Footrest turnover mechanism, footrest device and chair thereof

Abstract

The utility model relates to a footrest turnover mechanism, a footrest device and a chair, the footrest turnover mechanism comprises a support frame and a footrest which are rotatably connected with each other, a rotation limiting mechanism is arranged between the support frame and the footrest, the rotation limiting mechanism comprises a rotating seat, a telescopic piece is arranged on the rotating seat, and an unlocking knob is rotatably arranged on the rotating seat. One end of the telescopic part is connected with the unlocking knob, an elastic assembly is arranged in the rotating seat, and the other end of the telescopic part penetrates out of the rotating seat under the action of the elastic assembly; the rotation limiting mechanism is fixed to one of the supporting frame and the footrest, a corresponding lock hole is formed in the other one of the supporting frame and the footrest, and when the footrest is overturned to the use state position, the telescopic piece is inserted into the lock hole; a limiting notch is further formed in the side wall of the end of the rotating seat, a telescopic rod is further arranged on the supporting frame, and the telescopic rod stretches out of the supporting frame and then is inserted into the limiting notch, or the telescopic rod stretches out of the supporting frame and the foot rest and then is inserted into the limiting notch. The whole footrest turnover mechanism is convenient to operate and smooth in operation.

Description

TECHNICAL FIELD

[0001] The utility model belongs to furniture technical field, especially, relate to a foot rest plate turnover mechanism, foot rest plate device and chair thereof. BACKGROUND

[0002] Leisure chair is one of the furniture that is necessary for home office, people in long time rest and relax time, most of the time is sitting on the chair office, long time sitting is easy to cause body fatigue, so people often lie on the chair rest, but when lying on the chair, people's feet do not have suitable place to place, so that people lie on the chair is not very comfortable. So more and more seats are designed with a seat foot rest in the lower part, and the seat foot rest can make the leg stretch flat and promote blood circulation.

[0003] At present, the seat with foot rest on the market has two structures: one is to set up the foot rest plate of pull-out type, and the foot rest can be pulled out forward and backward to use or hide; the other is to set up the foot rest plate of turnover type, and the foot rest plate is turned over to make the foot rest plate have two use states of turning over and opening for use or folding at the bottom end of the seat part.

[0004] At present, the foot rest plate of turnover type is generally provided with a locking assembly in the foot rest assembly and the rotating support body, and an adjusting button is arranged on one side or both sides of the foot rest to adjust the foot rest. The existing adjusting structure needs to press the adjusting button to make the rotating shaft seat move, so that the clamping head is separated from the limiting convex ring. Whether it is single side adjusting mode or double side adjusting mode, it is more laborious to adjust, and the operation is not convenient. UTILITY MODEL CONTENTS

[0005] In order to solve the above technical problems, the first purpose of the utility model is to provide a foot rest plate turnover mechanism, which makes the turning out and storage of the foot rest plate more convenient. The second purpose of the utility model is to provide a foot rest plate device, and the third purpose of the utility model is to provide a chair.

[0006] In order to realize the first purpose of the utility model, the utility model adopts the following technical scheme:

[0007] The footboard turnover mechanism comprises a support frame and a footboard which are connected with each other to rotate, and a rotation limiting mechanism is arranged between the support frame and the footboard, the footboard is turned to a use state position and a storage state position relative to the support frame through the rotation limiting mechanism, the rotation limiting mechanism comprises a rotating base, a containing cavity is formed in the rotating base, an expansion piece is arranged in the containing cavity, an unlocking knob is further arranged on the rotating base, one end of the expansion piece is connected with the unlocking knob, an elastic assembly is further arranged in the containing cavity, and the other end of the expansion piece is arranged to pass out of the rotating base under the action of the elastic assembly, the rotation limiting mechanism is fixed on one of the support frame and the footboard, a corresponding lock hole is arranged on the other one, the expansion piece is inserted into the lock hole when the footboard is turned to the use state position, a limiting notch is further arranged on the side wall of the end of the rotating base, an expansion rod is further arranged on the support frame, and the expansion rod is inserted into the limiting notch after extending out of the support frame when the footboard is turned to the storage state position, or the expansion rod is inserted into the limiting notch after extending out of the support frame and the footboard.

