A ladder with casters

Abstract

This utility model discloses a ladder with casters, including two main ladders and a locking mechanism. Each main ladder includes support legs with multiple first steps spaced apart and arranged in an array along its length. Multiple insertion parts are arranged around the periphery of each support leg, all along the length of the support leg surface. Unlike the screw-fixing method of existing technologies, this application directly guides the movable part to rotate around the locking rod axis when the secondary leg is extended, moving the movable part from the first insertion point to the second insertion point. This achieves a spiral lifting of the locking rod, disengaging it from the corresponding insertion part and releasing the secondary leg from the lock. The entire unlocking process is rapid, and when re-locking the secondary leg, simply insert the locking rod into the insertion part.

Description

Technical Field

[0001] This utility model relates to the field of ladder technology, specifically to a ladder with casters. Background Technology

[0002] When using industrial ladders, the position of the ladders needs to be adjusted due to frequent changes in work location. This urgently requires a simple and easy-to-operate handling device. However, most ladders on the market currently lack such a device, making handling and repositioning extremely laborious.

[0003] To address the practical inconvenience for consumers and make moving ladders easier and more convenient, existing technology, such as patent document CN201520204003.7, discloses a ladder with a caster assembly. This ladder includes a ladder body with a caster assembly mounted on it. The caster assembly includes an outer frame, casters, and flanged rivets. The caster assembly is mounted on the ladder body via the outer frame, the flanged rivets are mounted on the outer frame, and the casters are mounted on the flanged rivets.

[0004] The aforementioned patent documents disclose a ladder with a caster assembly. While this solves the problem of transporting the ladder, it still has limitations in its use, as follows: The aforementioned patent document discloses a ladder consisting of a main ladder leg and an auxiliary leg, which are connected by a sliding mechanism. However, the method for fixing the connection and positioning of the main ladder leg and the auxiliary leg is rather cumbersome. Specifically, the locking mechanism connecting the two is mostly a pin or a screw. When extending the inner auxiliary leg, the locking mechanism must be manually pulled out to extend the auxiliary leg. However, due to the large length of the screw, it is difficult to pull it out quickly during operation. The screw must be unscrewed from the screw hole on the main ladder leg body for disassembly. In addition, during the subsequent reset process, the screw hole must be manually aligned and the screw screwed into the hole to achieve relocking, making the entire operation quite complicated.

[0005] Therefore, how to overcome the shortcomings of the existing technology mentioned above has become the subject of this utility model. Utility Model Content

[0006] This utility model provides a ladder with casters, which aims to solve the technical problems mentioned in the background art.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a ladder with casters, comprising two main ladders and a locking mechanism; the main ladders include support legs, with multiple insertion parts arranged along the periphery of the support legs; the upper ends of the opposing support legs of the two main ladders are hinged to form an A-frame ladder structure; it also includes auxiliary legs corresponding to the support legs; the auxiliary legs are sleeved on the outside of the support legs and slidably disposed relative to the support legs, so that the auxiliary legs have an extended state and a retracted state; the locking mechanism includes a locking rod, the end of which passes through the upper end of the auxiliary leg, and the locking rod is disposed corresponding to the insertion part; a through hole is provided on the surface of the auxiliary leg at a position corresponding to the locking rod, and the locking rod is movable relative to the auxiliary leg through the cooperation of the locking rod and the through hole; the locking rod is provided with a movable part; the locking mechanism also includes a positioning element. The positioning element is positioned on the auxiliary leg corresponding to the locking lever. The positioning element has an axially movable surface that is arranged around the axis of the locking lever. The bottom end of the axially movable surface is the first arrival point, and the top end is the second arrival point. The distance between the first arrival point and the second arrival point in the axial direction of the locking lever is greater than or equal to the depth of the locking lever inserted into the inserted part. The movable part acts on the positioning element and reciprocates between the first arrival point and the second arrival point on the axially movable surface. In the retracted state, the movable part is at the first arrival point, and the locking lever is embedded in a corresponding inserted part to complete the locking and positioning of the auxiliary leg. In order to enter the extended state, under the action of external force, the movable part is driven to rotate around the axis of the locking lever, so that the movable part moves from the first arrival point to the second arrival point, thereby realizing the axial movement of the locking lever to disengage from the corresponding inserted part and complete the release of the locking of the auxiliary leg.

[0008] In the above scheme, the inserted part can be a hole or a groove.

[0009] In the above scheme, the positioning element can be a triangular block or a spiral strip.

[0010] In the above scheme, the movable part can be an integral structure with the locking lever, such as an L-shaped structure, or it can be a structure connected by a connector.

