Gravity self-adapting angle-adjusting ladder foot device and ladder

Abstract

The utility model provides a gravity self -adaptation angle regulation ladder foot device and ladder, relate to the technical field of ladders, including ladder foot block and rotating block, the lower surface of ladder foot block is plane, the upper surface of ladder foot block is formed first arc plane and goes up arch, rotating block is located the top of ladder foot block, the lower surface of rotating block is equipped with recessed second arc plane, and second arc plane and first arc plane friction fit, rotating block and ladder foot block two, one is equipped with arc convex, the other is equipped with arc sliding slot, and arc convex and arc sliding slot concave and convex and up and down limit position cooperation, rotating block can reciprocate swing relative to ladder foot block, and when swinging, second arc plane slides along first arc plane, and simultaneously, arc convex slides along arc sliding slot. The utility model can realize no matter what angle of inclination the ladder is in, the two upright column lower ends of its ladder frame can keep larger contact area with the ground, to stabilize the support ladder frame, thereby reduce the sliding risk in the process of using the ladder.

Description

Technical Field

[0001] This utility model relates to the technical field of ladders, and in particular to a gravity-adaptive angle-adjustable ladder foot device and a ladder. Background Technology

[0002] Ladders, as a common tool for working at heights, are widely used in various fields such as building maintenance, power construction, and home cleaning. A ladder consists of a frame and treads. Traditional ladders have two uprights whose lower ends directly contact the ground, or they have feet that provide support.

[0003] In existing technology, regardless of whether ladder feet are installed at the bottom of the two uprights of the ladder frame, the angle of the contact points with the ground is fixed and cannot be adjusted according to the ground conditions of the environment. When the ladder is used in special environments such as sloping ground, smooth tiles, or soft soil, the limited contact area between the bottom of the two uprights or ladder feet and the ground, and the inability to adaptively adjust the contact angle, can easily lead to instability in the ladder's support. Especially during the user's climbing process, slippage may occur, posing a safety hazard. Utility Model Content

[0004] The purpose of this invention is to provide a gravity-adaptive angle-adjustable ladder foot device and a ladder, so that no matter what inclination angle the ladder is at, the lower ends of the two uprights of the ladder frame can maintain a large contact area with the ground to stably support the ladder and reduce the risk of slippage during ladder use.

[0005] To achieve the above objectives, the embodiments of this utility model adopt the following technical solutions: In a first aspect, the present invention provides a gravity-adaptive angle-adjustable ladder foot device, which includes a ladder foot block and a rotating block; The lower surface of the trapezoidal foot block is flat, and the upper surface of the trapezoidal foot block arches upward to form a first arc-shaped surface; The rotating block is located at the top of the trapezoidal foot block; the lower surface of the rotating block is provided with a recessed second arc-shaped surface, which is in frictional engagement with the first arc-shaped surface; Of the rotating block and the trapezoidal foot block, one has an arc-shaped protrusion and the other has an arc-shaped sliding groove. The arc-shaped protrusion and the arc-shaped sliding groove are concave and convex and are limited in their upper and lower positions. The rotating block can swing back and forth relative to the trapezoidal foot block. During the swing, the second arc-shaped surface slides along the first arc-shaped surface, while the arc-shaped protrusion slides along the arc-shaped groove.

[0006] In an optional implementation, the first arcuate surface and the second arcuate surface are concentric spheres.

[0007] In an optional embodiment, one of the arc-shaped protrusion and the arc-shaped groove is disposed on the first arc-shaped surface, and the other is disposed on the second arc-shaped surface.

[0008] In an optional embodiment, the arc-shaped protrusion is disposed on the first arc-shaped surface, and the arc-shaped groove is disposed on the second arc-shaped surface.

[0009] In an optional embodiment, the rotating block includes two fasteners disposed opposite to each other on both sides of the arc-shaped protrusion. The two fasteners are respectively provided with arc-shaped grooves on the side surface facing the arc-shaped protrusion, and the arc-shaped grooves of the two fasteners are joined together to form the arc-shaped sliding groove.

[0010] In an optional embodiment, the arc-shaped groove is provided on the opposite surfaces of the two fasteners facing each other; Wherein: the arc-shaped protrusion and the first arc-shaped surface are spaced apart from each other, a portion of the arc-shaped protrusion in the width direction is slidably installed inside the arc-shaped groove of one of the fasteners, and another portion of the arc-shaped protrusion in the width direction is slidably installed inside the arc-shaped groove of another fastener; Alternatively, the upper end of the arc-shaped protrusion is provided with flanges extending to both sides in the width direction of the arc-shaped protrusion. One flange in the width direction of the arc-shaped protrusion is slidably installed inside the arc-shaped groove of one of the fasteners, and the other flange in the width direction of the arc-shaped protrusion is slidably installed inside the arc-shaped groove of another fastener.

