Interlocking unlocking mechanism and extension ladder

Abstract

The utility model provides a kind of linkage unlocking mechanism and telescopic ladder, it is related to ladder field, including step stick, connecting sleeve and linkage unlocking assembly;Linkage unlocking assembly includes button, locking pin and spring;Spring is connected with locking pin and is relatively fixed in the inner cavity of step stick;Button is slidably installed on the lower surface of step stick, and the side wall of button is provided with inclined sliding slot, the side portion of locking pin is provided with protrusion, and the protrusion is slidably installed in inclined sliding slot;Under the action of spring elasticity, locking pin is inserted into connecting sleeve through pin hole, and the lower end of button is exposed outside step stick;When button is slid upward relative to step stick, protrusion is moved by sliding slot, so that locking pin is compressed along axial spring to exit connecting sleeve through pin hole.The linkage unlocking mechanism converts the vertical direction movement of button into horizontal axial movement of locking pin through the track structure of inclined sliding slot and protrusion when unlocking, which guarantees the stability and reliability of unlocking action, and the triggering response is sensitive, the unlocking action is more smooth, and the user experience is improved.

Description

Technical Field

[0001] This utility model relates to the field of ladders, and in particular to a linkage unlocking mechanism and a telescopic ladder. Background Technology

[0002] A bamboo-joint ladder is a type of telescopic ladder composed of two, three, or even more sections (commonly three to five sections). Each section includes a rung, two connecting sleeves symmetrically fixed to both ends of the rung, and an unlocking mechanism installed between the rung and the connecting sleeves. The unlocking mechanism typically includes a control button, a locking pin, and a spring. The spring extends horizontally, and the locking pin is connected to one end of the spring and linked to the control button. The connecting sleeve has a pin hole communicating with the inner cavity of the rung. The rung of the upper section is inserted into the connecting sleeve of the lower section. When the user moves the ladder upwards... When the ladder is pulled upwards, if the locking hole on the upper ladder frame rod is aligned with the pin hole on the connecting sleeve of the lower ladder frame, the locking pin will automatically pop out through the pin hole and extend into the locking hole on the upper ladder frame rod under the action of the spring, thus locking the upper and lower ladder frames. This process does not require manual operation; as long as the ladder is pulled to the appropriate height, it will automatically lock with a "click," which is convenient and quick. When unlocking is required, the locking pin is controlled by the control key to exit through the pin hole from the locking hole on the upper ladder frame rod and the connecting sleeve of the lower ladder frame, thus unlocking the ladder.

[0003] The traditional telescopic ladder's control buttons and pins are linked by pulling the control buttons horizontally relative to the footplates to drive the locking pins out of the pin holes to unlock. However, this method requires pushing the two control buttons at both ends of the footplates for each ladder frame to unlock, and requires operating layer by layer to fully close multiple ladder frames and complete the ladder retraction, which is inconvenient.

[0004] Based on this, some existing telescopic ladders have been improved to have a continuous unlocking function. Continuous unlocking means that when retracting the ladder, the user only needs to operate the control button on the bottom ladder frame to release the locking pin of the bottom ladder frame. Once the bottom ladder frame is unlocked, the ladder bar of the ladder frame above it loses support and begins to fall under its own weight. When the upper ladder frame falls to the point where the rung of the next ladder frame touches the rung of the next ladder frame, it will trigger the control button of the upper ladder frame, causing the control button of that ladder frame to operate and control its locking pin to exit the connecting sleeve of that ladder frame through the pin hole. In this way, like dominoes, one ladder frame after another will automatically unlock until all ladder frames are completely closed and the ladder is retracted. The entire retraction process only requires the user to operate the control button of the bottom ladder frame to unlock, and then let the ladder retract automatically. The operation is simple.

[0005] However, in the existing technology, in the unlocking mechanism that realizes the above-mentioned continuous unlocking function, the connection between the control key and the pin is that the control key is installed in the mounting groove on the lower surface of one end of the step rod by rotating the shaft. When the step rods of the upper and lower ladder frames come into contact, the control key is pressed into the mounting groove and rotates relative to the shaft and acts on the locking pin. The locking pin is then removed from the connecting sleeve in the horizontal direction through the pin hole to achieve unlocking. Although this method can realize the continuous unlocking function, this type of structure is not stable during use, and the unlocking process is prone to jamming. The smoothness of the continuous unlocking action is poor, which affects the user experience. Utility Model Content

[0006] The purpose of this utility model is to provide a linkage unlocking mechanism and a telescopic ladder to alleviate the above-mentioned technical problems existing in the prior art.

