Self-locking mechanism and foldable stroller

Abstract

This application provides a self-locking mechanism and a foldable trolley. The self-locking mechanism is used to automatically lock the movable rod of the foldable trolley. The self-locking mechanism includes a limiting seat, a push rod, a locking member, and an elastic member. The limiting seat forms a sliding groove and an adjusting groove. The sliding groove includes a movable sub-groove and a locking sub-groove that are connected and have different length directions. The sliding groove is used to slide the movable rod. One end of the push rod is slidably connected to the adjusting groove. One end of the locking member is connected to the push rod, and the other end of the locking member is close to the sliding groove. The elastic member is used to drive the push rod to slide towards the locking end of the adjusting groove. The self-locking mechanism includes a locked state and an unlocked state. In the locked state, the push rod is connected to the locking end, and the locking member prevents the movable rod from sliding from the locking sub-groove to the movable sub-groove. In the unlocked state, the push rod is connected to the unlocked end of the adjusting groove, the locking member is away from the sliding groove, and the movable rod can slide between the locking sub-groove and the movable sub-groove. The self-locking mechanism of this application can realize the automatic locking of the movable rod.

Description

Technical Field

[0001] This application relates to the field of trolley technology, and in particular to a self-locking mechanism and a foldable trolley. Background Technology

[0002] Foldable trolleys, as everyday tools that combine practicality and flexibility, are widely used in various scenarios such as homes, offices, and businesses due to their foldable core feature. Foldable trolleys are typically composed of multiple movable rods connected by hinges, buckles, and other connectors. When unfolded, they rely on the engagement and support of these connectors to maintain their overall shape.

[0003] However, when the weight of items on the foldable trolley is unevenly distributed or it is accidentally activated, the force is concentrated on a localized area of ​​the moving rods and connectors, resulting in significant pressure at the contact points between the moving rods and connectors. If this pressure exceeds its designed load-bearing threshold, the originally tightly engaged connectors may loosen, and the moving rods, which were originally in the locked position, may disengage, causing the foldable trolley's support structure to fail and leading to its tipping over. Items placed on the shelf will then fall, potentially causing damage and injuring nearby people, posing a safety hazard.

[0004] It is important to note that the techniques described in this section are not necessarily those previously conceived or adopted. Unless otherwise specified, no technique described in this section should be assumed to be prior art simply because it is included in this section. Similarly, unless otherwise specified, the issues mentioned in this section should not be considered to be recognized in any prior art. Utility Model Content

[0005] This application provides a self-locking mechanism and a foldable trolley, aiming to solve the technical problem of poor locking effect of foldable trolleys in the prior art.

[0006] A first aspect of this application provides a self-locking mechanism for automatically locking the movable lever of a foldable trolley, the self-locking mechanism comprising:

[0007] The limiting seat has a sliding groove and an adjusting groove. The sliding groove includes a connected movable sub-groove and a locking sub-groove. The length directions of the movable sub-groove and the locking sub-groove are different. The sliding groove is used to slide the movable rod. The adjusting groove includes a locking end and an unlocking end.

[0008] The push rod has one end slidably connected to the adjustment groove;

[0009] A locking element, one end of which is connected to the push rod, and the other end of which is close to the slide groove; and

[0010] An elastic element connects to the push rod and is used to drive the push rod to slide toward the locking end;

[0011] The self-locking mechanism includes a locked state and an unlocked state. In the locked state, the elastic element drives the push rod to connect to the locking end, the locking member approaches the slide groove and prevents the movable rod from sliding from the locking sub-slot to the movable sub-slot. In the unlocked state, the push rod connects to the unlocking end, the locking member moves away from the slide groove, and the movable rod can slide between the locking sub-slot and the movable sub-slot.

[0012] Optionally, the limiting seat includes a first connecting plate, the adjusting groove and the sliding groove are formed on the first connecting plate, the adjusting groove is located on one side of the movable sub-groove, and the adjusting groove is close to the communication between the movable sub-groove and the locking sub-groove.

[0013] Optionally, the limiting seat includes an auxiliary component and a second connecting plate respectively connected to the first connecting plate, the push rod movably passes through the auxiliary component and the second connecting plate, an abutment is fixedly sleeved on the outside of the push rod, the elastic component is sleeved on the outside of the push rod and is in a compressed state, and the second connecting plate, the abutment, the elastic component, the auxiliary component and the adjusting groove are arranged in sequence.

[0014] Optionally, the locking member is in the shape of an arc plate, the portion of the locking member connected to the push rod near the adjusting groove is bent away from the sliding groove, and in the locked state, the end of the locking member not connected to the push rod is located at the connection between the movable sub-groove and the locking sub-groove.

