Seat

Abstract

A seat, comprising: a base (1); a seat frame (2), rotatably mounted on the base (1), wherein a foot bracket (3) and a backrest frame (4) are hingedly connected to the seat frame (2), and the foot bracket (3) and the backrest frame (4) are both staggered from the rotation axis of the seat frame (2) relative to the base (1); a connecting rod mechanism (5), comprising a first connecting rod assembly (51) connected between the base (1) and the seat frame (2), and a second connecting rod assembly (52) connected between the seat frame (2) and the foot bracket (3); and a driving unit (6), configured to drive the first connecting rod assembly (51) and the second connecting rod assembly (52) to operate, so as to link the rotation of the seat frame (2) and the rotation of the foot bracket (3).

Description

A seat Cross-reference to related applications

[0000] This application claims the priority of a Chinese patent application with an application number of 202410072105.1 filed with the Chinese Patent Office on January 17, 2024, the entire content of which is incorporated herein by reference. Technical field This application relates to the field of household items, and particularly to a seat. Background art With the development of the household industry, people have more and more requirements for the functions of seats. Currently, existing seats have two usage states: sitting position and lying position, which enrich the usage requirements of seats and improve the user experience. Summary of the invention This application provides a seat, including: a base; a seat frame rotatably installed on the base, with a foot support and a backrest frame hinged on the seat frame, and both the foot support and the backrest frame are offset from the rotation axis of the seat frame relative to the base; a link mechanism including a first link assembly connected between the base and the seat frame and a second link assembly connected between the seat frame and the foot support; a drive unit for driving the first link assembly and the second link assembly to operate so as to link the rotation of the seat frame and the rotation of the foot support. By adopting the above technical solution, when installing and placing the seat, the base is placed on the ground, and the rotation direction of the seat frame relative to the base is the front-back direction. Moreover, both the foot support and the backrest frame are offset from the rotation axis of the seat frame, enabling the seat frame to rotate and lift up to keep the foot support away from the ground, so as to avoid interference and collision with the ground when the foot support extends, reduce the requirement for the installation height of the seat frame, and meet the installation requirement of "low seat height" for the seat frame, thereby improving the user experience in terms of the comfort of the sitting position state; in addition, the link mechanism is used as the power transmission structure, reducing the occupied space of the transmission structure, making the transmission structure more slender, enhancing the aesthetics, and at the same time being applicable to the installation method of "low seat height" for the seat frame, that is, the link mechanism will not interfere with the ground during operation. In some embodiments, the link mechanism operates within the thickness range of the seat frame. By adopting the above technical solution, the link mechanism will not exceed the thickness range of the seat frame during operation, playing a role in hiding the link mechanism and improving the user experience in terms of aesthetics. In some embodiments, the drive unit is installed on the side beam of the seat frame. By adopting the above technical solution, the drive unit is installed on the side to reduce the space occupied below the seat frame and at the same time reduce the interference effect on the rotation of the foot support. In some embodiments, the first link assembly includes a first connecting member and a second connecting member. Among them, both the first connecting member and the second connecting member are hinged between the seat frame and the base, so that the base, the first connecting member, the seat frame, and the second connecting member form a four-bar mechanism. In some embodiments, the first connecting member includes a rotating shaft, a toothed plate fixed on the rotating shaft, and a rotating rod. The rotating shaft is rotatably connected to two side beams of the seat frame. The toothed plate is engaged with the output end of the driving unit, and the rotating rod is hinged to the side of the base. In some embodiments, limiting slideways are provided on both the toothed plate and the first rod included in the second link assembly. A limiting member is fixed on the seat frame, and the limiting member is slidably matched with the limiting slideway to limit the rotation range of the toothed plate and the first rod. In some embodiments, the second link assembly includes a first rod, a second rod, a third rod, and a fourth rod; both the first rod and the third rod are hinged on the seat frame, the second rod is hinged between the first rod and the third rod, and the seat frame, the first rod, the second rod, and the third rod form a set of four-bar mechanisms; the fourth rod is hinged between the third rod and the foot bracket, and the seat frame, the third rod, the fourth rod, and the foot bracket form a set of four-bar mechanisms. In some embodiments, the second link assembly includes a first rod, a second rod, a third rod, and a speed regulation structure for regulating the rotation speed of the foot bracket; the first rod, the second rod, and the third rod are hinged in sequence, and the first rod is hinged on the seat frame, and the third rod is hinged on the foot bracket; the speed regulation structure includes a connecting slideway provided on the seat frame and a second sliding member slidably installed on the connecting slideway. The second sliding member is hinged at the hinge connection between the second rod and the third rod, so that the seat frame, the first rod, the second rod, and the second sliding member form a link-slider structure; the seat frame, the second sliding member, the third rod, and the foot bracket form a slider-link structure. Among them, the connecting slideway is divided into two sections. When the second sliding member slides along the two sections of the connecting slideway respectively under the same output power of the driving unit, the rotation speed of the foot bracket is different. In some embodiments, a first linkage is connected between the first link assembly and the second link assembly. By adopting the above technical solution, the first linkage connects the first link assembly and the second link assembly, links the rotation action of the seat frame with the rotation action of the foot bracket, and improves the operation linkage. In some embodiments, the seat frame and the footrest bracket are linked by the first linkage; one end of the first linkage is hinged to one of the first connecting member and the second connecting member included in the first link assembly, and the other end of the first linkage is hinged to one of the first rod, the second rod, the third rod, and the fourth rod included in the second link assembly. In some embodiments, the drive unit includes a first drive unit for driving the first link assembly to operate and a second drive unit for driving the second link assembly to operate. By adopting the above technical solution, the first link assembly and the second link assembly are independently driven by two different drive units to meet more drive operation requirements and the installation requirements of the drive units, and the cooperation of the seat frame rotation action and the footrest bracket rotation action