Extension ladder
By improving the "bread-shaped" design of the ladder frame tube, the arc-shaped rungs, and the multi-point support structure, the problems of insufficient torsional resistance and rung comfort of existing telescopic ladders have been solved, achieving higher stability and safety.
Patent Information
- Application Number
- CN202520294246.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2025-01-24
- Filing Date
- 2025-02-21
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2035-02-21
AI Technical Summary
Existing telescopic ladders have weak torsional resistance in their frames and unreasonable step bar design, which makes them prone to deformation, swaying, and poor safety during use.
The ladder frame tube adopts a "bread-shaped" cross-section design, the surface of the tread is arc-shaped and equipped with concave and convex anti-slip ribs, the inner wall of the bracket insertion channel is equipped with multiple matching protrusions, and the side wall of the ladder frame tube is equipped with tough and wear-resistant baffles.
It significantly improves the ladder's torsional resistance and stability, enhances user comfort and safety, and adapts to the needs of more complex usage scenarios.
Smart Images
Figure CN223781389U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a telescopic ladder. BACKGROUND
[0002] Telescopic ladder is a common tool product, which is widely used in family, engineering and other fields. Its portability and adjustable length characteristics make it an ideal choice for high-altitude operation, maintenance, cleaning and other work. However, the telescopic ladders sold on the market still have some technical limitations, which affect their performance, safety and user experience.
[0003] The edge frame of the existing telescopic ladder is usually designed as a round pipe. Although this design simplifies the production process to some extent, the round pipe has weak torsional resistance, which leads to deformation or shaking of the ladder during use, affecting its stability and safety.
[0004] The sizes of the steps of the existing telescopic ladder are the same, and most of them are designed as flat surfaces. This structure not only has poor comfort when stepping, but also limits the load-bearing capacity of the steps, especially in high-intensity operations, which may pose a safety hazard. SUMMARY
[0005] The utility model aims to provide a telescopic ladder which enhances the torsional resistance of the ladder frame and improves the user's comfort when stepping.
[0006] The utility model is achieved as follows:
[0007] A telescopic ladder includes a telescopic ladder section, the telescopic ladder section includes at least two levels of telescopic ladder frames, each ladder frame includes a step, a support and a ladder frame pipe, the support is provided with a through-plug channel, the support side is provided with a connecting head, the inner wall of the plug channel is provided with at least four matching protrusions, and the upper end of the plug channel is provided with an inverted edge extending towards the center of the plug channel.
[0008] The upper end of each ladder frame pipe is inserted into the plug channel of the corresponding support through the lower end of the plug channel and abuts against the inverted edge, realizing the connection between the ladder frame pipe and the support, and the matching protrusions reduce the matching gap between the ladder frame pipe and the plug channel of the support, and the lower end of each ladder frame pipe is provided with a slow descent device.
[0009] The step is arranged between the ladder frame pipes, and the end of the step is connected to the corresponding connecting head.
[0010] The ladder frame pipe of the upper ladder frame is sleeved in the ladder frame pipe of the lower ladder frame, and the upper ladder frame and the lower ladder frame are provided with a folding mechanism, the folding mechanism locks or releases the unfolded state between the upper ladder frame and the lower ladder frame.
[0011] The size of the ladder frame tube of the upper ladder frame is smaller than the size of the ladder frame tube of the lower ladder frame.
[0012] The ladder frame tube comprises a first arc side plate, a straight side plate and a second arc side plate, one end of the straight side plate is connected to the first arc side plate, the other end of the straight side plate is connected to the second arc side plate, the connection between the straight side plate and the first arc side plate forms a first arc angle, and the connection between the straight side plate and the second arc side plate forms a second arc angle, so as to form a ladder frame tube with a cross section in the shape of a bread.
[0013] The surface of the step rod is an arc surface for facilitating stepping, and the size of the step rod of the telescopic ladder section increases with the increase of the size of the ladder frame tube.
[0014] The ladder frame tube adopts a design with a cross section in the shape of a bread, and a stable structure is formed through the combination of the first arc side plate, the straight side plate and the second arc side plate. Compared with the traditional circular tube design, the torsional resistance of the ladder frame tube is significantly improved, the stability and safety of the ladder are ensured, and the ladder performs more excellently under high load working conditions.
[0015] At least four matching protrusions are added to the inner wall of the insertion channel of the support, the matching protrusions reduce the matching gap between the ladder frame tube and the insertion channel of the support, further improve the safety, and the optimized design effectively improves the torsional resistance and assembly quality of the ladder frame, and prolongs the service life of the product.
[0016] The surface of the step rod is designed to be arc-shaped, which increases the comfort of foot contact and reduces fatigue during long-term use. At the same time, the size of the step rod increases with the increase of the size of the ladder frame tube, and different ladder frame tubes are configured with corresponding size step rods, which improves the load bearing capacity and ensures the safety under different use heights.
[0017] Through the optimized structure design, the telescopic ladder is not only suitable for general household work, but also can meet the high strength operation demand in professional engineering. The improvement of the torsional resistance, load bearing capacity and safety performance makes it can adapt to more complex scenes and improves the applicability of the product.