[0015] Optionally, the locking member is rotatably connected to the push rod, and the end of the locking member not connected to the push rod extends further away from the movable sub-slot. In the locked state, the locking member can be pushed to rotate away from the slide groove to leave the slide groove.

[0016] Optionally, the limiting seat includes a limiting member connected to the first connecting plate, and the end of the lock connected to the push rod has a notch that is slidably connected to the push rod. The limiting member is used to cooperate with the push rod to limit the rotation of the lock.

[0017] Optionally, the self-locking mechanism includes:

[0018] A guide plate, connected to the movable sub-slot, is used to guide the movable rod to slide within the movable sub-slot; and

[0019] An operating component is connected to the end of the push rod that is away from the adjusting groove.

[0020] A second aspect of this application provides a foldable trolley, the foldable trolley comprising:

[0021] Support platform;

[0022] The first connecting rod is located on one side below the support platform;

[0023] The second link is rotatably connected at its top to the bottom side of the support platform and hinged in the middle to the middle of the first link.

[0024] The third link is located on the other side below the support platform and is opposite to the first link;

[0025] The fourth link is rotatably connected at its top to the bottom side of the support platform and hinged at its middle to the middle of the third link. The fourth link is opposite to the second link. The two ends of the movable rod are respectively connected to the top of the first link and the top of the third link.

[0026] A limiting plate is connected to the bottom surface of the support platform and sleeved on one end of the movable rod. The limiting plate has a sliding groove corresponding to the movable rod. The self-locking mechanism is sleeved on the other end of the movable rod and connected to the support platform. The extension direction of the sliding groove is parallel to the horizontal direction. The movable sub-groove is closer to the edge of the support platform than the locking sub-groove.

[0027] The first horizontal bar is connected at both ends to the bottom ends of the first connecting rod and the third connecting rod, respectively; and

[0028] The second crossbar is connected at both ends to the bottom end of the second connecting rod and the bottom end of the fourth connecting rod, respectively.

[0029] Optionally, the two ends of the first crossbar extend through the bottom end of the first connecting rod and the bottom end of the third connecting rod, respectively, and the foldable trolley includes:

[0030] Two pulleys rotatably connect the two ends of the first crossbar; and

[0031] A strap is attached to the movable rod at one end, and the other end of the strap is used to connect to the second crossbar.

[0032] In the self-locking mechanism of this application, the elastic element, push rod, and lock are precisely linked to form an efficient and reliable moving rod locking system. When the self-locking mechanism is locked, the continuous thrust of the elastic element presses the push rod firmly against the locking end of the adjustment slot, and the push rod in turn drives the lock and locking sub-slot to form a tight engagement with the moving rod. The thrust of the elastic element also provides a continuous preload force to the lock. Even if the foldable trolley is subjected to slight vibration or lateral force during use, this preload force can offset the impact of external forces on the lock, preventing the lock and locking sub-slot from loosening, maintaining the stable locking of the moving rod, and eliminating the risk of accidental slippage of the moving rod from the root. When it is necessary to unlock the moving rod, the user overcomes the resistance of the elastic element to move the push rod towards the unlocking end of the adjustment slot. During this process, the elastic element is further compressed (or twisted), and the elastic potential energy accumulated inside it increases accordingly. However, the elastic element always maintains a reverse thrust on the push rod. This reverse thrust is actually the reserve power for subsequent automatic locking, ensuring that once the external force is removed, the self-locking mechanism can immediately initiate the locking procedure. When the external force is removed, the elastic element does not require additional triggering; its continuously stored elastic potential energy is rapidly released, driving the push rod to quickly and smoothly reset to the locking end along the adjustment groove. Due to the rigid linkage between the push rod and the locking element, the locking element moves synchronously with the push rod. The entire process requires no manual adjustment by the user, achieving an automated effect of "locking immediately upon removal of external force."

[0033] It should be understood that the description in this section is not intended to identify key or important features of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0034] The accompanying drawings exemplify embodiments and form part of the specification, working together with the textual description to explain exemplary implementations of the embodiments. The drawings shown are for illustrative purposes only and do not limit the scope of the claims. Throughout the drawings, the same reference numerals refer to similar but not necessarily identical elements.

[0035] Figure 1 This is a schematic diagram of the locking state of an embodiment of the self-locking mechanism of this application;

[0036] Figure 2a for Figure 1 The illustrated embodiment demonstrates the usage process. Figure 1 ; Figure 2b for Figure 1 The second schematic diagram illustrates the usage process of the embodiment shown.

