Backrest folding locking mechanism and wheelchair

Abstract

The application discloses a back folding locking mechanism and a wheelchair. The back folding locking mechanism adopts a linkage mechanism, and a user can operate the back to be unlocked and folded by one hand, and the operation is convenient. The back folding locking mechanism comprises a lock hook assembly, a blocking buckle assembly, a back and a seat main frame. The back and the seat main frame are rotationally connected. The lock hook assembly is rotationally installed on the back. The blocking buckle assembly is installed on the seat main frame. The lock hook assembly comprises a pull rod, a first lock hook assembly and a second lock hook assembly which are installed at two ends of the pull rod. The first lock hook assembly and the second lock hook assembly are respectively rotationally installed on the back. The lock hook assembly and the blocking buckle assembly are clamped to be capable of limiting the back to rotate relative to the seat main frame.

Description

Technical Field

[0001] This application relates to the field of seating technology, and more particularly to a backrest folding locking mechanism and a wheelchair. Background Technology

[0002] Most fixed-frame wheelchair backrests on the market lack locking mechanisms, with the backrest and wheelchair frame using a fixed connection structure. Folding wheelchairs, on the other hand, require a locking mechanism to maintain the angle of the folding backrest. These folding wheelchair backrests typically employ two separate locking mechanisms located on either side of the backrest, requiring both hands to operate for locking and unlocking, which is inconvenient. Utility Model Content

[0003] This application provides a backrest folding locking mechanism and a wheelchair, which adopts a linkage mechanism, allowing the user to unlock and fold the backrest with one hand, making operation convenient.

[0004] An embodiment of this application provides a backrest folding locking mechanism including a locking hook assembly, a buckle assembly, a backrest and a seat main frame. The backrest and the seat main frame are rotatably connected. The locking hook assembly is rotatably mounted on the backrest, and the buckle assembly is mounted on the seat main frame.

[0005] The locking hook assembly includes a pull rod, and a first locking hook assembly and a second locking hook assembly installed at both ends of the pull rod. The first locking hook assembly and the second locking hook assembly are rotatably mounted on the backrest, and the locking hook assembly engages with the buckle assembly to restrict the rotation of the backrest relative to the main frame of the chair.

[0006] In the above embodiment, the first and second locking hook assemblies are symmetrically arranged at both ends of the pull rod. During installation, the locking hook assemblies are installed in the middle of the backrest, with the first locking hook assembly located on the left side of the backrest and the second locking hook assembly located on the right side of the backrest. This ensures that the force on the backrest is evenly distributed when locked. When the locking hook assemblies engage with the latch assembly, they restrict the rotation of the backrest, fixing its angle with the main frame of the chair, thus locking the backrest. To unlock, lifting the pull rod causes the first and second locking hook assemblies to rotate simultaneously and disengage from the latch assembly, unlocking the backrest. The linkage structure formed by the first and second locking hook assemblies and the pull rod allows the user to unlock the backrest with one hand, making operation convenient.

[0007] In one embodiment, the first locking hook assembly includes a locking hook and an elastic element, the locking hook having a first mounting hole, and at least a portion of the elastic element being disposed within the first mounting hole and located between the first locking hook assembly and the pull rod; the second locking hook assembly has the same structure as the first locking hook assembly.

[0008] In one embodiment, the locking hook is further provided with a second mounting hole. The first locking hook assembly and the second locking hook assembly are respectively mounted on the backrest via a connector. The connector includes a locking hook mounting base and a locking hook pin. The locking hook pin passes through the second mounting hole and is connected to the locking hook mounting base. The locking hook is rotatable around the locking hook pin.

[0009] In one embodiment, the locking hook includes a hook portion and a connecting portion, with a first mounting hole disposed in the hook portion and a second mounting hole disposed in the connecting portion.

[0010] In one embodiment, the connecting portion includes a first connecting plate and a second connecting plate arranged parallel to each other, the length of the first connecting plate being greater than the length of the second connecting plate, and the first connecting plate being used to abut against the mounting base to limit the rotation angle of the locking hook.