is realized by the sequential cooperation of the two drive units. In some embodiments, a second linkage is connected between the backrest frame and the link mechanism to link the rotation of the backrest frame with the rotation of the seat frame and / or the rotation of the footrest bracket. By adopting the above technical solution, the backrest frame and the link mechanism are connected by the second linkage to improve the linkage between the backrest frame, the seat frame, and the footrest bracket, and enhance the linkage of the entire seat operation. In some embodiments, the drive unit further includes a third drive unit for driving the backrest frame to rotate. By adopting the above technical solution, the backrest frame can also be driven to rotate by an independent drive unit to meet different usage requirements of users. In some embodiments, the footrest bracket includes a footrest main body hinged to the seat frame and an extension plate slidably mounted on the footrest main body, and a stretching mechanism is connected between the extension plate, the footrest main body, and the seat frame, so that the extension plate can slide relative to the footrest main body during the rotation of the footrest main body relative to the seat frame. By adopting the above technical solution, the extension plate can slide relative to the footrest main body during the rotation of the footrest bracket to change the area of the footrest bracket supporting the user's feet, so as to provide better support for the user's feet, improve the user experience, and also reduce the occupied space in the contracted state of the footrest bracket. In some embodiments, the stretching mechanism includes a fifth rod and a first slider. One end of the fifth rod is hingedly installed on the seat frame, the other end of the fifth rod is hingedly installed on the first slider, the first slider is slidably connected to the footrest main body and connected to the extension plate, and the seat frame, the footrest main body, the fifth rod, and the first slider form a link-slider mechanism. By rotating the footrest main body around the seat frame, the first slider slides relative to the footrest main body, thereby driving the extension plate to slide relative to the footrest main body. In some embodiments, a sixth rod and a seventh rod are mounted on the footrest main body. One end of the sixth rod is hinged to the footrest main body, and the other end is hinged to the seventh rod. One end of the seventh rod is hinged to the sixth rod, and the other end is hinged to the extension plate. The footrest main body, the sixth rod, the seventh rod, and the extension plate form a connecting rod slider mechanism. An avoidance slideway is provided on the sixth rod, and the first slider is located in the avoidance slideway. In some embodiments, during the rotation process of the footrest main body, it has a contracted state, an extended state, and an intermediate state between the contracted state and the extended state. During the rotation switching process of the footrest main body between the contracted state and the intermediate state, the extension plate is stationary relative to the footrest main body. During the rotation switching process of the footrest main body between the intermediate state and the extended state, the extension plate slides relative to the footrest main body. By adopting the above technical solution, since the rotation angle of the seat frame is relatively small in the early stage of the rotation adjustment of the footrest bracket, and the distance between the footrest bracket and the ground is relatively small at this time. Therefore, during the rotation switching process of the footrest main body from the contracted state to the intermediate state, the extension plate remains stationary relative to the footrest main body and does not slide and extend, reducing the probability of the extension plate sliding out relative to the footrest main body and interfering with and colliding with the ground. If the extension plate collides with the ground, it will not only cause damage to the footrest bracket, but also reduce the user experience. In the later stage of the rotation adjustment of the footrest bracket, that is, during the rotation switching process of the footrest main body from the intermediate state to the extended state, the seat frame has rotated a certain angle. At this time, the distance between the footrest bracket and the ground is relatively large, and the probability of the extension plate sliding and extending relative to the footrest main body and interfering with and colliding with the ground is small. In some embodiments, during the rotation process of the footrest bracket, it has a contracted state, an extended state, and a variable speed state between the contracted state and the extended state. A speed regulation structure for regulating the rotation speed of the footrest bracket is connected between the footrest bracket and the link mechanism. By adopting the above technical solution, the rotation speed of the footrest bracket is adjusted to meet more usage requirements of users. In some embodiments, the rotation speed of the footrest bracket during the rotation switching process between the contracted state and the variable speed state is n1; the rotation speed of the footrest bracket during the rotation switching process between the variable speed state and the extended state is n2, where: n1 > n2. By adopting the above technical solution, when the footrest bracket rotates and switches between the contracted state and the variable speed state, the rotation speed is relatively large, which can quickly expand the footrest bracket. During this process, the footrest bracket has not yet supported the user's foot, avoiding collision between the footrest bracket and the user's foot. When the footrest bracket rotates and switches between the variable speed state and the extended state, the rotation speed is relatively small, and the footrest bracket expands slowly. During this process, the footrest bracket supports the user's foot and rotates at a slower speed to improve the support comfort of the user's leg and enhance the user experience. In some embodiments, a seat frame has a recessed portion on a side for seating to increase seating space. In some embodiments, the seat frame and / or the foot support and / or the backrest frame have flanges. By adopting the above technical solution, a flange is provided to facilitate the buckling and disassembly of the face cover and to enhance the strength of the component. In addition, the flange can be bent directly on the component to make the flange in an arc shape to reduce the appearance of edges and corners and improve safety. In some embodiments, the chair further comprises a power source for supplying power, the power source being built into the base. By adopting the above technical solution, the power supply is built into the base, reducing space occupation. In some embodiments, an armrest mounting frame for mounting an armrest is fixedly provided on the seat frame. By adopting the above technical solution, the armrest mounting frame is fixed on the seat frame, so that the armrest can also rotate with the seat frame. When the seat is switched between a sitting position and a lying position, the user can always hold the armrest to ensure safety. In summary, the present application includes at least one of the following beneficial technical effects. In the present application, during the operation of the seat frame and the footrest, the seat frame will have a tilting action, which can move the footrest away from the ground and facilitate the rotation of the footrest to meet the installation requirements of the seat frame of "short seat and high seat" and improve the comfort of use. In the present application, a