Folding chair

Abstract

Folding chair, characterized by the fact that it a left frame a proper framework, includes a front cross tube arrangement and a rear cross tube arrangement, wherein both the front and rear cross tube arrangement each have an x-shaped cross structure connecting the left and right frames; Both the front and rear cross-tube arrangements each comprise a first tube, a second tube, a third tube and a first connecting element, wherein the first connecting element comprises a main body and two projections connected to the main body, the main body being provided with a through-hole into which the first tube is inserted, the first tube being arranged to pivotally connect to the main body, and the second and third tubes each being connected to the two projections.

Description

Technical area

[0001] The present utility model relates to the technical field of folding chairs and in particular to a folding chair. State of the art

[0002] Folding chairs are widely used in various educational institutions, schools at all levels, hospitals, businesses, and households, and are also indispensable for camping and other outdoor activities. Among current folding chairs, some are cumbersome to fold because they require multiple locking devices to be released. Some are large and too high after folding, making storage and transportation difficult. Some can only be stored lying down after folding and cannot stand upright. Some have seats made of a fabric that is not smooth enough, resulting in an uncomfortable sitting experience. Some are also insufficiently stable, causing them to fold back down when attempting to move the chair while opened. Contents of this utility model

[0003] In order to overcome the disadvantages of the prior art, the object of the present utility model is to provide a folding chair which mainly solves the problem of low stability and the easy falling apart when folding and unfolding of the current folding chairs.

[0004] To solve the above-mentioned problem, the present utility model is implemented by the following technical solutions:

[0005] A folding chair is provided, including a left frame, a right frame, a front cross tube assembly, and a rear cross tube assembly.

[0006] Both the front and rear cross tube arrangements each have an x-shaped cross structure that connects the left and right frames.

[0007] Each of the front and rear cross tube assemblies comprises a first tube, a second tube, a third tube, and a first connecting member, the first connecting member comprising a main body and two projections connected to the main body, the main body being provided with a through hole into which the first tube is inserted, the first tube being adapted to pivotally connect to the main body, and the second and third tubes being connected to the two projections, respectively.

[0008] In a specific embodiment, the main body is cuboid-shaped, the two projections are arranged at two opposite corners of the main body, the through-hole extends through the top and bottom of the first connecting element, the first tube is arranged to be pivotable in the through-hole in the left and right directions, and the second tube and the third tube are arranged in parallel.

[0009] In a specific embodiment, a first curved support surface is arranged at the upper left end of the through-hole, a second curved support surface is arranged at the upper right end of the through-hole, a first curved pressure surface is arranged at the lower left end of the through-hole, and a second curved pressure surface is arranged at the lower right end of the through-hole; the first tube assumes two limit positions in the through-hole, wherein in the first limit position the first curved support surface and the second curved pressure surface abut against the first tube and limit the first tube against pivoting in opposite directions, and in the second limit position the second curved support surface and the first curved pressure surface abut against the first tube and limit the first tube against pivoting in opposite directions.

[0010] The shapes of the first curved support surface, second curved support surface, first curved pressure surface and second curved pressure surface correspond to the shape of the outer surfaces of the first tube.

[0011] In a specific embodiment, each of the left and right frames comprises a front leg tube, a rear leg tube, a backrest tube, a seat tube, and an armrest, wherein a sliding bushing is fitted onto the rear leg tube, wherein the seat tube and the backrest tube are pivotally connected to the sliding bushing on the same side, the rear end of the seat tube protrudes from the sliding bushing and is pivotally connected to the rear cross tube assembly, the front leg tube is pivotally connected to the seat tube, the upper end of the front leg tube and the rear leg tube are connected via a second connecting element, and the armrest is attached to the upper end of the rear leg tube and connected to the backrest tube.

[0012] In a specific embodiment, the rear end of each seat tube is bent upwards, and when the folding chair is fully unfolded, the two seat tubes, the two backrest tubes and the rear cross tube assembly form a triangular support structure.

[0013] In a specific embodiment, the sliding bushing has a sliding hole into which the rear leg tube is inserted, and a first hinge groove and a second hinge groove arranged on the same side as the sliding hole, wherein the first hinge groove extends through the front, rear, and bottom of the sliding bushing, the sliding bushing is fitted onto the seat tube via the first hinge groove and is hingedly connected to the seat tube, a limiting surface is arranged on the top side of the first hinge groove, which limiting surface abuts the seat tube when the folding chair is fully unfolded in order to limit the maximum downward movement of the sliding bushing onto the rear leg tube, the limiting surface being a curved surface corresponding to the outer surface of the seat tube, and the lower end of the backrest tube is inserted into the second hinge groove and is hingedly connected to the groove wall of the second hinge groove.