[0037] Figure 3 for Figure 1 Exploded view of the embodiment shown;

[0038] Figure 4a This is the unfolded state of an embodiment of the foldable trolley of this application. Figure 1 ; Figure 4b for Figure 4a Figure 2 shows the unfolded state of the embodiment.

[0039] Figure 5a for Figure 4a The folding state of the embodiment shown Figure 1 ; Figure 5b for Figure 4a Figure 2 shows the folded state of the embodiment.

[0040] Figures 6a to 6c for Figure 4a The diagram shows the unfolding process of the embodiment shown;

[0041] Figures 7a to 7c for Figure 4a The folding process diagram of the embodiment shown.

[0042] Explanation of reference numerals in the attached figures:

[0043] Figure Labels name Figure Labels name 10 Self-locking mechanism 100 Limit seat 110 First connecting plate 111 Active sub-slot 112 Locking sub-slot 113 Adjustment groove 114 Locked end 115 Unlocking terminal 120 auxiliary parts 130 Second connecting plate 140 Third connecting plate 150 Fourth connecting plate 160 Guide plate 200 putter 210 Attachment 220 Operating components 300 Locks 310 gap 400 elastic element 1 Foldable stroller 20 support platform 31 First link 32 Second link 33 Third link 34 Fourth link 35 movable bar 40 Limit plate 41 Sliding groove 51 First horizontal bar 52 Second horizontal bar 60 pulley 70 Lace Detailed Implementation

[0044] To make the inventive objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0046] In the description of the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The term "multiple" means two or more, unless otherwise explicitly specified. The term "comprising" indicates the presence of the described feature, whole, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or sets thereof. The term "and / or" describes the relationship between related objects, indicating that three relationships may exist. For example, A and / or B may include three cases: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0047] Unless otherwise defined, all technical terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art; the terms used in the embodiments of this application are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "comprising" and "having" and any variations thereof in the specification, claims and foregoing description of the drawings of this application are intended to cover non-exclusive inclusion.

[0048] Furthermore, terms such as "exemplary," "for example," and "optional" are used to indicate illustrative purposes. Any technical solution described by the above terms in the embodiments of this application should not be construed as being more preferred or advantageous than other technical solutions. Specifically, these terms are intended to present the relevant technical concepts in terms of specific implementation methods.

[0049] This application provides a self-locking mechanism and a foldable trolley. The self-locking mechanism is used to automatically lock the movable rod of the foldable trolley. The self-locking mechanism may include a limiting seat, a push rod, a locking member, and an elastic member. The limiting seat has a sliding groove and an adjusting groove. The sliding groove includes a connected movable sub-groove and a locking sub-groove, which have different length directions. The sliding groove is used to slide the movable rod. The adjusting groove includes a locking end and an unlocking end. One end of the push rod is slidably connected to the adjusting groove. One end of the locking member is connected to the push rod, and the other end of the locking member is close to the sliding groove. The elastic member is connected to the push rod and is used to drive the push rod to slide toward the locking end. The self-locking mechanism includes a locked state and an unlocked state. In the locked state, the elastic member drives the push rod to connect to the locking end, the locking member is close to the sliding groove, and the movable rod is prevented from sliding from the locking sub-groove to the movable sub-groove. In the unlocked state, the push rod is connected to the unlocking end, the locking member is away from the sliding groove, and the movable rod can slide between the locking sub-groove and the movable groove.

[0050] In the self-locking mechanism of this application, the elastic element, push rod, and lock are precisely linked to form an efficient and reliable moving rod locking system. When the self-locking mechanism is locked, the continuous thrust of the elastic element presses the push rod firmly against the locking end of the adjustment slot, and the push rod in turn drives the lock and locking sub-slot to form a tight engagement with the moving rod. The thrust of the elastic element also provides a continuous preload force to the lock. Even if the foldable trolley is subjected to slight vibration or lateral force during use, this preload force can offset the impact of external forces on the lock, preventing the lock and locking sub-slot from loosening, maintaining the stable locking of the moving rod, and eliminating the risk of accidental slippage of the moving rod from the root. When it is necessary to unlock the moving rod, the user overcomes the resistance of the elastic element to move the push rod towards the unlocking end of the adjustment slot. During this process, the elastic element is further compressed (or twisted), and the elastic potential energy accumulated inside it increases accordingly. However, the elastic element always maintains a reverse thrust on the push rod. This reverse thrust is actually the reserve power for subsequent automatic locking, ensuring that once the external force is removed, the self-locking mechanism can immediately initiate the locking procedure. When the external force is removed, the elastic element does not require additional triggering; its continuously stored elastic potential energy is rapidly released, driving the push rod to quickly and smoothly reset to the locking end along the adjustment groove. Due to the rigid linkage between the push rod and the locking element, the locking element moves synchronously with the push rod. The entire process requires no manual adjustment by the user, achieving an automated effect of "locking immediately upon removal of external force."