connecting rod mechanism is used as the transmission structure, which makes the transmission structure slimmer and reduces space occupancy. In addition, the operating range of the connecting rod mechanism is within the thickness range of the seat frame, which has a hiding effect on the connecting rod mechanism and improves the aesthetics. In the present application, during the rotation and expansion process of the footrest, the rotation speed is high in the early stage and low in the later stage, which improves the expansion efficiency of the footrest and can reduce the impact effect of the footrest on the user's feet when supporting them, thereby improving the user experience; in addition, during the rotation and expansion process of the footrest, the extension plate is stationary relative to the footrest body in the early stage, and the extension plate slides relative to the footrest body in the later stage, which can reduce the probability of interference and collision between the extension plate and the ground. In the present application, the number of drive units is set in accordance with the linkage form of the connecting rod mechanism to meet more user requirements. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified schematic diagram of the seat operating structure of the first embodiment. FIG. 2 is a simplified schematic diagram of the seat operation structure in which the backrest frame and the seat frame are linked in the second embodiment. FIG. 3 is a simplified schematic diagram of the seat operation structure in which the backrest frame and the foot support frame are linked in the second embodiment. FIG. 4 is a simplified schematic diagram of the seat operation structure of the third and fourth embodiments. FIG. 5 is a simplified schematic diagram of the seat operating structure of the fifth embodiment. Figure 6 is a simplified schematic diagram of the seat operation structure of the sixth embodiment. Figure 7 is a schematic three-dimensional structure diagram of the seat of the sixth embodiment. Figure 8 is a top view schematic diagram of Figure 7. Figure 9 is an enlarged schematic diagram of A in Figure 8. Figure 10 is a schematic three-dimensional structure diagram of Figure 7 in an unfolded state. Figure 11 is an enlarged schematic diagram of B in Figure 10. Figure 12 is an enlarged schematic diagram of C in Figure 10. Figure 13 is an enlarged schematic diagram of D in Figure 10. Figure 14 is a side sectional schematic diagram with the base omitted, where the foot bracket is shown as disconnected. Figure 15 is an enlarged schematic diagram of E in Figure 14. Figure 16 is a side view schematic diagram of the sitting state when the foot bracket is in the middle state. Explanation of reference numerals: 1, base; 11, support leg; 12, connecting part; 13, side; 2, seat frame; 21, recessed part; 22, side beam; 23, cross beam; 24, support shaft; 25, support rod; 26, armrest mounting bracket; 3, foot bracket; 31, footrest main body; 311, slide bar; 32, extension plate; 321, guide slideway; 33, extension mechanism; 331, fifth rod; 332, first slider; 333, sixth rod; 334, seventh rod; 335, avoidance slideway; 34, speed regulation structure; 341, second slider; 342, connecting slideway; 4, backrest frame; 41, second linkage; 5, linkage mechanism; 51, first linkage assembly; 511, first connecting piece; 5111, rotating shaft; 5113, toothed plate; 5114, rotating rod; 512, second connecting piece; 52, second linkage assembly; 521, first rod; 522, second rod; 523, third rod; 524, fourth rod; 53, first linkage; 6, drive unit; 7, limit mechanism; 71, limit slideway; 72, limiting piece; 73, edge stop; 8, flanging; 9, power supply. Detailed implementation manners To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. Components of the embodiments of the present application described and illustrated in the drawings here can be arranged and designed in various different configurations. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application. It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances. In the description of the present application, it should be understood that the terms "up", "down", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application. In the current seat body, in order to satisfy the state switching between sitting and lying positions, one or more driving sources are set to drive the seat body, and the seat frame rotation adjustment, backrest and footrest angle adjustment are realized through a multi-stage transmission structure. However, the multi-stage transmission structure occupies a large space during operation, especially the space under the seat frame, which makes the overall look of the seat bloated, the aesthetics is poor, and the user experience is low. In addition, the seat needs to be installed at a certain height to prevent the footrest from colliding with the ground during rotation and expansion. The high installation of the seat frame will also affect the comfort of use, resulting in a low user experience. The present application is further described in detail below in conjunction with Figures 1-16. The present application discloses a chair capable of switching between a sitting position and a lying position, and specifically discloses the following embodiments. Embodiment 1 As shown in Figures 1 to 7, the chair includes a base 1, a seat frame 2, a foot support 3 and a backrest frame 4. The seat frame 2 is rotatably mounted on the base 1. The foot support 3 and the backrest frame 4 are both hinged on the seat frame 2. The backrest frame 4 and the foot support 3 are staggered with the rotation axis of the seat frame 2, so that when the seat frame 2 rotates from a sitting position to a lying position, the foot support 3 and the backrest frame 4 revolve around the rotation axis of the seat frame 2, resulting in obvious position movement. Specifically, when the chair is actually installed and used, the base 1 is rotatably mounted on the seat frame 2. The foot support 3 and the backrest frame 4 are hinged on the seat frame 2. 1 is placed on the ground, when the seat frame 2 rotates around the base 1 (i.e., the seat frame 2 rotates from a sitting position to a lying position on the base 1), its rotation axis is in a horizontal direction (e.g., parallel to the ground). At this time, the rotation direction of the seat frame relative to the base is a front-to-back direction, and at this time, the foot support 3 and the backrest frame 4 are displaced in the vertical direction to change the distance between the foot support 3 and the ground. In addition, a link mechanism 5 and a drive unit 6 are further provided on the seat. The link mechanism 5 includes a first link assembly 51 and a second link assembly 52. The first link assembly 51 is connected between the base 1 and the seat frame 2, and the second link assembly 52 is connected between the seat frame 2 and the footrest bracket 3. The drive unit 6 is used to drive the first link assembly 51 and the second link assembly 52 to operate, so as to link the rotation of the seat frame 2 and the rotation of the footrest bracket 3. In this embodiment, as shown in FIG. 7, the seat frame 2 includes two side beams 22 and two cross beams 23, and is integrally in the shape of a rectangular frame with a hollow middle part to provide sufficient space for the user to sit. There are recessed parts 21 on the two side beams 22. The recessed parts 21 can be processed by inclined planes, arc surfaces, etc. to increase the user's sitting space, give the user a surrounded sitting feeling, and improve the use experience. During the production and manufacturing stage, flanges 8 can be left on the seat frame 2 and / or the footrest bracket 3 and / or the backrest frame 4, or can be processed later, which is convenient for buckling the strips of the seat cover. Such a seat cover