Multi-stage linkage double-layer folding guardrail and ladder

Abstract

The utility model provides a kind of multistage linkage double-layer folding guardrail and ladder, it is related to tool ladder and its accessory technical field, including two vertical poles, double-layer guardrail, two groups of guardrail ladder frame connecting components and two groups of vertical pole ladder frame connecting components: guardrail open side two ends are respectively hinged in two vertical poles by first, second guardrail connecting piece;Two groups of guardrail ladder frame connecting components respectively include two hinged pieces and the loop fixed in any hinged piece, loop is one-to-one corresponding and is set in middle guardrail;Two groups of vertical pole ladder frame connecting components respectively include sliding sleeve, pin shaft and locking structure, sliding sleeve is one-to-one corresponding and is installed in two vertical poles;Locking structure locks or unlocks vertical pole in corresponding sliding sleeve.The multistage linkage double-layer folding guardrail can be folded to be substantially parallel with rear ladder frame, when ladder frame is opened, double-layer guardrail is not opened, and user does not be affected to use to climb, and ladder is more widely applicable in scene range, and, when ladder frame and double-layer guardrail are closed simultaneously, it occupies small space, easy to store.

Description

Technical Field

[0001] This utility model relates to the technical field of tool ladders and their accessories, and in particular to a multi-level linkage double-layer folding guardrail and ladder. Background Technology

[0002] Tool ladders are common auxiliary climbing equipment, widely used in construction, maintenance, cleaning, and other fields. To improve safety, many tool ladders are equipped with guardrails, providing extra protection for users when climbing or standing and reducing the risk of falls. However, most existing tool ladders only have a single guardrail, which offers limited protection and is insufficient to effectively cope with complex working environments and unexpected situations. Although some tool ladders have introduced double guardrail designs to enhance safety, in some existing ladders with double guardrails, the guardrails are directly fixed to the ladder frame, requiring removal for storage, which is inconvenient for users. Other ladders, while having double guardrails that can rotate relative to the ladder frame, are directly mounted to the frame via pins, with the hinge points between the guardrails and the frame fixed and immovable, presenting the following problems:

[0003] (1) Inconvenient to store: When stored, the guardrail cannot be completely folded, and it will take up a lot of space, increasing the difficulty of storage.

[0004] (2) Limited application scenarios: Since the guardrail cannot be fully folded, users can only climb the ladder normally when the guardrail is fully open (if the guardrail is not fully opened, it will form an obstacle to climbing the ladder at the top, affecting the user's normal use); if the work space is narrow (such as an indoor corner or narrow passage), the guardrail cannot be fully opened, thus limiting the scope of application of the tool ladder. Utility Model Content

[0005] The purpose of this utility model is to provide a multi-level linkage double-layer folding guardrail and ladder to alleviate the above-mentioned technical problems existing in the prior art.

[0006] To achieve the above objectives, the embodiments of this utility model adopt the following technical solutions:

[0007] In a first aspect, this utility model provides a multi-level linkage double-layer folding guardrail, comprising:

[0008] Two uprights, parallel to each other and spaced apart;

[0009] A double-layer guardrail is provided between two uprights, including a top guardrail and a middle guardrail arranged parallel to each other vertically. Both the top guardrail and the middle guardrail have a three-sided enclosed structure with one side open. One end of the open side of the three-sided enclosed structure is hinged to one of the uprights via a first guardrail connector, and the other end of the open side is hinged to the other upright via a second guardrail connector. The top guardrail has hinge holes near both ends of the open side for installing rotating pins.

[0010] Two sets of guardrail ladder frame connecting components, each set including two hinged members that are hinged to each other and a collar fixed to any of the hinged members, the collars of the two sets of guardrail ladder frame connecting components are fitted one-to-one on the parts of the middle guardrail near the open side.

[0011] The system includes two sets of upright ladder frame connecting assemblies, each set comprising a sliding sleeve, a pin, and a locking structure. The sliding sleeves of the two sets of upright ladder frame connecting assemblies are fitted onto the lower ends of the two uprights in a corresponding manner. The locking structure is installed on the upright and the sliding sleeve to lock or unlock the upright to the corresponding sliding sleeve. The pin passes through a mounting hole provided on the side wall of the sliding sleeve.