[0011] In the above solution, the quick separation and positioning of the auxiliary leg and the support leg can be achieved through the cooperation of the positioning component, the movable part, and the locking rod. Specifically, if the auxiliary leg and the support leg need to be separated, the movable part is driven to rotate around the axis of the locking rod under the action of external force, so that the movable part moves from the first arrival point to the second arrival point, thereby realizing the axial movement of the locking rod to disengage from the corresponding inserted part and release the lock on the auxiliary leg. Then, the auxiliary leg is pulled down to separate the two. If the auxiliary leg needs to be retracted, the auxiliary leg is pushed back until the locking rod corresponds to the inserted part on the support leg. Then, the locking rod is guided into the inserted part. In the retracted state, the movable part is at the first arrival point, and the locking rod is embedded in a corresponding inserted part to complete the locking and positioning of the auxiliary leg.

[0012] The above solution differs from the screw-fixing method in existing technologies. In this application, when the auxiliary leg extends, the movable part is directly guided to rotate around the axis of the locking rod, moving from the first insertion point to the second insertion point. This achieves axial movement of the locking rod, disengaging it from the corresponding inserted part and releasing the auxiliary leg from the lock. The entire operation is rapid, and when re-locking the auxiliary leg, simply inserting the locking rod into the inserted part is sufficient; the alignment requirements are not high. Furthermore, this application not only improves locking and unlocking efficiency but also avoids the risk of wear and loosening caused by frequent operations.

[0013] A further technical solution includes a fixing block that is positioned and connected to the surface of the auxiliary leg. The fixing block has a positioning hole corresponding to the position of the through hole. The locking rod is coaxially disposed in the positioning hole. The fixing block has multiple bosses, which are arranged circumferentially around the axis of the positioning hole and combined to form a ring structure. The side of the boss away from the fixing block has an inclined surface that is inclined from the bottom to the top. This inclined surface is an axially movable surface.

[0014] The ring structure includes a continuous ring structure composed of multiple protrusions connected in sequence, and a non-continuous ring structure in which multiple protrusions are spaced apart.

[0015] The above design allows for a smoother fit between the boss and the movable part. Specifically, during the rotation of the movable part around the locking rod axis, its bottom end contacts the inclined surface of the boss and slides along the inclined surface, thereby forcing the movable part to move along the locking rod axis, which in turn drives the locking rod to move synchronously, achieving disengagement from the inserted part. The inclined surface design ensures more even force distribution on the movable part during rotation, improving operational stability and unlocking efficiency. Simultaneously, the spaced bosses create clearance between adjacent bosses, facilitating adjustment of the movable part's movement trajectory and further enhancing the flexibility of the fit. This structural design is simple, easy to assemble, and ensures stable locking and unlocking performance even in complex environments.

[0016] A further technical solution involves a knob positioned at the end of the locking lever furthest from the auxiliary leg. A positioning groove is provided on the surface of the knob facing the locking lever, with the groove opening facing the auxiliary leg. Multiple lifting blocks are located at the bottom of the positioning groove, each corresponding to a specific boss. Each lifting block is a movable part. A ring-shaped structure is embedded within the positioning groove. When the movable part is not rotating around the locking lever axis, the end of the lifting block is at the bottom of the inclined surface, and the locking lever is embedded in the inserted part. When the movable part rotates around the locking lever axis to axially disengage from the locking lever, the end of the lifting block slides from the bottom to the top of the inclined surface, and the locking lever moves axially and disengages from the inserted part.

[0017] The above design makes the rotation of the movable part more convenient and faster. The knob design allows the operator to directly apply force to the knob, causing the lifting block to rotate. This drives the movable part to slide along the inclined plane of the boss towards the top of the inclined plane, achieving rapid axial movement and unlocking of the locking lever. This structure not only simplifies operation but also further reduces the requirements for operational precision. Simultaneously, the corresponding fit between the lifting block and the boss makes force transmission more direct and stable, reducing unnecessary frictional loss and improving the overall structural lifespan and reliability.

[0018] In a further technical solution, the locking mechanism also includes an elastic element that acts on the locking lever to drive the locking lever to always slide toward the support leg.

[0019] The above design enables the locking lever to lock automatically. Specifically, when the movable part slides along the inclined surface of the boss to the top of the inclined surface, achieving rapid axial movement and unlocking of the locking lever, the elastic element is compressed, and then the auxiliary leg slides upward. When the auxiliary leg slides to the position of a certain insertion part, the movable part can be reset, causing the locking lever to abut against the side wall of the support leg. Once the auxiliary leg, carrying the locking lever, slides to the position of the insertion part, the elastic element applies a force to make the locking lever slide towards the support leg, thereby quickly embedding into the insertion part and achieving automatic locking. This design reduces the number of manual adjustment steps and improves the operational efficiency of the locking mechanism. At the same time, the elastic element enhances the stability of the locking lever in the locked state, effectively preventing accidental unlocking due to external vibration, further improving the safety and reliability of the structure. In a further technical solution, the elastic element is a spring.