[0018] The purpose of the utility model can also be solved by the following technical measures:
[0019] Further, the step rod comprises an arc surface plate, a right angle plate and an inclined side plate, one end of the arc surface plate is connected to the right angle plate, the other end of the arc surface plate is connected to the inclined side plate, so as to form a step rod with a cross section in the shape of T, the surface of the arc surface plate is the arc surface, and the arc surface is provided with concave-convex anti-skid ribs at intervals.
[0020] The footboard adopts a "T-shaped" cross-sectional design, with the surface of the circular arc panel set as a circular arc shape, conforming to the foot structure and providing a more comfortable stepping experience. By setting the convex-concave anti-slip ribs, the anti-slip performance of the footboard surface is effectively increased, reducing the risk of slipping when used in wet and slippery environments.
[0021] Different ladder frame tubes are equipped with corresponding size footboards, and the width of the footboard increases with the size of the ladder frame tube, enhancing the load-bearing capacity of each level of footboard. This design better meets the demand for load-bearing performance as the ladder height increases, making the operation of ascending and descending the ladder more secure and stable, suitable for various work scenarios.
[0022] The circular arc stepping surface not only conforms to the foot structure, but also reduces the pressure on the feet during long-term work, significantly improving the comfort of the user. This design is particularly suitable for high-altitude work scenarios that require long-term standing or climbing.
[0023] By setting the convex-concave anti-slip ribs on the circular arc panel, the operational safety of users in various complex environments is effectively improved, especially in rainy or oily environments, significantly reducing the risk of slipping. In addition, the combination of circular arc, right-angle plate and bevel plate provides more stable support, further improving overall safety.
[0024] The design of footboards of different widths and sizes not only meets the needs of family use, but also can cope with more demanding professional scenarios such as engineering construction. As the size of the ladder frame increases, the width of the footboard increases synchronously, providing stable support for users operating at different heights, significantly improving the versatility of the ladder.
[0025] Further, the upper end of the insertion channel is provided with an inverted edge extending towards the center of the insertion channel, and the ladder frame tube is provided with a blocking block. The ladder frame tube of the upper level slides along the inner cavity of the ladder frame tube of the lower level until the blocking block rests on the inverted edge, and the ladder frame tubes of the upper and lower levels are in a fully expanded state.
[0026] The inner wall of the insertion channel of the bracket is provided with an inverted edge, which cooperates with the blocking block on the ladder frame tube to effectively limit the sliding range of the upper ladder frame tube. When the blocking block rests on the inverted edge, the ladder frame tubes of each level are in a fully expanded state. This design enhances the stability of the ladder after expansion and prevents the ladder frame tube from disengaging.
[0027] The cooperation of the inverted edge and the blocking block not only stabilizes the expanded state of the ladder frame tube, but also effectively prevents the ladder frame tube from accidentally disengaging due to external forces, significantly improving the safety of the ladder, especially in high-altitude operations.
[0028] The design of the inward flange and the blocking block has high universality, can adapt to ladder frame pipes of different sizes, and has simple structure and is easy to produce and assemble in modules. This optimized design reduces production cost while improving market adaptability of the product.
[0029] The innovative design of the inward flange and the blocking block effectively solves the problem of easy slipping and instability of traditional ladders during unfolding, significantly improving the safety and ease of use of the ladder.
[0030] Further, a wear-resistant and flexible blocking piece is provided on the side wall of the ladder frame pipe, and the blocking piece forms the blocking block.
[0031] By providing a wear-resistant and flexible blocking piece on the side wall of the ladder frame pipe to form the blocking block, the ladder frame pipe can be effectively prevented from coming off during stretching. When the blocking piece hits the inward flange of the support of the next ladder frame, the ladder frame pipe automatically stops stretching, achieving reliable anti-off function and greatly improving the safety performance of the ladder, especially in high-frequency use scenarios.
[0032] The direct anti-off structure of the traditional ladder frame pipe is prone to wear due to frequent use, increasing the cost of replacing parts. By using a wear-resistant blocking piece as the anti-off structure, the service life of the ladder frame pipe is extended, the risk of wear is reduced, the subsequent maintenance cost is reduced, and the durability of the ladder is improved.
[0033] The blocking piece can eliminate the gap between the upper ladder frame pipe and the lower ladder frame pipe, reducing the shaking or noise caused by loosening. This gap optimization design improves the overall stability of the ladder, making it more stable and safe during use.
[0034] The blocking piece plays a stable guiding role during the stretching of the ladder frame pipe, preventing the ladder frame pipe from deviating or jamming, making the ladder stretch more smoothly and efficiently.
[0035] The flexible blocking piece can adapt to stretching actions of different intensities while preventing off, and is wear-resistant and not easily damaged by environmental changes such as temperature or humidity. This design ensures that the ladder can maintain stable performance in various complex use environments.
[0036] The dual-function design of the blocking piece not only provides protection, but also takes into account the guiding and gap optimization functions, achieving one thing with multiple uses. This design not only improves the functionality of the ladder, but also further optimizes the overall structure, embodying the efficiency and innovation of the design.