[0011] In one embodiment, the backrest folding locking mechanism further includes a backrest pivot, the axis of which is aligned with the axis of the pull rod. The backrest rotates around the backrest pivot. The backrest includes a backrest portion and a mounting portion, which are located on opposite sides of the backrest pivot. The locking hook assembly is mounted on the mounting portion. In the unlocked state, when the backrest portion approaches the main frame of the chair, the mounting portion drives the locking hook assembly away from the latch assembly.

[0012] In one embodiment, the surface of the hook portion facing away from the backrest is an arc-shaped surface, and the arc-shaped surface curves toward the backrest.

[0013] In one embodiment, a reset member is provided between the locking hook and the locking hook mounting base, the reset member being used to drive the hook away from the backrest.

[0014] In one embodiment, the latch assembly includes a mounting base and a stop pin. The mounting base is fixedly mounted to the main frame of the chair, and the stop pin is mounted on the mounting base. The axial direction of the stop pin is aligned with the axial direction of the pull rod.

[0015] Embodiments of this application also provide a wheelchair, which includes the aforementioned backrest folding and locking mechanism. When the wheelchair needs to be moved or stored, the backrest is folded, and unlocking is achieved simply by lifting the lever with one hand. This user-friendly design makes the wheelchair easy to use. When the backrest is unfolded, the locking hook assembly and the latch assembly automatically engage reliably, improving the wheelchair's safety. Attached Figure Description

[0016] Figure 1 A backrest folding locking mechanism is provided as an embodiment of this application;

[0017] Figure 2 An assembly diagram showing the locked state of the locking hook assembly and the buckle assembly according to an embodiment of this application;

[0018] Figure 3 An assembly diagram showing the unlocked state of the locking hook assembly and the buckle assembly provided in one embodiment of this application;

[0019] Figure 4 An exploded view of a locking hook assembly and a latch assembly provided in one embodiment of this application;

[0020] Figure 5 A structural diagram of a locking hook provided in one embodiment of this application;

[0021] Figure 6 A structural diagram of a lock hook mounting base provided in one embodiment of this application;

[0022] Figure 7 A partial cross-sectional view of a backrest folding locking mechanism provided in one embodiment of this application;

[0023] Figure 8 A front view of a locking hook assembly provided in one embodiment of this application;

[0024] Figure 9A A partial sectional side view of the backrest folding locking mechanism in a fully folded state, provided as an embodiment of this application;

[0025] Figure 9B A partial sectional side view of the backrest folding locking mechanism in a semi-folded state, provided as an embodiment of this application;

[0026] Figure 9C This is a partial sectional side view of the backrest folding locking mechanism in the fully open state, according to an embodiment of this application.

[0027] Figure label:

[0028] 1-Hook assembly; 2-Block assembly; 3-Backrest; 4-Seating main frame; 11-Pull rod; 12-First hook assembly; 13-Second hook assembly; 121-Hook; 122-Elastic element; 111-Limiting block; 1211-First mounting hole; 1221-First part; 1222-Second part; 1212-Second mounting hole; 1213-Hook part; 1214-Connecting part; 12141-First connecting plate; 12142-Second connecting plate; 5-Connecting piece; 51-Hook mounting base; 511-Reset piece; 512-Clocking block; 52-Hook pin; 6-Backrest pivot; 31-Backrest part; 32-Mounting part; 41-L-shaped bracket; 21-Block mounting base; 22-Block pin; 12131-Arc-shaped surface; 12132-Locking surface. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description of the application is provided in conjunction with the accompanying drawings and embodiments.

[0030] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to also include expressions such as “one or more” unless the context clearly indicates otherwise.

[0031] References to “an embodiment” or “a specific embodiment” as used in this specification mean that one or more embodiments of this application include a particular feature, structure, or characteristic described in connection with that embodiment. The terms “comprising,” “including,” “having,” and variations thereof mean “including, but not limited to,” unless otherwise specifically emphasized.

[0032] With the accelerating aging of the population, the demand for wheelchairs among the elderly is increasing. In addition, people with mobility impairments also require wheelchair assistance. Folding wheelchairs, with their lightweight and easy-to-fold characteristics, are widely used in various life scenarios, meeting the travel needs of different groups, including the elderly. Application scenarios include home settings, caregiving settings, shopping settings, and medical treatment settings. Furthermore, the compact size of the folded wheelchair allows it to be easily placed in a car trunk or carried on public transportation.