[0011] In an optional embodiment, corner markings are provided on the ladder foot block.

[0012] In an optional embodiment, the gravity-adaptive angle-adjustable ladder foot device further includes an anti-slip structure disposed on the lower surface of the ladder foot block.

[0013] In an optional embodiment, the anti-slip structure includes a rubber pad fixedly connected to the lower end of the ladder block, and the lower surface of the rubber pad is provided with a plurality of anti-slip protrusions; or, the anti-slip structure is an anti-slip texture integrally formed on the lower surface of the ladder block.

[0014] Secondly, this utility model embodiment also provides a ladder, including a ladder frame and a gravity adaptive angle adjusting ladder foot device provided in any of the optional embodiments of the first aspect, wherein the upper end of the rotating block is fixedly installed on the lower end of the two uprights of the ladder frame.

[0015] When using the ladder, the bottom of the ladder foot block should face down and conform to the slope of the ground. Keep the ladder foot block in place and tilt the top of the ladder frame against the wall. During this process, the rotating block, under the influence of the ladder frame's own weight, follows the upright along the length of the arc-shaped protrusion relative to the ladder foot block to the required angle. During the swing, the second arc-shaped surface of the rotating block slides along the first arc-shaped surface of the ladder foot block to ensure stability during the swing. At the same time, the arc-shaped protrusion slides along the arc-shaped groove to define the swing path.

[0016] The gravity-adaptive angle-adjustable ladder foot device provided in this embodiment enables the ladder feet to automatically adapt and provide stable support in complex ground environments, significantly improving the safety and stability of the ladder when used on inclined or uneven ground, and has the following outstanding beneficial effects: (1) Automatic angle adjustment is achieved, ensuring maximum contact area during the process, effectively preventing slippage and overturning, and improving terrain adaptability: By utilizing the arc-shaped friction fit structure between the rotating block and the ladder foot block (i.e., the first arc-shaped surface and the second arc-shaped surface slide against each other), the rotating block can swing smoothly and stably relative to the ladder foot block. When the top of the ladder is tilted against the wall, the ladder frame and its uprights exert a downward torque on the rotating block due to their own weight, driving it to swing naturally along the arc-shaped path until it reaches a mechanical equilibrium position. This process does not require manual intervention and can achieve gravity-driven adaptive adjustment of the ladder foot angle. The lower surface of the ladder foot block is designed as a flat surface, always in contact with the ground during the adjustment process. No matter how the inclination angle of the ladder changes, the ladder foot block can maintain the maximum contact area with the ground. Compared with traditional ladder feet that are prone to point contact or edge contact with the ground, this significantly increases friction and fundamentally reduces the probability of slipping, tipping, and other safety accidents. It enhances the ladder's adaptability to different terrains (such as slopes, steps, and uneven ground). At the same time, compared with the traditional ladder feet that are prone to wear due to point contact, the ladder foot device provided by this utility model embodiment has a longer service life. (2) The dual-guide limiting mechanism ensures the reliability and safety of the motion: The interlocking structure of the arc-shaped protrusion and the arc-shaped groove serves as an auxiliary guide and upper / lower limiting mechanism between the rotating block and the trapezoidal foot block. This interlocking structure works in conjunction with the main friction pair formed by the two arc-shaped surfaces. On one hand, it constrains the lateral displacement and risk of disengagement of the rotating block during its swing, preventing instability. On the other hand, it controls the maximum swing angle range through physical limiting, avoiding excessive rotation that could lead to structural failure or loss of posture control. This dual constraint mechanism improves motion accuracy and repeatability, enhancing the reliability and safety of the trapezoidal foot device during use. (3) Flexible installation and strong compatibility, adaptable to various ladder structures: The upper part of the rotating block can be adapted to the uprights of ladder frames made of various materials such as aluminum alloy and steel, without affecting the structural strength of the original ladder frame, forming a modular design that is conducive to the rapid modification and upgrading of old and new ladders.

[0017] 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

[0018] 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.