[0020] A further technical solution includes a locking rod comprising an insertion part and a connecting part that are coaxially arranged and integrally connected, wherein the diameter of the insertion part is larger than the diameter of the connecting part; an elastic element is coaxially sleeved on the outside of the connecting part, and one end of the elastic element abuts against the end of the insertion part, while the other end abuts against the fixing block.

[0021] A further technical solution is that the inner wall of the positioning hole away from the knob is provided with a flared groove, the opening of the flared groove faces the auxiliary leg, and the end of the elastic element abuts against the bottom of the flared groove.

[0022] The above design ensures that the elastic element does not interfere with the normal use of the locking lever. Specifically, the elastic element is positioned within the flared groove, with one end abutting the bottom of the groove and the other end abutting the end of the insertion part. This arrangement prevents obstruction of the elastic element during the normal movement of the locking lever and ensures that the elastic element is always under appropriate stress, preventing displacement or failure due to uneven stress. Furthermore, the flared groove structure facilitates the installation and positioning of the elastic element, further improving the overall structural stability and assembly efficiency.

[0023] It is worth noting that the opening of the flared groove can also be conical to facilitate the guidance and positioning of the end of the elastic element. The conical surface allows the elastic element to slide more smoothly along the groove during compression or reset, avoiding jamming or stress concentration caused by abrupt changes in the contact surface, thereby further improving the smoothness of the locking mechanism's operation and structural durability.

[0024] A further technical solution involves installing a ring around the outside of the annular structure on the surface of the fixing block. The diameter of the ring is equal to the diameter of the positioning groove, and the axis of the ring coincides with the axis of the positioning hole. When the locking rod is inserted into the inserted part, the end of the ring abuts against the bottom of the positioning groove, and the opening of the positioning groove approaches the surface of the fixing block.

[0025] The above design prevents external debris from entering the area containing the annular structure. The ring effectively isolates dust and impurities from the external environment, preventing them from entering the positioning groove and interfering with the movement of the locking lever, thus ensuring the long-term stability and reliability of the locking mechanism. Furthermore, the ring also acts as a guide, ensuring that the locking lever remains aligned axially during movement and preventing misalignment or jamming. This design is compact and functionally clear, further enhancing the overall user experience and lifespan of the device.

[0026] A further technical solution involves inserting a circular hole, the diameter of which is greater than or equal to the diameter of the locking rod.

[0027] The round hole and the locking rod are generally fitted with a clearance fit. This ensures that the locking rod can be smoothly inserted and maintain good coaxiality. The clearance fit design effectively reduces assembly difficulty while ensuring smooth and unobstructed movement of the locking rod within the round hole. It prevents jamming or wear caused by an overly tight fit, thereby improving the overall flexibility and durability of the mechanism.

[0028] It should be noted that an annular oil groove can be provided on the inner wall of the round hole to store lubricating grease, further reducing the frictional resistance between the locking rod and the round hole, extending the service life of the parts, and ensuring that the locking mechanism can maintain stable performance after long-term use.

[0029] A further technical solution involves installing casters at the bottom of all auxiliary legs on one side of the A-frame ladder structure.

[0030] The above design allows operators to easily transport and move the A-frame ladder using casters, greatly improving its mobility and ease of use. The casters are made of wear-resistant and non-slip materials, ensuring stable operation on various ground conditions and effectively reducing damage to the ground during movement. It's important to note that the casters can be equipped with a locking mechanism to securely fix the ladder in place, preventing accidental slippage and further enhancing safety and stability during operation. This design is particularly suitable for scenarios requiring frequent movement or use of the A-frame ladder in complex environments, improving operational efficiency and safety.

[0031] The terms "first," "second," etc., used in this article do not specifically refer to order or sequence, nor are they intended to limit this case; they are merely used to distinguish components or operations described using the same technical terms.

[0032] The terms "connection" or "positioning" as used in this article can refer to two or more components or devices making direct physical contact with each other, or making indirect physical contact with each other, or to two or more components or devices operating or moving with each other.

[0033] The terms “include,” “including,” and “have” used in this article are all open-ended, meaning they include but are not limited to.

[0034] Unless otherwise specified, the terms used herein generally have their ordinary meaning in the context of the art, the subject matter, and the specific context. Certain terms used to describe this case will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the case.

[0035] The terms “front,” “back,” “up,” “down,” “left,” and “right” used in this article are directional terms. In this case, they are only used to describe the positional relationship between the structures and are not intended to limit the specific direction of the protection scheme or its actual implementation.