installation method is convenient and fast, and the installation cost is low. Among them, the footrest bracket 3 and the backrest frame 4 are both hinged and installed on the two side beams 22 of the seat frame 2. The footrest bracket 3 is hinged at the front end edge of the seat frame 2, and the backrest frame 4 is installed at the rear end edge of the seat frame 2. In addition, an armrest mounting bracket 26 is fixedly installed on the seat frame 2 to facilitate the installation of an armrest (not shown). In the sitting posture state, the footrest bracket 3 can be accommodated in the accommodation space in the middle of the seat frame 2 to improve the storage and hiding effect. When the seat is switched from the sitting posture state to the lying posture state, the footrest bracket 3 rotates out from below the seat frame 2 and rotates to the front side of the seat frame 2 to support the user's legs. In this embodiment, the seat frame 2 can rotate forward and backward relative to the base 1. When the seat is placed on the ground, by rotating the seat frame 2 backward (such as pressing down on the rear side of the seat frame 2), the front end of the seat frame 2 makes a lifting movement, raising the overall position of the footrest bracket 3, thereby increasing the distance between the footrest bracket 3 and the base 1 and the ground, and reducing the interference and collision between the footrest bracket 3 and the base 1 and the ground during rotation, so as to meet the installation requirement of the "low seat height" of the seat frame 2, that is, the height between the lowest point of the seat frame 2 and the ground is smaller than the length of the footrest bracket 3. It should be noted that when the user sits on the seat in the "low seat height" state, the knees can be fully bent and the sitting posture is relatively comfortable. In other words, "low seat height" can mean that when the length of the footrest bracket 3 remains unchanged, the distance from the ground increases during the opening process of the footrest bracket 3, and then the seat height can be appropriately reduced (the rotation center of the footrest bracket 3 is also reduced). For the linkage mechanism 5 and the drive unit 6, the rotational movement of the linkage seat frame 2 and the rotational movement of the footrest bracket 3 can be achieved, improving the linkage of the structural operation. Moreover, through reasonable dimension design and the design of the rotational speed of the seat frame 2 and the rotational speed of the footrest bracket 3, the situation where the footrest bracket 3 collides with the base 1 and the ground can be avoided. Among them, in the sitting position, the footrest bracket 3 is retracted inside the seat frame 2, and the seat frame 2 and the footrest bracket 3 are basically in a horizontal state. During the backward rotation of the seat frame 2, its front end tilts up and raises the height of the footrest bracket 3 from the ground. At the same time, the footrest bracket 3 rotates under the linkage of the linkage mechanism 5. During the entire rotation process, the lowest point of the footrest bracket 3 is always higher than the ground to avoid collision. The dimensions and rotational speeds of the seat frame 2 and the footrest bracket 3 can also be reasonably designed based on avoiding the collision between the footrest bracket 3 and the base 1. Among them, two sets of linkage mechanisms 5 are provided and are both located inside the side beam 22. The linkage mechanism 5 can improve the stability and reliability of the linkage structure, and the side beam 22 also plays a role in shielding and hiding the linkage mechanism 5, improving the aesthetics of the seat. Specifically, during the operation of the linkage mechanism 5, its operating range is within the thickness range of the seat frame 2. In addition, the linkage mechanism 5 occupies a small space during operation, can meet the installation requirements of the "low seat height" of the seat frame 2, and can avoid the situation where the linkage mechanism 5 collides with the ground during operation. Since the linkage mechanism 5 is located inside the side beam 22 and the footrest bracket 3 is retracted below the seat frame 2 in the sitting position, in this embodiment, the drive unit 6 is installed on the side beam 22 of the seat frame 2 to vacate the space below the seat frame 2. And the drive unit 6 is driven by a rotary motor to provide power, which occupies less space compared with a push rod motor and can meet the installation requirements of low seat height and seat thinness. The power supply 9 for power supply is built into the base 1 and can be fixed by means of a strapping tape, a rope or a steel wire, etc., which is convenient for disassembly and installation of the power supply 9 and does not occupy space separately. As shown in FIG. 1, for the first linkage assembly 51, it includes a first connecting member 511 and a second connecting member 512. Both the first connecting member 511 and the second connecting member 512 are hingedly installed between the seat frame 2 and the base 1, so that the base 1, the first connecting member 511, the seat frame 2 and the second connecting member 512 form a four-bar mechanism. The drive unit 6 is used to drive the first connecting member 511 or the second connecting member 512 to rotate to realize the operation of the first linkage assembly 51. In this embodiment, the drive unit 6 drives the first connecting member 511 to rotate. In this embodiment, as shown in FIG. 7, the base 1 is located at the middle position below the seat frame 2, and the seat frame 2 is in the shape of a hollow frame. For the convenience of connection and installation, a support shaft 24 is fixedly connected between two side beams 22 of the seat frame 2, and a support rod 25 is fixedly arranged on the support shaft 24 to facilitate the hinged installation of the second connecting member 512. In addition, the arrangement of the support shaft 24 can also improve the structural strength of the seat frame 2. As shown in FIGS. 7, 8 and 11, for the base 1, it includes feet 11, a connecting portion 12 fixed on the feet 11, and a side 13 fixed on the connecting portion 12. The arrangement of the connecting portion 12 facilitates the internal installation of the power supply 9, and the arrangement of the side 13 facilitates the hinged installation of the first connecting member 511 and the second connecting member 512. Specifically, one end of the first connecting member 511 is hinged to the main body of the seat frame 2, and the other end of the first connecting member 511 is hinged to the side 13 of the base 1. One end of the second connecting member 512 is hinged to the support rod 25, and the other end of the second connecting member 512 is hinged to the side 13 of the base 1. For the second link assembly 52, it includes a first rod 521, a second rod 522, a third rod 523 and a fourth rod 524, as shown in FIGS. 1 to 5. Specifically, both the first rod 521 and the third rod 523 are hinged to the seat frame 2. The second rod 522 is hinged between the first rod 521 and the third rod 523. The seat frame 2, the first rod 521, the second rod 522 and the third rod 523 form a set of four-bar mechanism. The fourth rod 524 is hinged between the third rod 523 and the foot bracket 3. The seat frame 2, the third rod 523, the fourth rod 524 and the foot bracket 3 form a set of four-bar mechanism. Two sets of four-bar mechanisms are used for connection to suit long-distance transmission scenarios. And to improve the structural reliability, the rods in the four-bar mechanism can be bent or in the form of flywheels, etc., to reduce jamming. The drive unit 6 includes a first drive unit, a second drive unit and a third drive unit (the three drive units are not shown). The first drive unit drives the first