioning clamping port, and the positioning plug and the lifting seat are further provided with a positioning spring capable of pushing the positioning part to the positioning clamping port.

[0019] Preferably, the support is rotatably connected with a connecting seat through an elastic mechanism, and the left backrest and the right backrest are movably installed on the connecting seat.

[0020] Preferably, the left backrest and the right backrest are provided with vertical lifting through grooves, the connecting seat is installed at the lifting through grooves and is provided with a plurality of lifting positioning holes at intervals along the vertical direction, the left backrest and the right backrest are provided with front and back movable lifting clamps, the lifting clamps are provided with positioning clamping blocks capable of being inserted into the lifting positioning holes, and the lifting clamps and the left backrest and the right backrest are further provided with lifting adjusting springs capable of pushing the lifting clamps to the lifting positioning holes.

[0021] Through the chair backrest, the backrest can be stably and accurately attached to the human back, and the comfort of the user is improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 、 2 is a structural schematic diagram of the chair backrest embodiment one.

[0023] Figure 3 is a top view structural schematic diagram of the chair backrest.

[0024] Figure 4 is a connecting structural schematic diagram of the left backrest and the back support.

[0025] Figure 5 is a local structural schematic diagram of the left backrest and the back support connection.

[0026] Figure 6 is a schematic diagram of the connection structure of the support and the elastic mechanism.

[0027] Figure 7 is a schematic diagram of the connection structure of the left backrest and the elastic mechanism.

[0028] Figures 8-10 is a schematic diagram of the structure of the back support.

[0029] Figure 11 is a schematic diagram of the connection structure of the lifting seat and the positioning block.

[0030] Figure 12 is a schematic diagram of the connection and lifting adjustment structure of the base and the positioning block.

[0031] Figure 13 is a schematic diagram of the structure of the chair backrest embodiment two.

[0032] Figures 14-16 is a schematic diagram of the partial structure of embodiment two.

[0033] Figure 17 is a schematic diagram of the structure of the chair backrest embodiment three.

[0034] Figure 18 is a schematic diagram of the structure of the chair backrest embodiment four.

[0035] Figure 19 is a schematic diagram of the partial structure of embodiment four.

[0036] Figure 20 is a schematic diagram of the adjustment state of embodiment four.

[0037] Figure 21 , 22 is a schematic diagram of the structure of the chair backrest embodiment five.

[0038] Figure 23 is a schematic diagram of the structure of the chair backrest embodiment six.

[0039] Figure 24 , 25 is a schematic diagram of the partial structure of embodiment six.

[0040] Figure 26 is a schematic diagram of the structure of the chair backrest embodiment seven.

[0041] Figure 27 , 28 is a schematic diagram of the structure of two different embodiments.

[0042] Figure 29 , 30 is a schematic diagram of the adjustment state of the chair backrest. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0044] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, top, bottom, inner, outer, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications also change accordingly.

[0045] In the description of the present application, it should be noted that unless explicitly specified and limited, the terms "mounting", "setting", "provided with", "connected", "connected" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be the communication between two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0046] If the embodiments of the present application involve "first" or "second" or the like, the "first" or "second" or the like is only for description purpose, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, if the meaning of several is more than one, the meaning of multiple is more than two, above, below, within, etc. are understood to include the number. In addition, the technical features of each embodiment can be combined arbitrarily, and in order to make the description simple, all possible combinations of the technical features in the embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, it should be considered that it is within the scope of the present application.

[0047] The present application provides a chair backrest.

[0048] Embodiment one, as shown in Figures 1-12 .

[0049] The chair backrest of this embodiment includes a fixed back frame 1 and a backrest installed on the back frame; the backrest includes a left backrest 2 and a right backrest 3 opposite to the left and right sides of the human back, and the left backrest and the right backrest are rotatably installed on the back frame by an elastic mechanism 4, and the deformation of the elastic mechanism applies a force to the left backrest and the right backrest to make them rotate.

