FRAME FOR FOLDABLE CHAIR AND FOLDABLE CHAIR

[0001] The present invention relates to the technical field of foldable chair, and specifically to a frame for foldable chair, and a foldable chair containing such frame.

[0002] Foldable chairs are easy to fold and portable, which are not only suitable for outdoor and temporary locations, but are also essential household items for standby use.

[0003] Currently, a traditional foldable chair typically contains a foldable frame and a supporting fabric cushion, wherein the foldable frame comprises multiple support rods fitted together. At present, the following problems exist in the use of foldable chairs. Firstly, the foldable frame of the traditional foldable chair will retract inward when being lifted. After relocating the foldable chair, therefore, the connection of the support rods of the foldable frame still needs to be readjusted, which severely affects the user experience. Secondly, the traditional foldable chair has a large volume and length after being folded, which is not convenient to carry and store. Especially when a lot of items have to be carried during outdoor activities, the foldable chair with a large volume could cause inconvenience, leading to poor user experience. Thirdly, unfolding a traditional foldable chair is complex and not smooth enough, so that problems such as time-consumption and inconvenience may occur.

[0004] Therefore, there is a need in the field to provide a frame for foldable chair and a foldable chair, in order to solve the above technical problems.

[0005] According to a first aspect of the present invention, a frame for foldable chair is provided. The frame comprises: a first mounting mechanism, including a first mounting body and support tubes arranged on the first mounting body; and a second mounting mechanism, including a second mounting body arranged above the first mounting body and in engagement therewith, leg tubes arranged on the second mounting body, and locking grooves within the second mounting body. Elastic elements engaging with the locking grooves are provided within the leg tubes. The second mounting body is configured to be movable downward under an external force, so that the leg tubes are splayed by means of the elastic elements, until the elastic elements are locked with the locking grooves.

[0006] According to a second aspect of the present invention, a foldable chair is provided. The foldable chair comprises the frame as mentioned above, and a chair cover covering the frame, wherein four corners of the chair cover are fixedly connected to the seat tube portions and the back tube portions, respectively.

[0016] In the following the present invention will be further described with reference to the accompanying drawings.

[0017] As shown in FIGS. 1A to 1C, 4B and 5, according to a first aspect of the present invention, a frame 100 for foldable chair is provided, which mainly includes a first mounting mechanism 120 and a second mounting mechanism 130. In the embodiment as illustrated, the first mounting mechanism 120 and the second mounting mechanism 130 are arranged one above the other. When the frame 100 is in an unfolded state, the first mounting mechanism 120 and the second mounting mechanism 130 can move towards each other until they are joined together. Conversely, when the frame 100 is in a folded state, they are separated and move in opposite directions until leg tubes 22 (which will be introduced below) of the second mounting mechanism 130 are fully retracted.

[0018] In one embodiment, as shown in FIG. 2, the first mounting mechanism 120 includes a first mounting body 11. Preferably, as shown in FIG. 4B, tracks 12 are provided on the first mounting body 11. Therefore, when the frame 100 is unfolded, the tracks 12 can effectively restrict the movement of the leg tubes 22, allowing the leg tubes 22 to move only along respective paths defined by the tracks 12. In the present invention, a plurality of inclined tracks 12 is arranged spaced apart on the first mounting body 11.

[0019] In the present invention, as shown in FIG. 4B, a guide inclined surface 121 for abutting against an upper end surface of the leg tube 22 is formed on an inner wall of the track 12. Preferably, when the frame 100 is in the unfolded state, the upper end surface of the leg tube 22 always abuts against the guide inclined surface 121 of the track 12. In this manner, the leg tubes 22 can have good firmness and stability in use, thus improving the user experience.

[0020] In one embodiment, as shown in FIG. 1C, the second mounting mechanism 130 includes a second mounting body 21, and leg tubes 22 arranged on the second mounting body 21. Preferably, the leg tubes 22 are hinged on the second mounting body 21 via respective mounting cavities 42. Further, a free end of the leg tube 22 of the second mounting mechanism 130 is configured to extend through a corresponding track 12 of the first mounting mechanism 120, and form a sliding connection therewith.

