High-molecular pedal module connecting structure special for long-service-life extension ladder

Abstract

The utility model discloses a special macromolecular pedal module connecting structure for a long-life extension ladder, which comprises a pedal body, the pedal body comprises a pedal positioned in the middle and sleeves positioned on two sides of the pedal and capable of being connected with an extension column, and the pedal body is integrally formed by macromolecular materials through a molding technology and cannot be separated. The pedal comprises a pedal shell module, a pedal reinforcing module and a pedal anti-skid module, the sleeve is provided with a sleeve shell, a telescopic column hoop and a sleeve reinforcing module, and the pedal is connected with the sleeve through a transition module. The telescopic ladder pedal is matched with the mechanical environment of the telescopic ladder pedal and the creep physicochemical property of a high polymer material, can be applied to the working environment where aluminum alloy and stainless steel are not suitable, and is low in cost and long in service life; the expansibility and replaceability are free, the defects that an aluminum alloy or stainless steel main pedal and hoop ring sleeves on the two sides are too many in working procedure, the die and material cost is too high, and appearance design is limited are overcome, and remarkable technical progress significance is achieved.

Description

Technical Field

[0001] The utility model relates to the field of telescopic ladder pedals, in particular to a special polymer pedal module connection structure for a long-life telescopic ladder. Background Art

[0002] The pedals of telescopic ladders are generally made of aluminum alloy or stainless steel. Metal has good dimensional stability and structural strength, can adapt to people's abuse of the pedals, and has good portability and safety. However, the connection between the aluminum alloy or stainless steel pedals and the telescopic rod body is inconvenient. The industry uses additional plastic connecting sleeves for connection. However, the industry currently has no plastic materials and structures to replace aluminum alloy or stainless steel pedals. This requires a lot of time, financial resources, energy and innovative power to try out new materials and their corresponding new structures. Different raw material characteristics and molding process limitations require the research and development of new structural forms to match them.

[0003] Creep characteristics of polymer materials: The creep of polymer materials is the phenomenon that the deformation of polymer materials gradually increases with time under the action of a certain temperature and a small constant external force (tension, pressure or torsion, etc.). The creep process includes the following three deformations: When a polymer material is subjected to an external force, the bond length and bond angle inside the molecular chain change immediately. This deformation is very small and is called general elastic deformation. The deformation that occurs when the molecular chain gradually stretches through the movement of the chain segment is called high elastic deformation. If there is no chemical cross-linking between molecules, relative slip will occur between linear polymers, which is called viscous flow. This flow is related to the bulk viscosity of the material. Below the glass transition temperature, the relaxation time of the chain segment movement is very long, and the internal friction resistance between molecules is very large, so general elastic deformation mainly occurs. Above the glass transition temperature, general elastic deformation and high elastic deformation mainly occur. When the temperature rises above the viscous flow temperature of the material, these three deformations are more significant. Since viscous flow cannot be restored, for linear polymers, when the external force is removed, a part of the deformation that cannot be restored will remain, which is called permanent deformation.

[0004] Fatigue characteristics of metal materials: Metal fatigue refers to the process in which materials and components gradually produce local permanent cumulative damage in one or several places under cyclic stress or cyclic strain, and cracks or sudden complete fractures occur after a certain number of cycles. When materials and structures are subjected to repeated changing loads, even if the stress value does not exceed the strength limit of the material, or even lower than the elastic limit, damage may occur. This phenomenon of material and structure damage under repeated alternating loads is called metal fatigue damage.

[0005] Therefore, because the fatigue properties of metal are completely different from the creep properties of polymer materials, when polymer materials are used instead of metal materials to make telescopic ladder pedals, conventional technical means cannot be directly used and referenced. The technical risks of blind substitution are very serious. Therefore, it is necessary to modify and design the telescopic ladder pedal structure that conforms to the characteristics of polymer materials, otherwise there will be serious failure risks.