[0037] Further, the center of the first circular arc side plate and the center of the second circular arc side plate are on the same straight line, the radius of the first circular arc side plate is greater than the radius of the second circular arc side plate, and the radius of the first circular arc angle is the same as the radius of the second circular arc angle.
[0038] The ladder frame pipe adopts a bread-shaped cross-section design, wherein the centers of the large circular arc of the first circular arc side plate and the small circular arc of the second circular arc side plate are on the same straight line, and the radius of the first circular arc angle and the radius of the second circular arc angle are the same. Such a structural design can effectively limit the relative rotation angle of the ladder frame pipe, significantly enhance the anti-torsion ability of the ladder, and make it more stable and reliable during use.
[0039] The cross-section design of the bread-shaped pipe combines two straight sides with circular arc sides of different sizes and four increasing circular angles, not only optimizing the stress distribution of the ladder frame pipe, but also reducing local stress concentration, thereby improving the overall carrying capacity and adapting to more complex working conditions.
[0040] The large circular arc side, small circular arc side and circular angle of each ladder frame pipe are designed according to the increasing rule, making the fitting clearance more accurate. The reduction of the fitting clearance effectively reduces the possible looseness and shaking during use, improving the use precision and comfort of the ladder.
[0041] The circular arc side and circular angle design of the ladder frame pipe cross-section not only helps to resist torsion, but also improves the smoothness of sliding between ladder frame pipes. Users can enjoy a smoother operation experience when stretching or folding the ladder, while reducing the phenomenon of jamming or blocking.
[0042] The design of the bread-shaped pipe is unique, combining the streamlined circular arc side and circular angle, not only making the appearance of the ladder more beautiful, but also increasing the sense of technology and professionalism of the product. Such a design better meets the aesthetic needs of users, further improving the market appeal of the product.
[0043] The ladder frame pipe with a bread-shaped cross-section can better resist deformation or damage that may occur during use through optimized structural design, prolonging the product life. At the same time, due to the improvement of anti-torsion ability and durability, the maintenance cost of the ladder is effectively reduced.
[0044] The unique bread-shaped cross-section design significantly distinguishes it from the common circular pipe structure on the market, not only making the ladder perform well in anti-torsion ability and carrying capacity, but also adapting to more complex environments and professional application scenarios, further improving the market competitiveness and user experience of the product.
[0045] Further, the fitting protrusions are arranged on the inner wall of the insertion channel of the bracket towards the position of the first circular arc angle, the position of the second circular arc angle, the position of the first circular arc side plate and the position of the second circular arc side plate.
[0046] The matching protrusions are arranged on the inner wall of the insertion channel of the support at the positions of the first circular corner, the second circular corner, the first circular edge plate and the second circular edge plate, so that the support and the ladder frame tube are more closely matched. This multi-point matching design effectively disperses the torsional moment, further enhances the anti-torsion ability of the ladder frame tube during use, and ensures that the ladder is more stable and reliable.
[0047] The reasonable distribution of the matching protrusions at the key stress points of the ladder frame tube can evenly disperse the pressure between the ladder frame tube and the support, avoid local overloading that causes wear or deformation, thereby prolonging the service life of the ladder and reducing the daily maintenance cost.
[0048] By adding matching protrusions at the positions of the first circular corner, the second circular corner and the circular edge plate, the gap between the support and the ladder frame tube is effectively reduced, so that the ladder does not shake or deviate.
[0049] The multi-point matching protrusion design makes the ladder frame tube more stable when subjected to lateral or torsional forces, reducing deformation or loosening problems caused by external forces. This design significantly improves the safety performance of the ladder, especially in high-load or high-frequency use scenarios.
[0050] The protrusions are distributed at specific positions of the first circular corner, the second circular corner and the edge plate, reflecting the refinement and scientific nature of the ladder design. This detailed matching design improves the technical content of the product, making the ladder more competitive in the market.
[0051] The improvement of the support matching protrusions enables the ladder to adapt to more complex working environments, including high-strength construction scenes or work sites that require frequent stretching and folding, providing users with a more stable and reliable use experience.
[0052] Compared with traditional support designs, this innovative design not only enhances the anti-torsion ability, but also optimizes the overall structural stability and durability, making the product stand out among similar products, further improving market competitiveness and user acceptance.
[0053] Further, the matching protrusions are seven.
[0054] The matching protrusions of the support are increased to seven, significantly improving the contact area and contact strength between the support and the ladder frame tube. The seven matching protrusions distributed by the new design evenly cover the key positions, effectively limiting the relative rotation angle of the ladder frame tube, and greatly improving the anti-torsion performance of the ladder.
[0055] The installation of the support is more secure, reducing the matching gap, while improving the stability and reliability of the ladder in complex working conditions, suitable for various high-strength operation scenarios.
[0056] The matching protrusions of the support are reasonably distributed, and force is evenly transmitted through seven matching points, avoiding assembly deformation caused by uneven force, and further improving the overall quality and durability of the product.
[0057] The newly added matching protrusions are distributed in the key stress area of the support, making the stress more uniform, reducing the wear rate between the ladder frame tube and the support, prolonging the service life of the ladder, and reducing the maintenance cost of the user.