[0008] As a preferred scheme, the unlocking knob comprises an integral hand holding part and a rotating shaft, the hand holding part is located on the end face of the rotating shaft base, the rotating shaft is located in the containing cavity, a connecting ball head is arranged on the side wall of the rotating shaft, and the connecting ball head is clamped into the end of the expansion piece and can rotate freely.

[0009] As a preferred scheme, a bottom plate is further arranged on the containing cavity, the bottom plate is fixed with the rotating base, a supporting column is arranged on the bottom plate, the rotating shaft is sleeved on the supporting column and is arranged in opposite rotation with the supporting column.

[0010] As a preferred scheme, the expansion piece comprises a sliding block and a lock rod, the sliding block is a frame structure, the lock rod is fixed on one end of the sliding block, a connecting column is further arranged in the containing cavity, the sliding block is sleeved on the connecting column, the elastic assembly is a spring C, and the two ends of the spring C are respectively abutted with the connecting column and the sliding block so that the lock rod passes out of the rotating base.

[0011] As a preferred scheme, an integral connecting strip is formed on the other end of the sliding block, a spherical recess is arranged on the connecting strip, and the connecting ball head of the unlocking knob is clamped in the spherical recess.

[0012] As a preferred scheme, rotating blocks are respectively fixed on the two ends of the rotating base, bearings are sleeved on the rotating blocks, and the outer rings of the bearings are embedded and fixed on the two ends of the support frame or the footboard.

[0013] As a preferred scheme, torsional springs are further sleeved on the rotating blocks, torsional spring clamping holes are further arranged on the support frame or the footboard, and limiting holes are further arranged on the ends of the rotating base, and the two torsional arms of the torsional spring are respectively clamped in the torsional spring clamping hole and the limiting hole.

[0014] As a preferred solution: the telescopic pieces are two, and are arranged in central symmetry around the rotation center of the unlocking knob.

[0015] In order to achieve the second purpose of the utility model, the utility model adopts the following technical scheme:

[0016] The footrest device comprises a fixed frame, telescopic pipes slidingly arranged on the fixed frame, and the footrest turnover mechanism of any one of the above-mentioned footrest devices, two ends of the support frame are fixed to front ends of the two telescopic pipes, the telescopic pipes are hollow tubular structures, the telescopic rod is arranged in the telescopic pipe, one end of the telescopic rod is fixed to a limiting block, the end of the telescopic rod is further sleeved with a spring B, one end of the spring B abuts against the limiting block, the other end of the spring B abuts against the end of the telescopic pipe, the other end of the telescopic rod is inserted into the limiting gap after extending out of the support frame and / or the footrest, one end of the telescopic pipe is further provided with a long strip-shaped through hole, and the limiting block passes out of the long strip-shaped through hole.

[0017] In order to achieve the third purpose of the utility model, the utility model adopts the following technical scheme:

[0018] The chair adopts the footrest device as described above.

[0019] Compared with the prior art, the utility model has the beneficial effects that:

[0020] The unlocking knob and the telescopic piece are matched in the position of the footrest in the use state, so that the footrest is kept in or withdrawn from the working state, the telescopic rod is used to keep or withdraw the footrest from the storage state in the position of the footrest in the storage state, the whole footrest turnover mechanism is convenient to operate and runs smoothly. BRIEF DESCRIPTION OF DRAWINGS

[0021] The drawings accompanying the specification provide further understanding of the present application, the illustrative embodiments thereof, and the description thereof serve the purpose of explaining the present application and do not constitute limitations thereof.

[0022] Figure 1 And Figure 2 are structural schematic diagrams of the footrest device of the utility model in two different angles in the folded storage state;

[0023] Figure 3 And Figure 4 are structural schematic diagrams of the footrest device of the utility model in two different angles in the unfolded extension state;

[0024] Figure 5 And Figure 6 are structural schematic diagrams of the footrest telescopic mechanism of the utility model in two different angles;

[0025] Figure 7 , Figure 8 and Figure 9 This is a schematic diagram of the footrest flipping mechanism of this utility model at three different angles;

[0026] Figure 10 This is a schematic diagram of the assembly structure of the sliding block, unlocking knob, and base plate of this utility model;

[0027] Figure 11 This is a cross-sectional structural diagram of the footrest device of this utility model in a folded-up state.