[0050] like Figures 1-4 As shown, when a user sits in a chair and leans back, the left and right sides of the backrest press against the left and right backrests respectively, causing the left and right backrests to rotate. During this rotation, the elastic mechanism 4 deforms, generating a restoring force. This force drives the left and right backrests to rotate in opposite directions. The direction of rotation may be... Figure 3 The counter-clockwise or clockwise rotation of the left and right backrests allows them to fit more closely to the user's back, providing additional support and enhancing user comfort.

[0051] The chair backrest has a horizontally or diagonally arranged support 5. One end of the support is rotatably connected to the left backrest 2 or the right backrest 3 via an elastic mechanism 4. The elastic mechanism 4 is located between the support and the left or right backrest, with the middle of the left or right backrest 2 or 3 connected to the end of the support 5. This allows the left and right backrests to rotate better in two different directions, thus closely conforming to the user's back. Furthermore, the other end of the support 5 is also rotatably connected to the back frame 1 via the elastic mechanism 4, forming two elastic rotation mechanisms. In addition to achieving the rotational conforming effect like a single elastic rotation mechanism, the two elastic rotation mechanisms can also create a forward or backward support effect by having one rotate in the forward direction and the other in the opposite direction. This increases the adjustment range of the backrest, better supports, follows, and conforms to the user's back or waist, and further avoids excessive pressure on certain parts of the back during leaning, further improving comfort. Figure 4 , 5 As shown, the elastic mechanism 4 is a torsion spring, which has a simple structure and stable operation. Of course, the elastic mechanism can also be a tension spring, compression spring, gas spring, elastic sheet, leaf spring, or any other device with elastic function; there are no restrictions here. Different springs or elastic sheets are simply installed on both sides of the hinge end of the backrest to drive the backrest to rotate. In some other embodiments, an elastic rotation mechanism can be provided only between the bracket and the left and right backrests, or only between the bracket and the back frame 1, to achieve the requirement of rotation only.

[0052] like Figure 5As shown, the backrest 1 is provided with a connecting seat 6, which can be integrally connected to the backrest or detachably connected to the backrest. The connecting seat has a recessed seat groove 61, and a limiting groove 62 is provided in the seat groove. The end of the bracket 5 is set in the seat groove and is hinged to the connecting seat through a rotating shaft 7. The end of the bracket also has a recessed torsion spring mounting groove 51, in which the torsion spring is installed and one end is set in the limiting groove 62. Furthermore, the back of the left backrest 2 and the right backrest 3 are also provided with connecting seats 6 that are integrally connected to or detachable from the backrests, such as... Figure 6 , 7 The connecting seat 6 has a recessed seat groove 61 and a limiting groove 62 inside the seat groove. The end of the bracket 5 is located in the seat groove and is hinged to the connecting seat via a rotating shaft 7. The end of the bracket also has a recessed torsion spring mounting groove 51. The torsion spring is installed in the torsion spring mounting groove, and one end of it is located in the limiting groove 62 of the seat groove. This structure can ensure the stability of the backrest rotation, thereby more accurately conforming to the human back and improving the comfort of use. Furthermore, a rubber sleeve or rubber tube can be fitted over the rotating shaft 7 to reduce the noise generated during rotation. Obviously, in some other embodiments, if the elastic mechanism is not a torsion spring, other elastic mechanisms can be used in the same way. In addition, in some other embodiments, the connecting seat 6 can be relatively lifted and lowered to the left backrest 2 and the right backrest 3, thereby adjusting the backrest to a suitable height to meet the user's needs; or, the connecting seat 6 can also be lifted and lowered and installed on the back frame 1.