[0019] Figure 1 A schematic diagram of the overall structure of the ladder provided in this embodiment of the utility model; Figure 2 for Figure 1 A partial enlarged view of the assembly structure of the ladder frame column and gravity adaptive angle adjustment ladder foot device shown in area A; Figure 3 This is an exploded view of the assembly structure of the ladder frame columns and the gravity-adaptive angle-adjustable ladder feet device from another perspective.

[0020] Icon: 100 - Gravity-adaptive angle adjustment ladder foot device; 1-Ladder foot block; 101-First arc surface; 2-Rotating block; 21-Fastener 1; 22-Fastener 2; 201-Second arc-shaped surface; 31-Arc-shaped protrusion; 32-Arc-shaped groove; 321-Arc-shaped groove one; 322-Arc-shaped groove two; 4-Corner Scale; 5-Anti-slip structure; 51-Rubber pad; 52-Anti-slip protrusion; 200 - Ladder frame; 210 - Column. Detailed Implementation

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] First aspect This embodiment provides a gravity-adaptive angle-adjustable ladder foot device 100, referring to... Figures 1 to 3A gravity-adaptive angle-adjustable ladder foot device 100 is applied to a ladder and installed at the lower ends of the two uprights 210 of its ladder frame 200. Specifically, the gravity-adaptive angle-adjustable ladder foot device 100 includes a ladder foot block 1 and a rotating block 2. The lower surface of the ladder foot block 1 is flat, and the upper surface of the ladder foot block 1 is arched upward to form a first arc-shaped surface 101. The rotating block 2 is located at the top of the ladder foot block 1. The lower surface of the rotating block 2 is provided with a recessed second arc-shaped surface 201, which frictionally engages with the first arc-shaped surface 101. One of the rotating block 2 and the ladder foot block 1 is provided with an arc-shaped protrusion 31, and the other is provided with an arc-shaped groove 32. The arc-shaped protrusion 31 and the arc-shaped groove 32 are concave and convex, and are vertically and vertically limited. The rotating block 2 can swing back and forth relative to the ladder foot block 1. During the swing, the second arc-shaped surface 201 slides along the first arc-shaped surface 101, while the arc-shaped protrusion 31 slides along the arc-shaped groove 32.

[0029] The upper end of the rotating block 2 of the gravity adaptive angle adjusting ladder foot device 100 is fixedly installed at the lower end of the two uprights 210 of the ladder frame 200. The fixed installation methods include, but are not limited to, the following: (1) insert the upper end of the rotating block 2 into the cavity corresponding to the lower end of the upright 210, and the upper end of the rotating block 2 and the lower end of the upright 210 are interference-fitted or fixedly connected by bolt and nut assembly; (2) fit the upper end of the rotating block 2 onto the outside of the lower end of the upright 210, and the upper end of the rotating block 2 and the lower end of the upright 210 are interference-fitted or fixedly connected by bolt and nut assembly; (3) weld the upper end of the rotating block 2 directly to the lower end of the upright 210; or use other fixed installation methods.

[0030] When using the ladder, the bottom surface of the ladder foot block 1 faces down and adapts to the ground slope to fit the ground. Keep the ladder foot block 1 in place and tilt the top of the ladder frame 200 against the wall. During the process, the rotating block 2, under the influence of the weight of the ladder frame 200, follows the column 210 and swings relative to the ladder foot block 1 along the length of the arc protrusion 31 to the required angle. During the swing, the second arc surface 201 of the rotating block 2 slides along the first arc surface 101 of the ladder foot block 1 to ensure stability during the swing. At the same time, the arc protrusion 31 slides along the arc groove 32 to define the swing path.