[0033] In related technologies, the backrest of a folding wheelchair can be flipped forward to fold. After the backrest is unfolded, a locking mechanism is required to lock it in order for it to be used normally. The locking mechanism adopts a split design, with one mechanism located on each side of the backrest. Users need to operate both hands to lock and unlock the backrest, which is inconvenient to use, especially for the elderly or disabled.

[0034] In view of this, embodiments of this application provide a backrest folding locking mechanism and a wheelchair. The locking mechanism adopts a linkage structure, which can unlock the backrest with one hand, making it convenient to use.

[0035] Figure 1 A backrest folding locking mechanism is provided as an embodiment of this application. Figure 2 This is an assembly drawing showing the locked state of the locking hook assembly and the latch assembly according to one embodiment of this application. Figure 3 An assembly diagram of the unlocked state of the locking hook assembly and the buckle assembly provided in one embodiment of this application is shown below. Figures 1-3As shown, an embodiment of this application provides a backrest folding locking mechanism including a locking hook assembly 1, a latch assembly 2, a backrest 3, and a seat main frame 4. The backrest 3 and the seat main frame 4 are rotatably connected, enabling the backrest 3 to be flipped and folded. The locking hook assembly 1 is rotatably mounted on the backrest 3, and the latch assembly 2 is fixedly mounted on the seat main frame 4. The locking hook assembly 1 includes a pull rod 11, and a first locking hook assembly 12 and a second locking hook assembly 13 mounted at both ends of the pull rod 11. The first locking hook assembly 12 and the second locking hook assembly 13 are rotatably mounted on the backrest 3, and the locking hook assembly 1 and the latch assembly 2 engage to restrict the rotation of the backrest 3 relative to the seat main frame 4.

[0036] In the above embodiment, the first locking hook assembly 12 and the second locking hook assembly 13 are symmetrically arranged at both ends of the pull rod 11. During installation, the locking hook assembly 1 is installed in the middle of the backrest 3, the first locking hook assembly 12 is located in the left side area of ​​the backrest 3, and the second locking hook assembly 13 is located in the right side area of ​​the backrest 3. This ensures that the force on the backrest 3 is evenly distributed when locked. When the locking hook assembly 1 engages with the stop assembly 2, it restricts the rotation of the backrest 3, fixing its angle with the main frame 4 of the chair, thus locking the backrest 3. When unlocking, lifting the pull rod 11 allows the first locking hook assembly 12 and the second locking hook assembly 13 to rotate simultaneously and disengage from the stop assembly 2, thereby unlocking the backrest 3. The linkage structure formed by the first locking hook assembly 12, the second locking hook assembly 13, and the pull rod 11 allows the user to complete the unlocking operation of the backrest 3 with one hand, making the operation convenient.

[0037] The first locking hook assembly 12 and the second locking hook assembly 13 have the same structure. The structure of the first locking hook assembly 12 will be introduced as an example.

[0038] Figure 4 An exploded view of a locking hook assembly and a buckle assembly provided in one embodiment of this application, in conjunction with... Figures 2-4In one embodiment, the first locking hook assembly 12 includes a locking hook 121 and an elastic element 122, with the elastic element 122 disposed between the locking hook 121 and the pull rod 11. Specifically, the locking hook 121 has a first mounting hole 1211, and the elastic element 122 is sleeved on the outer wall of the pull rod 11, with at least a portion of the elastic element 122 located within the first mounting hole 1211. Because the elastic element 122 can deform, the connection between the locking hook 121 and the pull rod 11 forms a floating connection, meaning that the locking hook 121 and the pull rod 11 can generate radial relative displacement or the locking hook 121 can rotate around the pull rod 11. The two locking hooks 121 can each rotate independently around the pull rod 11 within a certain preload range, or offset moderately in a direction perpendicular to the axial direction of the pull rod 11. The preload range refers to the allowable displacement or deformation range when a preload is applied to a material or structure in an engineering or mechanical system. The elastic element 122 enables automatic fine-tuning of the position of the locking hook 121, which can absorb the machining and assembly dimensional errors caused by the misalignment of the first mounting holes 1211 of the two locking hooks 121. This avoids the situation where the first mounting holes 1211 of the two locking hooks 121 are misaligned due to errors, resulting in one locking hook 121 being locked while the other locking hook 121 is not engaged with the buckle assembly 2, making the locking of the backrest folding locking mechanism more reliable.