[0028] Figure 12 This is a cross-sectional structural diagram of the footrest device of this utility model in its extended and unfolded state.

[0029] The attached figures are labeled as follows: 110, fixing frame; 111, rope fixing block; 112, guide wheel; 113, pulley; 114, support wheel A; 115, support wheel B; 120, telescopic tube; 121, fixing block; 122, positioning block; 130, gas spring; 131, roller; 140, pull rope; 150, lever; 151, support shaft; 152, lower buckle plate; 153, spring A; 154, limiting protrusion; 160, limiting block; 170, telescopic rod; 180, spring B; 200, rotating seat; 201, housing. Cavity; 202 Connecting post; 210 Support frame; 211 Buckle cover; 212 Flip lock hole A; 213 Torsion spring latch; 214 Flip lock hole B; 220 Foot rest; 221 Limiting port; 230 Unlocking knob; 231 Connecting ball head; 240 Base plate; 241 Supporting post; 250 Rotating block; 251 Limiting notch; 260 Torsion spring; 270 Sliding block; 271 Spring C; 272 Locking rod; 273 Connecting strip; 274 Spherical notch; 280 Bearing; 290 Locking screw. Detailed Implementation

[0030] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0031] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] Furthermore, in the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.

[0034] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0037] like Figures 1 to 6As shown, the footrest device includes a footrest telescopic mechanism and a footrest flipping mechanism. The footrest flipping mechanism is located at the front end of the footrest telescopic mechanism. The footrest telescopic mechanism includes a fixed frame 110 and a telescopic tube 120. The telescopic tube 120 is slidably mounted on the fixed frame 110. The fixed frame 110 is also provided with a driving component. The driving component directly or indirectly drives the telescopic tube 120 to move within the fixed frame 110. The fixed frame 110 is also provided with a toggle wrench 150 for limiting the position of the telescopic tube 120.

[0038] To ensure greater stability during the movement of the entire footrest telescopic mechanism, the fixed frame 110 and the telescopic tube 120 are arranged perpendicularly to each other, and both ends of the fixed frame 110 are provided with through holes. The two telescopic tubes 120 are respectively inserted into the two through holes. The upper and lower end faces of the through holes are also provided with pulleys 113 and support wheels. The support wheels that contact the lower end faces of the two telescopic tubes 120 are support wheel A114 and support wheel B115, respectively. The pulleys 113 and support wheels act on the upper and lower end faces of the telescopic tubes 120, making the telescopic tubes 120 move more smoothly in the fixed frame 110. The two telescopic tubes 120 are connected to each other. In this embodiment, the two telescopic tubes 120 are connected together by a footrest flipping mechanism.

[0039] The upper surface of the fixed frame 110 is provided with a groove, and the driving device is fixed in the groove. The driving device drives the telescopic tube 120 to move through the pull rope 140. The driving device is a pneumatic rod 130, which is arranged along the length of the fixed frame 110. The fixed end of the pneumatic rod 130 is close to one of the telescopic tubes 120. One end of the telescopic tube 120 is also fixed with a fixing block 121. A guide wheel 112 is also provided on one side of the pneumatic rod 130. One end of the pull rope 140 is locked on the fixing block 121, and the other end of the pull rope 140 passes around the guide wheel 112 and is fixed to the movable end of the pneumatic rod 130.

[0040] To make the movement of the pull rope 140 smoother, the movable end of the air rod 130 is also provided with a freely rotating roller 131. The fixed frame 110 is also provided with a pull rope fixing block 111 on the other side of the air rod 130. The pull rope fixing block 111 and the guide wheel 112 are respectively located on both sides of the air rod 130, and the guide wheel 112 is close to the fixed end of the air rod 130. One end of the pull rope 140 is locked on the fixing block 121, and the other end of the pull rope 140 passes around the guide wheel 112 and the roller 131 and is locked on the pull rope fixing block 111. When the air rod 130 extends, the telescopic tube is driven to extend through the pull rope.

[0041] As a further preferred embodiment, the groove sidewall of the fixing frame 110 is also provided with a notch for the pull rope to pass through, and the positions of the pull rope fixing block 111, roller 131, guide wheel 112 and fixing block 121 for locking the pull rope are on the same plane.