[0053] The chair backrest, the back frame 1 includes a fixed base 11 and a lifting seat 12 that moves up and down relative to the base. The left backrest 2 and right backrest 3 are both mounted on the lifting seat. The base has a vertically arranged guide groove, and several positioning slots 13 are arranged vertically on both sides of the guide groove, with the positioning slots inclined upwards. The lifting seat is equipped with two horizontally opposite positioning blocks 14. One end of each positioning block is rotatably mounted on the lifting seat, and the other end is a locking part 15. Between the middle of the two positioning blocks are a locking assembly 16 and a positioning elastic element 17 that engage and fix each other. The positioning elastic element applies a force to the positioning blocks pointing towards the positioning slots. The top of the guide groove is a locking guide part 18 that applies relative movement to the two positioning blocks and drives the locking assembly to engage and fix each other. The bottom of the guide groove is an unlocking guide block 19 that inserts between the two positioning blocks and drives the locking assembly to disengage. Figures 8-12 As shown, the two positioning blocks can be locked into the positioning slots under the action of the positioning elastic element. Because the positioning slots are tilted upwards, the lifting seat and its left and right backrests are fixed at a specific height to meet the needs of people of different body types. When the user needs to adjust the backrest height upwards, pulling the lifting seat upwards will move the positioning blocks to the uppermost positioning slots. Figure 12As shown, when it is needed to adjust the height downward, the positioning blocks are moved to the clamping guide portion by the lifting seat, the two positioning blocks are relatively moved under the action of the clamping guide portion until the clamping assembly between the two positioning blocks is fixed to each other, so that the two positioning blocks cannot be opened to the positioning clamping groove again, at this time, the lifting seat is lowered to the bottom of the guide groove, the clamping assembly is unlocked by unlocking the guide block, and the two positioning blocks are opened again under the action of the positioning elastic member, then the user can adjust the lifting seat and the backrest to the required height according to the foregoing method. The adjusting structure of the backrest is simple and small, can be conveniently set and installed, and is simple and convenient to use, and can stably position the backrest at the required height. The positioning elastic member 17 can be a compression spring as shown, or an elastic ring, or an elastic device with elasticity such as an elastic sheet. Figure 12 The clamping assembly 16 includes a clamping groove portion and a clamping block portion respectively arranged on the two positioning blocks 14, the clamping groove portion is provided with a clamping groove, and the end portion of the clamping block portion can be inserted and fixed in the clamping groove, so that clamping and fixing are conveniently performed. In addition, as shown in Figure 10 , the base 11 is provided with a lifting limiting groove 101, the base is further provided with a lifting limiting plate 102 which can be lifted, the lifting limiting groove is provided with a lifting limiting member 103 and is connected with the lifting limiting plate and the lifting seat 12, so that the stability and accuracy of the movement of the lifting seat are improved, and falling or front and back shaking of the lifting seat during lifting is avoided. The base 11 is provided with two vertically arranged guide strips 10 which are arranged side by side in front of and behind each other, the middle portions of the lifting limiting plate 102 and the lifting seat 12 are arranged between the two guide strips, so that the guide strips limit and guide the lifting seat from the horizontal direction, and left and right shaking of the lifting seat during lifting is avoided.

[0054] As shown in Figures 13-16 .

[0055] The chair backrest of the embodiment is provided with a connecting seat 6 on the left backrest 2, the right backrest 3 and the backrest 1, opposite ends of the connecting seat are provided with connecting plates 63, coaxial through holes are formed in the two connecting plates; one end of the support 5 is arranged between the two connecting plates, and the end portion of the support is provided with a containing cavity for placing the elastic mechanism 4, the elastic mechanism 4 is a torsion spring; a connecting shaft 65 passes through the two connecting plates and the containing cavity between the two connecting plates in sequence, the torsion spring is sleeved on the connecting shaft, the support and the backrest are provided with torsion spring positioning grooves 60, and the two ends of the torsion spring are limited in the torsion spring positioning grooves of the support and the backrest respectively. The backrest is driven to rotate relative to the support or the support is driven to rotate relative to the backrest by the action of the torsion spring, so that the backrest is tightly attached to the back of the user. The structure is not easy to deviate during rotation, and is more stable. Further, a rubber or plastic sleeve 651 is sleeved on the connecting shaft 65, and the torsion spring is sleeved on the rubber or plastic sleeve, so that the sound during rotation is reduced. The torsion spring positioning grooves arranged on the backrest, the support, the left backrest and the right backrest can be strip grooves similar to the end portions of the torsion spring, or cavities abutting against the end portions of the torsion spring.

[0056] The left backrest 2, the right backrest 3 and the bracket 5, and the bracket 5 and the back frame 1 are circumferentially provided with turning limiting blocks 54 and turning limiting grooves 69, so as to avoid excessive turning of the left and right backrests. Obviously, in some other embodiments, these limiting structures can also not be provided, so that the turning range is larger or more free. In addition, decorative covers 632 can also be added at both ends of the through hole of the connecting plate, so as to be more beautiful.