[0039] In one specific embodiment, the elastic element 122 can be a T-shaped rubber ring. The pull rod 11 has two limiting blocks 111, which can restrict the two locking hooks 121 from approaching each other. The two locking hooks 121 are respectively disposed on opposite sides of the two limiting blocks 111. The T-shaped rubber ring includes a first part 1221 and a second part 1222 that are perpendicular to each other. The first part 1221 is located between the inner wall of the first mounting hole 1211 and the outer wall of the pull rod 11, and the second part 1222 is located between the locking hook 121 and the limiting block 111.

[0040] In other embodiments, the elastic element 122 may also be a spring sheet (not shown in the figure).

[0041] In one embodiment, the locking hook 121 is further provided with a second mounting hole 1212. The first locking hook assembly 12 and the second locking hook assembly 13 are respectively mounted on the backrest 3 through the connector 5. The connector 5 includes a locking hook mounting base 51 and a locking hook pin 52. The locking hook pin 52 passes through the second mounting hole 1212 and is connected to the locking hook mounting base 51. The locking hook 121 can rotate around the locking hook pin 52.

[0042] Figure 5 This is a structural diagram of a locking hook provided in one embodiment of this application. Figure 6 A structural diagram of a lock hook mounting base provided in one embodiment of this application is shown below. Figure 5 and Figure 6As shown, in a further embodiment, the lock hook 121 includes a hook portion 1213 and a connecting portion 1214. The hook portion 1213 is used to engage with the latch assembly 2 to achieve locking. The connecting portion 1214 is used to connect with the lock hook mounting base 51 and install the lock hook pin 52, which serves as the pivot of the lock hook 121. A first mounting hole 1211 is provided in the hook portion 1213, and a second mounting hole 1212 is provided in the connecting portion 1214. The hook portion 1213 and the connecting portion 1214 are located at both ends of the lock hook, making the distance between the first mounting hole 1211 and the second mounting hole 1212 relatively large. The pull rod 11 is installed in the first mounting hole 1211 located in the hook portion 1213, which is relatively far from the pivot, making it easier for the user to pull the pull rod 11 to unlock.

[0043] In one embodiment, the connecting portion 1214 includes a first connecting plate 12141 and a second connecting plate 12142 arranged parallel to each other. Along the extending direction of the locking hook 121, the length of the first connecting plate 12141 is greater than the length of the second connecting plate 12142. Both the first connecting plate 12141 and the second connecting plate 12142 are provided with second mounting holes 1212, and the two second mounting holes 1212 are coaxially arranged. The second connecting plate 12142 has a gap with the locking hook mounting base 51. Since the length of the first connecting plate 12141 is greater than the length of the second connecting plate 12142, the portion of the first connecting plate 12141 that is longer than the second connecting plate 12142 can abut against the locking hook mounting base 51, thereby limiting the rotation angle of the locking hook 121.

[0044] Figure 7 A partial cross-sectional view of a backrest folding locking mechanism provided in one embodiment of this application, as shown below. Figure 7 As shown, in one embodiment, the backrest folding locking mechanism further includes a backrest pivot 6, which can specifically be a bolt. The backrest 3 and the main frame 4 of the chair are connected by the backrest pivot 6, the axial direction of which is consistent with the axial direction of the pull rod 11, and the backrest 3 rotates around the backrest pivot 6. The main frame 4 of the chair has an L-shaped bracket 41, and the backrest 3 is rotatably mounted on the L-shaped bracket 41. The backrest 3 includes a backrest portion 31 and a mounting portion 32, which are located on both sides of the backrest pivot 6. The locking hook assembly 1 is mounted on the mounting portion 32. In the unlocked state of the locking hook assembly 1 and the latch assembly 2, rotating the backrest 3 causes the backrest portion 31 to move closer to the main frame 4 of the chair, and the mounting portion 32 drives the locking hook assembly 1 away from the latch assembly 2.

