Telescopic a-frame ladder

Abstract

A telescopic A-frame ladder, comprising a first telescopic ladder and a second telescopic ladder, wherein step main bodies are provided on upper portions of telescopic sections of the first telescopic ladder and the second telescopic ladder, and locking sleeves are provided at two ends of each step main body. In the telescopic A-frame ladder of the present application, when the first telescopic ladder and the second telescopic ladder are pulled apart, limiting rods fall into fish-mouth limiting slots by means of guide slopes, such that a first articulated frame and a second articulated frame are limited by each other and cannot be folded, thereby allowing the entire A-frame ladder to form a stable triangular configuration.

Description

A retractable A-frame ladder

[0001] This application claims priority to Chinese Patent Application No. 202520316826.2, filed on February 26, 2025, entitled “A Novel A-Frame Ladder”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of assistive living tools, specifically a retractable A-frame ladder. Background Technology

[0003] A-frame ladders are tools used for working at heights in spaces above a flat surface, such as during interior decoration. When in use, the front and rear rungs form a triangle with the ground, creating a stable support structure. Most existing A-frame ladders connect the tops of two ladders with hinges, allowing them to be folded up for movement. Due to their flexibility, they are widely used in electrical work and ceiling installation. Early A-frame ladders were generally made of wood, but with the development of the metal industry, aluminum alloys are now more commonly used. Aluminum alloy A-frame ladders are lightweight, aesthetically pleasing, durable, and inexpensive, hence their widespread use. Furthermore, because aluminum alloy is generally hollow, telescopic A-frame ladders have been developed in modern technology.

[0004] Existing telescopic A-frame ladders typically require manual operation by pressing a button on the connecting block to retract the positioning mechanism before each section can be retracted. This lack of coordinated retraction results in poor usability and low efficiency. Consequently, the ladder often needs to be moved short distances while remaining open. Since there are usually only two hinged rods or ropes connecting the two sides of the ladder for limiting the opening angle, this only prevents the ladder from opening too wide. During transport, the uneven force on both sides causes the ladder to tend to close, and the hinged rods or ropes offer no support. This makes transport cumbersome. Accidentally closing the ladder not only shifts the center of gravity, increasing the difficulty of transport, but also poses a risk of trapping hands. There is room for further improvement. Summary of the Invention (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this application provides a retractable A-frame ladder, which solves the aforementioned problems. (II) Technical Solution

[0006] To achieve the above objectives, this application provides the following technical solution: a retractable A-frame ladder, comprising a first retractable ladder and a second retractable ladder, wherein a step body is provided above multiple retractable sections of the first and second retractable ladders, the step body comprising multiple base steps and two hand support steps, and locking sleeves are fixedly connected to both ends of the multiple step bodies of the first and second retractable ladders, wherein a telescopic locking mechanism is provided inside the locking sleeves at both ends of the multiple base steps, and an opening and closing locking mechanism is provided inside the locking sleeves at both ends of the two hand support steps;

[0007] Each of the two hand-holding pedals has a hinge sleeve fixedly connected below its locking sleeve. Each of the four hinge sleeves has an unlocking hook rotatably connected below its lower side. The first telescopic ladder and the second telescopic ladder are rotatably connected to a first hinge frame and a second hinge frame respectively via the unlocking hook. The two ends of the first hinge frame and the second hinge frame are hinged to each other.

[0008] The first hinge frame has limit grooves on both sides of one end near the hinge joint. The first hinge frame is slidably connected to a limit rod through the two limit grooves. Spring sleeves are fixedly connected to the outer side of the first hinge frame at positions corresponding to the two limit grooves. Return springs are fixedly connected to the inner side of the two spring sleeves near the end of the second hinge frame. The two sides of the limit rod pass through the grooves and are fixedly connected to the corresponding return springs. Fish mouth limit grooves are provided on both sides of the second hinge frame near the limit rod. A cross brace is fixedly connected to the inner side of the first hinge frame near the limit rod and the middle of the inner side of the second hinge frame.