[0014] In a specific embodiment, each of the left and right frames comprises a vertically telescopic support leg, the vertically telescopic support leg comprising an outer support leg and an inner support leg, the inner support leg being telescopic relative to the outer support leg, a telescopic locking assembly capable of locking the outer support leg being arranged on top of the inner support leg;The telescopic locking assembly comprises a locking base, a button, a spring, and a pin. The locking base is attached to the top of the inner support leg and is pivotally connected to the seat tube. The pin is connected to the button. The button is pivotally connected in the locking base. The two ends of the spring press against the locking base and the button, respectively. The outer support leg is provided with a pin hole. Pressing the button compresses the spring and thus moves the pin out of the pin hole.

[0015] In a specific embodiment, foot pads are attached to the lower ends of the two rear leg tubes, and foot pads are attached to the lower ends of the two outer support legs, wherein the lower ends of the front cross tube assembly are hingedly connected to the foot pads at the lower ends of the two outer support legs, and the lower ends of the two front leg tubes are each hingedly connected to the foot pads at the lower ends of the outer support legs on the same side.

[0016] In a specific embodiment, the folding chair further comprises a cup holder assembly, wherein the cup holder assembly comprises a cup holder body and a cup holder fastening element, wherein a block is arranged on one side of the cup holder body, the cup holder fastening element is provided with a C-shaped groove and a U-shaped receptacle, wherein the cup holder fastening element is locked to the seat tube with the C-shaped groove by a cup holder fastening groove being introduced into the surface of the seat tube, wherein the upper edge of the C-shaped groove is hooked into the cup holder fastening groove.

[0017] The present utility model has the following advantageous effects:

[0018] 1. The left frame and the right frame are connected by the front cross tube assembly and the rear cross tube assembly. Both the front and rear cross tube assemblies are connected to the first tube, the second tube, and the third tube by the first connecting element. The first connecting element is firmly connected to the second and third tubes. The first tube passes through the first connecting element and is pivotally connected to it. This design of the front and rear cross tube assemblies ensures a stable structure. When the first tube is rotated to either end position, it is limited by the first connecting element. This prevents the folding chair from easily falling apart during unfolding and folding, and eliminates the need for additional locking devices. The second tube and the third tube are shorter and are not easily bent.The first connecting element can be equipped with a decorative element bearing a logo or decorative pattern to enhance the aesthetics of the folding chair and promote brand advertising.

[0019] 2. A first curved support surface, a second curved support surface, a first curved pressure surface and a second curved pressure surface are arranged on the first connecting element, whereby the first tube is limited in both the first and second limit positions and cannot be pivoted arbitrarily, which increases the stability of the folding chair.

[0020] 3. When unfolding the folding chair, the telescopic locking assemblies fix the height and width of the chair. By fixing the width of the chair, the width of the backrest is also fixed, making the seat surface smoother and improving seating comfort. When folding the folding chair, the telescopic locking assemblies prevent the chair frame from falling apart. The telescopic locking assemblies facilitate the folding and unfolding of the folding chair. After folding, the packing volume is small, making storage and transportation easier. The seat surface becomes smoother and improving seating comfort.

[0021] 4. When the folding chair is unfolded, the vertically telescopic support legs automatically lock, and the vertically telescopic support legs lock the front cross-tube assembly, fixing the unfolded width between the two seat tubes. Once the seat tubes are locked, the unfolded width is simultaneously fixed between the rear cross-tube assemblies, fixing the unfolded width between the two backrest tubes. The backrest tubes are pivotally connected to the seat tubes via sliding sleeves. When the sliding sleeves slide along the rear leg tubes until the limiting surfaces rest against the seat tubes, the triangular structure formed by the backrest tubes, armrests, and rear leg tubes is fixed. This means that when the sliding sleeves rest against the seat tubes, they cannot slide further downward, thus limiting the tilt angles of the backrest tubes.Together with the rear cross-tube assembly, which forms a triangular support structure with the two backrest tubes and the two seat tubes, the entire structure of the chair frame is stabilized. No additional locking devices are required for the front and rear cross-tube assembly. Once the vertically telescopic support legs are automatically locked, the unfolded state of the folding chair is firmly fixed, and the structure remains stable.