[0045] Combination Figure 4 and Figure 7In one embodiment, the latch assembly 2 includes a latch mounting base 21 and a stop pin 22. The latch mounting base 21 is fixedly mounted on the main frame 4 of the chair, specifically on the L-shaped bracket 41. The latch mounting base 21 and the lock hook mounting base 51 are perpendicular to each other. The stop pin 22 is mounted on the latch mounting base 21, and the axis of the stop pin 22 is aligned with the axis of the pull rod 11. When the lock hook 121 engages the stop pin 22, locking is achieved.

[0046] When the locking hook 121 rotates, it moves from the first position A ( Figure 2 The position of the center lock hook is moved to the second position B. Figure 3 (Position of the locking hook), the first position A can be regarded as the initial position, and the second position B can be regarded as the unlocked position. When the locking hook 121 is in the first position A, the first connecting plate 12141 abuts against the locking hook mounting base 51. Lifting the pull rod 11 causes the locking hook 121 to rotate to the second position B, and the first connecting plate 12141 moves away from the locking hook mounting base 51.

[0047] Figure 8 A front view of a locking hook assembly provided in one embodiment of this application, as shown below. Figure 8 As shown, in one embodiment, a reset member 511 is provided between the hook 121 and the hook mounting base 51. The reset member 511 is used to drive the hook portion 1213 away from the backrest 3, that is, to rotate from the second position B to the first position A. Specifically, the reset member 511 can be a torsion spring, which is mounted on the hook pin 52. The hook mounting base 51 is provided with a locking block 512, one end of the torsion spring abuts against the locking block 512, and the other end abuts against the hook 121. When the pull rod 11 is pulled to make the hook 121 position B, the torsion spring stores force. When the pull rod 11 is released, the hook 121 automatically returns to the first position A under the drive of the reset member 511.

[0048] Figure 9A This is a partial sectional side view of the backrest folding locking mechanism in a fully folded state, according to one embodiment of this application. Figure 9B This is a partial sectional side view of the backrest folding locking mechanism in a semi-folded state, according to one embodiment of this application. Figure 9C A partial sectional side view of the backrest folding locking mechanism in the fully open state, provided as an embodiment of this application, is shown below. Figures 9A to 9C As shown, in one embodiment, the hook portion 1213 of the locking hook 121 has an arc-shaped surface 12131 on the side facing away from the backrest 3, and the arc-shaped surface 12131 curves towards the backrest 3. When the backrest 3 is fully folded, as... Figure 9AThe locking hook 121 and the stop pin 22 are spaced at a preset distance. During the process of the backrest 3 changing from a folded state to an open state, the backrest 3 rotates around the backrest pivot 6, and the mounting part 32 gradually approaches the L-shaped bracket 41, while the leaning part 31 gradually moves away from the L-shaped bracket 41. The mounting part 32 drives the locking hook 121 to gradually approach the stop assembly 2. After the arc-shaped surface 12131 of the hook 1213 impacts the stop pin 22, as... Figure 9B The stop pin 22 slides relative to the arc surface 12131. Under the pushing force of the stop pin 22, the locking hook 121 rotates to the second position B. When the stop pin 22 slides to the end of the arc surface 12131, the backrest 3 is fully opened. Under the action of the reset member 511, the locking hook 121 automatically rotates in the reverse direction, and the stop pin 22 slides into the hook part 1213 and engages with the hook part 1213, thereby locking the backrest 3. At this time, the backrest 3 is opened to the preset position. The plane where the front end of the locking surface 12132 on the inner side of the hook part 1213 is located is obliquely to the right ( Figure 9C As shown by the dotted line, it can effectively prevent the hook from coming off. Pushing the backrest 3 forward or pulling the backrest 3 backward will not cause the locking hook assembly 1 and the buckle assembly 2 to separate, making the locking of the backrest 3 reliable.