[0036] The working principle and advantages of this utility model are as follows: This invention achieves rapid separation and positioning of the auxiliary leg and the support leg through the cooperation of the positioning component, the movable part, and the locking rod. Specifically, if the auxiliary leg needs to be separated from the support leg, the movable part is driven to rotate around the axis of the locking rod under external force, so that the movable part moves from the first insertion point to the second insertion point, thereby realizing the axial movement of the locking rod to disengage from the corresponding inserted part and release the lock on the auxiliary leg. Then, pulling the auxiliary leg down will separate the two. If the auxiliary leg needs to be retracted, the locking rod is guided to unlock, and then the auxiliary leg is pushed back until the locking rod corresponds to the inserted part on the support leg. Then, the locking rod is guided into the inserted part. In the retracted state, the movable part is at the first insertion point, and the locking rod is embedded in a corresponding inserted part to complete the locking and positioning of the auxiliary leg.

[0037] Unlike existing screw-fixing methods, this application directly guides the movable part to rotate around the locking rod axis when the auxiliary leg extends, moving the movable part from the first insertion point to the second insertion point. This achieves axial movement of the locking rod, disengaging it from the corresponding inserted part and releasing the auxiliary leg from the lock. The entire operation is quick, and when re-locking the auxiliary leg, simply inserting the locking rod into the inserted part is sufficient; the alignment requirements are not high. Furthermore, this application not only improves locking and unlocking efficiency but also avoids the risk of wear and loosening caused by frequent operations. Attached Figure Description

[0038] Appendix Figure 1 This is a side view of the main ladder structure in an embodiment of the present invention; Appendix Figure 2 for Figure 1 Schematic diagram of the longitudinal section structure at point AA; Appendix Figure 3 for Figure 2 Enlarged view of section C in the image; Appendix Figure 4 This is a schematic diagram of the structure when the auxiliary leg is extended in an embodiment of this utility model; Appendix Figure 5 This is a schematic diagram of the caster structure in an embodiment of the present utility model; Appendix Figure 6 This is an exploded view of the positioning component in an embodiment of this utility model; Appendix Figure 7 This is a schematic diagram of the knob structure when the locking rod is not disengaged from the inserted part in an embodiment of this utility model; Appendix Figure 8 This is a schematic diagram of the longitudinal section structure of the locking rod in an embodiment of the present utility model when it is not disengaged from the inserted part; Appendix Figure 9 This is a schematic diagram of the knob structure when the locking rod is disengaged from the inserted part in an embodiment of the present utility model; Appendix Figure 10This is a schematic diagram of the longitudinal section structure of the locking rod when it is disengaged from the inserted part in an embodiment of this utility model.

[0039] In the above attached figures: 1. Main ladder; 2. Locking mechanism; 3. Support leg; 4. First step; 5. Inserted part; 6. Secondary leg; 7. Second step; 8. Locking rod; 9. Through hole; 10. Movable part; 11. Positioning element; 12. Axial moving surface; 13. First arrival point; 14. Second arrival point; 15. Fixing block; 16. Positioning hole; 17. Boss; 18. Knob; 19. Positioning groove; 20. Caster; 21. Elastic element; 22. Insertion part; 23. Connecting part; 24. Flared groove; 25. Ring. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings and embodiments: Example: The present invention will be clearly described below with illustrations and detailed description. Any person skilled in the art who understands the examples of the present invention can make changes and modifications based on the technology taught in the present invention without departing from the spirit and scope of the present invention.

[0041] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the scope of this work. Singular forms such as “a,” “this,” “this,” “the,” and “the” as used herein also include plural forms.

[0042] See appendix Figures 1-10As shown, a ladder with casters includes two main ladders 1 and a locking mechanism 2. Each main ladder 1 includes support legs 3, with multiple insertion portions 5 arranged along the length of the support legs 3. The upper ends of opposing support legs 3 in the two main ladders 1 are hinged to form an A-frame ladder structure. The ladder also includes auxiliary legs 6, each corresponding to a support leg 3. The auxiliary legs 6 are sleeved on the outside of the support legs 3 and slidably disposed relative to them, allowing for extended and retracted states. The locking mechanism 2 includes a locking rod 8, the end of which passes through the upper end of the auxiliary leg 6 and is positioned corresponding to the insertion portion 5. A through hole 9 is provided on the surface of the auxiliary leg 6 at a position corresponding to the locking rod 8. The locking rod 8 is movably disposed relative to the auxiliary leg 6 through the engagement of the through hole 9. A movable portion 10 is provided on the locking rod 8. The locking mechanism 2 also includes a positioning element 11, which is positioned on the auxiliary leg 6 corresponding to the locking rod 8. The positioning member 11 has an axially movable surface 12, which is arranged around the axis of the locking rod 8. The bottom end of the axially movable surface 12 is the first arrival point 13, and the top end is the second arrival point 14. The distance between the first arrival point 13 and the second arrival point 14 in the axial direction of the locking rod 8 is greater than or equal to the depth of the locking rod 8 inserted into the inserted part 5. The movable part 10 acts on the positioning member 11 and reciprocates between the first arrival point 13 and the second arrival point 14 on the axially movable surface 12. In the retracted state, the movable part 10 is at the first arrival point 13, and the locking rod 8 is embedded in a corresponding inserted part 5 to complete the locking and positioning of the auxiliary leg 6. In order to enter the extended state, under the action of external force, the movable part 10 is driven to rotate around the axis of the locking rod 8, so that the movable part 10 moves from the first arrival point 13 to the second arrival point 14, thereby realizing the axial movement of the locking rod 8 to disengage from the corresponding inserted part 5 and complete the release of the locking of the auxiliary leg 6.