[0031] The gravity-adaptive angle-adjustable ladder foot device 100 provided in this embodiment realizes automatic adaptation and stable support of the ladder feet in complex ground environments, significantly improving the safety and stability of the ladder when used on inclined or uneven ground, and has the following outstanding beneficial effects: (1) Automatic angle adjustment is achieved, ensuring maximum contact area during the process, effectively preventing slippage and overturning, and improving terrain adaptability: By utilizing the arc-shaped friction fit structure between the rotating block 2 and the ladder foot block 1 (i.e., the first arc surface 101 and the second arc surface 201 slide against each other), the rotating block 2 can swing smoothly and stably relative to the ladder foot block 1. When the top of the ladder is tilted against the wall, the ladder frame 200 and its uprights 210 exert a downward torque on the rotating block 2 due to their own weight, driving it to swing naturally along the arc path until it reaches the mechanical equilibrium position. This process does not require manual intervention and can achieve gravity-driven adaptive adjustment of the ladder foot angle. The lower surface of the ladder foot block 1 is designed as a plane and always contacts the ground during the adjustment process. No matter how the inclination angle of the ladder changes, the ladder foot block 1 can maintain the maximum contact area with the ground. Compared with traditional ladder feet that are prone to point contact or edge contact with the ground, this significantly increases friction and fundamentally reduces the probability of slipping, tipping and other safety accidents. It enhances the ladder's adaptability to different terrains (such as slopes, steps, uneven ground). At the same time, compared with the traditional ladder feet that are prone to wear due to point contact, the ladder foot device provided in this embodiment has a longer service life. (2) The dual-guide limiting mechanism ensures the reliability and safety of the motion: The concave-convex mating structure of the arc-shaped protrusion 31 and the arc-shaped groove 32 serves as an auxiliary guide and upper / lower limiting mechanism between the rotating block 2 and the trapezoidal foot block 1. This concave-convex mating structure works in conjunction with the main friction pair formed by the two arc-shaped surfaces. On the one hand, it constrains the lateral displacement and risk of disengagement of the rotating block 2 during the swinging process, preventing motion instability. On the other hand, it controls the maximum swing angle range through physical limiting, avoiding excessive rotation that could lead to structural failure or loss of attitude control. This dual constraint mechanism improves motion accuracy and repeatability, enhancing the reliability and safety of the trapezoidal foot device during use. (3) Flexible installation and strong compatibility, adaptable to various ladder structures: The upper part of the rotating block 2 can be adapted to the uprights of ladder frames made of various materials such as aluminum alloy and steel, without affecting the structural strength of the original ladder frame, forming a modular design, which is conducive to the rapid modification and upgrading of new and old ladders.

[0032] In an optional embodiment of this example, the first arc-shaped surface 101 and the second arc-shaped surface 201 are concentric spherical surfaces. In this optional embodiment, since the first arc-shaped surface 101 and the second arc-shaped surface 201 have the same center of gravity, they form a coaxial and concentric spherical mating structure. This concentric design ensures that during the rotation of the rotating block 2 relative to the ladder foot block 1, the load is symmetrically transmitted radially along the center of gravity, avoiding the generation of additional bending moments or torsional forces. This not only improves the smoothness and structural stability during the movement process, but also effectively reduces local stress concentration during long-term reciprocating oscillation motion, thereby delaying the wear of the rotating block 2 and the ladder foot block 1 and improving the service life of the ladder foot device.

[0033] In an optional embodiment of this invention, one of the arc-shaped protrusion 31 and the arc-shaped groove 32 is located on the first arc-shaped surface 101, and the other is located on the second arc-shaped surface 201. This design makes the assembly process more intuitive and simple, and can quickly achieve the alignment and fixation of the two components, the rotating block 2 and the ladder foot block 1, reducing complex adjustment steps and improving assembly efficiency.

[0034] For ease of assembly, preferably, the arc-shaped protrusion 31 is provided on the first arc-shaped surface 101, and the arc-shaped groove 32 is provided on the second arc-shaped surface 201. Further optionally, referring to... Figure 3 The rotating block 2 includes two fasteners, fastener 1 21 and fastener 22, which are disposed opposite each other on both sides of the arc-shaped protrusion 31. Each fastener has an arc-shaped groove on its surface facing the arc-shaped protrusion 31. The arc-shaped grooves of the two fasteners are joined together to form an arc-shaped sliding groove 32. In this optional embodiment, by inserting the arc-shaped protrusion 31 into the arc-shaped sliding groove 32 formed by the two fasteners, the assembly complexity of the rotating block 2 and the ladder-foot block 1 is further simplified, thereby further improving assembly efficiency. The fixing methods between fastener 1 21 and fastener 22 include, but are not limited to, snap-fitting, or fixing with fasteners such as screws or bolt-nut assemblies.