[0057] Embodiment three, as shown in Figure 17

[0058] The chair backrest of the embodiment, the bracket 5 includes a plurality of bracket rods 55 which are sequentially hinged at the ends, wherein the end of the bracket rod is rotatably connected between the end of the back frame 1 through the elastic mechanism 4, and the end of the other bracket rod is rotatably connected between the left backrest 2 or the right backrest 3 through the elastic mechanism 4. Further, the adjacent bracket rods can also be rotatably connected through the elastic mechanism 4, so as to provide more flexible support requirements. The bracket rod can be two hinged bracket rods, and when the hinged end is more than three, the structure can be set according to the above structure. The chair backrest through the setting of multiple hinged ends can form a larger adjustment range and adjustment state, and more hinged ends can further follow and fit the human back, further avoid the local position of the human back from being stressed too much, solve the problem of uneven stress of the human back, so as to further improve the use comfort of the user.

[0059] Embodiment four, as shown in Figures 18-20

[0060] The chair backrest of the embodiment, the back frame 1 includes a fixedly arranged base 11 and a lifting seat 12 which moves up and down relative to the base, and the left backrest 2 and the right backrest 3 are both mounted on the lifting seat; at the same time, the base 11 is provided with a toothed rack 111 which is obliquely upward, and there is a clamping plate 112, the clamping plate is provided with clamping teeth 113 which cooperate with the toothed rack, the lifting seat is provided with a clamping plate mounting groove 114 opposite the bottom of the toothed rack, the bottom of the clamping plate mounting groove is provided with a clamping plate limiting block 115 which can block the bottom of the clamping plate, the clamping plate is arranged in the clamping plate mounting groove and connected with the clamping plate spring 116 between the clamping plate mounting groove, the upper and lower parts of the base are respectively provided with an upper pressing block 117 and a lower top block 118, the upper and lower parts of the clamping plate mounting groove are respectively provided with a gap 119 for the upper pressing block or the lower top block to pass through, the upper pressing block passes through the gap and abuts against the top of the clamping plate and presses the bottom of the clamping plate into the inside of the clamping plate limiting block, the lower top block passes through the gap and abuts against the bottom of the clamping plate and lifts it out of the clamping plate limiting block, further, the upper and lower ends of the lifting seat 12 can also be provided with the gap 119, so as to facilitate the upper pressing block or the lower top block to pass through; as Figures 18-20 ​​As shown, the rack, the clamping plate, the clamping plate mounting slot are arranged in horizontal direction, when positioned at a certain height, the clamping plate is in the clamping plate mounting slot, the clamping tooth protrudes from the clamping plate mounting slot and is clamped with the tooth opening arranged on the rack, as shown in Figure 20 (b); when the backrest needs to be raised, pull the lifting seat up; when the backrest needs to be lowered, continue to pull the lifting seat to the highest position, so that the top of the clamping plate abuts against the upper pressing block, thereby applying a downward force to the clamping plate and making the bottom of the clamping plate retract into the inside of 16, as shown in Figure 20 (c), at this time the clamping tooth will be separated from the rack, as shown in Figure 20 (d), under the action of gravity, the lifting seat is lowered to the bottom, or the lifting seat is pulled down to the bottom, so that the bottom of the clamping plate abuts against the lower pressing block through the gap, thereby making the clamping plate separate from the clamping plate limiting block, as shown in Figure 20 (a), after that, the backrest can be adjusted upward to the required height. Further, the top of the clamping plate 112 is a circular arc, which avoids the clamping plate from being stuck in the process of swinging in the clamping plate mounting slot during the lifting of the backrest, thereby being more smooth. Similarly, the base 11 and the lifting seat 12 can also be matched with vertically arranged guiding components, such as guiding strips, lifting limiting plates, limiting grooves and limiting pieces, to improve the accuracy of lifting and adjusting.

[0061] Example five, as shown in Figures 21-22 .