[0022] 5. A pair of vertically telescopic support legs and two telescopic locking assemblies fix the width of the chair, thereby securing the backrest width, tightening the seat fabric, making the seat smoother, and improving seating comfort. It facilitates the folding and unfolding of the folding chair. After folding, the packing volume is small, making it convenient for storage and transportation. When the folding chair is fully unfolded, the two seat tubes, the two backrest tubes, and the rear cross tube assembly form a triangular support structure, which is stable. Short description of the drawing Fig. 1 is a schematic representation of a folding chair according to the present utility model in the fully unfolded state. Fig. 2 is a side view of the folding chair of Fig. 1. Fig. 3 is a schematic representation of the folding chair according to the present utility model in the half-folded state. Fig. 4 is a schematic representation of the folding chair of Fig. 1 in the fully folded state. Fig. 5 is a schematic representation of a first connecting element and a decorative element in one embodiment when they are not assembled. Fig. 6 is a schematic representation of the first connecting element and the decorative element in the embodiment when they are assembled together. Fig. 7 is a schematic representation of a rear cross tube assembly in one embodiment. Fig. Figure 8 is an illustration of a telescopic locking assembly, a vertically telescopic support leg, and a foot pad when assembled together. Fig. Figure 9 is a sectional view of the telescopic locking assembly and the vertically telescopic support leg when assembled. Fig. Figure 10 is a schematic diagram of the structure of a locking socket. Fig. Figure 11 is a schematic diagram of the locking base and a button. Fig. 12 is a schematic diagram of the vertically telescopic support leg with a partially omitted section. Fig. Figure 13 is a schematic representation of a spacer sleeve and an outer support leg when separated from each other. Fig. Figure 14 is a schematic diagram of the structure of the spacer sleeve. Fig. 15 is a view from a different angle of the spacer sleeve of Fig. 14. Fig. 16 is a schematic representation of a second connecting element. Fig. 17 is a view from a different angle of the second connecting element of Fig. 16. Fig. 18 is an illustration of a cup holder body and a cup holder attachment member when not assembled. Fig. 19 is a view from another angle of the cup holder body and the cup holder attachment member of Fig. 18.

[0023] List of reference numerals: 1, backrest tube; 2, seat tube; 3, armrest; 4, vertically telescopic support leg; 5, rear cross tube assembly; 6, telescopic locking assembly; 7, front cross tube assembly; 8, rear leg tube; 9, front leg tube; 10, cup holder assembly; 11, foot pad; 12, slide bushing; 13, U-shaped connecting member; 14, second connecting member; 141, first opening; 142, third pivot groove; 21, cup holder fixing groove; 41, inner support leg; 42, outer support leg; 43, spacer sleeve; 44, limit hole; 45, limit protrusion; 46, pivot hole; 61, locking socket; 62, button; 63, spring; 64, pivot; 65, recess; 66, clamp arm; 67, second opening; 68, button mounting groove; 69, pressing part; 612, nose; 101, cup holder body; 102, block; 103, cup holder fixing member; 104, C-shaped groove; 105, U-shaped receptacle; 121, sliding hole; 122, first hinge groove; 123, second hinge groove; 124, limiting surface; 51, first tube; 52, second tube; 53, third tube;54, first connecting element; 541, main body; 542, projection; 543, first curved support surface; 544, second curved support surface; 545, first curved pressure surface; 546, second curved pressure surface; 547, positioning hole; 15, decorative element; 151, positioning pin.; Detailed embodiments

[0024] The present utility model is described in more detail below in conjunction with the attached drawings and specific embodiments.

[0025] In the description of the present utility model, it is to be understood that the terms “top”, “bottom”, “front”, “back”, “left”, “right”, “top”, “bottom”, “inside”, “outside”, etc. indicate the directional or positional relationships in the fully unfolded state (i.e., in the state of use) of the folding chair.