[0006] CN208339291U discloses a foldable dining chair, including a seat, a connecting shaft, a footrest and a chair leg; the front leg, the rear leg, the backrest frame and the footrest, through the unique design of the matching structure at the connecting shaft, the use state of the dining chair is more diverse, the adjustment of the dining chair between various states and the overall folding operation are also easier; it has a lower processing cost. CN102811777A discloses a snowboard, which includes a slender board element, which has an upper surface, a lower surface and a pair of side edges, the pair of side brake pedals extend below the lower surface of the board element, and also provides a foot brake conversion accessory and a method for converting a conventional snowboard into a snowboard with a foot brake, so that skateboarders will be able to stand in any position they want, not just the sometimes awkward side-standing posture required by existing snowboards. CN108797908A discloses an assembled staircase and its installation method and construction method of a building project. The assembled staircase includes at least one middle section for stepping and climbing step by step, a top section for fixing the middle section with the upper ground or platform, and a first connecting device for fixing the middle section with the lower ground or platform. The middle section and / or the top section are assembled to form an integral structure; the connecting end surface of the middle section and the connecting end surface of the top section are connected and fixed by a first adjusting mechanism for controlling the longitudinal length of the assembled staircase. The integral components of the assembled staircase are assembled structures, and the length of the staircase is controlled by splicing the sections, which is convenient for installation, disassembly and transportation, and convenient for turnover and reuse. CN216741321U discloses a novel triangular insulating telescopic ladder that is easy to carry, comprising a supporting shell and a stopper, a non-slip base is fixed below the supporting shell, a non-slip sleeve is fixed above the telescopic rod, a pedal is connected to the side of the insulating device, a knob is arranged below the pedal, and a connecting rod is connected above the knob, the stopper is fixed to the side of the connecting rod, and a slot is arranged below the stopper. The portable insulating telescopic ladder is convenient for rapid telescopic operation, convenient for insulation protection measures, and convenient for anti-slip and stable measures during use. CN205330144U discloses a durable foot pedal with high safety for a building scaffold, comprising a flame retardant extruded foot pedal and a scaffolding pole, wherein the top surface of the flame retardant extruded foot pedal is provided with a wear-resistant coating, the top surface of the flame retardant extruded foot pedal is provided with neatly arranged anti-skid convex holes, the inner cavity of the flame retardant extruded foot pedal is provided with a reinforcement component, and the bottom of the flame retardant extruded foot pedal is densely and evenly distributed with buckles laterally arranged. The utility model has high safety, durability and long service life, high overall strength of the foot pedal, strong anti-aging and pressure resistance, making the foot pedal more durable, thereby extending its service life, preventing the foot pedal from breaking and causing collapse accidents when stepped on for a long time, effectively ensuring the personal safety of construction workers, and improving the safety of foot pedal use.CN209870252U discloses an anti-slip truck step ladder, whose structure includes a U-shaped rod, a handle cover, an armrest, a connecting piece, a rotating rod, a pedal, a first connecting strip, a balancing rod, a fixing device and a stable base. The utility model achieves a more stable connection between the step ladder and the truck, reduces the generation of safety hazards, greatly ensures the beneficial effects of use, and achieves that the bottom end of the step ladder is not easy to slide, reducing the generation of safety hazards. CN217564588U discloses a multi-layer co-extruded composite marine pedal, including a pedal body, a plurality of independent hollow chambers are arranged through the interior of the pedal body, a wear-resistant layer is arranged on the upper plane of the pedal body, a plurality of anti-skid protrusions are evenly arranged on the wear-resistant layer along the length direction of the pedal body, and a plurality of anti-skid grooves are evenly arranged on the anti-skid protrusions along the width direction of the pedal body; limiting protrusions are arranged in the hollow chambers on both sides of the pedal body, and a reinforcement layer is also arranged inside the pedal body; the utility model extends the service life of the marine pedal, improves the antioxidant ability, strength and anti-skid performance of the marine pedal, reduces the difficulty of production and manufacturing, and has low production costs, but the above design changes and innovations obviously do not take into account the ladder pedal structure and the characteristics of polymer materials in the use scenario of the telescopic ladder, and cannot be easily used in the field of telescopic ladder pedals.

[0007] In summary, when using polymer materials to replace aluminum alloy and stainless steel to make telescopic ladder pedals, it is necessary to significantly modify and verify the specific structural design of the pedals, and take appropriate and accurate preventive measures in advance. Conducting abuse risk tests and confirmation in advance can avoid a lot of losses and save a lot of regrets. To this end, we have studied a polymer pedal module connection structure specifically for long-life telescopic ladders. Summary of the invention

[0008] The purpose of the utility model is to overcome the above problems existing in the prior art and to provide a special polymer pedal module connection structure for a long-life telescopic ladder. When using polymer materials to replace aluminum alloy and stainless steel to make telescopic ladder pedals, the utility model also defines the target object according to the mechanical properties of the telescopic ladder, the stress deformation and material creep properties of the telescopic ladder pedals. Through special structural design, the mechanical environment of the telescopic ladder pedals and the creep physical and chemical properties of the polymer materials are matched, so that the adverse effects brought about by the material change can be overcome, the performance and safety of the polymer telescopic ladder pedals can be improved, and the production cost can be greatly reduced, the molding efficiency can be improved, and the disassembly and maintenance are convenient.