[0043] In this embodiment, the inserted part 5 can be a hole or a groove.

[0044] In this embodiment, the positioning element 11 can be a triangular block or a spiral strip, etc. The axial moving surface 12 is the inclined surface on the triangular block or the spiral surface on the spiral strip.

[0045] In this embodiment, the movable part 10 can be an integral structure with the locking lever 8, such as an L-shaped structure, or it can be a structure connected by a connector.

[0046] In this embodiment, a first pedal 4 is provided on the support leg 3, and a second pedal 7 is provided on the auxiliary leg.

[0047] In this embodiment, the positioning member 11, the movable part 10, and the locking rod 8 can cooperate to achieve the purpose of quick separation and quick positioning of the auxiliary leg 6 and the support leg 3. Specifically, if the auxiliary leg 6 needs to be separated from the support leg 3, the movable part 10 is driven to rotate around the axis of the locking rod 8 under the action of external force, so that the movable part 10 moves from the first arrival point 13 to the second arrival point 14, thereby realizing the axial movement of the locking rod 8 to disengage from the corresponding inserted part 5 and release the lock on the auxiliary leg 6. Then, the auxiliary leg 6 is pulled down to separate the two. If the auxiliary leg 6 needs to be retracted, the auxiliary leg 6 is pushed back until the locking rod 8 corresponds to the inserted part 5 on the support leg 3. Then, the locking rod 8 is guided into the inserted part 5. In the retracted state, the movable part 10 is at the first arrival point 13, and the locking rod 8 is embedded in a corresponding inserted part 5 to complete the locking and positioning of the auxiliary leg 6.

[0048] Unlike existing screw-fixing methods, this application directly guides the movable part 10 to rotate around the axis of the locking rod 8 when the auxiliary leg 6 extends. This moves the movable part 10 from the first arrival point 13 to the second arrival point 14, thereby achieving axial movement of the locking rod 8 to disengage from the corresponding inserted part 5 and release the lock on the auxiliary leg 6. The entire operation is quick, and when re-locking the auxiliary leg 6, it is only necessary to insert the locking rod 8 into the inserted part 5. The alignment requirements are not high. Furthermore, this application not only improves locking and unlocking efficiency but also avoids the risk of wear and loosening caused by frequent operations.

[0049] Preferably, the positioning component 11 includes a fixing block 15 positioned and connected to the surface of the auxiliary leg 6. The fixing block 15 is provided with a positioning hole 16 corresponding to the position of the through hole 9. The locking rod 8 is coaxially disposed in the positioning hole 16. The fixing block 15 is provided with a plurality of bosses 17. The plurality of bosses 17 are arranged circumferentially around the axis of the positioning hole 16 and combined to form a ring structure. The side of the boss 17 away from the fixing block 15 has an inclined surface that is inclined from the bottom end to the top end. This inclined surface is an axially movable surface 12.

[0050] The ring structure includes a continuous ring structure composed of multiple protrusions 17 connected in sequence, and a non-continuous ring structure in which multiple protrusions 17 are spaced apart.

[0051] The above design allows for a smoother fit between the boss 17 and the movable part 10. Specifically, during the rotation of the movable part 10 around the axis of the locking rod 8, its bottom end contacts the inclined surface of the boss 17 and slides along the inclined surface, thereby forcing the movable part 10 to generate axial displacement, causing the locking rod 8 to rise synchronously, thus achieving disengagement from the inserted part 5 (e.g., Figure 10According to locking lever 8), the inclined surface design makes the force on the moving part 10 more even during rotation, improving the stability of operation and unlocking efficiency. At the same time, when the bosses 17 are spaced apart, a clearance space is formed between adjacent bosses 17, which facilitates the adjustment of the movement trajectory of the moving part 10 and further improves the flexibility of the fit. This structural design is simple and easy to assemble, while ensuring that the locking mechanism still has stable locking and unlocking performance in complex environments.