[0058] Through the matching protrusions, the support of the ladder frame tube is more stable, which can effectively reduce the shaking risk caused by too large gap, especially when the ladder is fully expanded, further improving the overall safety performance of the ladder.
[0059] The seven-point matching design significantly improves the technical content of the ladder, not only enhances the torsional resistance, but also optimizes the stability and service life, making it more competitive in similar products and meeting the needs of users for high-performance ladders.
[0060] The beneficial effects of the utility model are as follows:
[0061] The utility model discloses a ladder frame tube adopts the design of the cross section being "bread-like", and through the combination of the first arc edge plate, the straight edge plate and the second arc edge plate, a stable structure is formed, compared with the traditional circular tube design, the structure significantly improves the torsional resistance of the ladder frame tube, guarantees the stability and durability of the ladder, and is particularly excellent under high-load operation conditions.
[0062] The utility model discloses a surface of the footrest is designed as an arc, increases the comfort of foot contact, reduces the fatigue feeling when using for a long time. Meanwhile, the size of the footrest gradually increases with the size of the ladder frame tube, and the footrest of different sizes is configured to different ladder frame tubes, which improves the bearing capacity and ensures the safety under different use heights.
[0063] The utility model discloses a support of the ladder frame tube is set with the fender that is good in toughness and wear -resisting, forms the blocking piece, can effectively avoid the ladder frame tube in the process of drawing and taking out. When the fender hits the inner turning edge of the support of the next ladder frame, the ladder frame tube stops drawing automatically, realizes reliable anti -drop function, greatly improves the safety performance of the ladder, and is particularly outstanding in high-frequency use scene.
[0064] The utility model discloses that the plug-in channel inner wall of support is set with matching protrusions at the position of the first arc angle, the second arc angle, the first arc edge plate and the second arc edge plate, so that the matching of the support and the ladder frame tube is more close. The multi-point matching design effectively disperses the torsional moment, further enhances the torsional resistance of the ladder frame tube in the use process, and ensures that the ladder is more stable and reliable. BRIEF DESCRIPTION OF DRAWINGS
[0065] Figure 1Fig. 1 is a schematic view of the extension ladder (folded state).
[0066] Figure 2 Fig. 2 is another angle schematic view of the extension ladder (folded state).
[0067] Figure 3 Fig. 3 is a front view of the extension ladder (folded state).
[0068] Figure 4 Fig. 4 is a detail of part A of Fig. 1. Figure 3
[0069] Figure 5 Fig. 5 is a detail of part B of Fig. 1. Figure 3
[0070] Figure 6 Fig. 6 is a sectional view of Fig. 1. Figure 3
[0071] Figure 7 Fig. 7 is a schematic view of the extension ladder (unfolded state).
[0072] Figure 8 Fig. 8 is another angle schematic view of the extension ladder (unfolded state).
[0073] Figure 9 Fig. 9 is a front view of the extension ladder (unfolded state).
[0074] Figure 10 Fig. 10 is a sectional view of Fig. 7.
[0075] Figure 11 Fig. 11 is a detail of part C of Fig. 7. Figure 10
[0076] Fig. 12 is a detail of part D of Fig. 7. Figure 12 Figure 10
[0077] Figure 13 Fig. 13 is a schematic view of the ladder frame.
[0078] Figure 14 Fig. 14 is an assembly view of the ladder frame.
[0079] Figure 15 Fig. 15 is a schematic view of the cross section of the ladder frame tube.
[0080] Figure 16 Fig. 16 is a schematic view of the cross section of the step bar.
[0081] Figure 17 Fig. 17 is a schematic view of the support.
[0082] Figure 18 Fig. 18 is another angle schematic view of the support.
[0083] Figure 19 Fig. 19 is a schematic view of the support.
[0084] Figure 20 Another angle view of the support.