[0009] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0010] A polymer pedal module connection structure specially used for a long-life telescopic ladder comprises a pedal body, wherein the pedal body comprises a pedal located in the middle and sleeves located on both sides of the pedal and capable of being connected to a telescopic column. The pedal body is integrally formed from a polymer material by molding technology and is inseparable. The pedal comprises a pedal shell module, a pedal reinforcement module and a pedal anti-slip module. The sleeve is provided with a sleeve shell, a telescopic column hoop and a sleeve reinforcement module. The pedal and the sleeve are connected via a transition module.

[0011] Preferably, the housing module includes a tread surface shell located in the middle and a connection side shell located at the periphery of the tread surface.

[0012] Preferably, the pedal reinforcement module is one or more of a reinforcement rib group, a hole column, a convex and concave surface or a curved surface.

[0013] Preferably, the pedal anti-skid module is one or more of a raised bulge, a sunken groove, a rib combination, a frosted roughened surface or an insert capable of increasing friction.

[0014] Preferably, the sleeve shell can be provided with edging, grooves, protrusions, decorative textures and external hole column buckles.

[0015] Preferably, the telescopic column hoop is provided with a draft angle, the smallest diameter is at most 0.10 mm smaller than the diameter of the telescopic column, and the largest diameter is at most 5 mm larger than the diameter of the telescopic column. The surface of the telescopic column hoop facing the telescopic column can be provided with more than 3 clearance ribs with a width of 1-5 mm, a thickness of 0.5-2.5 mm, and an unlimited height.

[0016] Preferably, the sleeve reinforcement module is one or more of spoke-shaped distributed ribs, concentric ring-shaped distributed ribs, parallel rib groups, and mesh cross rib groups.

[0017] Preferably, the transition module includes process fillets, smooth transition surfaces, a common shell wall thickness and a tangent direct connection.

[0018] Preferably, the wall thickness design rules are also included. The wall thickness of the pedal housing module and the sleeve housing is the first step wall thickness, which is 2-8mm. The wall thickness of the ribs, protrusions and recesses, holes, edging and buckles is the second step wall thickness, which is 0.5-6mm. The average wall thickness of the second step wall thickness should be 0.6-0.8 times the average wall thickness of the first step wall thickness, and the partial second step wall thickness is allowed to be greater than the first step wall thickness.

[0019] Preferably, it also includes draft design rules. The draft angle is generally set to 0.25-1°. At the same time, it is necessary to ensure that the thickness of the thin end is greater than 0.5 mm, and the thickness of the thick end is not greater than 1.5 times the material wall thickness of the connection.

[0020] The beneficial effects of the utility model are:

[0021] Through special structural design, matching the mechanical environment of telescopic ladder pedals and the creep physical and chemical properties of polymer materials, and using polymer materials instead of aluminum alloy and stainless steel to make telescopic ladder pedals, it is possible to overcome the adverse effects of material changes, improve the performance and safety of polymer telescopic ladder pedals, and greatly reduce production costs, improve molding efficiency, facilitate disassembly and maintenance, and have a wide range of applications. It can be used for all movable telescopic step ladders, has strong weather resistance, is not afraid of acid and alkali corrosion, and can be used in working environments where aluminum alloy and stainless steel are not suitable. It has low cost and high freedom in appearance design, and can manufacture various complex appearance forms at low cost, and has a long service life; the expandability and replaceability of parts are also high, breaking through the inherent defects in the field of telescopic ladders, where the main pedals are made of aluminum alloy or stainless steel, and the two sides have to be connected with additional polymer hoop sleeves, there are too many production processes, the mold cost is too high, the material cost is too high, and the appearance design is restricted. It has significant technological progress and economic benefits.