[0051] Please combine Figures 1 to 7c The structure of the self-locking mechanism 10 of this application will be described in detail below.

[0052] The self-locking mechanism 10 of this application includes a limiting seat 100, which includes a first connecting plate 110. The first connecting plate 110 has a sliding groove for slidingly connecting the movable rod 35 of the foldable trolley 1. The sliding groove includes a connected movable sub-groove 111 and a locking sub-groove 112, with different length directions for the movable sub-groove 111 and the locking sub-groove 112. In some embodiments, the movable sub-groove 111 extends horizontally, one end of the locking sub-groove 112 connects to one end of the movable sub-groove 111, and the other end of the locking sub-groove 112 extends upward toward the movable sub-groove 111, i.e., the included angle formed by the locking sub-groove 112 and the movable sub-groove 111 is an acute angle. The locking sub-groove 112 and the movable sub-groove 111 may be generally strip-shaped.

[0053] The first connecting plate 110 has an adjustment groove 113, which includes a locking end 114 and an unlocking end 115. The locking end 114 and the unlocking end 115 can be two extended ends of the adjustment groove 113. The adjustment groove 113 is located on one side of the movable sub-groove 111, near the connection between the movable sub-groove 111 and the locking sub-groove 112. In some embodiments, the length direction of the adjustment groove 113 is substantially parallel to the length direction of the movable sub-groove 111, and the length of the adjustment groove 113 is adapted to the horizontal length of the locking sub-groove 112. The adjustment groove 113 can also be substantially strip-shaped.

[0054] The movable sub-groove 111 and the adjusting groove 113 are formed on the same side of the first connecting plate 110. The movable sub-groove 111 and the adjusting groove 113 can be recesses in the surface of the first connecting plate 110 or protrusions in the surface of the first connecting plate 110. The movable sub-groove 111 and the adjusting groove 113 can also be through grooves formed in the first connecting plate 110.

[0055] The self-locking mechanism 10 includes a guide plate 160 connected to a movable sub-slot 111. The guide plate 160 guides the movable rod 35 to slide within the movable sub-slot 111, thereby improving the sliding effect of the movable rod 35 within the movable sub-slot 111. Specifically, the guide plate 160 can be strip-shaped, connected to one side of the movable sub-slot 111 along its length. There can be two guide plates 160, each connected to one side of the movable sub-slot 111 along its length, further enhancing the sliding effect of the movable rod 35 within the movable sub-slot 111.

[0056] The self-locking mechanism 10 of this application includes a push rod 200. One end of the push rod 200 is slidably connected to an adjustment groove 113, and the end of the push rod 200 connected to the adjustment groove 113 can slide between a locking end 114 and an unlocking end 115. One end of the push rod 200 is bent toward the adjustment groove 113, thereby achieving connection with the adjustment groove 113. In embodiments where the adjustment groove 113 is a through groove, one end of the push rod 200 can extend out of the adjustment groove 113. Therefore, the connection between the push rod 200 and the adjustment groove 113 is good, and the push rod 200 is not easily disengaged from the adjustment groove 113.

[0057] The limiting seat 100 also includes an auxiliary component 120 and a second connecting plate 130. Both the auxiliary component 120 and the second connecting plate 130 are connected to the first connecting plate 110. One side of the auxiliary component 120 and one side of the second connecting plate 130 are respectively connected to one side of the first connecting plate 110, forming an adjustment groove 113. The auxiliary component 120 and the second connecting plate 130 can be perpendicular to the first connecting plate 110. The push rod 200 movably passes through the auxiliary component 120 and the second connecting plate 130 (the end of the push rod 200 away from the adjustment groove 113 is located outside the limiting seat 100). The auxiliary component 120 and the second connecting plate 130 can limit and guide the movement of the push rod 200. The auxiliary component 120, the second connecting plate 130, and the adjustment groove 113 can be arranged sequentially. The number of auxiliary components 120 can be at least one, thus providing a better effect in limiting and guiding the push rod 200. The auxiliary component 120 and the first connecting plate 110 can be integrally formed or detachably connected (e.g., by welding, screwing, snap-fitting, or bonding). The second connecting plate 130 and the first connecting plate 110 can be integrally formed or detachably connected (e.g., by welding, screwing, snap-fitting, or bonding).