[0026] In the Fig. 1 to 19, a folding chair is shown by way of example, which comprises a left frame, a right frame, a front cross tube assembly 7, and a rear cross tube assembly 5. Both the front cross tube assembly 7 and the rear cross tube assembly 5 each have an X-shaped cross structure connecting the left and right frames. In a specific embodiment, both the front cross tube assembly 7 and the rear cross tube assembly 5 each comprise a first tube 51, a second tube 52, a third tube 53, and a first connecting element 54. The first connecting element 54 comprises a main body 541 and two projections 542 connected to the main body 541. The main body 541 is provided with a through hole 7. The first tube 51 is inserted into the through hole 7. The first tube 51 is configured to be pivotally connected to the main body 541.The second tube 52 and the third tube 53 are each connected to the two projections 542. The second tube 52 and the third tube 53 are arranged in parallel.

[0027] As in the Fig. As shown in Figures 5 to 7, the first connecting element 54 is formed as a single piece and can be made of various materials, such as plastic, composite material, or metal. In this embodiment, the first connecting element 54 is preferably made of plastic because of the low material costs and ease of manufacture.

[0028] The projection 542 is configured to be plug-in connected to the second tube 52 or the third tube 53. This plug-in connection can be established by inserting the projection 542 into the second tube 52 or the third tube 53. Alternatively, a hole can be provided on the projection 542 into which the second tube 52 or the third tube 53 is inserted. This hole can be a through hole or a blind hole. After the second tube 52 or the third tube 53 has been plugged together with the corresponding projection 542, the second tube 52 or the third tube 53 is fastened to the corresponding projection 542 by means of a fastening element (e.g., screw, rivet, bolt, etc.). In this exemplary embodiment, two projections 542 are each inserted into the second tube 52 and the third tube 53. A positioning ball can be attached to each of the projections 542. Positioning holes are arranged on the second tube 52 and the third tube 53.As the second tube 52 and the third tube 53 are inserted into the corresponding protrusions 542, the positioning ball enters the positioning hole. Alternatively, the second tube 52 and the third tube 53 can also be riveted to the corresponding protrusions 542. Once the frame of the folding chair is fully assembled, the second tube 52 and the third tube 53 cannot be removed from the protrusions 542.

[0029] The cross-section of each of the projections 542 should ideally be shaped to match the inner hole of the corresponding tube. For example, the inner holes of the second tube 52 and the third tube 53 can be round, oval, or rectangular. In this embodiment, the second tube 52 and the third tube 53 are non-circular. When holes are made in the second tube 52 and the third tube 53, the non-circular design facilitates positioning. Accordingly, in this embodiment, the projections 542 are formed as columns with a non-circular cross-section. Holes are provided on the projections 542 as well as on the second tube 52 and the third tube 53. The shapes of the two projections 542 are respectively adapted to the second tube 52 and the third tube 53, which facilitates the alignment of the holes in the projections and the tubes.

[0030] As in Fig. 6, the main body 541 is cuboid-shaped in this example. The two protrusions 542 are arranged at two opposite corners of the main body 541. This means that the two protrusions 542 are arranged in the upper left and lower right corners of the main body 541, or the two protrusions 542 are arranged in the lower left and upper right corners of the main body 541. The main body 541 can also be configured in other shapes, such as round. In this case, the two protrusions are located in positions 180° opposite each other.

[0031] The first tube 51 is pivotally mounted in the through-hole 7. The through-hole 7 is provided with a curved surface on the hole wall, which corresponds to the outer surface of the first tube 51. The curved surface is configured to limit the pivot angle of the first tube 51 in the through-hole 7. In particular, the through-hole 7 extends through the top and bottom surfaces of the first connecting element 54. A pivot axis is axially arranged in the front and rear directions in the through-hole 7. The first tube 51 can pivot left and right in the through-hole 7 around this pivot axis as a rotation center. A first curved support surface 543 is arranged at the upper left end of the through-hole 7, a second curved support surface 544 is arranged at the upper right end of the through-hole 7, a first curved pressure surface 545 is arranged at the lower left end of the through-hole 7, and a second curved pressure surface 546 is arranged at the lower right end of the through-hole 7.The first tube 51 assumes two limiting positions in the through-hole 7. In the first limiting position, the first curved support surface 543 and the second curved pressure surface 546 abut the first tube 51 and limit the first tube 51 against pivoting in opposite directions. In the second limiting position, the second curved support surface 544 and the first curved pressure surface 545 abut the first tube 51 and limit the first tube 51 against pivoting in opposite directions. The first curved support surface 543, the second curved support surface 544, the first curved pressure surface 545, and the second curved pressure surface 546 are specifically designed to correspond to the shape of the outer surface of the first tube 51 and thus exert a limiting function on the first tube 51. When the first tube 51 is in the first or second limit position, the pivoting of the first tube 51 is limited so that it cannot pivot arbitrarily.This ensures that both the front cross tube assembly 7 and the rear cross tube assembly 5 remain stable in the fully folded and fully unfolded states.