[0085] Figure 21 Another angle view of the support. DETAILED DESCRIPTION
[0086] The utility model will be further described in connection with the drawings and embodiments:
[0087] Embodiments, in connection with Figures 1 to 21 As shown in the figure, a telescopic ladder comprises a telescopic ladder section 1 and a ladder foot section 2, the telescopic ladder section 1 comprises at least two levels of telescopic cooperation ladder frames 3, each level of ladder frame 3 comprises a step stick 4, a support 5 and a ladder frame tube 6,
[0088] The support 5 is provided with an upper and lower through plug-in channel 52, the side of the support 5 is provided with a connecting head 55, the inner wall of the plug-in channel 52 is provided with at least four cooperation protrusions 51 at intervals, and the upper end of the plug-in channel 52 is provided with an inverted edge 53 extending towards the center direction of the plug-in channel 52;
[0089] The upper end of each ladder frame tube 6 is inserted into the plug-in channel 52 of the corresponding support 5 through the lower end of the plug-in channel 52 and abuts on the inverted edge 53, realizing the connection of the ladder frame tube 6 and the support 5, and the cooperation protrusions 51 reduce the cooperation gap of the plug-in channel 52 of the ladder frame tube 6 and the support 5, and the lower end of each ladder frame tube 6 is provided with a slow descent device;
[0090] The step stick 4 is placed between the ladder frame tubes 6, and the end of the step stick 4 is connected to the corresponding connecting head 55 respectively;
[0091] The ladder frame tube 6 of the upper level of ladder frame 3 is sleeved in the ladder frame tube 6 of the lower level of ladder frame 3, and a folding mechanism is arranged between the upper level of ladder frame 3 and the lower level of ladder frame 3, the folding mechanism locks or releases the unfolded state between the upper level of ladder frame 3 and the lower level of ladder frame 3;
[0092] The ladder foot section 2 comprises a step stick 4, a support 5 and a ladder foot tube 21, the support 5 is arranged on the ladder foot tube 21, the step stick 4 is placed between the ladder foot tubes 21, and the end of the step stick 4 is connected to the connecting head 55 of the corresponding support 5 respectively;
[0093] The ladder frame tube 6 of the last level of ladder frame 3 is sleeved in the ladder foot tube 21 of the ladder foot section 2;
[0094] The size of the ladder frame tube 6 of the upper level of ladder frame 3 is smaller than the size of the ladder frame tube 6 of the lower level of ladder frame 3, and the size of the ladder frame tube 6 of the last level of ladder frame 3 is smaller than the size of the ladder foot tube 21;
[0095] The ladder frame tube 6 comprises a first arc edge plate 61, a straight edge plate 62 and a second arc edge plate 63, one end of the straight edge plate 62 is connected to the first arc edge plate 61, the other end of the straight edge plate 62 is connected to the second arc edge plate 63, and the connection between the straight edge plate 62 and the first arc edge plate 61 forms a first arc corner 64, and the connection between the straight edge plate 62 and the second arc edge plate 63 forms a second arc corner 65, thereby forming a "bread-shaped" cross-section of the ladder frame tube 6.
[0096] The surface of the step rod 4 is a circular arc surface 411 for easy stepping, and the size of the step rod 4 of the telescopic ladder section 1 increases with the increase of the size of the ladder frame tube 6.
[0097] Further, the step rod 4 comprises a circular arc surface plate 41, a right angle plate 42 and an inclined edge plate 43, one end of the circular arc surface plate 41 is connected to the right angle plate 42, and the other end of the circular arc surface plate 41 is connected to the inclined edge plate 43, thereby forming a "T-shaped" cross-section of the step rod 4, the surface of the circular arc surface plate 41 is the circular arc surface 411, and the circular arc surface 411 is provided with concave-convex anti-skid ribs 412 at intervals.
[0098] Further, the slow descent device comprises a bottom cover 7, the bottom cover 7 is arranged at the lower end of the ladder frame tube 6, and the bottom cover 7 is provided with air holes.
[0099] Further, the upper end of the insertion channel 52 of the support 5 is provided with an inverted edge 53 extending towards the center of the insertion channel 52, the ladder frame tube 6 is provided with a blocking block, the ladder frame tube 6 of the upper ladder frame 3 slides along the inner cavity of the ladder frame tube 6 of the lower ladder frame 3 until the blocking block abuts against the inverted edge 53, and the ladder frame tube 6 of the upper ladder frame 3 and the ladder frame tube 6 of the lower ladder frame 3 are in a fully unfolded state.
[0100] Further, it further comprises a good toughness and wear-resistant blocking piece 300, the blocking piece 300 is arranged on the side wall of the ladder frame tube 6, and the blocking piece 300 forms the blocking block.
[0101] Further, the center positions of the first arc edge plate 61 and the second arc edge plate 63 are on the same straight line, the radius of the first arc edge plate 61 is greater than the radius of the second arc edge plate 63, and the radii of the first arc corner 64 and the second arc corner 65 are the same.
[0102] Further, the inner wall of the insertion channel 52 of the support 5 is provided with the matching protrusions 51 towards the positions of the first arc corner 64, the second arc corner 65, the first arc edge plate 61 and the second arc edge plate 63.
[0103] Further, the matching protrusions 51 are seven.