[0058] The self-locking mechanism 10 of this application includes an operating element 220, which connects to the end of the push rod 200 away from the adjusting groove 113 (i.e., the end extending beyond the limiting seat 100). The operating element 220 is designed to facilitate user-driven movement of the push rod 200. The operating element 220 may be a pull ring.

[0059] The self-locking mechanism 10 of this application includes a locking member 300, one end of which is connected to a push rod 200, and the other end of which is close to a slide groove. In some embodiments, the locking member 300 is in the shape of an arc plate, and the portion of the locking member 300 connected to the push rod 200 near the adjusting groove 113 is bent away from the slide groove. In the locked state, the end of the locking member 300 not connected to the push rod 200 is located at the connection between the movable sub-groove 111 and the locking sub-groove 112.

[0060] The self-locking mechanism 10 of this application includes an elastic element 400, which is connected to a push rod 200 and used to drive the push rod 200 to slide toward the locking end 114. The elastic element 400 may be a spring. In some embodiments, an abutment 210 (which may be in the form of a ring) is fixedly sleeved on the outside of the push rod 200, and the elastic element 400 is sleeved on the outside of the push rod 200 and is in a compressed state. The second connecting plate 130, the abutment 210, the elastic element 400, the auxiliary element 120, and the adjusting groove 113 are arranged in sequence, that is, the two ends of the elastic element 400 abut against the abutment 210 and the auxiliary element 120, respectively. Thus, the elastic element 400 can play the role of driving the push rod 200 to slide toward the locking end 114. In the above embodiment, the portion of the push rod 200 located between the auxiliary member 120 and the elastic member 400 may also be fitted with an abutment member 210, that is, there are two abutment members 210. The two abutment members 210 are located at both ends of the elastic member 400. Thus, by setting the two abutment members 210, the axis of the elastic member 400 is always aligned with the central axis of the push rod 200, ensuring that the thrust of the elastic member 400 is output entirely along the axial direction of the push rod 200 without any additional radial force loss; the surface contact can disperse the pressure, and at the same time, it can also make the thrust of the elastic member 400 evenly transmitted to the push rod 200.

[0061] The self-locking mechanism 10 includes a locked state and an unlocked state. In the locked state, the elastic element 400 drives the push rod 200 to connect to the locking end 114, and the locking element 300 approaches the slide groove and prevents the movable rod 35 from sliding from the locking sub-slot 112 to the movable sub-slot 111. In the unlocked state, the push rod 200 connects to the unlocking end 115, the locking element 300 moves away from the slide groove, and the movable rod 35 can slide between the locking sub-slot 112 and the movable sub-slot 111.

[0062] In the self-locking mechanism 10 of this application, the elastic element 400, push rod 200, and lock 300 are precisely linked to form an efficient and reliable locking system for the movable rod 35. When the self-locking mechanism 10 is in the locked state, the continuous pushing force of the elastic element 400 will press the push rod 200 tightly against the locking end 114 of the adjusting groove 113. The push rod 200 will then drive the lock 300 and the locking sub-groove 112 to form a tight engagement with the movable rod 35. The pushing force of the elastic element 400 will also provide a continuous preload force to the lock 300. Even if the foldable trolley 1 is subjected to slight vibration or lateral force during use, this preload force can offset the impact of external forces on the lock 300, prevent the lock 300 and the locking sub-groove 112 from loosening, maintain the stable locking of the movable rod 35, and eliminate the risk of accidental slippage of the movable rod 35 from the root. When the movable lever 35 needs to be unlocked, the user overcomes the resistance of the elastic element 400 to move the push rod 200 towards the unlocking end 115 of the adjustment groove 113. During this process, the elastic element 400 is further compressed (or twisted), and the elastic potential energy accumulated inside it increases accordingly. However, the elastic element 400 always maintains a reverse thrust on the push rod 200. This reverse thrust is actually the reserve power for subsequent automatic locking, ensuring that once the external force is removed, the self-locking mechanism 10 can immediately start the locking procedure. When the external force is removed, the elastic element 400 does not need to be triggered additionally; its continuously stored elastic potential energy will be released rapidly, driving the push rod 200 to quickly and smoothly reset towards the locking end 114 along the adjustment groove 113. Due to the rigid linkage between the push rod 200 and the locking element 300, the locking element 300 will move synchronously with the push rod 200. The entire process does not require manual adjustment by the user, achieving the automated effect of "locking immediately upon removal of external force".