[0042] The lower end face of the through hole on the fixed frame 110 is also provided with a through hole. The bottom front end of the telescopic tube 120 is fixed with a positioning block 122. The toggle wrench 150 is also provided with a limiting protrusion 154. The toggle wrench 150 is hinged to one end of the fixed frame 110, and a spring A153 is provided between the toggle wrench 150 and the fixed frame 110. Under the action of the spring A153, the toggle wrench 150 is always pressed against the bottom of the fixed frame 110, and the limiting protrusion 154 passes through the through hole and is locked at the positioning block 122.

[0043] The toggle wrench 150 is provided with a support shaft 151, and one end of the fixing frame 110 is provided with a slot. The support shaft 151 is embedded in the slot. The bottom of the fixing frame 110 is also provided with a buckle plate 152. The buckle plate 152 encloses the toggle wrench 150 at the bottom of the fixing frame 110. The spring A is provided between the toggle wrench 150 and the buckle plate 152.

[0044] Press and pull the lever 150, and the lever 150 will rotate downward, causing the limiting protrusion 154 to disengage from the positioning block 122. The telescopic tube 120 will extend forward under the action of the air rod 130 and the pull rope 140. When the telescopic tube 120 retracts, manually push the telescopic tube 120 backward until the positioning block 122 on the telescopic tube 120 is engaged in the limiting protrusion 154 of the lever 150.

[0045] When the telescopic tube 120 retracts, the mating surface between the positioning block 122 and the limiting protrusion 154 is inclined. In addition, in order to make the extension position of the telescopic tube 120 adjustable, multiple positioning blocks 122 can be set at a certain distance at the bottom of the telescopic tube 120.

[0046] In other embodiments, the driving device can be a spring, which can directly replace the gas spring in the footrest telescopic mechanism, or the spring can be arranged parallel to the telescopic tube to directly drive the extension of the telescopic tube. Of course, the gas spring in this embodiment can also be arranged parallel to the telescopic tube. In other embodiments, the driving device can also be a forward and reverse motor, and be used in conjunction with gears, racks, lead screws, nuts, etc. In this case, the toggle switch can be the switch for the forward and reverse motor.

[0047] like Figures 7 to 9As shown, the footrest flipping mechanism includes a support frame 210 and a footrest 220 rotatably connected to each other, and a rotation limiting mechanism is provided between them. The footrest 220 can be flipped relative to the support frame 210 to a use position and a storage position through the rotation limiting mechanism. The rotation limiting mechanism includes a rotating base 200, on which a receiving cavity 201 is opened. The receiving cavity 201 is also covered by a base plate 240. A telescopic component is provided in the receiving cavity 201. An unlocking knob 230 is also provided on the rotating base 200. One end of the telescopic component is connected to the unlocking knob 230. An elastic component is also provided in the receiving cavity. Under the action of the elastic component, the other end of the telescopic component protrudes from the rotating base 200. The rotation limiting mechanism is fixed on one of the support frame 210 and the footrest 220, and the other has a corresponding locking hole. When the footrest 220 is flipped to the use position, the telescopic component is inserted into the locking hole.

[0048] Rotating blocks 250 are fixed at both ends of the rotating seat 200. The rotating blocks 250 are fixed to the ends of the rotating seat by locking screws 290. Bearings 280 are sleeved on the rotating blocks 250. The outer ring of the bearings 280 is embedded and fixed at both ends of the support frame 210 or the foot plate 220. Torsion springs 260 are also sleeved on the rotating blocks 250. Torsion spring slots 213 are also provided on the support frame 210 or the foot plate 220. The end of the rotating seat is also provided with a limiting port 221. The two torsion arms of the torsion spring 260 are respectively locked in the torsion spring slots 213 and the limiting port 221.

[0049] like Figure 10 As shown, the telescopic component includes a sliding block 270 and a locking rod 272. The sliding block 270 is a frame structure, consisting of two connected rectangular frames. The locking rod 272 is fixed to one end of the sliding block 270. The base plate 240 is fixed to the rotating seat 200 by screws. The receiving cavity 201 of the rotating seat is also provided with a connecting post 202 that cooperates with the screws. The connecting post 202 is a threaded post. One of the rectangular frames of the sliding block 270 is sleeved on the threaded post. The elastic component is a spring C271. The two ends of the spring C271 abut against the side walls of the threaded post and the rectangular frame, respectively. The spring C271 causes the locking rod 272 to pass through the rotating seat 200.