link assembly 51 to operate. The second drive unit drives the second link assembly 52 to operate. The third drive unit drives the backrest frame 4 to operate. Specifically, in this embodiment, the first drive unit drives the first connecting member 511 to rotate, and the second drive unit drives the first rod 521 to rotate. In other embodiments, the first drive unit can also drive the second connecting member 512, and the second drive unit can drive the second rod 522, the third rod 523 and / or the fourth rod 524. The third drive unit can directly drive the backrest frame 4 to rotate. Among them, as shown in FIGS. 10 and 13, the first connecting member 511 includes a rotating shaft 5111, a toothed plate 5113 and a rotating rod 5114 fixed on the rotating shaft 5111. The rotating shaft 5111 is rotatably connected to two side beams 22, which is equivalent to the first connecting member 511 being hinged to the seat frame 2. The toothed plate 5113 meshes with the output end of the driving unit 6, and the rotating rod 5114 is hinged to the side 13 of the base 1, which is equivalent to the rotating rod 5114 being hinged to the base 1; teeth are also machined on the first rod member 521 to facilitate meshing with the output end of the second driving unit. Through the cooperation of the three driving units 6, the linkage of the rotation of the seat frame 2, the rotation of the footrest bracket 3 and the rotation of the backrest frame 4 is realized, improving the linkage of the seat. In addition, as shown in FIGS. 13 and 14, a limiting mechanism 7 is provided on the seat frame 2 to limit the operating range of the seat. Specifically, in this embodiment, limiting slideways 71 are provided on both the toothed plate 5113 of the first connecting member 511 in the first link assembly 51 and the first rod member 521 of the second link assembly 52. A limiting member 72 is fixed on the seat frame 2, and the limiting member 72 is slidably engaged with the limiting slideway 71 to limit the rotation range of the toothed plate 5113 and the first rod member 521. Further, as shown in FIG. 11, a stop edge 73 is provided on the side 13 of the base 1, which can block the first connecting member 511 and the second connecting member 512 and also has a limiting effect, thereby limiting the rotation range of the seat frame 2, and the cross beam 23 in the seat frame 2 also directly limits the rotation range of the footrest bracket 3. As shown in FIGS. 8 to 12, for the footrest bracket 3, it includes a footrest main body 31 and an extension plate 32. The footrest main body 31 is hingedly installed on the seat frame 2, and the extension plate 32 is slidably connected to the footrest main body 31. A slide bar 311 is provided on the footrest main body 31, and a guiding slideway 321 is provided on the extension plate 32. The sliding of the extension plate 32 is guided by the sliding fit between the slide bar 311 and the guiding slideway 321. An extension mechanism 33 is connected between the extension plate 32, the footrest main body 31 and the seat frame 2. As shown in FIG. 9, the extension plate 32 can slide relative to the footrest main body 31 during the rotation of the footrest main body 31 relative to the seat frame 2. Moreover, the footrest main body 31 has a contracted state, an extended state and an intermediate state between the contracted state and the extended state during rotation. During the rotation switching process of the footrest main body 31 between the contracted state and the intermediate state, the extension plate 32 is stationary relative to the footrest main body 31. During the rotation switching process of the footrest main body 31 between the intermediate state and the extended state, the extension plate 32 slides relative to the footrest main body 31, that is: in the early stage of the unfolding process of the footrest bracket 3, the extension plate 32 does not slide out relative to the footrest main body 31 to avoid collision with the ground, and the extension plate 32 slides out relative to the footrest main body 31 only in the later stage of the unfolding process of the footrest bracket 3. ​In this embodiment, when the distance between the foot bracket 3 and the ground is at its minimum, it is in the middle state. During the process of the foot bracket 3 rotating from the retracted state to the middle state, the distance between the foot bracket 3 and the ground gradually decreases. And during the process of the foot bracket 3 rotating from the middle state to the extended state, the distance between the foot bracket 3 and the ground gradually increases. The extension plate 32 starts to slide only after reaching the middle state, thereby effectively reducing the probability of the extension plate 32 colliding with the ground. As shown in FIG. 9, for the extension mechanism 33, it includes a fifth rod member 331 and a first sliding member 332. One end of the fifth rod member 331 is hinged to the seat frame 2, and the other end of the fifth rod member 331 is hinged to the first sliding member 332. The first sliding member 332 is slidably connected to the footrest main body 31 and connected to the extension plate 32. The seat frame 2, the footrest main body 31, the fifth rod member 331, and the first sliding member 332 form a link-slider mechanism. By rotating the footrest main body 31 around the seat frame 2, the first sliding member 332 slides relative to the footrest main body 31, thereby driving the extension plate 32 to slide relative to the footrest main body 31. In addition, a sixth rod member 333 and a seventh rod member 334 are installed on the footrest main body 31 to connect the first sliding member 332 of the extension mechanism 33 and the extension plate 32. One end of the sixth rod member 333 is hinged to the footrest main body 31, the other end of the sixth rod member 333 is hinged to the seventh rod member 334. One end of the seventh rod member 334 is hinged to the sixth rod member 333, and the other end of the seventh rod member 334 is hinged to the extension plate 32. The footrest main body 31, the sixth rod member 333, the seventh rod member 334, and the extension plate 32 form a link-slider mechanism. An avoidance slideway 335 is provided on the sixth rod member 333, and the first sliding member 332 is located in the avoidance slideway 335. During the process of the foot bracket 3 rotating and unfolding from the retracted state to the middle state, the first sliding member 332 slides relative to the footrest main body 31 and simultaneously slides relative to the sixth rod member 333 along the avoidance slideway 335. At this time, the first sliding member 332 does not push the sixth rod member 333 to rotate, so as to realize that in the early stage of the rotation of the foot bracket 3, that is, the footrest main body 31 rotates while the extension plate 32 does not slide and unfold. When the foot bracket 3 rotates to the middle state, the first sliding member 332 slides to the end of the avoidance slideway 335. At this time, the footrest main body 31 continues to rotate and causes the first sliding member 332 to slide, thereby being able to push the sixth rod member 333 to rotate to push the extension plate 32 to extend, thus realizing the later stage of the rotation of the foot bracket 3, that is, the footrest main body 31 rotates and the extension plate 32 slides out. Embodiment Two The difference from the first embodiment is that the driving unit 6 includes a first driving unit and a second driving unit, and the seat further includes a second linkage member 41 connecting the backrest frame 4 and the linkage mechanism 5, so that the rotation of the backrest frame 4 is linked with the rotation of the seat frame 2 or the rotation of the backrest frame 4 is linked with the rotation of the footrest bracket 3. For example, as shown in FIGS. 13 