Ladder foot

Abstract

The utility model discloses a ladder foot capable of switching states, which comprises a main shell used for being connected with the lower end of a ladder rod, and an anti-skidding part arranged at the lower end of the main shell; the moving wheel is arranged on one side of the main shell, and the moving wheel can be operated to move between a first position and a second position higher than the first position in the linear direction; when the moving wheel is located at the first position, the lowest point of the moving wheel is lower than the anti-skid part, so that the moving wheel provides support; the moving wheels are higher than the anti-skid parts when located at the second positions so that the anti-skid parts can provide support.

Description

Technical Field

[0001] The present application relates to the field of supporting components, and in particular to a ladder foot. Background Art

[0002] Ladders are commonly used to provide their users with improved access to locations that may not be directly accessible. Ladders come in many shapes and sizes, such as straight ladders, straight extension ladders, and combination step and telescoping ladders (referred to herein as combination ladders). Combination ladders incorporate many of the advantages of other ladder designs in a single ladder, as they can be used as either an adjustable step stool or an extension ladder.

[0003] Since the engineering combination ladder has two ladders, an inner ladder and an outer ladder, and has many pedals, it is heavy and therefore difficult to carry. For example, the ladder disclosed in US10501990B2 has wheels installed at the ladder feet for easy carrying. The use process of the ladder is as follows: when it is limited by site conditions and the distance requirement cannot be met by operating on the ladder alone, the added wheels are lowered so that the ladder can move forward and backward. After the movement is completed, the wheels can be put away and the ladder can be used normally.

[0004] However, the wheels configured for the engineering combination ladder need to be rotated to be folded and lowered, and the switching operation requires a large space. It is difficult to complete the state switching in the corner position. In addition, when the wheels are lowered to support the ladder, manual assistance is required to lift the ladder and then lower the wheels. The operation is complicated and increases the intensity of manual work. Utility Model Content

[0005] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a ladder foot to facilitate the ladder to switch between a normal state and a moving state.

[0006] One purpose of the utility model is to provide a ladder foot with switchable states so as to reduce the switching operation space.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A ladder foot, comprising:

[0009] A main housing for connecting the lower end of the ladder beam, wherein the lower end of the main housing is provided with an anti-slip portion;

[0010] A moving wheel is arranged on one side of the main shell, and the moving wheel can be manipulated to move between a first position and a second position higher than the first position; when the moving wheel is at the first position, the lowest point of the moving wheel is lower than the anti-slip part, so that the moving wheel provides support; when the moving wheel is at the second position, it is higher than the anti-slip part, so that the anti-slip part provides support.

[0011] As a preferred embodiment, the moving wheel is configured to be manipulated in an up-down direction to switch between a first position and a second position.

[0012] As a preferred embodiment, a container is provided on one side of the main housing; the container has a cavity with an opening facing downward; a linkage is provided in the cavity, and the moving wheel is rotatably connected to the lower end of the linkage; the linkage is restricted to slide up and down in the cavity along the up and down direction, thereby driving the moving wheel to switch between the first position and the second position;

[0013] The main housing is provided with an operating member; the operating member is connected to the linkage body through a linkage shaft; the operating member can rotate around the central axis of the linkage shaft;

[0014] The operating member has a first operating position corresponding to the first position and a second operating position corresponding to the second position; the operating member has a force-applying portion for receiving force, and the operating member generates an action by applying force, and switches between the first operating position and the second operating position, thereby driving the moving wheel to switch between the first position and the second position; when the operating member switches from the first operating position to the second operating position, it rotates around the central axis and lifts the linkage shaft.

[0015] As a preferred embodiment, the operating member has a first positioning plane and a second positioning plane arranged at an angle, and the angle is 60 to 120 degrees;

[0016] A limit platform is fixedly provided on one side of the main shell; the operating member rotates around the central axis so that the first positioning plane and the second positioning plane are switched to contact and position with the limit platform; when the operating member is located at the first operating position, the first positioning plane is contacted and positioned with the limit platform; when the operating member is located at the second operating position, the second positioning plane is contacted and positioned with the limit platform; the distance between the linkage shaft and the limit platform is a variable distance, and the variable distance is greater when the second positioning plane is contacted and positioned with the limit platform than when the first positioning plane is contacted and positioned with the limit platform.