[0063] In the above embodiments, the self-locking mechanism 10 of this application is used as follows: one hand pushes the push rod 200 toward the unlocking end 115, and while pushing, the other hand slides the movable rod 35 from the movable sub-slot 111 to the locking sub-slot 112; after installation, the push rod 200 is released, the elastic element 400 rebounds, the locking element 300 automatically locks the movable element in the locking sub-slot 112, and the movable rod 35 is released.

[0064] In some preferred embodiments, the locking member 300 is rotatably connected to the push rod 200, and the end of the locking member 300 not connected to the push rod 200 extends further away from the movable sub-slot 111. In the locked state, the locking member 300 can be pushed to rotate away from the slide to leave the slide.

[0065] In the above-mentioned preferred embodiments, during use (e.g.) Figure 2a and Figure 2bAs shown), there is no need to push the push rod 200 toward the unlocking end 115. When the push rod 35 slides from the movable sub-slot 111 to the locking sub-slot 112, the movement of the movable rod 35 will push the lock 300 to rotate. The rotation of the lock 300 will automatically open the passage for the movement of the movable rod 35, thus making the use of the self-locking mechanism 10 of this application more convenient.

[0066] The limiting seat 100 includes a limiting member connecting the first connecting plate 110. The locking member 300 has a notch 310 at one end connected to the push rod 200, which is slidably connected to the push rod 200. The limiting member is used to cooperate with the push rod 200 to limit the rotation of the locking member 300. In some embodiments, the limiting member may include a third connecting plate 140 and a fourth connecting plate 150. The third connecting plate 140 and the fourth connecting plate 150 may be located on adjacent sides of the locking member 300 away from the slide groove. One side of the third connecting plate 140 and the fourth connecting plate 150 is connected to the first connecting plate 110. The third connecting plate 140 and the fourth connecting plate 150 are perpendicular to each other and also perpendicular to the first connecting plate 110. The third connecting plate 140 and the fourth connecting plate 150 may be integrally formed with the first connecting plate 110, or they may be detachably connected (e.g., by welding, screwing, snap-fitting, or bonding).

[0067] In some embodiments, as the locking member 300 rotates away from the slide rail, it can move closer to the push rod 200 (and move away from the push rod 200 when rotating in the opposite direction) under the constraints of the third connecting plate 140 and the fourth connecting plate 150. This results in a more stable connection between the locking member 300 and the push rod 200, and requires less clearance for the locking member 300 to rotate, allowing for a smaller size of the self-locking mechanism 10.

[0068] Please combine Figures 4a to 7c This application proposes a foldable trolley 1, which includes a movable rod 35 and the aforementioned self-locking mechanism 10. The sliding groove of the self-locking mechanism 10 is slidably connected to the movable rod 35. The foldable trolley 1 of this application includes the aforementioned self-locking mechanism 10, and therefore has all the beneficial effects of the aforementioned self-locking mechanism 10, which will not be described in detail here.

[0069] The foldable trolley 1 also includes a support platform 20, a first connecting rod 31, a second connecting rod 32, a third connecting rod 33, a fourth connecting rod 34, a limiting plate 40, a first crossbar 51, and a second crossbar 52. The support platform 20 is used to carry heavy items. The first connecting rod 31 is located on one side below the support platform 20. The top end of the second connecting rod 32 is rotatably connected to the bottom side of the support platform 20, and its middle part is hinged to the middle part of the first connecting rod 31. The bottom surface of the support platform 20 is connected to a first hinge corresponding to the second connecting rod 32. The third connecting rod 33 is located on the other side below the support platform 20 and is opposite to the first connecting rod 31. The top end of the fourth connecting rod 34 is rotatably connected to the bottom side of the support platform 20, and its middle part is hinged to the middle part of the third connecting rod 33. The fourth connecting rod 34 is opposite to the second connecting rod 32. The bottom surface of the support platform 20 is connected to a second hinge corresponding to the fourth connecting rod 34. The four-point support of the support platform 20 can be achieved through the first link 31, the second link 32, the third link 33 and the fourth link 34.

[0070] The two ends of the movable rod 35 are connected to the top ends of the first connecting rod 31 and the third connecting rod 33, respectively. The limiting plate 40 is connected to the bottom surface of the support platform 20 and is sleeved on one end of the movable rod 35. The limiting plate 40 has a sliding groove 41 corresponding to the movable rod 35. The self-locking mechanism 10 is sleeved on the other end of the movable rod 35 and connected to the support platform 20. That is, the self-locking mechanism 10 and the limiting plate 40 are arranged opposite to each other. The sliding groove 41 of the limiting plate 40 can cooperate with the sliding groove to guide and limit the movement of the movable rod 35. The shape of the sliding groove 41 and the sliding groove can be roughly the same.