[0062] The back frame 1 comprises a fixed base 11 and a lifting seat 12 moving up and down relative to the base, and several lifting seats, each left backrest 2 and right backrest 3 is installed on each lifting seat, and each left backrest 2 and right backrest 3 can also be vertically arranged in multiple and installed on each lifting seat, so that each independent backrest can be arbitrarily adjusted and fixed. In this embodiment, two left backrests and two right backrests, the lifting seat can also be provided with two, and the left backrest 2 and the right backrest 3 at the same height are installed on the same lifting seat, so that the left backrest 2 and the right backrest 3 at the same height can be lifted simultaneously. In addition, in order to adjust the backrest, a vertical lifting guide slot 126 can be provided on the base 11, the side wall of the guide slot is provided with a plurality of positioning sockets 123 at intervals, the lifting seat 12 is installed on the lifting guide slot through the lifting guide 127, and the lifting seat 12 is provided with a transversely movable positioning plug 124, and the positioning plug is provided with a positioning part which can be inserted into the positioning socket, and the positioning plug and the lifting seat are further provided with a positioning spring 125 which pushes the positioning part to the positioning socket, thereby forming a lock. When the height of the backrest needs to be adjusted, press the positioning plug and make the positioning part exit the positioning socket, then pull the backrest to the desired height and release the positioning plug, the positioning plug is relocked under the action of the positioning spring, thereby meeting the user's different height support adjustment requirements of each part of the shoulder, back, waist and the like. Similarly, a vertical guide bar can also be added to improve stability. Further, the number of backrests 2 and right backrests 3 can be increased, such as three or more, and the lifting mechanism is used to adjust each backrest more carefully.

[0063] As shown in Figures 23-25

[0064] ​The main difference between the embodiment five and the embodiment six is that the left and right backrests of the embodiment five are independently liftable and installed on the back frame, while the left and right backrests of the embodiment six are independently liftable and installed on the support 5, so as to avoid the insufficient space structure of the back frame or to be more convenient for adjustment due to being closer to the user. Like the chair backrest of the embodiment, the support 5 is rotatably connected with the connecting seat 6 through the elastic mechanism 4, and the left backrest 2 and the right backrest 3 are independently liftable and installed on the connecting seat, so as to form more adjustment states and meet different use needs. Specifically, the left backrest 2 and the right backrest 3 are provided with vertical lifting through-slots 21, the connecting seat 6 is installed at the lifting through-slots and is vertically spaced apart and provided with a plurality of lifting positioning holes 57, in order to realize the lifting clamping, the left backrest and the right backrest are provided with lifting clamping blocks 22 which are movable forward and backward, the lifting clamping blocks are provided with positioning clamping blocks 23 which are insertable into the lifting positioning holes, and the lifting clamping blocks are provided with lifting adjustment springs 24 which are arranged between the lifting clamping blocks and the left backrest and the right backrest and push the lifting clamping blocks to the lifting positioning holes, so as to form the positioning, and when adjustment is needed, the lifting clamping blocks are pressed and separated from the lifting positioning holes, so that the left backrest and the right backrest can be independently liftable and adjustable and locked. The connecting seat 6 can be installed on the lifting through-slots 21 through the clamping blocks 25, and the left backrest 2 and the right backrest 3 are further provided with placing cavities 26 for placing the lifting clamping blocks 22, so as to install the lifting clamping blocks.

[0065] It can be understood that the independent lifting seats of the embodiment 5 or the supports of the embodiment 6 can be installed on the entire lifting seat in addition to being installed on the back frame, so that the left and right backrests can be independently lifted and the left and right backrests can be simultaneously lifted.

[0066] The embodiment 7 is shown in Figure 26 .

[0067] The connecting seat 6 and the left backrest and the right backrest can be further provided with a buffering mechanism 601 respectively, such as a plurality of springs or elastic soft glue, so as to reduce vibration when the backrest is rotated.

[0068] In some embodiments, the left and right backrests adopting the connecting structure of the utility model can be one, such as Figure 27 , or two, such as Figure 1 , which are respectively an upper backrest and a lower backrest and support the left and right back portions and the left and right waist portions, in addition to which, there can be more than three, which are left and right shoulder pillows, left and right backrests and left and right waist pillows, such as Figure 28 , or even left and right neck pillows, left and right head pillows and the like. Various combinations can be better independently adjusted and fixed and provide more personalized support.