[0007] To achieve the above objectives, the embodiments of this utility model adopt the following technical solutions: In a first aspect, this utility model provides a linkage unlocking mechanism for use in a telescopic ladder, the linkage unlocking mechanism including a step, a connecting sleeve, and a linkage unlocking component; The two connecting sleeves are symmetrically fixed to both ends of the pedal, and the connecting sleeves are provided with pin holes that communicate with the inner cavity of the pedal; Each end of the foot pedal is equipped with a set of linkage unlocking components, and each set of linkage unlocking components includes a button and a linkage mechanism located in the inner cavity of the foot pedal. The linkage mechanism includes a locking pin and a spring; the first end of the spring is connected to the locking pin, and the second end of the spring is fixed relative to the inner cavity of the pedal. The button is slidably mounted in the mounting opening on the lower surface of the foot pedal. An inclined groove is provided on the side wall of the button, and a protrusion is provided on the side of the locking pin. The protrusion is slidably mounted in the inclined groove. Under the action of the spring force, the end of the locking pin away from the spring extends into the connecting sleeve through the pin hole, while the lower end of the button protrudes outside the pedal. When the button slides upward relative to the pedal, the inclined groove drives the protrusion to move, causing the locking pin to compress the spring axially and exit the connecting sleeve through the pin hole.

[0008] In an optional embodiment, the connecting sleeve includes a collar and a connecting block that is fixedly or integrally connected to the collar; The pin hole is located on the side wall of the collar facing the connecting block; The connecting block and the pedal are assembled. Inside the connecting block, there is an installation cavity that connects the pin hole and the inner cavity of the pedal. Inside the installation cavity, there is a limiting rib and a limiting groove. The locking pin is slidably disposed in the limiting groove.

[0009] In an optional embodiment, the linkage unlocking mechanism further includes a spring expansion container, which includes a receiving tube fixed to the inner wall of the mounting cavity, and the second end of the spring is inserted into and fixedly connected to the cavity of the receiving tube.

[0010] In an optional embodiment, the spring expansion container further includes an insert plate sleeved around the outside of the receiving tube; The mounting cavity is provided with a positioning rib, the side of the positioning rib is provided with a slot, the upper part and the side of the slot are provided with an insertion port, and the insertion plate is inserted into the slot through the insertion port.

[0011] In an optional embodiment, a guide block is provided on one side of the button, and a guide groove is provided inside the mounting cavity. The guide block is slidably mounted inside the guide groove.

[0012] In an optional embodiment, the diameter of the cavity of the receiving tube is larger than the diameter of the locking pin, and the locking pin is inserted into the cavity of the receiving tube when it is out of the connecting sleeve through the pin hole.

[0013] In an optional embodiment, the top surface of the button is provided with an elongated groove, and the locking pin is inserted into the elongated groove; wherein: The bottom wall of the long groove has a downwardly concave arc-shaped surface, and the side wall of the locking pin facing the bottom wall of the groove has an arc-shaped side wall that matches the bottom wall of the groove. And / or, the sidewalls of the groove located on both sides of the bottom wall of the groove, and the sidewall of the locking pin facing the sidewall of the groove, are all planar.

[0014] In an optional embodiment, the protrusions are symmetrically provided on both radially opposite sides of the locking pin, and the inclined slide grooves are symmetrically provided on both radially opposite side walls of the button, with each protrusion correspondingly slidably installed inside the inclined slide groove on the corresponding side.

[0015] In an optional embodiment, the sidewall of the connecting sleeve is provided with an elastic buckle.

[0016] Secondly, this utility model embodiment also provides a telescopic ladder, including multiple ladder frames and multiple linkage unlocking mechanisms provided by any optional implementation of the first aspect; Each section of the ladder frame is equipped with a linkage unlocking mechanism on the outside of the ladder rods on both sides. The connecting sleeve of the linkage unlocking mechanism is fitted and fixed to the outside of the ladder rods on both sides of the corresponding section of the ladder frame. The ladder rods are provided with locking holes for the locking pins to pass through.