[0050] The other end of the sliding block 270 is integrally formed with a connecting strip 273. The connecting strip 273 is provided with a spherical recess 274. The unlocking knob 230 includes an integrally formed grip and a rotating shaft. The grip is located on the end face of the rotating shaft seat for easy operation. The rotating shaft is located in the receiving cavity 201. The base plate 240 is provided with a support column 241. The rotating shaft is sleeved on the support column 241 and rotates relative to the support column 241. The side wall of the rotating shaft is provided with a connecting ball head 231. The connecting ball head 231 is engaged in the spherical recess 274. When the unlocking knob 230 is rotated, the connecting ball head 231 generates an arc-shaped movement trajectory, which in turn drives the sliding block 270 to compress the spring C271, so that the locking rod 272 at the end of the sliding block 270 retracts into the rotating seat 200.

[0051] To make the footrest more stable during use, there are two telescopic components, which are arranged symmetrically around the rotation center of the unlocking knob. Two connecting ball heads 231 are symmetrically arranged on the outer wall of the unlocking knob 230, and the two connecting ball heads 231 are respectively connected to the sliding blocks 270 of the two telescopic components.

[0052] like Figure 11 and Figure 12 As shown, the rotating block 250 has a limiting notch 251 on its side wall. The two ends of the support frame 210 are respectively fixed to the front ends of two telescopic tubes 120. The telescopic tube 120 is a hollow tubular structure. A telescopic rod 170 is also provided inside the telescopic tube 120. A limiting block 160 is fixed to one end of the telescopic rod 170. A spring B180 is also sleeved on the end of the telescopic rod 170. One end of the spring B180 abuts against the limiting block 160, and the other end abuts against the fixing block 121. The other end of the telescopic rod 170 extends out of the support frame 210 and / or the footrest 220 and inserts into the limiting notch 251. A long, narrow through hole is also provided at the end of the telescopic tube 120 near the fixing block 110. The limiting block 160 passes through the long, narrow through hole. Figure 5 and Figure 6 As shown.

[0053] In this embodiment, the rotating seat 200 and the foot plate 220 are integrally formed. The lock holes on the end faces of the support frame 210 in the length direction are flip lock holes A212. The support frame 210 is also provided with buckle caps 211 at both ends. The support frame 210 is also provided with flip lock holes B214 in the width direction. After the telescopic rod 170 extends out of the flip lock hole B214, it is inserted into the limiting notch 251 of the rotating block 250 on the rotating seat 200.

[0054] Pressing the lever 150 causes the telescopic tube 120 to extend under the action of the gas spring 130. The limiting block 160 moves forward with the telescopic tube 120 until it abuts against the fixing frame 110. The telescopic tube 120 continues to extend forward, causing the limiting block 160 to compress the spring B180. Consequently, the telescopic rod 170 retracts relative to the telescopic tube 120 until it exits the limiting notch 251. The footrest 220 flips to the working state under the action of the torsion spring 260. Once in position, the locking rod 272 is inserted into the locking hole under the action of the spring C271, keeping the footrest 220 in the working state.

[0055] When retracting the footrest 220, turn the unlocking knob 230 to disengage the locking rod 272 from the flip lock hole A212. Then, manually flip the footrest 220 to the storage position and retract the telescopic tube 120 so that the telescopic rod 170 can be inserted into the limiting notch 251 again, locking the footrest 220 in the storage position. After the telescopic tube 120 is retracted to its position, turn the wrench 150 to lock it in the retracted position.