[0069] In some embodiments, the elastic mechanism 4 or the connecting seat 6 can be provided with a locking mechanism to lock at multiple angles during rotation. For example, a locking block is provided above or below the connecting seat, and a spring is connected to the locking block. When the locking block is locked, the locking block is engaged with the locking tooth. When unlocking, the locking block is separated from the locking tooth.

[0070] The following describes some specific operations and use methods of the chair with the backrest, including but not limited to the following: Figure 29 As shown in (a), (b), (c) and (d) of FIG. 1, the entire backrest can be adjusted upward to adapt to the height of the user. The upper left and right backrests rotate in the opposite direction to move backward. The lower left and right backrests only rotate in one direction to better wrap the waist of the user. Figure 30 As shown in (a), (b) and (c) of FIG. 2, the left and right backrests are adapted to the sitting posture of the user through various elastic rotations. In addition, these functional parts can be used alone or in combination to meet the different support needs of the user.

[0071] The utility model also provides a chair structure which is provided with the chair backrest described above. The chair backrest can be applied to various fixed or movable chairs to provide support for the back of the user and achieve the effective effect of the chair backrest described above.

[0072] The above description is only the preferred embodiments of the utility model, and does not limit the patent range of the utility model. Any equivalent structural transformation or direct / indirect application in other related technical fields based on the utility model description and the drawings is included in the patent protection range of the utility model. In the description of the utility model, the description of the terms "one embodiment", "some embodiments", "embodiment", "illustrative embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the utility model. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments, and the embodiments of the utility model and the features in the embodiments can be combined.

Claims

1. A chair backrest, comprising a fixedly mounted back frame (1) and a backrest installed on the back frame, characterized in that: The backrest includes a left backrest (2) and a right backrest (3) opposite to the left and right sides of the human back. The left backrest and the right backrest are rotatably mounted on the back frame through an elastic mechanism (4). The deformation of the elastic mechanism applies a force to the left backrest and the right backrest to make them rotate.

2. The chair backrest according to claim 1, characterized in that: There is a horizontal or diagonal bracket (5), one end of which is rotatably connected to the left backrest (2) or the right backrest (3) through an elastic mechanism (4), and the other end of the bracket (5) is rotatably connected to the back frame (1) through an elastic mechanism (4).

3. The chair backrest according to claim 2, characterized in that: The support (5) includes several support rods (55) that are hinged end to end. The end of one support rod is hinged to the back frame (1), and the end of the other support rod is hinged to the left backrest (2) or the right backrest (3). Adjacent support rods are rotatably connected by an elastic mechanism (4).

4. The chair backrest according to claim 2 or 3, characterized in that: The elastic mechanism (4) is a torsion spring; the left backrest (2), right backrest (3) or back frame (1) is provided with a connecting seat (6), the connecting seat is provided with a recessed seat groove (61), the seat groove is provided with a limiting groove (62), the end of the bracket (5) is set in the seat groove and is hinged to the connecting seat through a rotating shaft (7), the end of the bracket is also provided with a recessed torsion spring mounting groove (51), the torsion spring is installed in the torsion spring mounting groove and one end of it is set in the limiting groove (62).

5. The chair backrest according to claim 2 or 3, characterized in that: The left backrest (2), right backrest (3), and back frame (1) are provided with connecting seats (6), and the upper and lower ends of the connecting seats are provided with connecting plates (63) respectively. The two connecting plates have coaxial through holes. One end of the bracket (5) is located between the two connecting plates, and the end of the bracket is provided with a receiving cavity for placing the elastic mechanism (4). The elastic mechanism (4) is a torsion spring. The connecting shaft (65) passes through the two connecting plates and the receiving cavity between them in sequence. The torsion spring is sleeved on the connecting shaft. The bracket and the left backrest, right backrest, and back frame are provided with torsion spring positioning grooves (60) for placing the end of the torsion spring.

6. The chair backrest according to claim 5, characterized in that: A steering limit block (54) and a steering limit groove (69) are provided circumferentially between the left backrest (2), the right backrest (3) and the bracket (5), and between the bracket and the back frame (1).