and 14. One end of the second linkage member 41 is hinged to the backrest frame 4, and the other end of the second linkage member 41 is hinged to the first connecting member 511, so that the backrest frame 4 and the seat frame 2 are linked. The seat frame 2, the first connecting member 511, the second linkage member 41, and the backrest frame 4 form a four-bar mechanism; or one end of the second linkage member 41 is hinged to the backrest frame 4, and the other end of the second linkage member 41 can be hinged to any one of the four rods in the second link assembly 52, so that the backrest frame 4 is linked with the footrest bracket 3. Embodiment Three The difference from the first embodiment is that the driving unit 6 includes a first driving unit and a third driving unit, and the seat further includes a first linkage member 53 connecting the first link assembly 51 and the second link assembly 52, and the seat frame 2 and the footrest bracket 3 are linked through the first linkage member 53, as shown in FIG. 14. In this embodiment, one end of the first linkage member 53 is hinged to the first connecting member 511 in the first link assembly 51, and the other end of the first linkage member 53 is hinged to the first rod 521 in the second link assembly 52. In other embodiments, the first linkage member 53 can also be hinged between the first connecting member 511 and other rods in the second link assembly 52, or the first linkage member 53 is hinged between the second connecting member 512 in the first link assembly 51 and the rods in the second link assembly 52 to realize the linked operation of the seat frame 2 and the footrest bracket 3. In other words, one end of the first linkage member 53 is hinged to one of the first connecting member 511 and the second connecting member 512 included in the first link assembly 51, and the other end of the first linkage member 53 is hinged to one of the first rod 521, the second rod 522, the third rod 523, and the fourth rod 524 included in the second link assembly 52. In this embodiment, the first link assembly 51 is directly driven by the first driving unit to operate, and then the second link assembly 52 and the footrest bracket 3 are linked through the first linkage member 53, and the backrest frame 4 is independently driven by the third driving unit to operate. Embodiment Four The difference from the third embodiment is that the driving unit 6 includes a second driving unit and a third driving unit and does not include the first driving unit. The second link assembly 52 is directly driven by the second driving unit to operate, and then the first link assembly 51 and the seat frame 2 are linked through the first linkage member 53, and the backrest frame 4 is independently driven by the third driving unit to operate. Embodiment Five ​The difference from the first embodiment is that: a second linkage 41 is connected between the backrest frame 4 and the linkage mechanism 5, and a first linkage 53 is connected between the first link assembly 51 and the second link assembly 52. As shown in FIG. 14, any one of the three drive units 6 can be used as the drive unit 6, so that the three-way linkage of the seat frame 2, the backrest frame 4 and the footrest 3 can be realized. Embodiment Six This embodiment provides a new embodiment of the second link assembly 52. The setting of the drive unit 6 and the linkage relationship between the seat frame 2, the backrest frame 4, and the footrest 3 can be selected from any one of the first to fifth embodiments. Specifically, as shown in FIGS. 6 and 15, the second link assembly 52 includes a first rod 521, a second rod 522, a third rod 523, and a speed regulation structure 34 for adjusting the rotation speed of the footrest 3. In this embodiment, the first rod 521, the second rod 522, and the third rod 523 are sequentially hinged, and the first rod 521 is hinged to the seat frame 2, and the third rod 523 is hinged to the footrest 3. The speed regulation structure 34 includes a connecting slideway 342 provided on the seat frame 2 and a second slider 341 slidably mounted on the connecting slideway 342. The second slider 341 is hinged at the hinge connection between the second rod 522 and the third rod 523, so that the seat frame 2, the first rod 521, the second rod 522, and the second slider 341 form a link-slider structure; the seat frame 2, the second slider 341, the third rod 523, and the footrest 3 form a slider-link structure. The connecting slideway 342 is divided into two sections. When the output power of the drive unit 6 is the same, the rotation speed of the footrest 3 is different during the process of the second slider 341 sliding along the two sections of the connecting slideway 342 respectively. Specifically, the footrest 3 further has a variable speed state between the retracted state and the extended state. The rotation speed of the footrest 3 during the rotation switching process between the retracted state and the variable speed state is n1; the rotation speed of the footrest 3 during the rotation switching process between the variable speed state and the extended state is n2, where: n1 > n2. That is: the rotation speed of the footrest 3 is relatively large in the early stage of the unfolding process, which can realize rapid unfolding and ensure the operation efficiency. In the later stage of the unfolding process, the rotation speed is relatively small. At this time, the footrest 3 will be used to contact and support the user's leg to lift, avoiding the excessive speed when the footrest 3 contacts the user's leg and causing impact on the user's leg, which affects the application experience. It should be noted that: the rotation speed mentioned above does not refer to the rotation speed of the footrest 3 rotating at a constant speed between the two states, but refers to the instantaneous rotation speed of the footrest 3 at any moment between the two states. That is: the instantaneous rotation speed of the footrest 3 at any moment between the retracted state and the variable speed state is greater than the instantaneous rotation speed of the footrest 3 at any moment between the variable speed state and the extended state, or in other words, the minimum rotation speed of the footrest 3 between the retracted state and the variable speed state is greater than the maximum rotation speed of the footrest 3 between the variable speed state and the extended state. In addition, the variable speed state and the intermediate state are further described as follows: the state when the footrest 3 rotates to the vertical state is the variable speed state, and the intermediate state can occur after the vertical state, that is, the intermediate state and the variable speed state of the footrest 3 can be two different states. In other embodiments, the intermediate state can also occur during the variable speed state, or the intermediate state is the same as the variable speed state. The above are some embodiments of the present application, and the protection scope of the present application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A seat, comprising: A base (1); A seat frame (2), rotatably mounted on the base (1), a footrest bracket (3) and a backrest frame (4) are hinged on the seat frame (2), and the rotation axes of the footrest bracket (3) and the backrest frame (4) relative to the base (1) are offset from the rotation axis of the seat frame (2); A linkage mechanism (5), comprising a first linkage assembly (51) connected between the base (1) and the seat frame (2), and a second linkage assembly (52) connected between the seat frame (2) and the footrest bracket (3); A drive unit (6) for driving the first linkage assembly (51) and the second linkage assembly (52) to operate, so as to link the rotation of the seat frame (2) and the rotation of the footrest bracket (3).