[0012] In an optional implementation, the locking structure includes:

[0013] A curved spring is disposed in a cavity inside the lower end of the upright and abuts against the inner wall of the cavity;

[0014] A stop pin passes through a first through hole located on the lower side wall of the upright. One end of the stop pin is fixedly connected to the curved spring, and the other end is a free end.

[0015] The unlocking pin passes through a second through hole located on the lower side wall of the upright, with one end of the unlocking pin fixedly connected to the curved spring and the other end being a free end.

[0016] With the upright locked in the corresponding sliding sleeve, the stop pin is embedded in or passes through the third through hole provided on the side wall of the sliding sleeve, and along the length direction of the upright, the unlocking pin moves away from the sliding sleeve.

[0017] The unlocking pin is configured to press the curved spring piece under pressure directed toward the inside of the upright, causing the curved spring piece to pull the stop pin out of the third through hole and retract into the sliding sleeve, thereby unlocking the upright to the corresponding sliding sleeve.

[0018] In an optional embodiment, the locking structure further includes an end cap fitted onto the lower end of the upright, the side wall of which has a fourth through hole, and the upright is locked in the state corresponding to the sliding sleeve, with the unlocking pin passing through the fourth through hole.

[0019] In an optional embodiment, the collar in the guardrail ladder frame connecting assembly is an O-bolt with an annular head.

[0020] In an optional embodiment, the double-layer guardrail further includes an auxiliary guardrail assembly, which comprises:

[0021] The top guardrail has its first end hinged to a first guardrail connector that is hinged to the open side end of the top guardrail.

[0022] The central guardrail has its first end hinged to a first guardrail connector that is hinged to the open side end of the central guardrail.

[0023] The linkage rod is hinged at one end to the top protective rod and at the other end to the middle protective rod;

[0024] The top guardrail and the middle guardrail are rotatable relative to the first guardrail connector, such that in the first state, the second end of the top guardrail is engaged with the second guardrail connector hinged to the open side end of the top guardrail, and the second end of the middle guardrail is engaged with the second guardrail connector hinged to the open side end of the middle guardrail; and in the second state, the top guardrail, the linkage rod, and the middle guardrail are folded onto one side of the upright.

[0025] In an optional embodiment, the second guardrail connector has an extension on one side of its body, and the top surface of the extension has a slot, allowing the top guardrail and the middle guardrail to engage or disengage from the slots of the corresponding second guardrail connectors.

[0026] In an optional embodiment, the first guardrail connector and the second guardrail connector each include their own body and connecting pipe;

[0027] The main body is a U-shaped plate structure. The connecting pipe is partially enclosed and fixed or integrally connected to the outer wall of the connecting pipe. The upright passes through the connecting pipe of the corresponding guardrail connector. The open side ends of the three-sided enclosure structure of each double-layer guardrail are respectively rotatably installed on the two side plate structures of the main body of the corresponding guardrail through rotating pins.

[0028] In an optional embodiment, a tool tray is also provided on the front side of the top guardrail.

[0029] Secondly, this utility model provides a ladder, including a front ladder frame, a rear ladder frame, and the multi-level linkage double-layer folding guardrail described in any optional embodiment of the first aspect; wherein:

[0030] The length of the rear ladder frame is greater than the length of the front ladder frame, and the portions of the top guardrail near the open side are respectively hinged to the upper end of the rear ladder frame by rotating pins passing through their hinge holes.

[0031] The two hinges of each set of guardrail ladder frame connecting components are respectively fixedly connected to the front ladder frame and the rear ladder frame of the ladder;

[0032] The pins of each set of upright ladder frame connecting assemblies pass through the mounting holes provided on the side wall of the corresponding sliding sleeve to rotatably connect the sliding sleeve to the rear ladder frame of the ladder.

[0033] In an optional embodiment, in the guardrail ladder frame connection assembly, the hinge has a U-shaped cavity, and the front or rear ladder frame of the ladder passes through the U-shaped cavity of the corresponding hinge and is fixedly connected to the corresponding hinge by bolts.