[0104] Further, the connecting head 55 of each support 5 is internally provided with a receiving cavity 551, each support 5 is provided with a protruding part 54 facing the upper ladder frame 3, and each ladder frame tube 6 and ladder leg tube 21 is provided with a socket;
[0105] The folding mechanism comprises an automatic folding mechanism 8 and a manual folding mechanism 9, the penultimate rung 4 of the ladder leg section 2 is provided with the manual folding mechanism 9, and the rest of the ladder frames 3 are provided with the automatic folding mechanism 8;
[0106] The manual folding mechanism 9 comprises a second locking pin 91, a second spring 92 and a button 93, the second locking pin 91 is arranged in the receiving cavity 551 of the penultimate support 5 of the ladder leg section, the second spring 92 is sleeved on the second locking pin 91, one end of the second spring 92 abuts against the second locking pin 91, and the other end of the second spring 92 abuts against the inner wall of the receiving cavity 551, and the second spring 92 constitutes a reset mechanism of the second locking pin 91, and the button 93 is connected with the second locking pin 91;
[0107] The elastic force of the second spring 92 pushes the second locking pin 91 to pass through the support 5 and sequentially insert into the sockets of the last ladder frame tube 6 and the ladder leg tube 21, so as to lock the extension and contraction states of the last ladder frame tube 6 and the ladder leg tube 21;
[0108] The automatic folding mechanism 8 comprises a first locking pin 81, a first spring 82 and a lever 83, the first locking pin 81 is arranged in the receiving cavity 551 of the support 5 of the rest of the ladder frames 3, the first spring 82 is sleeved on the first locking pin 81, one end of the first spring 82 abuts against the first locking pin 81, and the other end of the first spring 82 abuts against the inner wall of the receiving cavity 551, and the first spring 82 constitutes a reset mechanism of the first locking pin 81, and one end of the lever 83 is connected with the first locking pin 81, and the other end of the lever 83 extends out of the rung 4 to form a lever part 831;
[0109] The elastic force of the first spring 82 pushes the first locking pin 81 to pass through the support 5 and sequentially insert into the sockets of the adjacent two ladder frame tubes 6, so as to lock the extension and contraction states of the adjacent two ladder frame tubes 6;
[0110] The button 93 is pressed, the button 93 drives the second locking pin 91 to move against the elastic force of the second spring 92, the second locking pin 91 moves away from the sockets of the last ladder frame tube 6 and the ladder leg tube 21, so that the last ladder frame tube 6 and the ladder leg tube 21 are in a free state;
[0111] The last ladder frame tube 6 slides into the inner cavity of the ladder leg tube 21 under the action of gravity;
[0112] Meanwhile, under the action of gravity, the pushing part 831 of the upper ladder frame 3 of the telescopic ladder section 1 touches the protruding part 54 of the lower ladder frame 3, and at the same time, the pushing part 831 drives the pushing rod 83 to move against the elastic force of the first spring 82, and the movement of the pushing rod 83 drives the first locking pin 81 to move away from the sockets of the adjacent two ladder frame tubes 6, so that the adjacent two ladder frame tubes 6 are in a free state.
[0113] The upper ladder frame tube 6 slides into the inner cavity of the lower ladder frame tube 6 under the action of gravity, and so on, to complete the stacking of the ladder frames 3 of the telescopic ladder section 1, and the anti-pinch gap 10 larger than the thickness of a palm is formed between the foot bar 4 of the upper ladder frame 3 and the foot bar 4 of the lower ladder frame 3.
[0114] Further, the bottom of the second-to-last foot bar 4 of the ladder foot section 2 is provided with a handle 100, the keys 93 are arranged on both sides of the handle 100, and the foot bar 4 of the first ladder frame 3 and the second-to-last foot bar 4 of the ladder foot section 2 are both provided with a binding belt 200.
[0115] The "bread-shaped" ladder frame tube 6 has the following advantages:
[0116] The "bread-shaped" design of the ladder frame tube 6 makes its shape round and the edges free of sharp corners, which not only makes it more beautiful, but also reduces the potential harm to the user during use, thereby improving the safety and user experience.
[0117] The "bread-shaped" cross section of the ladder frame tube 6 is composed of a first circular arc side plate 61, a second circular arc side plate 63 and a straight side plate 62, and the overall shape is symmetrical and compact. The distribution of the radii of the circular arc side plates increases the torsional rigidity of the pipe material, which can effectively disperse the torque and avoid deformation of the pipe material.
[0118] The straight side plate 62 connects the two circular arc side plates to form a strong support structure, which improves the bending strength of the ladder frame tube 6 and can withstand higher loads.
[0119] The arc surface design of the first circular arc side plate 61 and the second circular arc side plate 63 increases the contact area between the bracket 5 and the ladder frame tube 6, improves the fitting stability, and reduces the shaking and displacement caused by the gap.
[0120] The combination of the arc surface and the straight side enables the ladder frame tube 6 to resist both torsional force and bending force, thereby avoiding instability caused by a single stress mode during use.
[0121] In combination with the distribution characteristics of the protrusions 51:
[0122] Seven matching protrusions 51 are arranged on the inner wall of the insertion channel 52 of the bracket 5 at the key stress positions of the ladder frame tube 6 (the positions of the first circular arc corner 64, the second circular arc corner 65, the first circular arc side plate 61 and the second circular arc side plate 63). These protrusions are evenly distributed and precisely fit the "bread-shaped" structure of the cross section of the ladder frame tube 6.
[0123] The matching relationship between the ladder frame tube 6 and the support 5:
[0124] The ladder frame tube 6 of the current level is inserted into the insertion channel 52 of the corresponding support 5, realizing the connection of the ladder frame tube 6 and the support 5. The seven matching protrusions 51 form multi-point support and constraint for the ladder frame tube 6, and the distribution of the matching protrusions 51 is adapted to the shape of the ladder frame tube 6, providing comprehensive anti-torsion constraint.
[0125] The reason for the enhanced anti-torsion capability:
[0126] The seven matching protrusions 51 provide more contact points, which can more effectively limit the rotational freedom of the ladder frame tube 6 compared to the traditional design.
[0127] The matching protrusions 51 cover the key parts of the circular arc angle and the edge plate, so that the torque is dispersed to multiple support points, avoiding deformation or loosening caused by concentrated stress.