[0035] To improve the swing stability of the rotating block 2 relative to the trapezoidal foot block 1, in an optional embodiment of this invention, the aforementioned arc-shaped groove 32 is provided on the opposing surfaces of the two fasteners, i.e., as shown... Figure 3 The arc-shaped groove 321 of fastener 21 and the arc-shaped groove 322 of fastener 22 are shown. The arc-shaped groove 321 and the arc-shaped groove 322 are joined together to form an arc-shaped sliding groove 32. Based on this, the specific cooperation methods between the arc-shaped sliding groove 32 and the arc-shaped protrusion 31 include at least the following two: Cooperation method one: The arc-shaped protrusion 31 and the first arc-shaped surface 101 are spaced apart. A portion of the arc-shaped protrusion 31 in the width direction is slidably installed inside the arc-shaped groove of one fastener, and another portion in the width direction is slidably installed inside the arc-shaped groove of another fastener. Cooperation method two: The upper end of the arc-shaped protrusion 31 is provided with flanges extending to both sides in the width direction of the arc-shaped protrusion 31. One flange in the width direction of the arc-shaped protrusion 31 is slidably installed inside the arc-shaped groove of one fastener, and the other flange in the width direction of the arc-shaped protrusion 31 is slidably installed inside the arc-shaped groove of another fastener. In this embodiment, by setting the arc-shaped groove 32 on the opposite surfaces of the two fasteners, it can be ensured that the arc-shaped protrusion 31 is always evenly supported by both sides during the swinging process, thereby improving the stability and accuracy of the swinging. This design reduces the shaking and offset during the swinging process, making the relative movement between the rotating block 2 and the ladder foot block 1 smoother and more reliable.

[0036] In an optional embodiment of this example, corner markings 4 are provided on the ladder foot block 1. The design includes, but is not limited to, the ladder foot block 1 being an injection-molded part, with the corner markings 4 integrally injection-molded with the ladder foot block 1; or, the corner markings 4 being printed, pasted, or engraved on the surface of the ladder foot block 1. Correspondingly, angle indicator arrows can be designed on the rotating block 2, but are not limited to, the rotating block 2 being an injection-molded part, with the angle indicator arrows integrally injection-molded with the rotating block 2; or, the angle indicator arrows being printed, pasted, or engraved on the surface of the rotating block 2. This allows the user to know the current tilt angle of the ladder at any time, eliminating the need for an inclinometer. For example, the standard safe working tilt angle for a ladder against a wall is typically 65°~75°. When setting up the ladder, simply observing the angle indicator arrows to ensure the tilt angle is between 65°~75° meets safety requirements; angles exceeding this range constitute a dangerous usage condition, further improving the safety of ladder use. In addition, the corner scale 4 and the angle indicator arrow can be coated with eye-catching paint to clearly mark the corner scale. The corner scale 4 and the angle indicator arrow can be designed to be visible in the dark or reflect light. The design method includes, but is not limited to, coating with special paint or using special materials to adhere to the ladder foot block 1 and the rotating block 2 so that the corner scale 4 and the angle indicator arrow are clearly visible in the dark.

[0037] To further improve the anti-slip effect when the ladder is tilted, in an optional embodiment of this example, the gravity-adaptive angle adjustment ladder foot device 100 further includes an anti-slip structure 5 disposed on the lower surface of the ladder foot block 1. Specifically, in some optional embodiments of this example, the anti-slip structure 5 includes a rubber pad 51 fixedly connected to the lower end of the ladder foot block 1. The lower surface of the rubber pad 51 is provided with multiple anti-slip protrusions 52. The rubber pad 51 may be made of rubber material, but is not limited to rubber. The connection method of fixing it to the ladder foot block 1 includes, but is not limited to, bonding, snap-fitting, or fixing with fasteners such as screws or bolt-nut assemblies. In other optional embodiments of this example, the anti-slip structure 5 is an anti-slip texture integrally disposed on the lower surface of the ladder foot block 1. The integral disposal method includes, but is not limited to, etching or integral molding using an injection molding process.

[0038] Second aspect This embodiment provides a ladder, which includes a ladder frame 200 and a gravity-adaptive angle-adjustable ladder foot device 100 provided in any optional embodiment of the first aspect. The upper end of the rotating block 2 of the gravity-adaptive angle-adjustable ladder foot device 100 is fixedly installed at the lower end of the two uprights 210 of the ladder frame 200. The fixed installation methods include, but are not limited to, the following: (1) inserting the upper end of the rotating block 2 into the cavity corresponding to the lower end of the upright 210, with the upper end of the rotating block 2 and the lower end of the upright 210 being interference-fitted or fixedly connected by a bolt and nut assembly; (2) fitting the upper end of the rotating block 2 onto the outside of the lower end of the upright 210, with the upper end of the rotating block 2 and the lower end of the upright 210 being interference-fitted or fixedly connected by a bolt and nut assembly; (3) directly welding the upper end of the rotating block 2 to the lower end of the upright 210; or using other fixed installation methods.