[0049] When the locking hook assembly 1 and the latch assembly 2 are engaged, the backrest 3 is in an unfolded state, and the backrest 3 forms a preset angle with the seat area of ​​the main frame 4 of the chair. This angle can be close to 90°. This application does not impose specific restrictions on the preset angle when the backrest is unfolded. When the locking hook 121 and the latch assembly 2 are not engaged, the backrest 3 can be in a folded state or in a freely rotating state.

[0050] It is worth noting that the aforementioned backrest folding locking mechanism can be applied to wheelchairs, as well as to seats, such as office chairs, student chairs, children's seats, folding chairs, dining chairs, or other scenarios where the backrest can be folded.

[0051] Embodiments of this application also provide a wheelchair, which can be a folding wheelchair, including the backrest folding locking mechanism in any of the above embodiments. When the wheelchair needs to be moved and stored, the backrest 3 is folded, and the backrest 3 can be unlocked simply by lifting the lever 11 with one hand. The user-friendly design makes the wheelchair easy to use. When the backrest 3 is unfolded, the locking hook assembly 1 and the buckle assembly 2 can automatically lock together, and the engagement is reliable, improving the safety of the wheelchair.

[0052] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A backrest folding locking mechanism, characterized in that, The chair includes a locking hook assembly, a buckle assembly, a backrest, and a main frame of the chair. The backrest and the main frame of the chair are rotatably connected. The locking hook assembly is rotatably mounted on the backrest, and the buckle assembly is mounted on the main frame of the chair. The locking hook assembly includes a pull rod, and a first locking hook assembly and a second locking hook assembly installed at both ends of the pull rod. The first locking hook assembly and the second locking hook assembly are rotatably mounted on the backrest, and the locking hook assembly engages with the buckle assembly to restrict the rotation of the backrest relative to the main frame of the chair.

2. The backrest folding locking mechanism according to claim 1, characterized in that, The first locking hook assembly includes a locking hook and an elastic element. The locking hook has a first mounting hole, and at least part of the elastic element is disposed in the first mounting hole and located between the first locking hook assembly and the pull rod. The second locking hook assembly has the same structure as the first locking hook assembly.

3. The backrest folding locking mechanism according to claim 2, characterized in that, The locking hook is also provided with a second mounting hole. The first locking hook assembly and the second locking hook assembly are respectively mounted on the backrest through a connector. The connector includes a locking hook mounting base and a locking hook pin. The locking hook pin passes through the second mounting hole and is connected to the locking hook mounting base. The locking hook can rotate around the locking hook pin.

4. The backrest folding locking mechanism according to claim 3, characterized in that, The lock hook includes a hook portion and a connecting portion, with the first mounting hole disposed in the hook portion and the second mounting hole disposed in the connecting portion.

5. The backrest folding locking mechanism according to claim 4, characterized in that, The connecting part includes a first connecting plate and a second connecting plate arranged parallel to each other. The length of the first connecting plate is greater than the length of the second connecting plate. The first connecting plate is used to abut against the locking hook mounting base to limit the rotation angle of the locking hook.

6. The backrest folding locking mechanism according to claim 1, characterized in that, It also includes a backrest pivot, the axis of which is consistent with the axis of the pull rod. The backrest rotates around the backrest pivot. The backrest includes a backrest part and a mounting part, which are located on opposite sides of the backrest pivot. The locking hook assembly is mounted on the mounting part. In the unlocked state, when the backrest part is close to the main frame of the chair, the mounting part drives the locking hook assembly away from the buckle assembly.

7. The backrest folding locking mechanism according to claim 4, characterized in that, The surface of the hook portion facing away from the backrest is an arc-shaped surface, and the arc-shaped surface curves towards the backrest.

8. The backrest folding locking mechanism according to claim 4, characterized in that, A reset element is provided between the locking hook and the locking hook mounting base, and the reset element is used to drive the hook away from the backrest.

9. The backrest folding locking mechanism according to claim 1, characterized in that, The buckle assembly includes a buckle mounting base and a stop pin. The buckle mounting base is fixedly installed on the main frame of the chair, and the stop pin is installed on the buckle mounting base. The axial direction of the stop pin is consistent with the axial direction of the pull rod.

10. A wheelchair, characterized in that, Includes the backrest folding locking mechanism as described in any one of claims 1 to 9.

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