[0128] The matching protrusions 51 closely match the ladder frame tube 6, reducing the assembly gap and further enhancing the stability and anti-torsion performance of the structure.
[0129] The combination of the seven matching protrusions 51 of the support 5 and the "bread-like" ladder frame tube 6 fully utilizes the advantages of multi-point support and shape matching, greatly improving the anti-torsion capability of the ladder frame 3 and ensuring the stability and durability of the ladder frame 3 in use.
[0130] Structural features of the step bar 4:
[0131] Different ladder frame tubes 6 are equipped with corresponding size step bars 4, and the width of the step bar 4 increases with the size of the ladder frame tube 6, enhancing the load-bearing capacity of each level of the step bar 4. This design better meets the demand for load-bearing performance when the ladder height increases, making the operation of ascending and descending the ladder more safe and stable, and suitable for various work scenarios.
[0132] The circular arc-shaped tread surface not only fits the foot structure, but also reduces the pressure on the feet during long-term work, significantly improving the comfort of the user. This design is particularly suitable for high-altitude work scenarios that require long-term standing or climbing.
[0133] By setting the concave-convex anti-slip ribs 412 on the circular arc panel 41 at intervals, the operation safety of the user in various complex environments is effectively improved, especially in rainy or oily sites, which can significantly reduce the risk of slipping.
[0134] Benefits of the handle 100:
[0135] The handle 100 not only protects the keys 93 from external damage, but also facilitates the user to grip when carrying, enhancing the portability and practicality of the ladder.
[0136] The benefits of increasing the contact area of the button 93:
[0137] The increased contact area of the button 93 makes it easier to press compared to traditional designs, reducing the pressure on the hand during pressing and making the operation more comfortable and labor-saving for the user, further improving the user experience.
[0138] The benefits of the binding belt 200:
[0139] The binding belt 200 is provided on the last step ladder frame 3 and the second-to-last step ladder frame 4, which can be used to fix the ladder after folding to avoid loose state, improve the neatness and safety of storage.
[0140] The benefits of using the blocking piece 300:
[0141] By setting the blocking piece 300 with good toughness and wear resistance on the side wall of the ladder frame tube 6, a blocking block is formed, which automatically stops stretching when the blocking piece 300 hits the inner turning edge 53 of the support 5 of the next ladder frame 3, realizing reliable anti-falling function and greatly improving the safety performance of the ladder, especially in high-frequency use scenarios.
[0142] Using the wear-resistant blocking piece 300 as an anti-falling structure not only prolongs the service life of the ladder frame tube 6, but also reduces the risk of wear and tear, thereby reducing subsequent maintenance costs and improving the durability of the ladder.
[0143] The setting of the blocking piece 300 can eliminate the gap between the upper ladder frame tube 6 and the lower ladder frame tube 6, reducing the shaking or noise problem caused by loosening. This gap optimization design improves the overall stability of the ladder, making it more stable and safe during use.
[0144] The blocking piece 300 plays a stable guiding role during the stretching process of the ladder frame tube 6, avoiding the deviation or jamming of the ladder frame tube 6, making the ladder stretching more smooth and efficient.
[0145] Method for unfolding the telescopic ladder
[0146] Check the ladder status
[0147] Place the ladder horizontally or stand against the wall, untie the binding belt 200 that fixes the ladder, and ensure that the ladder frame 3 and the ladder foot section 2 are not damaged, and the button 93 and the locking pin are in normal working condition.
[0148] Unfold the ladder frame 3 step by step
[0149] Starting from the ladder foot section 2, pull the last ladder frame 3 upwards to make the ladder frame tube 6 slide out of the inner cavity of the ladder foot tube 21.
[0150] When the ladder frame tube 6 moves up to the limit position of the inner flange 53 in the support 5, the blocking block abuts against the inner flange 53, ensuring that the ladder frame 3 is fully unfolded.
[0151] At the same time, the second locking pin 91 is inserted into the sockets of the ladder leg tube 21 and the ladder frame tube 6 under the elastic force of the second spring 92, locking the telescopic state.
[0152] Unfold the other ladder frames 3 in sequence
[0153] Gradually lift the upper ladder frame tube 6 out of the lower ladder frame tube 6.
[0154] When each ladder frame tube 6 moves to the limit position of the support 5, the blocking block abuts against the inner flange 53, and the first locking pin 81 is automatically inserted into the sockets of the adjacent two ladder frame tubes 6 under the elastic force of the first spring 82, completing the locking.
[0155] Check the stability of unfolding
[0156] Confirm that each ladder frame 3 has been fully unfolded and locked, check whether the foot bar 4 is stable, and ensure the safety of the ladder.
[0157] Adjust the use angle
[0158] Adjust the placement angle of the ladder leg section 2 as needed to make the ladder stable and ensure safety.
[0159] Folding operation method of telescopic ladder
[0160] Start the manual folding mechanism 9
[0161] Press the keys 93 set on both sides of the handle 100 to overcome the elastic force of the second spring 92, and move the second locking pin 91 out of the sockets of the last ladder frame tube 6 and the ladder leg tube 21, releasing the locking state.