[0039] When the above method (1) is used: the upper end of the rotating block 2 is inserted into the cavity corresponding to the lower end of the column 210, and the upper end of the rotating block 2 and the lower end of the column 210 are interference-fitted or fixedly connected by bolt and nut assembly, preferably, a boss is provided on the outside of the rotating block 2 so that the lower end face of the column 210 abuts against the upper surface of the boss, thereby achieving installation positioning and making the installation more stable.

[0040] The specific structure and achievable effects of the ladder provided in this embodiment can be obtained by referring to the optional or preferred implementation methods in the first aspect.

[0041] Finally, it should be noted that 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 not 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 gravity-adaptive angle-adjustable ladder leg device, characterized in that, Includes a ladder foot block (1) and a rotating block (2); The lower surface of the trapezoidal foot block (1) is flat, and the upper surface of the trapezoidal foot block (1) is arched upward to form a first arc-shaped surface (101). The rotating block (2) is located at the top of the ladder block (1); the lower surface of the rotating block (2) is provided with a recessed second arc surface (201), and the second arc surface (201) is in frictional engagement with the first arc surface (101); Of the rotating block (2) and the trapezoidal foot block (1), one is provided with an arc-shaped protrusion (31) and the other is provided with an arc-shaped groove (32). The arc-shaped protrusion (31) and the arc-shaped groove (32) are concave and convex and are matched with upper and lower limits. The rotating block (2) can swing back and forth relative to the ladder block (1). When swinging, the second arc surface (201) slides along the first arc surface (101), and the arc protrusion (31) slides along the arc groove (32).

2. The gravity-adaptive angle-adjustable ladder leg device according to claim 1, characterized in that, The first arc surface (101) and the second arc surface (201) are concentric spheres.

3. The gravity-adaptive angle-adjustable ladder leg device according to claim 1, characterized in that, One of the arc-shaped protrusion (31) and the arc-shaped groove (32) is provided on the first arc-shaped surface (101), and the other is provided on the second arc-shaped surface (201).

4. The gravity-adaptive angle-adjustable ladder leg device according to claim 3, characterized in that, The arc-shaped protrusion (31) is provided on the first arc-shaped surface (101), and the arc-shaped groove (32) is provided on the second arc-shaped surface (201).

5. The gravity-adaptive angle-adjustable ladder leg device according to claim 4, characterized in that, The rotating block (2) includes two fasteners disposed opposite to each other on both sides of the arc-shaped protrusion (31). The two fasteners are respectively provided with arc-shaped grooves on the side surface facing the arc-shaped protrusion (31). The arc-shaped grooves of the two fasteners are joined together to form the arc-shaped slide groove (32).

6. The gravity-adaptive angle-adjustable ladder leg device according to claim 5, characterized in that, The arc-shaped groove (32) is provided on the opposite surfaces of the two fasteners facing each other; Wherein: the arc-shaped protrusion (31) and the first arc-shaped surface (101) are spaced apart from each other, a portion of the arc-shaped protrusion (31) in the width direction is slidably installed in the arc-shaped groove of one of the fasteners, and another portion of the arc-shaped protrusion (31) in the width direction is slidably installed in the arc-shaped groove of another fastener; Alternatively, the upper end of the arc-shaped protrusion (31) is provided with flanges extending to both sides of the width direction of the arc-shaped protrusion (31). The flange on one side of the width direction of the arc-shaped protrusion (31) is slidably installed inside the arc-shaped groove of one of the fasteners, and the flange on the other side of the width direction of the arc-shaped protrusion (31) is slidably installed inside the arc-shaped groove of another fastener.

7. The gravity-adaptive angle-adjustable ladder leg device according to any one of claims 1-5, characterized in that, Angle markings (4) are provided on the step block (1).

8. The gravity-adaptive angle-adjustable ladder leg device according to any one of claims 1-5, characterized in that, The gravity-adaptive angle-adjustable ladder foot device also includes an anti-slip structure (5) disposed on the lower surface of the ladder foot block (1).

9. The gravity-adaptive angle-adjustable ladder leg device according to claim 8, characterized in that, The anti-slip structure (5) includes a rubber pad (51) fixedly connected to the lower end of the ladder block (1), and the lower surface of the rubber pad (51) is provided with a plurality of anti-slip protrusions (52); or, the anti-slip structure (5) is an anti-slip texture integrally provided on the lower surface of the ladder block (1).

10. A ladder, characterized in that, Includes a ladder frame (200) and a gravity adaptive angle adjusting ladder foot device (100) as described in any one of claims 1-9, wherein the upper end of the rotating block (2) is fixedly installed at the lower end of the two columns (210) of the ladder frame (200).

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