[0021] Therefore, when the frame 100 is unfolded or folded, the leg tubes 22 can pivot around the second mounting body 21, thereby splaying outward or retracting inward. In other words, the leg tubes 22 can switch between the unfolded state and the folded state through the cooperation of elastic elements and the tracks 12, as described below.

[0022] As shown in FIG. 1A, in the frame 100 for foldable chair according to the present invention, although the first mounting mechanism 120 is overall located above the second mounting mechanism 130, the first mounting body 11 of the first mounting mechanism 120 is arranged below the second mounting body 21 of the second mounting mechanism 130.

[0023] In the present invention, as shown in FIG. 4D, a locking cavity 111 is provided within the first mounting body 11, and a locking tongue 211 is arranged longitudinally in the second mounting body 21 and embedded into the locking cavity 111. In this manner, the first mounting body 11 can fit the second mounting body 21. In this text, “fit” has the meaning as described below. When the frame 100 is in the unfolded state, the locking tongue 211 of the second mounting body 21 can be embedded into the locking cavity 111 of the first mounting body 11, so that an upper end surface of the first mounting body 11 and a lower end surface of the second mounting body 21 form a sealed connection, at which time it can be considered that the first mounting body 11 fits the second mounting body 21.

[0024] According to the present invention, as shown in FIGS. 4B and 4D, the second mounting mechanism 130 includes locking grooves 23 within the second mounting body 21. Preferably, a plurality of mounting cavities 42 is arranged spaced apart around the locking tongue 211 in a circumferential direction, and the locking grooves 23 are formed on upper end surfaces of the mounting cavities 42. In the meantime, elastic elements adapted to the locking grooves 23 are also provided within the leg tubes 22. In a specific example of the present invention, the elastic element may be a torsion spring 30. According to the present invention, the torsion springs 30 are locked with the locking grooves 23, ensuring a stable and firm connection between the first mounting body 11 and the second mounting body 21.

[0025] In the present invention, when the torsion springs 30 and the locking grooves 23 are in a locked state, the leg tubes 22 will be in the unfolded state under the force of the torsion springs 30, while also being restricted by the tracks 12. Therefore, in a downward movement of the first mounting body 11, the leg tubes 22 splay outward through the cooperation of the torsion springs 30 and the tracks 12. In this manner, the firmness and stability of the frame 100 can be further improved.

[0026] Preferably, since the leg tubes 22 can remain in the unfolded state when the torsion springs 30 and the locking grooves 23 are in a locked state, an overall gesture of the frame 100 (i.e., the unfolded state of the leg tubes 22) will not change when the foldable chair is moved. Further, the frame 100 can continue to be used as it is after the foldable chair is moved, and thus there is no need to readjust the gesture of the foldable frame. Therefore, the user does not need to spend the time and effort readjusting the frame, further improving the convenience in use.

[0027] In the present invention, the second mounting body 21 is configured to be movable downward under an external force (e.g., an axial push force from a user). Therefore, the leg tubes 22 can gradually switch from the folded state to the unfolded state along the paths defined by the tracks 12 by means of the torsion springs 30, until the torsion springs 30 engage with the locking grooves 23 to form a locked state. In this case, the leg tubes 22 will be fully splayed, so that the frame 100 is in the unfolded state.

[0028] In a specific embodiment of the present invention, as shown in FIG. 4D, the torsion spring 30 is a double torsion spring and comprises a connecting portion 31 in a spiral form, a first support portion 32 at a first end of the connecting portion 31, and a second support portion 33 at a second end of the connecting portion 31. Preferably, the first support portion 32 is configured to always abut against an inner wall of the leg tube 22, thereby applying an outward force on the leg tube 22 to ensure it can splay outward smoothly. The second support portion 33 is configured to engage into the locking groove 23 to form a locking connection therewith, thereby ensuring the firmness and stability of the frame 100.

[0029] In one embodiment of the present invention, the first mounting body 11 is configured to release the locked state between the torsion springs 30 and the locking grooves 23 under an external force (e.g. an axial push force from a user) and continues to move downward. In this procedure, the leg tubes 22 will retract inward along the paths defined by the tracks 12 to be in the folded state.