[0052] Preferably, a knob 18 is positioned and connected to the end of the locking lever 8 away from the auxiliary leg 6. The surface of the knob 18 facing the locking lever 8 is provided with a positioning groove 19. The opening of the positioning groove 19 faces the auxiliary leg 6. Multiple lifting blocks are provided at the bottom of the positioning groove 19. Each lifting block is provided in a one-to-one correspondence with each boss 17. The lifting block is a movable part 10. The annular structure is embedded in the positioning groove 19. When the movable part 10 does not rotate around the axis of the locking lever 8, the end of the lifting block is at the bottom of the inclined surface, and the locking lever 8 is embedded in the insertion part 5. When the movable part 10 rotates around the axis of the locking lever 8 to spirally lift the locking lever 8, the end of the lifting block slides from the bottom of the inclined surface to the top, and the locking lever 8 is lifted and disengaged from the insertion part 5.

[0053] The above design makes the rotation of the movable part 10 more convenient and faster. Through the design of the knob 18, the operator can directly apply force to the knob 18 and rotate the movable part 10, thereby driving the movable part 10 to slide along the bottom end to the top end of the inclined surface of the boss 17, achieving rapid axial displacement and unlocking of the locking lever 8. This structure not only simplifies the operation but also further reduces the requirements for operational precision. At the same time, the corresponding cooperation between the movable part 10 and the boss 17 makes the force transmission more direct and stable, reducing unnecessary frictional loss and improving the service life and reliability of the overall structure.

[0054] Preferably, the locking mechanism 2 further includes an elastic element 21 that acts on the locking lever 8 to drive the locking lever 8 to have a tendency to slide toward the support leg 3 at all times.

[0055] With the above design, the locking lever 8 can achieve automatic locking. Specifically, when the movable part 10 slides along the bottom end to the top end of the inclined surface of the boss 17, achieving rapid axial displacement and unlocking of the locking lever 8, the elastic element 21 is compressed, and then the auxiliary leg 6 can slide upward. When the auxiliary leg 6 slides to the position of a certain inserted part 5, the movable part 10 can be reset, so that the locking lever 8 abuts against the side wall of the support leg 3. Once the auxiliary leg 6 slides with the locking lever 8 to the position of the inserted part 5, the elastic element 21 applies a force to make the locking lever 8 slide towards the support leg 3, thereby quickly embedding into the inserted part 5 to achieve automatic locking. This design reduces the steps of manual adjustment and improves the operating efficiency of the locking mechanism. At the same time, the setting of the elastic element 21 enhances the stability of the locking lever 8 in the locked state, effectively preventing accidental unlocking caused by external force vibration, and further improving the safety and reliability of the structure. In a further technical solution, the elastic element 21 is a spring.

[0056] Preferably, the locking lever 8 includes an insertion part 22 and a connecting part 23 that are coaxially arranged and integrally connected. The diameter of the insertion part 22 is larger than the diameter of the connecting part 23. An elastic member 21 is coaxially sleeved on the outside of the connecting part 23, and one end of the elastic member 21 abuts against the end of the insertion part 22, and the other end abuts against the fixing block 15.

[0057] Preferably, the inner wall of the positioning hole 16 away from the knob 18 is provided with a flared groove 24, the opening of the flared groove 24 faces the auxiliary leg 6, and the end of the elastic member 21 abuts against the bottom of the flared groove 24.

[0058] With the above design, the elastic element 21 will not affect the normal use of the locking lever 8. Specifically, the elastic element 21 is located within the flared groove 24, with one end abutting the bottom of the groove 24 and the other end abutting the end of the insertion part 22. This arrangement ensures that the elastic element 21 is not obstructed during the normal movement of the locking lever 8, while also ensuring that the elastic element 21 is always under appropriate stress, preventing it from shifting or failing due to uneven stress. Furthermore, the structure of the flared groove 24 facilitates the installation and positioning of the elastic element 21, further improving the overall structural stability and assembly efficiency.

[0059] It should be noted that the opening of the flared groove 24 can also be a conical surface to facilitate the guidance and positioning of the end of the elastic element 21. The conical surface allows the elastic element 21 to slide more smoothly along the groove during compression or reset, avoiding jamming or stress concentration caused by abrupt changes in the contact surface, thereby further improving the smoothness of the locking mechanism's operation and structural durability.

[0060] Preferably, a ring 25 is installed on the surface of the fixing block 15, which surrounds the outer side of the annular structure. The diameter of the ring 25 is equal to the diameter of the positioning groove 19, and the axis of the ring 25 coincides with the axis of the positioning hole 16. When the locking rod 8 is inserted into the inserted part 5, the end of the ring 25 abuts against the bottom of the positioning groove 19, and the opening of the positioning groove 19 approaches the surface of the fixing block 15.