[0034] This utility model can achieve the following beneficial effects:

[0035] A tool ladder with a rear frame longer than the front frame (and a rear frame higher than the front frame) is selected. The aforementioned multi-stage, double-layer folding guardrail is installed on this tool ladder to assemble a ladder with a double-layer guardrail. The connection points between the double-layer guardrail and the ladder frame include: the top guardrail, near both ends of the open side, is hinged to the upper end of the rear ladder frame via rotating pins passing through its hinge holes; two hinges are fixedly connected to the front and rear ladder frames respectively; and a pin passes through a mounting hole on the side wall of the sliding sleeve, rotatably connecting the sliding sleeve to the rear ladder frame. After unlocking the locking mechanism, pulling down the upright relative to the sliding sleeve allows the double-layer guardrail to fold in a multi-stage linkage under the action of each hinge point.

[0036] In addition to the hinge points, this multi-level linkage double-layer folding guardrail features two sets of guardrail frame connecting components with corresponding collars fitted onto the two ends of the middle guardrail near the open side. During the folding process, the middle guardrail can slide relative to the ladder frame using the collars. Furthermore, a pin passes through the mounting hole on the side wall of the sliding sleeve, rotatably connecting the sliding sleeve to the rear ladder frame. This means the sliding sleeve can rotate relative to the ladder frame along with the corresponding upright, allowing the double-layer guardrail to be folded to be essentially parallel to the rear ladder frame. Thus, regardless of whether the front and rear ladder frames are folded or open, the double-layer guardrail can be folded to be essentially parallel to the rear ladder frame. This allows for use in narrow spaces without opening the double-layer guardrail, only opening the front and rear ladder frames, thus broadening the applicability of the ladder. Moreover, when the ladder frame and double-layer guardrail are folded and stored, the space occupied by the ladder is reduced, making it easier to store. Attached Figure Description

[0037] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 A schematic diagram of the overall structural assembly of the multi-level linkage double-layer folding guardrail in the open state, provided for an embodiment of this utility model;

[0039] Figure 2 for Figure 1 Enlarged view of the local structure of region A in the middle;

[0040] Figure 3 for Figure 1 Enlarged view of the local structure of region B in the middle;

[0041] Figure 4 for Figure 1 Enlarged view of the local structure of region C in the middle;

[0042] Figure 5 for Figure 1 Enlarged view of the local structure of region D in the middle;

[0043] Figure 6 A partial structural diagram of the locking structure locking the uprights to the corresponding sliding sleeve from another perspective of the multi-level linkage double-layer folding guardrail provided in this utility model embodiment;

[0044] Figure 7 for Figure 6 EE-directed sectional view;

[0045] Figure 8 A schematic diagram of the overall structure of the ladder provided in this embodiment of the utility model, with the ladder frame open but the guardrail folded.

[0046] Figure 9 This is a schematic diagram of the overall structure of the ladder provided in this embodiment of the utility model, with both the ladder frame and the guardrail in the open state.

[0047] Icons: 1-Upright post; 21-Top guardrail; 22-Middle guardrail; 31-First guardrail connector; 32-Second guardrail connector; 321-Extension; 322-Slot; 301-Body; 302-Connecting pipe; 4-Guardrail ladder frame connecting assembly; 41-Hinge; 42-Loop; 5-Upright post ladder frame connecting assembly; 51-Sliding sleeve; 52-Pin; 53-Bending spring; 54-Stop pin; 55-Unlocking pin; 56-End cap; 61-Top guardrail; 62-Middle guardrail; 63-Linkage rod; 71-Front ladder frame; 72-Rear ladder frame. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0049] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0050] It should be noted that similar labels and letters in the accompanying drawings indicate similar items. Therefore, once an item is defined in one accompanying drawing, it does not need to be further defined and explained in subsequent accompanying drawings.