[0017] Specifically, in the present invention, the term "and / or" indicates that the structure before "and / or" and the structure after "and / or" are set simultaneously or selectively.

[0018] The embodiments of this utility model can achieve at least the following beneficial effects: The linkage unlocking mechanism provided in this embodiment, during unlocking, causes the button on the step of the upper ladder frame to fall and contact the step of the lower ladder frame as the upper ladder frame falls naturally. The button of the upper ladder frame is compressed under the reverse force and slides upward relative to the step of that ladder frame. During this process, the button drives the protrusion of that ladder frame to move through the inclined slide groove, causing the locking pin to compress the spring along the axis and exit the connecting sleeve through the pin hole. This transmission process utilizes the inclined slide groove on the button, which forms an inclined sliding pair with the protrusion on the locking pin. The vertical movement of the button is converted into the horizontal axial movement of the locking pin through the track structure of the inclined slide groove and the protrusion. Compared with rotation drive, this ensures the smoothness and reliability of the unlocking action. In addition, the trigger response is sensitive, the unlocking action is smoother, and the user experience is improved (for specific usage, please refer to the detailed description in the specific implementation section of this application specification).

[0019] In addition, this utility model embodiment also provides several optional implementation methods. The specific implementation method section of this specification will provide a detailed description and explanation of the specific structure and functional effects of these optional implementation methods. Attached Figure Description

[0020] 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.

[0021] Figure 1 An isometric view of the overall structure of the linkage unlocking mechanism provided in this embodiment of the utility model; Figure 2 An exploded view of the linkage unlocking mechanism provided in an embodiment of this utility model; Figure 3 A schematic diagram of the assembly structure of the linkage unlocking component in the linkage unlocking mechanism provided in this embodiment of the utility model; Figure 4 for Figure 3Exploded view of the assembly structure shown Figure 1 ; Figure 5 for Figure 3 Exploded view of the assembly structure shown Figure 2 ; Figure 6 A front view of the overall structure of the linkage unlocking mechanism provided in this embodiment of the utility model; Figure 7 for Figure 6 Sectional view along axis AA; Figure 8 for Figure 7 Enlarged view of the local structure of region B in the middle; Figure 9 Top view of the overall structure of the linkage unlocking mechanism provided in this embodiment of the utility model; Figure 10 A bottom view of the overall structure of the linkage unlocking mechanism provided in this embodiment of the utility model; Figure 11 for Figure 10 CC-direction sectional view; Figure 12 for Figure 11 Enlarged view of the local structure of region D in the middle; Figure 13 A schematic diagram of the overall structure of the telescopic ladder in the closed state according to an embodiment of this utility model; Figure 14 A schematic diagram illustrating the unfolding process of the telescopic ladder provided in this embodiment of the utility model when it is unfolded from the closed state. Figure 15 A schematic diagram of the overall structure of the telescopic ladder after it has been fully extended and locked, according to an embodiment of this utility model. Figure 16 A schematic diagram of the closing process of the telescopic ladder provided in this embodiment of the present invention when it returns to the closed state from the unfolded state.

[0022] Icons: 100-Step bar; 200-Connecting sleeve; 210-Loop ring; 211-Elastic buckle; 220-Connecting block; 221-Limiting rib; 222-Guide groove; 300-Linkage unlocking component; 1-Button; 11-Inclined slide; 12-Guide block; 13-Long slot; 131-Bottom wall of slot; 132-Side wall of slot; 2-Locking pin; 21-Protrusion; 3-Spring; 4-Spring expansion container; 41-Receiving tube; 42-Insertion plate. Detailed Implementation

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] First aspect This embodiment provides a linkage unlocking mechanism, as shown in the following example. Figures 1 to 12 The linkage unlocking mechanism is used in telescopic ladders and includes a step 100, a connecting sleeve 200, and a linkage unlocking component 300.

[0031] Specifically, two connecting sleeves 200 are symmetrically fixed at both ends of the pedal 100. The connecting sleeves 200 are provided with pin holes that communicate with the inner cavity of the pedal 100. A set of linkage unlocking components 300 are respectively installed at both ends of the pedal 100.