[0071] The two ends of the first crossbar 51 are connected to the bottom ends of the first connecting rod 31 and the third connecting rod 33, respectively; the two ends of the second crossbar 52 are connected to the bottom ends of the second connecting rod 32 and the fourth connecting rod 34, respectively. The arrangement of the first crossbar 51 and the second crossbar 52 can enhance the connection stability of the first connecting rod 31, the second connecting rod 32, the third connecting rod 33 and the fourth connecting rod 34, and also provide contact points to facilitate the user to fold and unfold the foldable trolley 1.

[0072] The top side of the first connecting plate 110 is connected to the bottom surface of the support platform 20. The extension direction of the slide is parallel to the horizontal direction. The movable sub-slot 111 is located below the locking sub-slot 112, and the movable sub-slot 111 is closer to the edge of the support platform 20 than the locking sub-slot 112. The adjustment slot 113 is located above the movable sub-slot 111. The second connecting plate 130 is opposite to the fourth connecting plate 150, and the second connecting plate 130 is closer to the movable sub-slot 111 than the fourth connecting plate 150. The third connecting plate 140 is located above the first connecting plate 110, and the third connecting plate 140 is parallel to the support platform 20. The top surface of the third connecting plate 140 is connected to the bottom surface of the support platform 20. Based on the above settings, the moving direction of the movable rod 35 and the push rod 200 is horizontal, so that the movable rod 35 can cooperate with the first connecting rod 31, the second connecting rod 32, the third connecting rod 33 and the fourth connecting rod 34 to realize the unfolding and folding of the foldable trolley 1.

[0073] The foldable trolley 1 has an unfolded state and a folded state. In the unfolded state, the movable rod 35 is located in the locking sub-slot 112, and the bottom ends of the first link 31, the second link 32, the third link 33 and the fourth link 34 are at a first distance from the bottom side of the support platform 20. In the folded state, the movable rod 35 is located at the end of the movable sub-slot 111 away from the locking sub-slot 112 (or away from the slide, that is, outside the end of the movable sub-slot 111 away from the locking sub-slot 112), and the bottom ends of the first link 31, the second link 32, the third link 33 and the fourth link 34 are at a second distance from the bottom side of the support platform 20. The first distance is greater than the second distance.

[0074] The foldable trolley 1 includes two casters 60. The two ends of the first crossbar 51 extend beyond the bottom ends of the first connecting rod 31 and the third connecting rod 33, respectively. The two casters 60 are rotatably connected to the two ends of the first crossbar 51. The casters 60 make the movement of the foldable trolley 1 more convenient.

[0075] The foldable stroller 1 includes a strap 70, one end of which is connected to a movable rod 35, and the other end of which is used to connect to a second crossbar 52. When the foldable stroller 1 is folded, the strap 70 can stabilize the folded state of the foldable stroller 1. The strap 70 can be a Velcro structure.

[0076] The unfolding process of the foldable trolley 1 of this application is as follows: Untie the strap 70, step on the second crossbar 52 with your foot, support the bottom of the support platform 20 with your hand, and pull the entire trolley upward. The movable rod 35 slides backward, and the movable rod 35 pushes the locking piece 300 to rotate outward and slide into the locking sub-slot 112. Further pull the trolley upward to the highest point, and the movable rod 35 is fully inserted into the locking sub-slot 112. After hearing a clear "click" sound (the locking piece 300 resets and cooperates with the locking sub-slot 112 to lock the movable rod 35), press down the support platform 20 slightly to stabilize the overall structure, and the foldable trolley 1 is fully unfolded.

[0077] The folding process of the foldable trolley 1 is as follows: Step on the second crossbar 52 with your foot, push the push rod 200 with one hand until it is fully pushed, the push rod 200 causes the locking piece 300 to move backward, and the self-locking mechanism 10 enters the unlocked state. At the same time, lift the support platform 20 with the other hand, and the movable rod 35 slides into the movable sub-slot 111 under gravity. Release the push rod 200, the elastic element 400 drives the push rod 200 and the locking piece 300 to reset, press down the support platform 20, the movable rod 35 slides forward, and finally lay the foldable trolley 1 flat downward. Secure the movable rod 35 and the second crossbar 52 with the strap 70 to complete the folding.

[0078] The above embodiments are only used to illustrate the present application and are not intended to limit it. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included within the protection scope of the present application.