[0162] Under the action of gravity, the last ladder frame tube 6 slowly slides into the inner cavity of the ladder leg tube 21.
[0163] Trigger the automatic folding mechanism 8
[0164] When the last ladder frame 3 slides into the inner cavity of the ladder leg tube 21, the actuating part 831 touches the protruding part 54 of the support 5 connected to the second-to-last foot bar 4 of the ladder leg section 2.
[0165] The second-to-last foot bar 4 of the ladder leg section 2 and the foot bar 4 of the last ladder frame 3 form an anti-pinch gap 10 greater than the thickness of a palm, ensuring safety.
[0166] The actuating part 831 overcomes the elastic force of the first spring 82, drives the actuating rod 83 to move, and moves the first locking pin 81 out of the sockets of the adjacent two ladder frame tubes 6, releasing the locking.
[0167] Step by step folding ladder frame 3
[0168] Under the action of gravity, the second last ladder frame tube 6 slowly slides into the inner cavity of the last ladder frame tube 6.
[0169] Repeat the above process, ladder frame tube 6 step by step into the completion of all the ladder frame 3 stack.
[0170] Ensure safety against pinch
[0171] When the push part 831 of each ladder frame 3 touches the protruding part 54 of the next ladder frame 3, a safety anti-pinch gap 10 is formed, avoiding the injury of fingers during operation.
[0172] Complete folding and fixing
[0173] After all the ladder frame tubes 6 are completely folded, use the binding belt 200 to fix the foot bar 4 of the first ladder frame 3 and the second last foot bar 4 of the ladder foot section 2, to ensure that the ladder will not be loose during transportation or storage.
[0174] Check whether the handle 100 and the key 93 of the ladder are in normal state.
Claims
1. A telescopic ladder comprising a telescopic ladder section, the telescopic ladder section comprising at least two levels of telescopically coupled ladder frames, characterized in that: each ladder frame comprises a step bar, a support and a ladder frame tube, the support is provided with a through upper and lower insertion channel, the support side is provided with a connecting head, and the inner wall of the insertion channel is provided with at least four matching protrusions at intervals, and the upper end of the insertion channel is provided with an inward flange extending towards the center of the insertion channel; the upper end of each ladder frame tube is inserted into the insertion channel of the corresponding support through the lower end of the insertion channel and abuts against the inward flange, realizing the connection of the ladder frame tube and the support, and the matching protrusions reduce the matching gap between the ladder frame tube and the insertion channel of the support, and the lower end of each ladder frame tube is provided with a slow descent device; the step bar is arranged between the ladder frame tubes, and the ends of the step bar are connected to the corresponding connecting heads, respectively; the ladder frame tube of the upper level is sleeved on the ladder frame tube of the lower level, and a folding mechanism is arranged between the upper level and the lower level, the folding mechanism locks or releases the unfolded state between the upper level and the lower level; the size of the ladder frame tube of the upper level is smaller than that of the ladder frame tube of the lower level; the ladder frame tube comprises a first circular arc side plate, a straight side plate and a second circular arc side plate, one end of the straight side plate is connected to the first circular arc side plate, the other end of the straight side plate is connected to the second circular arc side plate, the connection between the straight side plate and the first circular arc side plate forms a first circular arc angle, the connection between the straight side plate and the second circular arc side plate forms a second circular arc angle, thereby forming a ladder frame tube with a "bread-like" cross section; the surface of the step bar is a circular arc surface for easy stepping, and the size of the step bar of the telescopic ladder section increases with the increase of the size of the ladder frame tube.
2. The extension ladder of claim 1, wherein: the step bar comprises a circular arc surface plate, a right angle plate and an inclined side plate, one end of the circular arc surface plate is connected to the right angle plate, the other end of the circular arc surface plate is connected to the inclined side plate, thereby forming a step bar with a "T-shaped" cross section, the surface of the circular arc surface plate is the circular arc surface, and the circular arc surface is provided with concave-convex anti-skid ribs at intervals.
3. The extension ladder of claim 1, wherein: the ladder frame tube is provided with a blocking block, the ladder frame tube of the upper level slides along the inner cavity of the ladder frame tube of the lower level until the blocking block abuts against the inward flange, and the ladder frame tube of the upper level and the ladder frame tube of the lower level are in a fully unfolded state.
4. The extension ladder of claim 3, wherein: a wear-resistant and flexible blocking piece is further included, the blocking piece is arranged on the side wall of the ladder frame tube, and the blocking piece forms the blocking block.
5. The extension ladder of claim 1, wherein: the center positions of the first circular arc side plate and the second circular arc side plate are on the same straight line, the radius of the first circular arc side plate is greater than the radius of the second circular arc side plate, and the radius of the first circular arc angle is the same as the radius of the second circular arc angle.
6. The extension ladder of claim 1, wherein: the inner wall of the insertion channel of the support is provided with the matching protrusions towards the positions of the first circular arc angle, the second circular arc angle, the first circular arc side plate and the second circular arc side plate.
7. The extension ladder of claim 6, wherein: the matching protrusions are seven.