[0030] As shown in FIG. 1B, according to the present invention, the first mounting mechanism 120 further comprises fixed cavities 41, and support tubes 60 hinged on the first mounting body 11 via the fixed cavities 41. As shown, the support tube 60 includes seat tube portions 13 and back tube portions 14, wherein the seat tube portions 13 and the back tube portions 14 are all connected to the fixed cavity 41 (which will be described in detail below). Thus, when the frame 100 is unfolded, the support tubes 60 can be splayed outward manually. Preferably, a limit block (not shown) for limiting a maximum range of motion of the support tube 60 is provided within the fixed cavity 41, thereby ensuring the stability and firmness of the support tube 60 in use.

[0031] Preferably, the fixed cavities 41 and the tracks 12 are arranged alternately along the circumferential direction of the frame 100. Since the support tubes 60 are hinged on the first mounting body 11 via the fixed cavities 41, and the leg tubes 22 need to pass through the tracks 12 to form a sliding connection therewith, the support tubes 60 and the leg tubes 22 in the frame 100 of the present invention are actually arranged alternately along the circumferential direction.

[0032] In the prior arts, a pairwise symmetrical arrangement is usually adopted, i.e. two support tubes are arranged between two adjacent leg tubes. Obviously, for such structure, the chair is prone to tilt backward or tip over when the user stands up or sits down. According to the present invention, the support tubes 60 and the leg tubes 22 are arranged alternately along the circumferential direction, which can effectively ensure balanced force distribution and stability of the foldable chair, further ensuring the safety of the user.

[0033] In other embodiments, three leg tubes 22 can be provided, with every two adjacent leg tubes 22 spaced apart by 120°. In this manner, the stability of the foldable chair can be ensured, while the overall mass of the foldable chair and the production cost can be reduced, further improving the portability of the chair.

[0034] According to the present invention, as shown in FIG. 1B, the support tubes 60 comprise at least two adjacent seat tube portions 13 and at least two adjacent back tube portions 14. To meet the user needs, a length of the back tube portion 14 is usually larger than that of the seat tube portion 13, whereby the foldable chair can provide a firm sitting and leaning environment for the user.

[0035] In one embodiment, the seat tube portions 13 and the back tube portions 14 are each typically composed of a plurality of interconnected telescopic tubes, and adjacent telescopic tubes are connected to each other through an anchor. In the present invention, the user can extend the corresponding telescopic tubes and easily lock two adjacent telescopic tubes through the anchors at the corresponding positions, so that the operation of the chair is more convenient.

[0036] In one embodiment of the present invention, the anchor may be a spring-loaded ball. Therefore, the locking between two adjacent telescopic tubes can be achieved by popping out the spring-loaded ball. It is readily understood that other types of anchors can also be selected, and any structure capable of locking two adjacent telescopic tubes together can be used in the present invention.

[0037] In one embodiment, a tube plug 62 is provided at each free end of the seat tube portions 13 and the back tube portions 14, as shown in FIG. 1B. The tube plug 62 can prevent hand injury, protect chair fabric from being cut, or the like, in order to further enhance the safety of the chair in use.

[0038] In one embodiment, a foot pad 221 is provided at a bottom end of each leg tube 22, as shown in FIG. 4B. Preferably, the foot pad 221 wraps around the bottom end of the leg tube 22, thereby increasing its contact area with the ground and further improving the stability of the foldable chair in use. In other embodiments, the foot pad 221 may also be installed inside the leg tube 22.

[0039] Preferably, the second mounting mechanism 130 further comprises limit seats 65 engaging with the support tubes 60. Preferably, the limit seats and the mounting cavities 42 are arranged alternately along the circumferential direction on the second mounting body 21. When the frame 100 is fully unfolded, the limit seats 65 can fully seat onto the support tubes 60 to prevent the support tubes 60 from shaking left and right, thereby further improving the stability of the foldable chair.