[0056] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0057] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A footrest turnover mechanism, comprising a support frame (210) and a footrest (220) which are connected to each other in rotation, and a rotation limiting mechanism is arranged between the support frame (210) and the footrest (220), the footrest (220) is turned to a use state position and a storage state position relative to the support frame (210) through the rotation limiting mechanism; characterized in that: The rotation limiting mechanism comprises a rotating seat (200), the rotating seat (200) is provided with a containing cavity (201), the containing cavity (201) is provided with a telescopic part, the rotating seat (200) is further provided with an unlocking knob (230), one end of the telescopic part is connected with the unlocking knob (230), the containing cavity (201) is further provided with an elastic assembly, and the other end of the telescopic part is out of the rotating seat (200) under the action of the elastic assembly; the rotation limiting mechanism is fixed on one of a supporting frame (210) and a foot rest (220), and the other is provided with a corresponding lock hole, the telescopic part is inserted into the lock hole when the foot rest (220) is turned to a use state position; the side wall of the end of the rotating seat (200) is further provided with a limiting notch (251), the supporting frame (210) is further provided with a telescopic rod (170), and the telescopic rod (170) is inserted into the limiting notch (251) after extending out of the supporting frame (210) when the foot rest is turned to a storage state position, or the telescopic rod (170) is inserted into the limiting notch (251) after extending out of the supporting frame (210) and the foot rest (220).

2. The footrest roll-over mechanism of claim 1, wherein: The unlocking knob (230) comprises an integral hand holding part and a rotating shaft, the hand holding part is located on the end face of the rotating shaft seat, the rotating shaft is located in the containing cavity (201), the side wall of the rotating shaft is provided with a connecting ball head (231), the connecting ball head (231) is clamped into the end of the telescopic part, and can freely rotate.

3. The footrest roll-over mechanism of claim 2, wherein: The containing cavity (201) is further covered with a bottom plate (240), the bottom plate (240) is fixed with the rotating seat (200), the bottom plate (240) is provided with a supporting column (241), the rotating shaft is sleeved on the supporting column (241), and is oppositely arranged with the supporting column (241).

4. The footrest roll-over mechanism according to claim 2 or 3, characterized in that: The telescopic part comprises a sliding block (270) and a lock rod (272), the sliding block (270) is a frame structure, the lock rod (272) is fixed on one end of the sliding block (270), the containing cavity (201) is further provided with a connecting column (202), the sliding block (270) is sleeved on the connecting column (202), the elastic assembly is a spring C (271), and the two ends of the spring C (271) are respectively abutted with the connecting column (202) and the sliding block (270), so that the lock rod (272) is out of the rotating seat (200).

5. The footrest roll-over mechanism of claim 4, wherein: The other end of the sliding block (270) is integrally provided with a connecting strip (273), the connecting strip (273) is provided with a spherical recess (274), and the connecting ball head (231) of the unlocking knob (230) is clamped in the spherical recess (274).

6. The footrest roll-over mechanism of claim 1, wherein: The rotating seat (200) is fixed with rotating blocks (250) at both ends, the rotating blocks (250) are sleeved with bearings (280), and the outer rings of the bearings (280) are embedded and fixed at both ends of the supporting frame (210) or the foot rest (220).

7. The footrest roll-over mechanism of claim 6, wherein: A torsional spring (260) is further sleeved on the rotating block (250), the support frame (210) or the footrest (220) is further provided with a torsional spring socket (213), and the end of the rotating seat (200) is further provided with a limiting socket (221), and the two torsional arms of the torsional spring (260) are respectively clamped in the torsional spring socket (213) and the limiting socket (221).

8. The footrest roll-over mechanism according to claim 1, wherein: The two telescopic members are centrally symmetrically arranged around the rotation center of the unlocking knob (230).

9. A footrest device comprising a fixed frame (110) and a telescopic tube (120) slidingly arranged on the fixed frame (110), characterized in that: The footrest overturning mechanism in any one of claims 1 to 8 is further adopted, two ends of the support frame (210) are respectively fixed at the front ends of the two telescopic pipes (120), the telescopic pipe (120) is a hollow tubular structure, the telescopic rod (170) is arranged in the telescopic pipe (120), one end of the telescopic rod (170) is fixed with the limiting block (160), the end of the telescopic rod (170) is further sleeved with the spring B (180), one end of the spring B (180) abuts against the limiting block (160), the other end abuts against the end of the telescopic pipe (120), the other end of the telescopic rod (170) is inserted into the limiting gap (251) after extending out of the support frame (210) and / or the footrest (220), one end of the telescopic pipe (120) is further provided with a long strip-shaped through hole, and the limiting block (160) passes through the long strip-shaped through hole.

10. A chair, characterized by: The footrest device in claim 9 is adopted.

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