[0022] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiment of the utility model with the accompanying drawings. The specific implementation method of the utility model is given in detail by the following embodiments and their drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0024] Figure 1 This is a schematic diagram of a telescopic ladder step axis side view of an embodiment of the utility model;

[0025] Figure 2 This is a schematic diagram of the axial side observation of the assembly relationship of the telescopic ladder steps of one embodiment of the utility model;

[0026] Figure 3 This is a cross-sectional schematic diagram of a pedal reinforcement module and an anti-skid module according to an embodiment of the utility model;

[0027] Figure 4 This is a cross-sectional schematic diagram of a pedal reinforcement module and an anti-skid module according to an embodiment of the utility model;

[0028] Figure 5 This is a cross-sectional schematic diagram of an anti-skid module according to an embodiment of the utility model;

[0029] Figure 6This is a cross-sectional schematic diagram of a telescopic column hoop sleeve reinforcement module according to an embodiment of the utility model;

[0030] Figure 7 This is a cross-sectional schematic diagram of a telescopic column hoop sleeve reinforcement module according to an embodiment of the utility model;

[0031] Figure 8 This is a schematic diagram of the overall structure design of the bottom of an embodiment of the utility model;

[0032] Fig. 9 This is a schematic diagram of the overall top structure design of an embodiment of the utility model;

[0033] Fig.10 This is a schematic diagram of the design of the bottom position structure of the sleeve in one embodiment of the utility model;

[0034] Fig.11 This is a schematic diagram of the top position structure design of the sleeve in one embodiment of the utility model;

[0035] Fig.12 This is a top view of a finished product after the telescopic ladder of one embodiment of the utility model is assembled;

[0036] Fig.13 It is a front schematic diagram of a finished product after the telescopic ladder of one embodiment of the utility model is assembled.

[0037] Explanation of the numbers in the figure: 1. pedal; 2. sleeve; 3. telescopic column; 4. transition module; 11. pedal shell module; 12. pedal reinforcement module; 13. pedal anti-skid module; 21. sleeve shell; 22. telescopic column hoop; 23. sleeve reinforcement module; 111. pedal surface shell; 112. connecting side shell; 121. reinforcing rib group; 122. hole column; 123. surface convex and concave; 124. arc-shaped surface; 131. raised bulge; 132. recessed groove; 133. rib combination; 134. frosted and roughened surface; 135. insert; 221. gap-removing rib; 231. spoke-shaped ribs; 232. concentric ring-shaped ribs; 233. parallel rib group; 234. mesh cross rib group. DETAILED DESCRIPTION

[0038] The utility model is further described below in conjunction with the accompanying drawings:

[0039] Reference Figures 1 to 13As shown in the figure, the polymer pedal module connection structure dedicated to the long-life telescopic ladder is integrally formed of polymer materials through molding technology. A reinforcing module for the outer surface of the ring is arranged around the pedal shell, a pedal anti-slip module is arranged on the front of the main stepping position of the pedal, and a main force anti-deformation reinforcing module is arranged on the back. An auxiliary anti-deformation reinforcing module is used to connect the outer surface reinforcing module of the ring and the main force anti-deformation reinforcing module. At the same time, a sleeve reinforcing module is also arranged at the sleeve of the telescopic ladder, and an auxiliary anti-deformation reinforcing module is also arranged at the connecting part of the pedal and the sleeve transition module. When designing specifically, the reinforcing module The blocks, anti-deformation modules and anti-skid modules are designed together, such as: lengthening and deepening the anti-skid module, so that the anti-skid module can naturally obtain a certain reinforcement effect and anti-deformation effect while improving the anti-skid performance; another example: adding reinforcing ribs, rib groups, arc-shaped surfaces, etc. to the anti-skid module or anti-deformation module or hole column can enhance the anti-skid performance and anti-deformation performance; another example: the surface convexity and concave are alternately raised bulges and sunken grooves, and connected with a combination of ribs, which can also improve the anti-skid effect, reinforcement effect and anti-deformation effect at the same time, and adding inserts, edging, decorative textures and external hole column buckles are also possible.

[0040] Because the utility model adopts polymer material injection molding or compression molding to batch produce finished products, a draft angle needs to be set along the demolding direction. In order to improve the pedal resistance and the service life of the mold, the pedal should not have sharp edges, and the edges and joints should be designed with process fillets and smooth transition surfaces as much as possible, and the shell wall thickness should be shared as much as possible.

[0041] According to the design rules of wall thickness, the wall thickness of the pedal housing module 11 and the sleeve housing 21 is the first step wall thickness, the first step wall thickness is 2-8mm, the wall thickness of the ribs, protrusions and recesses, holes and columns, edging and buckles is the second step wall thickness, the second step wall thickness is 0.5-6mm, the average wall thickness of the second step wall thickness should be 0.6-0.8 times the average wall thickness of the first step wall thickness, and some second step wall thicknesses are allowed to be greater than the first step wall thickness.