[0032] Each set of linkage unlocking components 300 includes a button 1 and a linkage mechanism located within the inner cavity of the foot pedal 100. The linkage mechanism includes at least a locking pin 2 and a spring 3; the first end of the spring 3 is connected to the locking pin 2, and the second end of the spring 3 is relatively fixed to the inner cavity of the foot pedal 100. The button 1 is slidably mounted in an mounting opening on the lower surface of the foot pedal 100, and an inclined groove 11 is provided on the side wall of the button 1, such as... Figure 11 As shown, the inclined direction of the inclined slide groove 11 is such that its upper end is closer to the corresponding end of the connecting sleeve 200 than its lower end. When the central axis of the two inclined slide grooves 11 distributed at both ends of the pedal 100 is translated along the axial direction of the pedal 100, they can be combined into a "V" shape in the longitudinal plane. The side of the locking pin 2 is provided with a protrusion 21, which is slidably installed in the inclined slide groove 11. Under the action of the spring force of the spring 3, the end of the locking pin 2 away from the spring 3 extends into the connecting sleeve 200 through the pin hole. At the same time, the lower end of the button 1 is exposed outside the pedal 100. When the button 1 slides upward relative to the pedal 100, the inclined slide groove 11 drives the protrusion 21 to move, so that the locking pin 2 compresses the spring 3 along the axial direction and exits the connecting sleeve 200 through the pin hole.

[0033] Reference Figures 13 to 16 When applied to telescopic ladders, the telescopic ladder includes multiple ladder frames and multiple linkage unlocking mechanisms. Specifically, each ladder frame has a linkage unlocking mechanism installed on the outside of the ladder rods on both sides. The connecting sleeve 200 of the linkage unlocking mechanism is fitted and fixed to the outside of the ladder rods on both sides of the corresponding ladder frame. The ladder rods are provided with locking holes for the locking pin 2 to pass through.

[0034] When the user pulls the ladder upwards by one section, so that the locking hole on the upper section's ladder rod is aligned with the pin hole on the connecting sleeve 200 of the lower section, the locking pin 2 will automatically pop out through the pin hole and extend into the locking hole on the upper section's ladder rod under the action of the spring 3, thus locking the upper and lower sections of the ladder. This process does not require manual operation; it will automatically lock when pulled to the appropriate height, which is convenient and quick. At this time, the button 1 on the upper section of the two locked sections will not contact the step bar 100 on the lower section, and the lower end of the button 1 will protrude from the outside of the step bar 100. When unlocking, once the locking pin 2 of the bottommost ladder frame is unlocked, the ladder bar of the ladder frame above it loses support and begins to fall under its own weight. When the button 1 on the step bar 100 of the upper ladder frame falls and contacts the step bar 100 of the next ladder frame, the button 1 of the upper ladder frame is compressed under the reverse force and slides upward relative to the step bar 100 of that layer of ladder frame. During this process, the button 1 drives the protrusion 21 of that layer of ladder frame to move through the inclined slide groove 11, causing the locking pin 2 to compress the spring 3 axially and exit the connecting sleeve 200 through the pin hole. In this way, like dominoes, the ladder unlocks automatically one by one until all ladder frames are fully retracted and the ladder is closed. The user only needs to unlock the locking pin 2 of the bottommost ladder frame and then let the ladder retract automatically. The operation is simple.

[0035] like Figure 13 As shown, when the telescopic ladder is in a fully closed state, all buttons 1 are compressed, and the locking pins 2 are disengaged from the corresponding connecting sleeves 200.

[0036] like Figure 14 As shown, during the deployment of the telescopic ladder: If the fully extended height of the ladder is required, each ladder frame can be extended section by section from top to bottom. The connecting sleeves 200 at both ends of the ladder rod 100 of the extended ladder frame and the treads 100 of the next ladder frame are automatically locked by locking pins 2 to prevent them from falling. Each ladder frame is lifted layer by layer until the desired height is achieved. Figure 15 As shown, the locking pins 2 of the connecting sleeves 200 at both ends of the bottommost ladder frame automatically lock the ladder rods of the next bottommost ladder frame, and the ladder is fully unfolded. After being fully unfolded, the lower ends of all the buttons 1 are exposed outside the corresponding footboards 100.

[0037] like Figure 16 As shown, if the height of the ladder fully extended is not required, it can be extended upwards from the section above the bottom section. When the appropriate height is reached, the extended section will automatically lock and will not descend.