[0032] The first connecting element 54 can be equipped with a decorative element 15, as in Fig. 5. Two positioning holes 547 are arranged on the main body 541. Two positioning pins 151 are arranged on the decorative element 15. The two positioning pins 151 are each inserted into the two positioning holes 547 of the main body 541. The positioning pins 151 are provided with threaded holes. The decorative element 15 is fastened to the main body 541 by means of screws. The decorative element 15 is provided with a logo or a decorative pattern. The first connecting element 54 is made of plastic or metal using an injection molding process to ensure a uniform wall thickness. Process holes are arranged on the first connecting element 54, which can be covered by the decorative element 15 to improve aesthetics.

[0033] Both the left and right frames of the folding chair each include a front leg tube 9, a rear leg tube 8, a backrest tube 1, a seat tube 2, and an armrest 3. A sliding bushing 12 is fitted onto the rear leg tube 8. The seat tube 2 and the backrest tube 1 are pivotally connected to the sliding bushing 12 on the same side. The sliding bushing 12 has a sliding hole 121 into which the rear leg tube 8 is inserted, and a first hinge groove 122 and a second hinge groove 123 located on the same side as the sliding hole 121 at both ends. The first joint groove 122 extends through the front, back and bottom of the sliding bushing 12. The sliding bushing 12 is fitted onto the seat tube 2 via the first joint groove 122, and the seat tube 2 is pivotally connected to the groove wall of the first joint groove 122 by means of a pivot axis.The rear end of the seat tube 2 protrudes from the sliding bushing 12 and is pivotally connected to the rear cross tube assembly 5. A limiting surface 124 is arranged on the upper side of the first pivot groove 122. When the folding chair is fully unfolded, this limiting surface abuts the seat tube 2 to limit the maximum downward movement of the sliding bushing 12 onto the rear leg tube 8. This limiting surface 124 is a curved surface corresponding to the outer surface of the seat tube 2. The second pivot groove 123 is located above and behind the first pivot groove 122. The lower end of the backrest tube 1 is inserted into the second pivot groove 123 and pivotally connected to the groove wall of the second pivot groove 123. The folding chair is provided with two sliding bushings 12, wherein the sliding bushing 12 on the rear leg tube 8 of the left frame is arranged symmetrically to the sliding bushing 12 on the rear leg tube 8 of the right frame.

[0034] The front leg tube 9 is pivotally connected to the seat tube 2. The front leg tube 9 is connected at its upper end to the rear leg tube 8 via a second connecting element 14. The second connecting element 14 is provided with a first opening 141. The upper end of the front leg tube 9 is inserted into the first opening 141. The front leg tube 9 and the second connecting element 14 are fastened by means of screws, rivets, or similar fastening parts. The second connecting element 14 is also provided with a third pivot groove 142. The rear leg tube 8 passes through the third pivot groove 142, and the upper middle point of the rear leg tube 8 is pivotally connected to the groove wall of the third pivot groove 142. The armrest 3 is attached to the upper end of the rear leg tube 8 and pivotally connected to the backrest tube 1.

[0035] The upper ends of the rear cross-tube assembly 5 are each pivotally connected to the two backrest tubes 1 via a U-shaped connecting element 13. The rear end of each of the seat tubes 2 is bent upward. The lower ends of the rear cross-tube assembly 5 are each pivotally connected to the rear ends of the two seat tubes 2 via a U-shaped connecting element 13. The lower ends of the two backrest tubes 1 are each pivotally connected to the rear middle points of the two seat tubes 2 via a first connecting element 54. When the folding chair is fully unfolded, the upper ends of the rear cross-tube assembly 5 tilt forward. The two seat tubes 2, the two backrest tubes 1, and the rear cross-tube assembly 5 form a triangular support structure. The triangular support structure provides stable support for the user's back and ensures the stability of the entire chair frame.The rear sections of the seat tubes 2 are bent upward, which not only makes the design of the folding chair aesthetically pleasing, but also shortens the length of the rear cross tube assembly 5 and reduces the overall length of the folding chair in the front and rear directions, thereby saving costs.