2. The seat according to claim 1, wherein, The linkage mechanism (5) operates within the thickness range of the seat frame (2).

3. The seat according to claim 1, wherein, The drive unit (6) is mounted on the side beam (22) of the seat frame (2).

4. The seat according to claim 1, wherein, The first linkage assembly (51) includes a first connecting member (511) and a second connecting member (512), wherein, both the first connecting member (511) and the second connecting member (512) are hinged between the seat frame (2) and the base (1), so that the base (1), the first connecting member (511), the seat frame (2) and the second connecting member (512) form a four-bar mechanism.

5. The seat according to claim 4, wherein, The first connecting member (511) includes a rotating shaft (5111) and a toothed plate (5113) and a rotating rod (5114) fixed on the rotating shaft (5111), The rotating shaft (5111) is rotatably connected to two side beams (22) of the seat frame (2), The toothed plate (5113) is engaged with the output end of the drive unit (6), The rotating rod (5114) is hinged to the side edge (13) of the base (1).

6. The seat according to claim 5, wherein, Limiting sliding grooves (71) are provided on both the toothed plate (5113) and a first rod member (521) included in the second linkage assembly (52), A limiting member (72) is fixed on the seat frame (2), The limiting member (72) is slidably engaged with the limiting sliding groove (71) to limit the rotation range of the toothed plate (5113) and the first rod member (521).

7. The seat according to claim 1, wherein, The second linkage assembly (52) includes a first rod member (521), a second rod member (522), a third rod member (523) and a fourth rod member (524); Both the first rod member (521) and the third rod member (523) are hinged on the seat frame (2), The second rod member (522) is hinged between the first rod member (521) and the third rod member (523), and the seat frame (2), the first rod member (521), the second rod member (522) and the third rod member (523) form a set of four-bar mechanism; The fourth rod member (524) is hinged between the third rod member (523) and the footrest bracket (3), and the seat frame (2), the third rod member (523), the fourth rod member (524) and the footrest bracket (3) form a set of four-bar mechanism.