[0038] When the ladder needs to be closed, the user only needs to manually unlock the locking pin 2 of the bottom ladder frame, and the unfolded ladder frames will automatically fall and close.

[0039] It should be noted that, in this embodiment, the "bottommost ladder frame" refers to the last ladder frame related to the linkage unlocking mechanism. If the bottommost ladder frame is a ladder frame composed of multiple ladder frame units stacked on top of each other, the whole of these ladder frame units is called the "bottommost ladder frame".

[0040] In this embodiment, the linkage unlocking mechanism, when unlocking, causes the button 1 on the step bar 100 of the previous ladder frame to fall naturally and contact the step bar 100 of the next ladder frame. The button 1 of the previous ladder frame is compressed under the reverse action and slides upward relative to the step bar 100 of that ladder frame. During this process, the button 1 drives the protrusion 21 of that ladder frame to move through the inclined slide groove 11, causing the locking pin 2 to compress the spring 3 axially and exit the connecting sleeve 200 through the pin hole. This transmission process utilizes the inclined slide groove 11 on the button 1, which forms an inclined sliding pair with the protrusion 21 on the locking pin 2. The vertical movement of the button 1 is converted into the horizontal axial movement of the locking pin 2 through the track structure of the inclined slide groove 11 and the protrusion 21. Compared with rotation drive, this ensures the smoothness and reliability of the unlocking action. In addition, the trigger response is sensitive, the unlocking action is smoother, and the user experience is improved.

[0041] In an optional embodiment of this example, the connecting sleeve 200 includes a collar 210 and a connecting block 220 fixedly or integrally connected to the collar 210; a pin hole is provided on the side wall of the collar 210 facing the connecting block 220; the connecting block 220 and the pedal 100 are fitted together (the two are fitted together and are interference-fitted, snap-fitted, or fixedly connected by screws, pins, or other connecting parts); an installation cavity is provided inside the connecting block 220 that connects the pin hole and the inner cavity of the pedal 100; a limiting rib 221 is provided inside the installation cavity; a limiting groove is provided on the limiting rib 221; and the locking pin 2 is slidably disposed in this limiting groove. In this optional embodiment, the design of the connecting block 220 improves the stability of the mating part between the connecting sleeve 200 and the corresponding foot rod 100; the mounting cavity is provided with a limiting rib 221, and the limiting rib 221 is provided with a limiting groove. The locking pin 2 is slidably disposed in the limiting groove. Through the design of the limiting groove, the movement range of the locking pin 2 is limited, ensuring that the locking pin 2 does not deviate during the sliding process, so as to ensure that the locking pin 2 can normally extend into or exit the corresponding pin hole, and avoid structural failure caused by the inability to lock or unlock normally due to sliding deviation.

[0042] In an optional embodiment of this invention, the linkage unlocking mechanism further includes a spring expansion container 4, which includes a receiving tube 41 fixed to the inner wall of the mounting cavity. The second end of the spring 3 is inserted into and fixedly connected to the cavity of the receiving tube 41. In this optional embodiment, by setting the spring expansion container 4 and using the receiving tube 41 as the mounting tube of the spring 3, a specific assembly position is provided for the installation of the spring 3. This structural design makes the installation of the spring 3 simpler and more intuitive, reduces the assembly difficulty, and the fixed connection between the receiving tube 41 and the inner wall of the mounting cavity can effectively prevent the spring 3 from shifting or falling off during use, thus enhancing the transmission stability of the entire linkage unlocking mechanism.

[0043] Optionally, the spring expander 4 further includes an insert plate 42 sleeved around the receiving tube 41; a positioning rib is provided inside the mounting cavity, and a slot is provided on the side of the positioning rib. The upper part and side of the slot are provided with insertion openings, and the insert plate 42 is inserted into the slot through the insertion openings. In this optional embodiment, the cooperation between the insert plate 42 and the slot on the side of the positioning rib provides more precise positioning for the spring expander 4, which can effectively prevent the spring expander 4 from loosening due to vibration or external force during use.