[0036] Both the left and right frames each include a vertically telescopic support leg 4. The vertically telescopic support leg 4 includes an outer support leg 42 and an inner support leg 41. The inner support leg 41 is telescopic relative to the outer support leg 42. A telescopic locking assembly 6 is arranged on the top of the inner support leg 41, which can lock and unlock the telescopic movement of the vertically telescopic support leg 4. The upper ends of the front cross tube assembly are respectively pivotally connected to the two telescopic locking assemblies 6. When the folding chair is unfolded, the vertically telescopic support legs automatically lock, and the vertically telescopic support legs lock the cross tube assembly 7, thereby fixing the unfolded width of the folding chair.

[0037] In particular, as in the Fig. 12 and Fig. As shown in Figure 13, the vertically telescopic support leg 4 includes an inner support leg 41, an outer support leg 42, and a spacer sleeve 43. The spacer sleeve 43 is inserted into the top surface of the outer support leg 42 to separate the inner support leg 41 and the outer support leg 42 and prevent direct contact and wear between the inner support leg 41 and the outer support leg 42. In this embodiment, a pair of limiting protrusions 45 are arranged at both ends of the spacer sleeve 43. The outer support leg 42 is provided with a pair of limiting holes 44. The two limiting protrusions 45 engage with the two limiting holes 44, thereby firmly connecting the spacer sleeve 43 to the outer support leg 42. In other embodiments, the number of limiting protrusions 45 is not limited to two; there may be one or more.The limiting protrusions 45 are preferably shaped so that they gradually widen outward from bottom to top. This shape of the limiting protrusions 45 makes them easy to engage in the limiting holes 44 from top to bottom, but difficult to pull out from bottom to top, making it difficult to remove the spacer sleeve 43 from the outer support leg 42 and ensuring a secure connection.

[0038] The two telescopic locking assemblies 6 are each pivotally connected to two seat tubes 2 and to the upper ends of the front cross tube assembly 7. As shown in the Fig. As shown in Figures 8 to 11, the telescopic locking assembly 6 includes a locking base 61, a button 62, a spring 63, and a pin 64. A recess 65 is provided on the top of the locking base 61 to receive the seat tube 2. This recess 65 extends in the front and rear directions. The two side walls of the recess 65 extend rearward to form two opposing clamping arms 66. The seat tube 2 is pivotally connected between the two clamping arms 66. Both the two clamping arms 66 and the seat tube 2 are provided with opposing pivot holes. The seat tube 2 is connected to the two clamping arms 66 by rivets or pivot shafts inserted into the pivot holes.

[0039] A downwardly open second opening 67 is provided on the underside of the locking base 61. A lug 612 is provided on the front of the locking base 61. The front and rear side walls of the second opening 67 are provided with opposing through-holes. The through-hole on the front side wall of the second opening 67 extends through the lug 612. The top of the inner support leg 41 is inserted into the second opening 67. The upper end of the front cross tube assembly 7 is in contact with the lug 612. A single rivet or pivot shaft penetrates the corresponding holes of the front cross tube assembly 7, the inner support leg 41, and the locking base 61, thereby connecting the front cross tube assembly 7, the inner support leg 41, and the locking base 61.This allows the three parts to be connected with a single rivet or pivot pin, reducing assembly steps and simplifying the assembly process. The tab 612 helps reduce the contact area between the front cross tube assembly 7 and the locking base 61, thereby reducing wear on the surfaces of the front cross tube assembly 7.