[0009] In some embodiments, the opening and closing locking mechanism includes a limiting sleeve, a spring locking pin, a sliding block, an oblique slide groove, and a lifting pressure plate. The limiting sleeve is fixedly embedded inside the locking sleeve. A sliding block is slidably connected inside the limiting sleeve. A spring locking pin is fixedly sleeved in the middle of the sliding block. A corresponding spring is provided at one end of the spring locking pin near the pedal body. An oblique slide groove with a 45-degree inclination is provided on both sides of the sliding block. A lifting pressure plate is provided at the bottom of the limiting sleeve that can be raised and lowered. Push rods are fixedly connected to both sides of the upper part of the lifting pressure plate. A transverse slide column is fixedly connected to the top of each of the two push rods. Vertical strip holes are provided on both sides of the limiting sleeve at positions corresponding to the push rods. The two ends of the transverse slide column are respectively embedded in the corresponding vertical strip holes and oblique slide grooves.

[0010] In some embodiments, hinged rods are rotatably connected to the upper sides of both sides of the first telescopic ladder, and the ends of the two hinged rods away from the first telescopic ladder are rotatably connected to the second telescopic ladder, with the hinge points of the two hinged rods located at the middle position.

[0011] In some embodiments, the opening and closing locking mechanism has the same structure as the telescopic locking mechanism.

[0012] In some embodiments, the locking sleeve includes a sleeve body and a collar. Both sides of the collar are provided with one-way buckles for fixed connection of corresponding telescopic joints. The opening and closing locking mechanism and the telescopic locking mechanism are both located inside the sleeve body. A protrusion is provided at the position corresponding to the lifting pressure plate on the upper part of the sleeve body. The first telescopic ladder and the second telescopic ladder are provided with locking pin holes corresponding to the pin heads of the spring locking pins at the positions corresponding to the collar.

[0013] In some embodiments, a hand support plate is provided at the lower center of both hand support pedals.

[0014] In some embodiments, a tool tray is fixedly connected above the two telescopic joints at the top of the first telescopic ladder. Both sides of the tool tray are provided with hanging ear grooves, and the tool tray has multiple tool placement slots.

[0015] In some embodiments, the ends of the first hinge frame and the second hinge frame are both fixedly inserted into the hook handles of the corresponding unlocking hooks, and the hook tips of the plurality of unlocking hooks correspond to the positions of the lifting pressure plates below the corresponding opening and closing locking mechanisms.

[0016] In some embodiments, a guide slope is provided above each of the two fish mouth limiting grooves. (III) Beneficial Effects

[0017] This application provides a retractable A-frame ladder. It has the following advantages:

[0018] 1. The telescopic A-frame ladder of this application is provided with a first hinge frame and a second hinge frame. The first hinge frame is provided with a sliding groove and a limiting rod at the hinge position, and both ends of the limiting rod are provided with a return spring. In conjunction with the fish mouth limiting groove and guide slope on the second hinge frame, when the first telescopic ladder and the second telescopic ladder are pulled apart, the limiting rod is allowed to fall into the fish mouth limiting groove through the guide slope, so that the first hinge frame and the second hinge frame are mutually limited and cannot be folded, thereby making the entire A-frame ladder form a stable triangular state. With the addition of a hand support block, it is convenient for short-distance transportation during work.

[0019] 2. The telescopic locking mechanism and opening / closing locking mechanism of the telescopic A-frame ladder of this application, together with the locking sleeve, hinge sleeve and unlocking hook, can cause the unlocking hook to rotate on the hinge sleeve by the downward folding of the two hinge frames when the first telescopic ladder and the second telescopic ladder are closed. This allows the hook tip to press against the push plate below the opening / closing locking mechanism, thereby driving the push rod to push the horizontal sliding column upward. Then, with the cooperation of the vertical limiting groove and the linkage inclined groove, the sliding block drives the spring locking pin to overcome the resistance of the locking spring and move axially, thus canceling the locking of the two telescopic sections. The remaining telescopic sections can then be unlocked sequentially through the protrusion above the locking sleeve, reducing the amount of operation required for the telescopic folding A-frame ladder. Attached Figure Description

[0020] Figure 1 is a schematic diagram of the overall structure of this application;

[0021] Figure 2 is a structural schematic diagram of the locking sleeve and the opening and closing locking mechanism of this application;

[0022] Figure 3 is a cross-sectional view of the opening and closing locking mechanism of this application;

[0023] Figure 4 is a three-dimensional structural diagram of the opening and closing locking mechanism of this application;

[0024] Figure 5 is a schematic diagram of the internal structure of the telescopic locking mechanism of this application;

[0025] Figure 6 is a schematic diagram of the hinge joint structure of the first hinge frame and the second hinge frame of this application;

[0026] Figure 7 is a three-dimensional structural diagram of the spring sleeve of this application.