[0044] In an optional embodiment of this example, a guide block 12 is provided on one side of the button 1, and a guide groove 222 is provided inside the mounting cavity. The guide block 12 is slidably installed inside the guide groove 222. In this optional embodiment, the guide block 12 serves two purposes: firstly, it guides the button 1 vertically to prevent it from tilting when sliding up and down; secondly, it serves as an anti-slip structure to prevent the button 1 from slipping off the mounting opening on the lower surface of the pedal 100 when sliding down. This anti-slip structure can also be other structures, including but not limited to a flange provided on any side wall of the button 1. The projection of the flange on the lower surface of the pedal 100 covers the mounting opening, so as to prevent the button 1 from slipping off the mounting opening when sliding down. Alternatively, a longitudinal spring extending in the vertical direction is provided and installed between the inner wall of the mounting cavity and the button 1 to prevent slippage. When the button 1 is compressed, the longitudinal spring is compressed.

[0045] In an optional embodiment of this invention, the diameter of the cavity of the receiving tube 41 is larger than the diameter of the locking pin 2. With the locking pin 2 withdrawn from the connecting sleeve 200 through the pin hole, the locking pin 2 is inserted into the cavity of the receiving tube 41. This optional embodiment avoids interference between the receiving tube 41 as the mounting tube of the spring 3 and the movement path of the locking pin 2, and prevents the locking pin 2 from failing to withdraw from the pin hole due to an excessively long receiving tube 41. This design reduces assembly precision and improves assembly efficiency. In an optional embodiment of this example, the top surface of the button 1 is provided with an elongated groove 13, and the locking pin 2 is inserted into the elongated groove 13. Further, optionally, the bottom wall 131 of the elongated groove 13 has a downwardly concave arc-shaped surface, and the side wall of the locking pin 2 facing the bottom wall 131 has an arc-shaped side wall matching the bottom wall 131. Optionally, the side walls 132 of the elongated groove 13 located on both sides of the bottom wall 131, and the side wall of the locking pin 2 facing the side wall 132, are all planar. In this optional embodiment, by optimizing the contact surface design of the elongated groove 13 and the locking pin 2, friction and wear are reduced, allowing the locking pin 2 to move smoothly within the elongated groove 13, making the up-and-down sliding of the button 1 smoother, and further improving the user experience.

[0046] In an optional embodiment of this invention, protrusions 21 are symmetrically provided on both radially opposite sides of the locking pin 2, and inclined grooves 11 are symmetrically provided on both radially opposite side walls of the button 1 along the locking pin 2. Each protrusion 21 is slidably installed inside the inclined groove 11 on the corresponding side. In this optional embodiment, the cooperation structure between the protrusions 21 and the inclined grooves 11 on both sides, as a symmetrical structural design, makes the force on the locking pin 2 within the button 1 more uniform, reducing the situation of excessive force on one side. This balance reduces shaking or radial offset of the locking pin 2, and improves the transmission stability of the linkage unlocking mechanism.

[0047] In an optional embodiment of this example, the side wall of the connecting sleeve 200 is provided with an elastic buckle 211 to provide sufficient clamping force to ensure a firm and reliable connection between the connecting sleeve 200 and the corresponding ladder rod.

[0048] Second aspect This embodiment also provides a telescopic ladder, as shown in the following figure. Figures 13 to 16 The telescopic ladder includes multiple ladder frames and multiple linkage unlocking mechanisms provided by any of the optional embodiments of the first aspect.

[0049] Each ladder frame has a linkage unlocking mechanism installed on the outside of the ladder rods on both sides. The connecting sleeve 200 of the linkage unlocking mechanism is fitted and fixed to the outside of the ladder rods on both sides of the corresponding ladder frame. The ladder rods are provided with locking holes for the locking pin 2 to pass through.

[0050] The specific structure and achievable effects of the telescopic ladder provided in this embodiment can be obtained by referring to the optional or preferred embodiments in the first aspect.