[0040] As in Fig. As shown in Figure 11, a key mounting groove 68 is provided on one side of the locking base 61. The key 62 is riveted to the center of the two groove walls of the key mounting groove 68. A pressing part 69 is formed at one end of the key 62. A spring 63 is arranged between the pressing part 69 and the groove bottom of the key mounting groove 68. The other end of the key 62, which is remote from the pressing part 69, is connected to a pin 64 on the side facing the key mounting groove 68 (the pin 64 is connected to the key 62 via a pin or rivet). The groove bottom of the key mounting groove 68 is provided with a through hole through which the pin 64 passes. A pin hole 46 is arranged on the outer support leg 42, opposite the through hole. The spring 63 exerts a force that causes the pin 64 to protrude through the through hole and engage the pin hole 46 of the outer support leg 42.When the pin 64 engages the pin hole 46, the outer support leg 42 is locked. By pressing the push part 69 of the button 62, the pin 64 can be released from the outer support leg 42. When the folding chair is fully extended, the pin engages the pin hole 46 of the outer support leg 42, locking the length of the inner support leg 41 protruding from the outer support leg 42, thus fixing the height of the seat tube 2. At the same time, the extended angle of the front cross tube assembly 7 and the rear cross tube assembly 5 is fixed, thereby locking the distance between the two vertically telescopic support legs 4, thus achieving the goal of fixing the extended width of the folding chair. The telescopic locking assemblies 6 fix the width and height of the extended folding chair, making the seat surface smoother and improving seating comfort.Pulling on the folding chair will not automatically fold it. After assembling the telescopic locking assemblies 6, pressing the push button releases the pin from the outer support leg 42, allowing the folding chair to be folded. When unfolding the folding chair, the return force of the spring 63 pushes the pin 64 into the pin hole 46 if the button 62 is not influenced by external forces.

[0041] After installing the telescopic locking assemblies, pressing the button pulls the pin out of the pin hole to unlock, and the chair can be telescopically folded; when the button is released, the spring presses the pin to lock. When unfolding the folding chair, the telescopic locking assemblies 6 fix the height and width of the chair. By fixing the width of the chair, the back width of the chair is also fixed, making the seat surface smoother and improving seating comfort. When folding the folding chair, the telescopic locking assemblies 6 prevent the chair frame from falling apart. The telescopic locking assemblies 6 facilitate the folding and unfolding of the folding chair. After folding, the packing volume is small, which facilitates storage and transportation. The seat surface becomes smoother and seating comfort is improved.

[0042] The folding chair further comprises a cup holder assembly 10 as shown in the Fig. 18 and Fig.19. The cup holder assembly 10 includes a cup holder body 101 and a cup holder attachment member 103. The cup holder body 101 has a cavity for receiving cups and similar objects. A block 102 is arranged on one side of the cup holder body 101. The cup holder attachment member 103 is provided with a C-shaped groove 104 and a U-shaped receptacle 105. The cup holder attachment member is locked to the seat tube 2 via the C-shaped groove 104. The cup holder attachment member is made of materials such as plastic, which impart a certain elastic deformability to the C-shaped groove 104, so that the cup holder attachment member can be locked to the seat tube 2. A cup holder attachment groove 21 is formed in the surface of the seat tube 2. The upper edge of the C-shaped groove 104 is hooked into the cup holder attachment groove 21.The cup holder mounting groove 21 extends from the front end of the seat tube 2 to the rear end of the seat tube 2, allowing the cup holder assembly to slide along the cup holder mounting groove 21 and be moved into a comfortable position for use. The cup holder assembly can be mounted on the left or right side of the folding chair, or one each on the left and right sides.

[0043] Foot pads 11 are attached to the lower ends of the two rear leg tubes 8, and foot pads 11 are attached to the lower ends of the two outer support legs 42. The lower ends of the front cross tube assembly 7 are pivotally connected to the foot pads 11 at the lower ends of the two outer support legs 42, and the lower ends of the two front leg tubes 9 are pivotally connected to the foot pads 11 at the lower ends of the outer support legs 42 on the same side.

[0044] The above-described embodiments serve only to illustrate the technical concept of the present utility model and do not constitute a limitation thereof. Although the present utility model has been described in detail with reference to the above embodiments, a person skilled in the art should understand that they may nevertheless make modifications to the technical solutions described in the above embodiments or substitute some technical features with equivalents. However, these modifications or substitutions do not cause the corresponding technical solutions to depart from the spirit and scope of the technical solutions of the embodiments of the present utility model. Therefore, any other embodiments achieved by a person skilled in the art without creative effort fall within the scope of the present utility model.