7. The chair backrest according to claim 1, characterized in that: The backrest (1) includes a fixed base (11) and a lifting seat (12) that moves up and down relative to the base. The left backrest (2) and the right backrest (3) are mounted on the lifting seat.

8. The chair backrest according to claim 7, characterized in that: All left backrests (2) and right backrests (3) are mounted on the same lifting seat (12).

9. The chair backrest according to claim 7, characterized in that: The left backrest (2), the right backrest (3) and the lifting seat (12) are each provided with two or more in the vertical direction. The left backrest and the right backrest at the same horizontal height are installed on the same lifting seat.

10. The chair backrest according to claim 7, 8 or 9, characterized in that: The base is provided with a vertically arranged guide groove, and several positioning slots (13) are provided on both sides of the guide groove along the vertical direction, and the positioning slots are inclined upward; the lifting seat is equipped with two horizontally opposite positioning blocks (14), one end of the two positioning blocks is rotatably installed on the lifting seat, and the other end of the two positioning blocks is a clamping part (15). Between the middle of the two positioning blocks, there are respectively a clamping component (16) and a positioning elastic element (17) that are mutually clamped and fixed. The positioning elastic element applies a force to the positioning blocks pointing towards the positioning slots; the top of the guide groove is a clamping guide part (18) that applies relative movement to the two positioning blocks and drives the clamping component to clamp and fix each other, and the bottom of the guide groove is provided with an unlocking guide block (19) that is inserted between the two positioning blocks and drives the clamping component to disengage from each other.

11. The chair backrest according to claim 10, characterized in that: The locking assembly (16) includes a slot portion and a block portion respectively disposed on two positioning blocks (14). The slot portion has a recessed slot, and the end of the block portion can be inserted and fixed in the slot.

12. The chair backrest according to claim 7, 8 or 9, characterized in that: The base is provided with a rack (111) with the toothed edge tilted upwards, and a clamping plate (112). The clamping plate is provided with clamping teeth (113) that cooperate with the rack. The lifting seat is provided with a clamping plate mounting groove (114) opposite to the bottom of the rack. The bottom of the clamping plate mounting groove is provided with a clamping plate limiting block (115) that can block the bottom of the clamping plate. The clamping plate is set in the clamping plate mounting groove and is connected to the clamping plate mounting groove by a clamping plate spring (116). The base is provided with an upper pressing block (117) and a lower pushing block (118) above and below the rack, respectively. The clamping plate mounting groove (114) is provided with notches (119) above and below for the upper pressing block or the lower pushing block to pass through. The upper pressing block passes through the notch and abuts against the top of the clamping plate and presses the bottom of the clamping plate into the inner side of the clamping plate limiting block. The lower pushing block passes through the notch and abuts against the bottom of the clamping plate and pushes it out of the clamping plate limiting block.

13. The chair backrest according to claim 7, 8 or 9, characterized in that: The base (11) is provided with a vertically arranged lifting guide groove. The side wall of the lifting guide groove is provided with a number of positioning slots (123) at intervals. The lifting seat (12) is equipped with a positioning block (124) that can move laterally. The positioning block is provided with a positioning part that can be inserted into the positioning slot. A positioning spring (125) that pushes the positioning part to the positioning slot is also installed between the positioning block and the lifting seat.

14. The chair backrest according to claim 2 or 3, characterized in that: The bracket (5) is rotatably connected to the connecting seat (6) via the elastic mechanism (4), and the left backrest (2) and right backrest (3) are mounted on the connecting seat in a height-adjustable manner.

15. The chair backrest according to claim 14, characterized in that: The left backrest (2) and right backrest (3) are provided with vertical lifting channels (21). The connecting seat (6) is installed at the lifting channel and is provided with several lifting positioning holes (57) at intervals along the vertical direction. The left backrest and right backrest are provided with lifting blocks (22) that can move back and forth. The lifting blocks are provided with positioning blocks (23) that can be inserted into the lifting positioning holes. The lifting blocks are connected to the left backrest and right backrest with lifting adjustment springs (24) that push the lifting blocks to the lifting positioning holes.

16. A chair structure, characterized in that: It is equipped with a chair back as described in any one of claims 1-15.

Images