[0027] The components include: 1. First telescopic ladder; 2. Second telescopic ladder; 3. Hinge rod; 4. Step body; 41. Basic step; 42. Hand support step; 5. Locking sleeve; 6. Opening and closing locking mechanism; 61. Limiting sleeve; 62. Spring locking pin; 63. Sliding block; 64. Angled slide groove; 65. Lifting pressure plate; 66. Push rod; 67. Horizontal slide column; 68. Vertical strip hole; 7. Hinge sleeve; 8. Unlocking hook; 9. First hinge frame; 10. Second hinge frame; 11. Limiting slide groove; 12. Limiting rod; 13. Spring sleeve; 14. Return spring; 15. Fish mouth limiting groove; 16. Guide slope; 17. Horizontal support rod; 18. Tool tray; 19. Telescopic locking mechanism. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. 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.

[0029] Example 1:

[0030] As shown in Figures 1-7, this application embodiment provides a telescopic A-frame ladder, including a first telescopic ladder 1 and a second telescopic ladder 2. Each of the multiple telescopic sections of the first telescopic ladder 1 and the second telescopic ladder 2 is equipped with a footboard body 4. The footboard body 4 includes multiple base footboards 41 and two hand support footboards 42. Locking sleeves 5 are fixedly connected to both ends of the multiple footboard bodies 4 of the first telescopic ladder 1 and the second telescopic ladder 2. Telescopic locking mechanisms 19 are provided inside the locking sleeves 5 at both ends of the multiple base footboards 41. Opening and closing locking mechanisms 6 are provided inside the locking sleeves 5 at both ends of the two hand support footboards 42. The opening and closing locking mechanisms 6 and the telescopic locking mechanisms 19 have the same structure. The locking sleeve 5 includes a sleeve body and a collar. One-way buckles for fixed connection of the corresponding telescopic sections are provided on both sides of the collar, reducing installation difficulty. The opening and closing locking mechanisms 6 and the telescopic locking mechanisms 19 are both located inside the sleeve body, improving parts versatility and reducing production costs.

[0031] The opening and closing locking mechanism 6 includes a limiting sleeve 61, a spring locking pin 62, a sliding block 63, an inclined slide groove 64, and a lifting pressure plate 65. The limiting sleeve 61 is fixedly embedded inside the locking sleeve 5. The sliding block 63 is slidably connected inside the limiting sleeve 61. The spring locking pin 62 is fixedly sleeved in the middle of the sliding block 63. The first telescopic ladder 1 and the second telescopic ladder 2 are provided with locking pin holes corresponding to the pin heads of the spring locking pin 62 at positions corresponding to the collar. The first telescopic ladder 1 and the second telescopic ladder 2 are provided with locking pin holes corresponding to the pin heads of the spring locking pin 62 at positions corresponding to the collar. The end of the spring locking pin 62 near the pedal body 4 is provided with a corresponding spring. The sliding block 63 is provided with inclined slide grooves 64 at a 45-degree angle on both sides. The bottom of the limiting sleeve 61 is provided with a lifting pressure plate 65 that can be raised and lowered. The upper sides of the lifting pressure plate 65 are fixedly connected with push rods 66. The top of each of the 66 is fixedly connected with a horizontal sliding column 67. Vertical strip holes 68 are opened on both sides of the limiting sleeve 61 at positions corresponding to the push rod 66. The two ends of the horizontal sliding column 67 are respectively embedded in the corresponding vertical strip holes 68 and oblique sliding grooves 64. When the hook tip of the unlocking hook 8 rotates, it will push against the lifting pressure plate 65, thereby driving the push rod 66 to push the horizontal sliding column 67 upward. Then, with the cooperation of the vertical strip holes 68 and oblique sliding grooves 64, the sliding block 63 drives the spring locking pin 62 to overcome the resistance of the locking spring and move axially, thus canceling the locking of the two telescopic joints at the hand support pedal 42 position, so that the upper telescopic joint can retract. The upper part of the sleeve is provided with protrusions at positions corresponding to the lifting pressure plate 65. After the upper telescopic joint retracts, the upper layer of lifting pressure plate 65 can be lifted by the protrusions on the lower locking sleeve 5 in sequence, canceling the limit of the corresponding telescopic joint and completing the overall telescopic movement.