[0051] In the description of this utility model, it should be noted that the terms "upper," "lower," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0052] Furthermore, the terms "horizontal" and "vertical" do not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0053] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0054] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0055] First aspect

[0056] This embodiment provides a multi-level linkage double-layer folding guardrail, as shown in the following reference. Figures 1 to 9 The multi-level linkage double-layer folding guardrail includes two uprights 1, a double-layer guardrail, two sets of guardrail ladder frame connecting components 4, and two sets of upright ladder frame connecting components 5.

[0057] Specifically: The two uprights 1 are parallel to each other and spaced apart. The double-layer guardrail is located between the two uprights 1 and includes a top guardrail 21 and a middle guardrail 22 that are parallel to each other and spaced apart. Both the top guardrail 21 and the middle guardrail 22 have a three-sided enclosed structure with one side open. One end of the open side of this three-sided enclosed structure is hinged to one upright 1 through a first guardrail connector 31, and the other end of the open side is hinged to another upright 1 through a second guardrail connector 32. The top guardrail 21 has hinge holes near the two ends of the open side, which are used to install rotating pins.

[0058] The two sets of guardrail ladder frame connecting components 4 each include two hinged parts 41 that are hinged to each other and a collar 42 fixed to any one of the hinged parts 41. The collars 42 of the two sets of guardrail ladder frame connecting components 4 are fitted one-to-one on the parts of the middle guardrail 22 near the open side.

[0059] The two sets of upright ladder frame connecting assemblies 5 each include a sliding sleeve 51, a pin 52, and a locking structure. The sliding sleeves 51 of the two sets of upright ladder frame connecting assemblies 5 are fitted one-to-one on the lower ends of the two uprights 1. The locking structure is installed on the uprights 1 and the sliding sleeves 51 to lock or unlock the uprights 1 to the corresponding sliding sleeves 51. The pin 52 passes through the mounting hole provided on the side wall of the sliding sleeve 51.

[0060] Choose such Figure 8 and Figure 9 The tool ladder shown has a rear ladder frame that is longer than the front ladder frame (and a rear ladder frame that is taller than the front ladder frame). The aforementioned multi-stage linkage double-layer folding guardrail is installed on the ladder frame to assemble a ladder with a double-layer guardrail. The connection points between the double-layer guardrail and the ladder frame include: the top guardrail 21, near both ends of the open side, is hinged to the rear ladder frame 72 via rotating pins passing through its hinge holes; two hinge pieces 41 are fixedly connected to the front ladder frame 71 and the rear ladder frame 72 respectively; and a pin 52 passes through a mounting hole on the side wall of the sliding sleeve 51 to rotatably connect the sliding sleeve 51 to the rear ladder frame 72. After unlocking the locking structure, pulling down the upright 1 relative to the sliding sleeve 51 allows the double-layer guardrail to fold in a multi-stage linkage under the action of each hinge point.

[0061] When the multi-level linkage double-layer folding guardrail is opened, it is like... Figure 9 As shown, when folded... Figure 8 As shown, apart from the various hinge points, since the collars 42 of the two sets of guardrail ladder frame connecting components 4 are fitted one-to-one on the parts of the middle guardrail 22 near the open side, during the folding process of the double-layer guardrail, the middle guardrail 22 can slide relative to the ladder frame with the help of the collars 42. In addition, the pin 52 passes through the mounting hole provided on the side wall of the sliding sleeve 51 to rotatably connect the sliding sleeve 51 to the rear ladder frame 72. That is, the sliding sleeve 51 can rotate relative to the ladder frame with the corresponding upright 1. Thus, the double-layer guardrail can be folded to be basically parallel to the rear ladder frame 72. In this way, regardless of the front ladder frame of the ladder... Whether the front ladder frame 71 and the rear ladder frame 72 are folded or open, both layers of guardrails can be folded to be basically parallel to the rear ladder frame 72. In this way, even in narrow spaces, the front ladder frame and the rear ladder frame can be opened without opening the double-layer guardrails, making the ladder more versatile (tests show that when the front ladder frame 71 and the rear ladder frame 72 are tilted within the range of 50°-70°, both layers of guardrails can be folded to be basically parallel to the rear ladder frame 72). Furthermore, when the ladder is in the folded storage state with both the ladder frame and the double-layer guardrails folded, the space occupied by the ladder is reduced, making it easier to store.