Claims

[1] Folding chair, characterized by that he a left frame, a right frame, a front cross tube assembly and a rear cross tube assembly, wherein both the front and rear cross tube assemblies each have an x-shaped cross structure connecting the left and right frames; both the front and rear cross tube assemblies each comprise a first tube, a second tube, a third tube, and a first connecting member, the first connecting member comprising a main body and two projections connected to the main body, the main body being provided with a through hole into which the first tube is inserted, the first tube being adapted to pivotally connect to the main body, and the second and third tubes being connected to the two projections, respectively. [2] Folding chair according to claim 1, characterized bythat the main body is cuboid-shaped, the two projections are arranged at two opposite corners of the main body, the through-hole extends through the top and bottom of the first connecting element, the first tube is arranged so that it can be pivoted in the through-hole in the left and right directions, and the second tube and the third tube are arranged in parallel. [3] Folding chair according to claim 1, characterized bythat a first curved support surface is arranged at the upper left end of the through-hole, a second curved support surface is arranged at the upper right end of the through-hole, a first curved pressure surface is arranged at the lower left end of the through-hole, and a second curved pressure surface is arranged at the lower right end of the through-hole; the first tube assumes two limit positions in the through-hole, wherein in the first limit position the first curved support surface and the second curved pressure surface bear against the first tube and limit the first tube against pivoting in opposite directions, and in the second limit position the second curved support surface and the first curved pressure surface bear against the first tube and limit the first tube against pivoting in opposite directions. [4] Folding chair according to claim 3, characterized bythat the shapes of the first curved support surface, second curved support surface, first curved pressure surface and second curved pressure surface correspond to the shape of the outer surfaces of the first tube. [5] Folding chair according to claim 1, characterized bythat both the left and right frames each comprise a front leg tube, a rear leg tube, a backrest tube, a seat tube and an armrest, wherein a sliding bushing is slipped onto the rear leg tube, wherein the seat tube and the backrest tube are pivotally connected to the sliding bushing on the same side, the rear end of the seat tube projects from the sliding bushing and is pivotally connected to the rear cross tube assembly, the front leg tube is pivotally connected to the seat tube, the upper end of the front leg tube and the rear leg tube are connected via a second connecting element, and the armrest is attached to the upper end of the rear leg tube and connected to the backrest tube. [6] Folding chair according to claim 5, characterized bythat the rear end of each seat tube is bent upwards, and when the folding chair is fully unfolded, the two seat tubes, the two backrest tubes and the rear cross tube assembly form a triangular support structure. [7] Folding chair according to claim 5, characterized byin that the sliding bushing has a sliding hole into which the rear leg tube is inserted, and a first hinge groove and a second hinge groove which are arranged on the same side as the sliding hole, wherein the first hinge groove extends through the front, back and bottom of the sliding bushing, the sliding bushing is placed on the seat tube via the first hinge groove and is hingedly connected to the seat tube, a limiting surface is arranged on the top side of the first hinge groove which, when the folding chair is fully unfolded, abuts the seat tube in order to limit the maximum downward movement of the sliding bushing onto the rear leg tube, wherein the limiting surface is a curved surface which corresponds to the outer surface of the seat tube, and the lower end of the backrest tube is inserted into the second hinge groove and is hingedly connected to the groove wall of the second hinge groove. [8] Folding chair according to claim 5, characterized bythat both the left and right frames each comprise a vertically telescopic support leg, wherein the vertically telescopic support leg comprises an outer support leg and an inner support leg, wherein the inner support leg is telescopic relative to the outer support leg, a telescopic locking assembly is arranged on the top of the inner support leg and can lock the outer support leg;the telescopic locking assembly comprises a locking base, a button, a spring, and a pin, wherein the locking base is attached to the top of the inner support leg and is pivotally connected to the seat tube, the pin is connected to the button, the button is pivotally connected in the locking base, the two ends of the spring press against the locking base and the button, the outer support leg is provided with a pin hole, wherein pressing the button compresses the spring and thus moves the pin out of the pin hole; [9] Folding chair according to claim 8, characterized bythat foot pads are attached to the lower ends of the two rear leg tubes, and foot pads are attached to the lower ends of the two outer support legs, wherein the lower ends of the front cross tube assembly are hingedly connected to the foot pads at the lower ends of the two outer support legs, and the lower ends of the two front leg tubes are each hingedly connected to the foot pads at the lower ends of the outer support legs on the same side. [10] Folding chair according to claim 5, characterized bythat it further comprises a cup holder assembly, wherein the cup holder assembly comprises a cup holder body and a cup holder fastening element, wherein a block is arranged on one side of the cup holder body, the cup holder fastening element is provided with a C-shaped groove and a U-shaped receptacle, wherein the cup holder fastening element is locked to the seat tube with the C-shaped groove by a cup holder fastening groove being introduced into the surface of the seat tube, wherein the upper edge of the C-shaped groove is hooked into the cup holder fastening groove.

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