[0040] According to a second aspect of the present invention, a foldable chair (not shown) is provided, comprising the frame 100 as described above, and a chair cover (not shown) covering the frame. Preferably, four corners of the chair cover are fixedly connected (e.g., fixed through screws) to the seat tube portions 13 and the back tube portions 14 respectively, thereby providing a comfortable sitting and leaning experience for the user.

[0041] In one embodiment, the chair cover may comprise a seat portion and a back portion fixedly connected to each other. Preferably, an angle between the seat portion and the back portion is generally within a range of 90° to 110°. After the chair cover and the frame are assembled, the chair can provide a comfortable sitting and leaning experience for the user.

[0042] The unfolding procedure of the frame 100 according to the present invention is described below with reference to FIGS. 6 to 10. In an initial stage, the frame 100 is in the folded state, as shown in FIG. 6. Then, as shown in FIG. 7, the seat tube portions 13 and the back tube portions 14 of the support tubes 60 of the first mounting mechanism 120 are splayed outward. Next, the second mounting body 21 of the second mounting mechanism 130 is pushed downward by an external force (e.g., an axial push force from a user). At this time, the leg tubes 22 of the second mounting mechanism 130 move along the paths defined by the tracks 12 under the force of the torsion springs 30, gradually switching from the folded state to the unfolded state, until the torsion springs 30 engage into the locking grooves 23 to lock with each other. In this case, the leg tubes 22 will be fully splayed, so that the frame 100 is in the unfolded state. The above procedure is shown in FIGS. 8 to 10.

[0043] The folding procedure of the frame 100 according to the present invention is described below.

[0044] First, an external force (e.g., an axial push force from a user) is applied to release the locked state between the torsion springs 30 and the locking grooves 23, and the first mounting body 11 is pushed downward, until the leg tubes 22 are fully retracted along the path defined by the tracks 12 to be in the folded state. It is worth noting that during this procedure, external forces need to be applied simultaneously to the seat tube portions 13 and the back tube portions 14 arranged diagonally (i.e. in MM or PP direction in FIG. 4A), so that the first mounting body 11 moves downward. In the meantime, under the lever principle, the second mounting body 21 receives an upward force, thus overcoming the force of the torsion springs 30 and moving upward. In this case, the first mounting body 11 and the second mounting body 21 are separated from each other. Then, the seat tube portions 13 and the back tube portions 14 are retracted inward, so that the frame 100 is in the fully folded state.

[0045] Compared with the prior arts, the present invention has the following advantages.

[0046] Firstly, the present invention can control the switch between the folded state and the unfolded state of the leg tubes 22 through the relative movement of the first mounting body 11 and the second mounting body 21 as well as the cooperation of the torsion springs 30 and the tracks 12, so that the frame 100 can be quickly unfolded and stored, making the operation of the frame 100 more convenient.

[0047] In other words, when the first mounting body 11 and the second mounting body 21 are in a separated state, both the leg tubes 22 and the support tubes 60 in the present invention can retract inward, effectively reducing the overall size of the foldable chair, which facilitates the portability and storage during outdoor activities. When the first mounting body 11 and the second mounting body 21 are in an engaged state and the torsion springs 30 are locked with the locking grooves 23, both the leg tubes 22 and the support tubes 60 can splay outward, thereby cooperating with the chair cover to provide a sitting and leaning space for the user, facilitating a comfortable experience.

[0048] Secondly, when the frame 100 is in the unfolded state, the leg tubes 22 splay outward under the force of the torsion springs 30, while the upper end surfaces of the leg tubes 22 abut against the guide inclined surfaces 121 of the tracks 12, thereby providing the effective restriction. In this manner, the leg tube 22 can always remain in the unfolded state. When the foldable chair is moved, therefore, its overall gesture will not change, so that the foldable chair can continue to be used, in order to avoid readjusting the gesture of the foldable frame, further improving the user experience.

[0049] Thirdly, according to the present invention, the support tubes 60 and the leg tubes 22 are arranged alternately along the circumferential direction, which can effectively ensure balanced force distribution and stability of the foldable chair, thus further ensuring the safety of the user. Additionally, such structure can effectively prevent the chair from tilting backward or tipping over when the user stands up or sits down.