8. The seat according to claim 1, wherein, The second link assembly (52) includes a first rod member (521), a second rod member (522), a third rod member (523), and a speed regulation structure (34) for regulating the rotational speed of the footrest bracket (3); The first rod member (521), the second rod member (522), and the third rod member (523) are sequentially hinged, and the first rod member (521) is hinged to the seat frame (2), and the third rod member (523) is hinged to the footrest bracket (3); The speed regulation structure (34) includes a connecting slideway (342) provided on the seat frame (2) and a second sliding member (341) slidably mounted on the connecting slideway (342), and the second sliding member (341) is hinged to the hinged connection between the second rod member (522) and the third rod member (523), so that the seat frame (2), the first rod member (521), the second rod member (522), and the second sliding member (341) form a link-slider structure; The seat frame (2), the second sliding member (341), the third rod member (523), and the footrest bracket (3) form a slider-link structure. Among them, the connecting slideway (342) is divided into two sections. When the output power of the drive unit (6) is the same, the rotational speed of the footrest bracket (3) is different during the sliding of the second sliding member (341) along the two sections of the connecting slideway (342) respectively.

9. The seat according to claim 1, wherein, A first linkage member (53) is connected between the first link assembly (51) and the second link assembly (52).

10. The seat according to claim 9, wherein, The seat frame (2) and the footrest bracket (3) are linked through the first linkage member (53); One end of the first linkage member (53) is hinged to one of the first connecting member (511) and the second connecting member (512) included in the first link assembly (51), and the other end of the first linkage member (53) is hinged to one of the first rod member (521), the second rod member (522), the third rod member (523), and the fourth rod member (524) included in the second link assembly (52).

11. The seat according to claim 1, wherein, The drive unit (6) includes a first drive unit for driving the first link assembly (51) to operate and a second drive unit for driving the second link assembly (52) to operate.

12. The seat according to claim 1, wherein, A second linkage member (41) is connected between the backrest frame (4) and the linkage mechanism (5) to enable the rotation of the backrest frame (4) to be linked with the rotation of the seat frame (2) and / or the rotation of the footrest bracket (3).

13. The seat according to claim 1, wherein The drive unit (6) further includes a third drive unit for driving the backrest frame (4) to rotate.

14. The seat according to claim 1, wherein, The footrest bracket (3) includes a footrest main body (31) hinged to the seat frame (2) and an extension plate (32) slidably mounted on the footrest main body (31), An extension mechanism (33) is connected between the extension plate (32), the footrest main body (31), and the seat frame (2) to enable the extension plate (32) to slide relative to the footrest main body (31) during the rotation of the footrest main body (31) relative to the seat frame (2).

15. The seat according to claim 14, wherein, The stretching mechanism (33) includes a fifth rod member (331) and a first sliding member (332). One end of the fifth rod member (331) is hingedly installed on the seat frame (2), and the other end of the fifth rod member (331) is hingedly installed on the first sliding member (332). The first sliding member (332) is slidably and cooperatively connected to the footrest main body (31) and is connected to the extension plate (32). The seat frame (2), the footrest main body (31), the fifth rod member (331), and the first sliding member (332) form a link-slider mechanism. By rotating the footrest main body (31) around the seat frame (2), the first sliding member (332) slides relative to the footrest main body (31), thereby driving the extension plate (32) to slide relative to the footrest main body (31).

16. The seat according to claim 15, wherein, A sixth rod member (333) and a seventh rod member (334) are installed on the footrest main body (31). One end of the sixth rod member (333) is hinged to the footrest main body (31), and the other end is hinged to the seventh rod member (334). One end of the seventh rod member (334) is hinged to the sixth rod member (333), and the other end is hinged to the extension plate (32). The footrest main body (31), the sixth rod member (333), the seventh rod member (334), and the extension plate (32) form a link-slider mechanism. An avoidance slideway (335) is provided on the sixth rod member (333), and the first sliding member (332) is located in the avoidance slideway (335).

17. The seat according to claim 14, wherein, During the rotation process, the footrest main body (31) has a contracted state, an extended state, and an intermediate state between the contracted state and the extended state. During the rotation switching process of the footrest main body (31) between the contracted state and the intermediate state, the extension plate (32) is stationary relative to the footrest main body (31). During the rotation switching process of the footrest main body (31) between the intermediate state and the extended state, the extension plate (32) slides relative to the footrest main body (31).

18. The seat according to claim 1, wherein, During the rotation process, the footrest bracket (3) has a contracted state, an extended state, and a variable-speed state between the contracted state and the extended state. A speed-regulating structure (34) for adjusting the rotation speed of the footrest bracket (3) is connected between the footrest bracket (3) and the link mechanism (5).

19. The seat according to claim 18, wherein, The rotation speed of the footrest bracket (3) during the rotation switching process between the contracted state and the variable-speed state is n1; the rotation speed of the footrest bracket (3) during the rotation switching process between the variable-speed state and the extended state is n2, where n1 > n2.

20. The seat according to claim 1, wherein, On the side of the seat frame (2) for sitting, there is a recessed portion (21) to increase the sitting activity space; and / or There is a flanging (8) on the seat frame (2) and / or the footrest bracket (3) and / or the backrest frame (4); and / or The seat further includes a power source (9) for power supply, and the power source (9) is built into the base (1); and / or An armrest mounting frame (26) for mounting an armrest is fixedly provided on the seat frame (2).

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