[0051] Finally, it should be noted that: 1. In this specification, "and / or" means that the structure before "and / or" and the structure after "and / or" are set simultaneously or selectively; 2. 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 are not intended 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 linkage unlocking mechanism applied to a telescopic ladder, characterized in that, Includes a foot pedal (100), a connecting sleeve (200), and a linkage unlocking component (300); Two connecting sleeves (200) are symmetrically fixed at both ends of the pedal (100), and the connecting sleeves (200) are provided with pin holes that communicate with the inner cavity of the pedal (100); Each end of the foot pedal (100) is equipped with a set of linkage unlocking components (300), and each set of linkage unlocking components (300) includes a button (1) and a linkage mechanism located in the inner cavity of the foot pedal (100). The linkage mechanism includes a locking pin (2) and a spring (3); the first end of the spring (3) is connected to the locking pin (2), and the second end of the spring (3) is fixed relative to the inner cavity of the foot pedal (100); The button (1) is slidably installed in the mounting opening on the lower surface of the foot pedal (100). An inclined groove (11) is provided on the side wall of the button (1). A protrusion (21) is provided on the side of the locking pin (2). The protrusion (21) is slidably installed in the inclined groove (11). Under the elastic force of the spring (3), the end of the locking pin (2) away from the spring (3) extends into the connecting sleeve (200) through the pin hole. At the same time, the lower end of the button (1) is exposed outside the pedal (100). When the button (1) slides upward relative to the pedal (100), the protrusion (21) is driven to move through the inclined groove (11), so that the locking pin (2) compresses the spring (3) axially and exits the connecting sleeve (200) through the pin hole.

2. The linked unlocking mechanism according to claim 1, characterized in that, The connecting sleeve (200) includes a collar (210) and a connecting block (220) that is fixedly or integrally connected to the collar (210). The pin hole is located on the side wall of the collar (210) facing the connecting block (220); The connecting block (220) is fitted with the foot pedal (100). The connecting block (220) has an installation cavity inside that connects the pin hole and the inner cavity of the foot pedal (100). The installation cavity has a limiting rib (221) inside, and a limiting groove is provided on the limiting rib (221). The locking pin (2) is slidably disposed in the limiting groove.

3. The linked unlocking mechanism according to claim 2, wherein, The linkage unlocking mechanism also includes a spring expansion container (4), which includes a receiving tube (41). The receiving tube (41) is fixed to the inner wall of the mounting cavity, and the second end of the spring (3) is inserted into and fixedly connected to the cavity of the receiving tube (41).

4. The linked unlocking mechanism according to claim 3, wherein, The spring expansion container (4) also includes an insert plate (42) sleeved on the outside of the receiving tube (41). A positioning rib is provided inside the mounting cavity, and a slot is provided on the side of the positioning rib. An insertion port is provided on the upper part and side of the slot, and the insertion plate (42) is inserted into the slot through the insertion port.

5. The linked unlocking mechanism of claim 3, wherein, A guide block (12) is provided on one side of the button (1), and a guide groove (222) is provided inside the mounting cavity. The guide block (12) is slidably installed inside the guide groove (222).

6. The linkage unlocking mechanism according to claim 3, characterized in that, The diameter of the cavity of the receiving tube (41) is larger than the diameter of the locking pin (2). When the locking pin (2) is out of the connecting sleeve (200) through the pin hole, the locking pin (2) is inserted into the cavity of the receiving tube (41).

7. The linkage unlocking mechanism according to claim 1, characterized in that, The top surface of the button (1) is provided with an elongated groove (13), and the locking pin (2) is inserted into the elongated groove (13); wherein: The bottom wall (131) of the long groove (13) has a downwardly concave arc-shaped surface, and the side wall of the locking pin (2) facing the bottom wall (131) has an arc-shaped side wall that matches the bottom wall (131). And / or, the sidewalls (132) of the groove (13) located on both sides of the bottom wall (131) of the groove body, and the sidewall of the locking pin (2) facing the sidewall (132) of the groove body are all planar.

8. The linked unlock mechanism of claim 1, wherein, The protrusions (21) are symmetrically arranged on the radially opposite sides of the locking pin (2), and the inclined grooves (11) are symmetrically arranged on the radially opposite sides of the button (1) along the locking pin (2). Each protrusion (21) is slidably installed inside the inclined groove (11) on the corresponding side.

9. The linked unlock mechanism of claim 1, wherein, The side wall of the connecting sleeve (200) is provided with an elastic buckle (211).

10. An extension ladder characterized by Includes a multi-section ladder frame and multiple linkage unlocking mechanisms as described in any one of claims 1 to 9; Each section of the ladder frame is equipped with a linkage unlocking mechanism on the outside of the ladder rods on both sides. The connecting sleeve (200) of the linkage unlocking mechanism is fitted and fixed to the outside of the ladder rods on both sides of the corresponding section of the ladder frame. The ladder rods are provided with locking holes for the locking pin (2) to pass through.

Images