[0042] According to the draft design rules, the draft angle is generally set to 0.25-1°. At the same time, the thickness of the thin end must be greater than 0.5mm and the thickness of the thick end must not be greater than 1.5 times the material wall thickness of the connection.

[0043] The utility model has a wide scope of application and can be used for all movable step ladders. It has strong weather resistance and is not afraid of acid and alkali corrosion. It can be applied to working environments where aluminum alloy and stainless steel are not suitable. It has low cost and high freedom in appearance design. It can manufacture various complex appearance forms at low cost and has a long service life. The expandability and replaceability of parts are also high. It breaks through the defects in the field of telescopic ladders that the main pedal is made of aluminum alloy or stainless steel, and both sides are made of polymer hoop sleeves, there are too many production processes, the mold cost is too high, the material cost is too high, and there are many restrictions on appearance design. It has significant technological progress significance.

[0044] The above description is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention.

Claims

1. A polymer pedal module connection structure for a long-life telescopic ladder, comprising a pedal body, wherein the pedal body comprises a pedal located in the middle and sleeves (2) located on both sides of the pedal (1) and capable of being connected to a telescopic column (3), characterized in that: The pedal body is integrally formed of a polymer material by molding technology and is inseparable; the pedal (1) comprises a pedal housing module (11), a pedal reinforcement module (12) and a pedal anti-slip module (13); the sleeve (2) is provided with a sleeve housing (21), a telescopic column hoop (22) and a sleeve reinforcement module (23); the pedal (1) and the sleeve (2) are connected via a transition module (4).

2. The polymer pedal module connection structure for a long-life telescopic ladder according to claim 1 is characterized in that: The housing module (11) comprises a tread surface shell (111) located in the middle and a connection side shell (112) located at the periphery of the tread surface.

3. The polymer pedal module connection structure for a long-life telescopic ladder according to claim 1 is characterized in that: The pedal reinforcement module (12) is one or more of a reinforcement rib group (121), a hole column (122), a convex and concave surface (123), or an arc-shaped curved surface (124).

4. The polymer pedal module connection structure for a long-life telescopic ladder according to claim 1 is characterized in that: The pedal anti-skid module (13) is one or more of a raised bulge (131), a recessed groove (132), a rib combination (133), a frosted roughened surface (134), or an insert (135) capable of increasing friction.

5. The polymer pedal module connection structure for a long-life telescopic ladder according to claim 1 is characterized in that: The sleeve shell (21) can be provided with edging, grooves, protrusions, decorative textures and external hole column buckles.

6. The polymer pedal module connection structure for a long-life telescopic ladder according to claim 1 is characterized in that: The telescopic column hoop (22) is provided with a draft angle, and the smallest diameter is at most 0.10 mm smaller than the diameter of the telescopic column (3), and the largest diameter is at most 5 mm larger than the diameter of the telescopic column (3). The surface of the telescopic column hoop (22) facing the telescopic column (3) can be provided with more than three clearance-removing ribs (221) with a width of 1-5 mm, a thickness of 0.5-2.5 mm, and an unlimited height.

7. The polymer pedal module connection structure for a long-life telescopic ladder according to claim 1 is characterized in that: The sleeve reinforcement module (23) is one or more of spoke-distributed ribs (231), concentric ring-distributed ribs (232), a parallel rib group (233), and a mesh-shaped cross rib group (234).

8. The polymer pedal module connection structure for a long-life telescopic ladder according to claim 1 is characterized in that: The transition module (4) comprises a process fillet, a smooth transition curved surface, a common shell wall thickness and a tangent direct connection.

9. The polymer pedal module connection structure for a long-life telescopic ladder according to claim 1, characterized in that: The invention also includes design rules for wall thickness. The wall thickness of the pedal housing module (11) and the sleeve housing (21) is the first step wall thickness, which is 2-8 mm. The wall thickness of the ribs, convex and concave portions, hole columns, hemming and buckles is the second step wall thickness, which is 0.5-6 mm. The average wall thickness of the second step wall thickness should be 0.6-0.8 times the average wall thickness of the first step wall thickness. It is allowed that the wall thickness of some second steps is greater than the wall thickness of the first step.

10. The polymer pedal module connection structure for a long-life telescopic ladder according to claim 9, characterized in that: It also includes draft design rules. The draft angle is generally set to 0.25-1°. At the same time, it is necessary to ensure that the thickness of the thin end is greater than 0.5mm and the thickness of the thick end is no more than 1.5 times the material wall thickness of the connection.

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