[0061] The above design prevents external debris from entering the area containing the annular structure. The ring 25 effectively isolates dust and impurities from the external environment, preventing them from entering the positioning groove 19 and interfering with the movement of the locking lever 8, thus ensuring the long-term stability and reliability of the locking mechanism. Furthermore, the ring 25 also serves as an auxiliary guide, ensuring that the locking lever 8 remains aligned with its axis during movement, preventing misalignment or jamming. This design is compact and functionally clear, further enhancing the overall user experience and lifespan of the device.

[0062] Preferably, the insertion part 5 is a circular hole, the diameter of which is greater than or equal to the diameter of the locking rod 8.

[0063] The round hole and the locking rod 8 are generally fitted with a clearance fit. This ensures that the locking rod 8 can be smoothly inserted and maintain good coaxiality. The clearance fit design effectively reduces assembly difficulty, while ensuring that the locking rod 8 moves smoothly and unimpeded within the round hole, preventing jamming or wear due to an overly tight fit, thereby improving the flexibility and durability of the overall mechanism.

[0064] It should be noted that an annular oil groove can be provided on the inner wall of the round hole to store lubricating grease, further reducing the frictional resistance between the locking rod 8 and the round hole, extending the service life of the parts, and ensuring that the locking mechanism can maintain stable performance after long-term use.

[0065] Preferably, on one side of the A-frame structure, casters 20 are provided at the bottom of all the secondary legs 6 on that side.

[0066] The above design allows operators to easily transport and move the A-frame ladder using the casters 20, greatly improving its mobility and ease of use. The casters 20 are made of wear-resistant and non-slip materials, ensuring stable operation on various ground conditions and effectively reducing damage to the ground during movement. It is important to note that the casters 20 can be equipped with a locking mechanism to securely fix the ladder in place, preventing accidental slippage and further enhancing safety and stability during operation. This design is particularly suitable for scenarios requiring frequent movement or use of the A-frame ladder in complex environments, significantly improving operational efficiency and safety.

[0067] Working principle: The explanation is based on the extension and retraction of the secondary leg 6.

[0068] Under normal circumstances, the auxiliary leg 6 is in the retracted state. In this state, the movable part 10 is at the first arrival point 13, and the locking rod 8 is embedded in a corresponding inserted part 5 to complete the locking and positioning of the auxiliary leg 6.

[0069] Afterwards, the operator can directly apply force to the knob 18 and rotate the lifting block, thereby driving the movable part 10 to slide along the bottom end of the inclined surface of the boss 17 to the top end of the inclined surface, realizing the rapid axial displacement and unlocking of the locking lever 8. When the locking lever 8 is raised and unlocked, the elastic element 21 will be compressed. Specifically, as shown... Figures 7-10 As shown, when knob 18 rotates 90 degrees, the bottom end of movable part 10 contacts the inclined surface of boss 17 during its rotation around the axis of locking rod 8, and slides along the inclined surface, moving from the first arrival point 13 to the second arrival point 14. This forces movable part 10 to move along the axis of locking rod 8, so that the locking rod 8 moves synchronously through knob 18, thereby disengaging from the inserted part 5, i.e., unlocking the auxiliary leg 6. Since the first arrival point 13 is in a planar state, knob 18 will not easily return to its original position.

[0070] Then the auxiliary leg 6 can be slid down to extend it. Once the through hole 9 on the auxiliary leg 6 is aligned with a certain insertion part 5, the reset knob 18 is turned so that the movable part 10 is at the first position 13. Then the locking rod 8 is inserted into a corresponding insertion part 5 to complete the locking and positioning of the auxiliary leg 6.

[0071] When the auxiliary leg 6 needs to be retracted, rotate the knob 18 again to unlock the auxiliary leg 6 and position the movable part 10 at the second arrival point 14. Slide the auxiliary leg 6 upward. When it gradually approaches the position that needs to be fixed, first reset the knob 18 so that the locking rod 8 abuts against the side wall of the support leg 3. Once the auxiliary leg 6 slides with the locking rod 8 to the position of the inserted part 5, the elastic element 21 resets, thereby applying force to make the locking rod 8 slide towards the support leg 3, thereby quickly embedding into the inserted part 5 to achieve automatic locking.