[0062] In this embodiment, the locking structure provides strong support for the stability of the double-layer guardrail in the open state. The locking structure has several specific optional forms, including but not limited to a fixing hole one on the side wall of the sliding sleeve 51 and a fixing hole two at the lower end of the upright 1. The upright 1 is locked to the sliding sleeve 51 by a bolt passing through fixing holes one and two and then being locked by a nut, thus opening the double-layer guardrail. However, this structure requires frequent disassembly and reassembly of the nut and bolt, making operation inconvenient and the bolt and nut assembly easily lost. To facilitate user operation, in some optional embodiments of this embodiment, the locking structure includes a bending spring 53, a stop pin 54, and an unlocking pin 55. The bending spring 53 is located in a cavity inside the lower end of the upright 1 and abuts against the inner wall of the cavity. The stop pin 54 passes through a first through hole in the side wall of the lower end of the upright 1, with one end fixedly connected to the bending spring 53 and the other end being a free end. The unlocking pin 55 passes through a second through hole located on the lower side wall of the upright 1. One end of the unlocking pin 55 is fixedly connected to the curved spring 53, and the other end is free. When the upright 1 is locked in the corresponding sliding sleeve 51, the stop pin 54 is inserted into or passes through a third through hole located on the side wall of the sliding sleeve 51. Along the length of the upright 1, the unlocking pin 55 moves away from the sliding sleeve 51. The unlocking pin 55 is configured to press the curved spring 53 under pressure directed towards the inside of the upright 1, causing the curved spring 53 to pull the stop pin 54 out of the third through hole and retract into the sliding sleeve 51, thereby unlocking the upright 1 in the corresponding sliding sleeve 51. This structure is easy to operate and can achieve automatic locking and one-button unlocking functions.

[0063] To prevent the upright 1 from slipping off the sliding sleeve 51, the locking structure may further include an end cap 56 fitted onto the lower end of the upright 1. The side wall of the end cap 56 has a fourth through hole. When the upright 1 is locked in the corresponding sliding sleeve 51, the unlocking pin 55 passes through the aforementioned fourth through hole to form a blocking part through the end cap 56, preventing the lower end of the upright 1 from slipping off the sliding sleeve 51, making the structure more reliable.

[0064] In an optional embodiment of this example, in the guardrail ladder frame connecting assembly 4, the collar 42 can be an O-bolt with an annular head, which is threaded to the corresponding hinge 41.

[0065] To further enhance the stability of the double-layer guardrail during operation, in an optional embodiment of this invention, the double-layer guardrail further includes an auxiliary guardrail assembly, which comprises a top guardrail 61, a middle guardrail 62, and a linkage rod 63. The first end of the top guardrail 61 is hinged to a first guardrail connector 31 hinged to the open end of the top guardrail 21; the first end of the middle guardrail 62 is hinged to the first guardrail connector 31 hinged to the open end of the middle guardrail 22; one end of the linkage rod 63 is hinged to the top guardrail 61, and the other end is hinged to the middle guardrail 62. The top guardrail 61 and the middle guardrail 62 are rotatable relative to their respective first guardrail connectors 31. In the first state, the second end of the top guardrail 61 is engaged with the second guardrail connector 32, which is hinged to the open side of the top guardrail 21; the second end of the middle guardrail 62 is engaged with the second guardrail connector 32, which is hinged to the open side of the middle guardrail 22. In the second state, the top guardrail 61, the linkage rod 63, and the middle guardrail 62 are folded onto one side of a single upright post 1. The aforementioned first state is the open state of the double-layer guardrail. This structure increases the stability of the top guardrail 21 and the middle guardrail 22 and also provides rear-view protection for the user, enhancing safety.