Claims

1. A self-locking mechanism, characterized in that, The self-locking mechanism is used to automatically lock the movable lever of the foldable trolley, and the self-locking mechanism includes: The limiting seat has a sliding groove and an adjusting groove. The sliding groove includes a connected movable sub-groove and a locking sub-groove. The length directions of the movable sub-groove and the locking sub-groove are different. The sliding groove is used to slide the movable rod. The adjusting groove includes a locking end and an unlocking end. The push rod has one end slidably connected to the adjustment groove; A locking element, one end of which is connected to the push rod, and the other end of which is close to the slide groove; and An elastic element connects to the push rod and is used to drive the push rod to slide toward the locking end; The self-locking mechanism includes a locked state and an unlocked state. In the locked state, the elastic element drives the push rod to connect to the locking end, the locking member approaches the slide groove and prevents the movable rod from sliding from the locking sub-slot to the movable sub-slot. In the unlocked state, the push rod connects to the unlocking end, the locking member moves away from the slide groove, and the movable rod can slide between the locking sub-slot and the movable sub-slot.

2. The self-locking mechanism according to claim 1, characterized in that The limiting seat includes a first connecting plate, the adjusting groove and the sliding groove are formed on the first connecting plate, the adjusting groove is located on one side of the movable sub-groove, and the adjusting groove is close to the connection between the movable sub-groove and the locking sub-groove.

3. The self-locking mechanism according to claim 2, characterized in that, The limiting seat includes an auxiliary component and a second connecting plate that are respectively connected to the first connecting plate. The push rod is movably passed through the auxiliary component and the second connecting plate. An abutment is fixedly sleeved on the outside of the push rod. The elastic component is sleeved on the outside of the push rod and is in a compressed state. The second connecting plate, the abutment, the elastic component, the auxiliary component, and the adjusting groove are arranged in sequence.

4. The self-locking mechanism according to claim 2, characterized in that, The locking element is in the shape of an arc plate. The portion of the locking element connected to the push rod near the adjusting groove is bent away from the sliding groove. In the locked state, the end of the locking element not connected to the push rod is located at the connection between the movable sub-groove and the locking sub-groove.

5. The self-locking mechanism according to claim 4, characterized in that, The locking member is rotatably connected to the push rod, and the end of the locking member not connected to the push rod extends further away from the movable sub-slot. In the locked state, the locking member can be pushed to rotate away from the slide groove to leave the slide groove.

6. The self-locking mechanism according to claim 5, characterized in that, The limiting seat includes a limiting member connected to the first connecting plate. The end of the lock member connected to the push rod has a notch that is slidably connected to the push rod. The limiting member is used to cooperate with the push rod to limit the rotation of the lock member.

7. The self-locking mechanism according to claim 1, characterized in that, The self-locking mechanism includes: A guide plate, connected to the movable sub-slot, is used to guide the movable rod to slide within the movable sub-slot; and An operating component is connected to the end of the push rod that is away from the adjusting groove.

8. A foldable trolley, characterized in that, The foldable trolley includes: movable rod; and The self-locking mechanism according to any one of claims 1 to 7, wherein the slide groove of the self-locking mechanism is slidably connected to the movable rod.

9. The foldable trolley according to claim 8, characterized in that, The foldable trolley includes: Support platform; The first connecting rod is located on one side below the support platform; The second link is rotatably connected at its top to the bottom side of the support platform and hinged in the middle to the middle of the first link. The third link is located on the other side below the support platform and is opposite to the first link; The fourth link is rotatably connected at its top to the bottom side of the support platform and hinged at its middle to the middle of the third link. The fourth link is opposite to the second link. The two ends of the movable rod are respectively connected to the top of the first link and the top of the third link. A limiting plate is connected to the bottom surface of the support platform and sleeved on one end of the movable rod. The limiting plate has a sliding groove corresponding to the movable rod. The self-locking mechanism is sleeved on the other end of the movable rod and connected to the support platform. The extension direction of the sliding groove is parallel to the horizontal direction. The movable sub-groove is closer to the edge of the support platform than the locking sub-groove. The first horizontal bar is connected at both ends to the bottom ends of the first connecting rod and the third connecting rod, respectively; and The second crossbar is connected at both ends to the bottom end of the second connecting rod and the bottom end of the fourth connecting rod, respectively.

10. The foldable trolley according to claim 9, characterized in that, The two ends of the first crossbar extend through the bottom end of the first connecting rod and the bottom end of the third connecting rod, respectively. The foldable trolley includes: Two pulleys rotatably connect the two ends of the first crossbar; and A strap is attached to the movable rod at one end, and the other end of the strap is used to connect to the second crossbar.

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