[0072] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. A ladder having casters, characterized by: It includes two main elevators (1) and a locking mechanism (2); The main ladder (1) includes a support leg (3), and a plurality of insertion parts (5) are provided around the support leg (3), and the plurality of insertion parts (5) are arranged in the length direction of the support leg (3); The upper ends of the opposing support legs (3) of the two main ladders (1) are hinged together to form a A-frame ladder structure; It also includes auxiliary legs (6) that are set one-to-one with the supporting leg (3); The auxiliary leg (6) is sleeved on the outside of the support leg (3) and is slidably arranged relative to the support leg (3) so that the auxiliary leg (6) has an extended state and a retracted state; The locking mechanism (2) includes a locking rod (8), the end of which passes through the upper end of the auxiliary leg (6), and the locking rod (8) is provided corresponding to the insertion part (5); A through hole (9) is provided on the surface of the auxiliary leg (6) at the position corresponding to the locking rod (8). The locking rod (8) is movably set relative to the auxiliary leg (6) by cooperating with the through hole (9). The locking lever (8) is provided with a movable part (10); The locking mechanism (2) also includes a positioning element (11), which is set on the auxiliary leg (6) corresponding to the locking rod (8). The positioning element (11) has an axial moving surface (12), which is set around the axis of the locking rod (8). The bottom end of the axial moving surface (12) is the first arrival point (13), and the top end is the second arrival point (14). The distance between the first arrival point (13) and the second arrival point (14) in the axial direction of the locking rod (8) is greater than or equal to the depth of the locking rod (8) inserted into the inserted part (5). The moving part (10) acts on the positioning element (11) and reciprocates between the first arrival point (13) and the second arrival point (14) on the axial moving surface (12). In the retracted state, the movable part (10) is at the first arrival point (13), and the locking rod (8) is embedded in a corresponding inserted part (5) to complete the locking and positioning of the auxiliary leg (6); In order to enter the extended state, under the action of external force, the movable part (10) is driven to rotate around the axis of the locking rod (8) so that the movable part (10) moves from the first arrival point (13) to the second arrival point (14), thereby realizing the axial movement of the locking rod (8) to disengage from the corresponding inserted part (5) and complete the release of the lock on the auxiliary leg (6).

2. The ladder with casters according to claim 1, characterized in that: The positioning component (11) includes a fixing block (15) that is positioned and connected to the surface of the auxiliary leg (6). The fixing block (15) is provided with a positioning hole (16) corresponding to the position of the through hole (9). The locking rod (8) is coaxially arranged in the positioning hole (16). The fixing block (15) is provided with multiple bosses (17). The multiple bosses (17) are arranged circumferentially around the axis of the positioning hole (16) and combined to form a ring structure. The boss (17) has an inclined surface (12) on the side away from the fixed block (15) that is inclined from the bottom to the top.

3. The ladder with casters according to claim 2, characterized in that: A knob (18) is positioned and connected to the end of the locking lever (8) away from the auxiliary leg (6). The surface of the knob (18) facing the locking lever (8) is provided with a positioning groove (19). The opening of the positioning groove (19) faces the auxiliary leg (6). Multiple lifting blocks are provided at the bottom of the positioning groove (19). Each lifting block is provided in correspondence with each boss (17). The lifting block is a movable part (10). The annular structure is embedded in the positioning groove (19); When the movable part (10) does not rotate around the axis of the locking rod (8), the end of the lifting block is at the bottom of the inclined plane, and the locking rod (8) is embedded in the inserted part (5). When the movable part (10) rotates around the axis of the locking rod (8) to axially disengage from the locking rod (8), the end of the lifting block slides from the bottom end to the top end of the inclined surface, and the locking rod (8) moves axially and disengages from the inserted part (5).

4. The ladder with casters according to claim 1 or 2, characterized in that: The locking mechanism (2) also includes an elastic element (21) that acts on the locking lever (8) to drive the locking lever (8) to have a tendency to slide toward the support leg (3) at all times.

5. The ladder with casters according to claim 2, characterized in that: The locking lever (8) includes an insertion part (22) and a connecting part (23) that are coaxially arranged and integrally connected, wherein the diameter of the insertion part (22) is larger than the diameter of the connecting part (23); The elastic element (21) is coaxially sleeved on the outside of the connecting part (23), and one end of the elastic element (21) abuts against the end of the insertion part (22), and the other end abuts against the fixing block (15).

6. The ladder with casters according to claim 5, characterized in that: The inner wall of the positioning hole (16) away from the knob (18) is provided with a flared groove (24), the opening of the flared groove (24) faces the auxiliary leg (6), and the end of the elastic member (21) abuts against the bottom of the flared groove (24).

7. The ladder with casters according to claim 2, characterized in that: A ring (25) is installed on the surface of the fixing block (15) and surrounds the outer side of the ring structure. The diameter of the ring (25) is equal to the diameter of the positioning groove (19), and the axis of the ring (25) coincides with the axis of the positioning hole (16). When the locking rod (8) is inserted into the inserted part (5), the end of the ring (25) abuts against the bottom of the positioning groove (19), and the opening of the positioning groove (19) approaches the surface of the fixing block (15).

8. The ladder with casters according to claim 1, characterized in that: The insertion part (5) is a round hole, the diameter of which is greater than or equal to the diameter of the locking rod (8).

9. The ladder with casters according to claim 1, characterized in that: On one side of the A-frame structure, casters (20) are provided at the bottom of all the secondary legs (6) on that side.

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