[0032] Two locking sleeves 5 of the two hand-holding pedals 42 are fixedly connected to hinge sleeves 7 below each of the four hinge sleeves 7. Unlocking hooks 8 are rotatably connected to the bottom of each of the four hinge sleeves 7. The first telescopic ladder 1 and the second telescopic ladder 2 are rotatably connected to the first hinge frame 9 and the second hinge frame 10 respectively via the unlocking hooks 8. The ends of the first hinge frame 9 and the second hinge frame 10 are fixedly inserted into the hook handles of the corresponding unlocking hooks 8. The hook tips of the multiple unlocking hooks 8 correspond to the positions of the lifting pressure plate 65 below the corresponding opening and closing locking mechanism 6. The two ends of the first hinge frame 9 and the second hinge frame 10 are hinged to each other. Hinged rods 3 are rotatably connected to the upper sides of both sides of the telescopic ladder 1. The ends of the two hinged rods 3 away from the first telescopic ladder 1 are rotatably connected to the second telescopic ladder 2. The hinge points of the two hinged rods 3 are set in the middle position. Hand support plates are set in the middle of the lower part of the two hand support pedals 42 for easy short-distance transport during work. Tool trays 18 are fixedly connected to the upper sides of the telescopic joints at the top of the first telescopic ladder 1. The tool trays 18 have hanging ear grooves on both sides and multiple tool placement slots on the tool trays 18, which can be used to hang and place various tools to avoid the risk of repeatedly picking up and putting down tools.

[0033] The first hinge frame 9 has limiting grooves 11 on both sides near the hinge joint. The first hinge frame 9 is slidably connected to a limiting rod 12 via the two limiting grooves 11. Spring sleeves 13 are fixedly connected to the outer side of the first hinge frame 9 at positions corresponding to the two limiting grooves 11. Return springs 14 are fixedly connected to the inner side of each spring sleeve 13 near the second hinge frame 10. Both sides of the limiting rod 12 pass through the grooves 11 and are fixedly connected to the corresponding return springs 14. The second hinge frame 10 has limiting grooves 11 on both sides near the limiting rod 12. There are fish-mouth limiting grooves 15, and guide slopes 16 are provided above the two fish-mouth limiting grooves 15. A cross brace 17 is fixedly connected to the inner end of the first hinge frame 9 near the limiting rod 12 and the middle of the inner side of the second hinge frame 10. When unfolded, the two ends of the limiting rod 12 can fall into the corresponding fish-mouth limiting grooves 15 through the guide slopes 16 on the second hinge frame 10, so that the first hinge frame 9 and the second hinge frame 10 are mutually limited and cannot be folded, thereby making the entire A-frame ladder form a stable triangular state and preventing the center of gravity from changing during transportation.

[0034] Working principle: In use, the slidable limiting rod 12 on the first hinge frame 9 can, when unfolded, allow the two ends of the limiting rod 12 to fall into the corresponding fish-mouth limiting grooves 15 via the guide slope 16 on the second hinge frame 10. This prevents the first hinge frame 9 and the second hinge frame 10 from folding, thus forming a stable triangular shape for the entire A-frame ladder and preventing changes in the center of gravity during transport. Combined with the hand support block, this facilitates short-distance transport during work. When folding is required, the hinged first hinge frame 9 and the second hinge frame 10 can be closed by the two hinges. The downward folding of the connecting frame causes the unlocking hook 8 to rotate on the hinge sleeve 7. When the hook tip of the unlocking hook 8 rotates, it will press against the lifting pressure plate 65 below the opening and closing locking mechanism 6, thereby driving the push rod 66 to push the horizontal sliding column 67 upward. Then, with the cooperation of the vertical strip hole 68 and the oblique sliding groove 64, the sliding block 63 drives the spring locking pin 62 to overcome the resistance of the locking spring and move axially, thus canceling the locking of the two telescopic joints at the hand support pedal 42 position, so that the upper telescopic joint can retract. Then, the protrusion above the lower locking sleeve 5 pushes up the upper layer of lifting pressure plate 65 in sequence, canceling the limit of the corresponding telescopic joint, and completing the overall telescopic movement.