[0066] Optionally, the second guardrail connector 32 has an extension 321 on one side of its body 301, and a slot 322 on its top surface. The top guardrail 61 and the middle guardrail 62 can engage or disengage from the slots 322 of the corresponding second guardrail connector 32. In the first state, the second end of the top guardrail 61 engages with the slot 322 of the second guardrail connector 32, which is hinged to the open end of the top guardrail 21, and the second end of the middle guardrail 62 engages with the slot 322 of the second guardrail connector 32, which is hinged to the open end of the middle guardrail 22.

[0067] In an optional embodiment of this example, the first guardrail connector 31 and the second guardrail connector 32 each include their own body 301 and connecting pipe 302; the body 301 is a U-shaped plate structure, and the connecting pipe 302 is partially enclosed and fixed or integrally connected to the outer wall of the connecting pipe 302. The upright 1 passes through the connecting pipe 302 of the corresponding guardrail connector, and the open side ends of each three-sided enclosure structure of the double-layer guardrail are respectively rotatably installed on the two side plate structures of the body 301 of the corresponding guardrail component through rotating pins.

[0068] In an optional embodiment of this example, a tool tray is also provided on the front side of the top guardrail 21 for users to place tools after climbing the ladder, further enhancing the user experience.

[0069] Second aspect

[0070] This embodiment also provides a ladder, which includes a front ladder frame 71, a rear ladder frame 72, and a multi-level linkage double-layer folding guardrail provided in any of the optional embodiments of the first aspect; see reference Figure 8 and Figure 9 The length of the rear ladder frame 72 is greater than that of the front ladder frame 71. The two ends of the top guardrail 21 near the open side are respectively hinged to the upper end of the rear ladder frame 72 by rotating pins passing through their hinge holes. The two hinges 41 of each set of guardrail ladder frame connecting components 4 are respectively fixedly connected to the front ladder frame 71 and the rear ladder frame 72 of the ladder. The pins 52 of each set of upright ladder frame connecting components 5 pass through the mounting holes provided on the side wall of the corresponding sliding sleeve 51 to rotatably connect the sliding sleeve 51 to the rear ladder frame 72 of the ladder.

[0071] The ladder provided in this embodiment can achieve all the beneficial effects that the multi-level linkage double-layer folding guardrail in Embodiment 1 can achieve. Its specific structure and the effects it can achieve can be obtained by referring to the optional or preferred implementation methods in Embodiment 1.

[0072] In particular, in an optional embodiment of this example, in the guardrail ladder frame connection assembly 4, the hinge 41 has a U-shaped cavity, and the front ladder frame 71 or the rear ladder frame 72 of the ladder passes through the U-shaped cavity of the corresponding hinge 41 and is fixedly connected to the corresponding hinge 41 by bolts to increase the connection stability.

[0073] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to mutually. The above embodiments in this specification are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model 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 or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of this utility model.

Claims

1. A multi-level linkage double-layer folding guardrail, characterized in that, include: Two uprights, parallel to each other and spaced apart; A double-layer guardrail is provided between two uprights, including a top guardrail and a middle guardrail arranged parallel to each other vertically. Both the top guardrail and the middle guardrail have a three-sided enclosed structure with one side open. One end of the open side of the three-sided enclosed structure is hinged to one of the uprights via a first guardrail connector, and the other end of the open side is hinged to the other upright via a second guardrail connector. The top guardrail has hinge holes near both ends of the open side for installing rotating pins. Two sets of guardrail ladder frame connecting components, each set including two hinged members that are hinged to each other and a collar fixed to any of the hinged members, the collars of the two sets of guardrail ladder frame connecting components are fitted one-to-one on the parts of the middle guardrail near the open side. The system includes two sets of upright ladder frame connecting assemblies, each set comprising a sliding sleeve, a pin, and a locking structure. The sliding sleeves of the two sets of upright ladder frame connecting assemblies are fitted onto the lower ends of the two uprights in a corresponding manner. The locking structure is installed on the upright and the sliding sleeve to lock or unlock the upright to the corresponding sliding sleeve. The pin passes through a mounting hole provided on the side wall of the sliding sleeve.