[0035] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A retractable A-frame ladder, comprising a first retractable ladder and a second retractable ladder, wherein a step body is provided above multiple retractable sections of the first and second retractable ladders, the step body comprising multiple base steps and two hand support steps, and locking sleeves are fixedly connected to both ends of the multiple step bodies of the first and second retractable ladders, wherein a telescopic locking mechanism is provided inside the locking sleeves at both ends of the multiple base steps, and an opening and closing locking mechanism is provided inside the locking sleeves at both ends of the two hand support steps; Each of the two hand-holding pedals has a hinge sleeve fixedly connected below its locking sleeve. Each of the four hinge sleeves has an unlocking hook rotatably connected below its lower side. The first telescopic ladder and the second telescopic ladder are rotatably connected to a first hinge frame and a second hinge frame respectively via the unlocking hook. The two ends of the first hinge frame and the second hinge frame are hinged to each other. The first hinge frame has limit grooves on both sides of one end near the hinge joint. The first hinge frame is slidably connected to a limit rod through the two limit grooves. Spring sleeves are fixedly connected to the outer side of the first hinge frame at positions corresponding to the two limit grooves. Return springs are fixedly connected to the inner side of the two spring sleeves near the end of the second hinge frame. The two sides of the limit rod pass through the grooves and are fixedly connected to the corresponding return springs. Fish mouth limit grooves are provided on both sides of the second hinge frame near the limit rod. A cross brace is fixedly connected to the inner side of the first hinge frame near the limit rod and the middle of the inner side of the second hinge frame.

2. A retractable A-frame ladder according to claim 1, wherein, The opening and closing locking mechanism includes a limiting sleeve, a spring locking pin, a sliding block, an oblique sliding groove, and a lifting pressure plate. The limiting sleeve is fixedly embedded inside the locking sleeve. The sliding block is slidably connected inside the limiting sleeve. A spring locking pin is fixedly sleeved in the middle of the sliding block. A corresponding spring is provided at the end of the spring locking pin near the pedal body. An oblique sliding groove with a 45-degree inclination is provided on both sides of the sliding block. A lifting pressure plate is provided at the bottom of the limiting sleeve. Push rods are fixedly connected to both sides of the upper part of the lifting pressure plate. A transverse sliding column is fixedly connected to the top of each of the two push rods. Vertical strip holes are provided on both sides of the limiting sleeve at positions corresponding to the push rods. The two ends of the transverse sliding column are respectively embedded in the corresponding vertical strip holes and oblique sliding grooves.

3. A retractable A-frame ladder according to claim 1, wherein, The first telescopic ladder has hinged rods rotatably connected to the upper sides of both sides. The ends of the two hinged rods away from the first telescopic ladder are rotatably connected to the second telescopic ladder. The hinge points of the two hinged rods are located in the middle position.

4. A retractable A-frame ladder according to claim 2, wherein, The opening and closing locking mechanism has the same structure as the telescopic locking mechanism.

5. A retractable A-frame ladder according to claim 2, wherein, The locking sleeve includes a sleeve body and a collar. Both sides of the collar are provided with one-way buckles for fixing the corresponding telescopic joints. The opening and closing locking mechanism and the telescopic locking mechanism are both located inside the sleeve body. A protrusion is provided on the upper part of the sleeve body at a position corresponding to the lifting pressure plate. The first telescopic ladder and the second telescopic ladder are provided with locking pin holes corresponding to the pin heads of the spring locking pins at positions corresponding to the collar.

6. A retractable A-frame ladder according to claim 1, wherein, Both of the aforementioned hand support pedals are provided with a hand support plate at the lower center.

7. A retractable A-frame ladder according to claim 1, wherein, A tool tray is fixedly connected above the two telescopic joints at the top of the first telescopic ladder. Both sides of the tool tray are provided with hanging ear grooves, and the tool tray has multiple tool placement slots.

8. A retractable A-frame ladder according to claim 2, wherein, The ends of the first and second hinge frames are fixedly inserted into the hook handles of the corresponding unlocking hooks, and the hook tips of the multiple unlocking hooks correspond to the positions of the lifting pressure plates below the corresponding opening and closing locking mechanisms.

9. A retractable A-frame ladder according to claim 1, wherein, A guide slope is provided above each of the two fish mouth limiting grooves.

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