2. The multi-level linkage double-layer folding guardrail according to claim 1, characterized in that, The locking structure includes: A curved spring is disposed in a cavity inside the lower end of the upright and abuts against the inner wall of the cavity; A stop pin passes through a first through hole located on the lower side wall of the upright. One end of the stop pin is fixedly connected to the curved spring, and the other end is a free end. The unlocking pin passes through a second through hole located on the lower side wall of the upright, with one end of the unlocking pin fixedly connected to the curved spring and the other end being a free end. With the upright locked in the corresponding sliding sleeve, the stop pin is embedded in or passes through the third through hole provided on the side wall of the sliding sleeve, and along the length direction of the upright, the unlocking pin moves away from the sliding sleeve. The unlocking pin is configured to press the curved spring piece under pressure directed toward the inside of the upright, causing the curved spring piece to pull the stop pin out of the third through hole and retract into the sliding sleeve, thereby unlocking the upright to the corresponding sliding sleeve.

3. The multi-level linkage double-layer folding protective fence according to claim 2, characterized in that, The locking structure also includes an end cap fitted onto the lower end of the upright, and a fourth through hole is provided on the side wall of the end cap. When the upright is locked in the state corresponding to the sliding sleeve, the unlocking pin passes through the fourth through hole.

4. The multi-level linkage double-layer folding guardrail according to claim 1, characterized in that, In the guardrail ladder frame connection assembly, the collar is an O-bolt with an annular head.

5. The multi-level linkage double-layer folding guardrail according to claim 1, characterized in that, The double-layer guardrail also includes an auxiliary guardrail assembly, which comprises: The top guardrail has its first end hinged to a first guardrail connector that is hinged to the open side end of the top guardrail. The central guardrail has its first end hinged to a first guardrail connector that is hinged to the open side end of the central guardrail. The linkage rod is hinged at one end to the top protective rod and at the other end to the middle protective rod; The top guardrail and the middle guardrail are rotatable relative to the first guardrail connector, such that in the first state, the second end of the top guardrail is engaged with the second guardrail connector hinged to the open side end of the top guardrail, and the second end of the middle guardrail is engaged with the second guardrail connector hinged to the open side end of the middle guardrail; and in the second state, the top guardrail, the linkage rod, and the middle guardrail are folded onto one side of the upright.

6. The multi-level linkage double-layer folding guardrail according to claim 5, characterized in that, The second guardrail connector has an extension on one side of its main body, and a slot on the top surface of the extension. The top guardrail and the middle guardrail can engage or disengage from the slots of the corresponding second guardrail connectors.

7. The multi-level linkage double-layer folding guardrail according to claim 1, characterized in that, The first guardrail connector and the second guardrail connector each include their own body and connecting pipe; The main body is a U-shaped plate structure. The connecting pipe is partially enclosed and fixed or integrally connected to the outer wall of the connecting pipe. The upright passes through the connecting pipe of the corresponding guardrail connector. The open side ends of the three-sided enclosure structure of each double-layer guardrail are respectively rotatably installed on the two side plate structures of the main body of the corresponding guardrail through rotating pins.

8. The multi-level linkage double-layer folding guardrail according to claim 1, characterized in that, A tool tray is also provided on the front side of the top guardrail.

9. A ladder, characterized in that, Includes a front ladder frame, a rear ladder frame, and a multi-level linkage double-layer folding guardrail as described in any one of claims 1 to 8; wherein: The length of the rear ladder frame is greater than the length of the front ladder frame, and the portions of the top guardrail near the open side are respectively hinged to the upper end of the rear ladder frame by rotating pins passing through the hinge holes. The two hinges of each set of guardrail ladder frame connecting components are respectively fixedly connected to the front ladder frame and the rear ladder frame of the ladder; The pins of each set of upright ladder frame connecting assemblies pass through the mounting holes provided on the side wall of the corresponding sliding sleeve to rotatably connect the sliding sleeve to the rear ladder frame of the ladder.

10. The ladder according to claim 9, characterized in that, In the guardrail ladder frame connection assembly, the hinge has a U-shaped cavity, and the front or rear ladder frame of the ladder passes through the U-shaped cavity of the corresponding hinge and is fixedly connected to the corresponding hinge by bolts.

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