[0017] As a preferred embodiment, the operating member includes an operating handle and a cam plate arranged at one end of the operating handle; the first positioning plane and the second positioning plane are adjacent vertical side surfaces on both sides of the cam plate; the linkage shaft passes through the cam plate; the distance between the linkage shaft and the first positioning plane is smaller than the distance between the linkage shaft and the second positioning plane.

[0018] As a preferred embodiment, the limit platform is fixedly arranged on one side of the accommodating body; and the lower opening of the accommodating body is higher than the lower end surface of the anti-slip portion.

[0019] As a preferred manner, the accommodating body is further provided with an elastic member, and the elastic member applies a downward elastic force to the linkage body.

[0020] As a preferred embodiment, the linkage body has a wheel mounting cavity for accommodating the moving wheel and a spring accommodating cavity with an upward opening; the elastic member is a cylindrical spring accommodated in the spring accommodating cavity; the cylindrical spring is compressed between the bottom wall of the spring accommodating cavity and the top wall of the accommodating body.

[0021] As a preferred embodiment, the upper end of the linkage body is provided with two spring-containing cavities arranged side by side; a plurality of reinforcing plates are provided between the cavity walls of the two spring-containing cavities; two opposite side walls of the linkage body are provided with long grooves; and a plurality of reinforcing plates are located between the two long grooves.

[0022] The movable wheel is rotatably connected to the linkage body via a wheel axle; the linkage body is provided with an axial hole for the wheel axle to pass through; the axial hole is located at the lower end of the long slot; the long slot extends downward from the upper end of the linkage body to the axial hole and ends.

[0023] As a preferred embodiment, two opposite side walls of the housing body are respectively provided with long guide holes; the linkage shaft passes through the long guide holes and moves up and down along the long guide holes.

[0024] As a preferred method, the vertical distance between the center axis and the second positioning plane is L2, and the vertical distance between the center axis and the first positioning plane is L1, wherein L2≥1.5*L1, further, 4*L1≥L2≥2*L1, and further, 3.5*L1≥L2≥2.5*L1.

[0025] As a preferred manner, the length of the first positioning plane is L3, wherein L3>L1.

[0026] As a preferred embodiment, a transition arc surface is provided between the first positioning plane and the second positioning plane, and the transition arc surface is a quarter arc; the length of the first positioning plane is greater than the radius of the transition arc surface. Beneficial Effects

[0027] The ladder foot (foot shell) of the utility model can quickly realize the switching between the mobile and fixed modes of the ladder. The ladder does not need to be disassembled for switching between the mobile and fixed states, which is easy to manage and not easy to lose. In addition, the ladder foot structure of this embodiment is reliable, easy to operate, and occupies little space.

[0028] With reference to the following description and the accompanying drawings, specific embodiments of the present invention are disclosed in detail, indicating the manner in which the principles of the present invention can be adopted. It should be understood that the embodiments of the present invention are not limited in scope.

[0029] Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0030] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps or components. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For those skilled in the art, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 This is a three-dimensional structural diagram of a ladder foot provided by an embodiment of the utility model;

[0033] Figure 2 yes Figure 1 Another view of;

[0034] Figure 3 yes Figure 1 Another view of;

[0035] Figure 4 yes Figure 1 Schematic diagram of the limit platform;

[0036] Figure 5 yes Figure 1 Schematic diagram of the coordination structure between the linkage body and the operating part;

[0037] Figure 6 yes Figure 1 A schematic diagram of another matching structure of the linkage body and the operating member;

[0038] Figure 7 yes Figure 1 Front view of the control parts.

[0039] 1. Bolt; 2. Moving wheel; 3. Wheel axle; 4. Linkage body; 5. Operating part; 6. Main housing; 7. Linkage shaft; 8. Cylindrical spring;

[0040] 42. reinforcement plate; 45. long groove;

[0041] 51. operating handle; 52. cam plate; 521. first positioning plane; 522. second positioning plane; 523. transition arc surface;

[0042] 61. Main cavity; 611. Connecting convex rod; 62. Accommodating body; 623. Long guide hole; 625. Top wall; 65. Anti-slip part; 651. Anti-slip pattern; 67. Additional body; 671. Limiting platform; DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0044] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be another element centered thereon. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be another element centered thereon at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0046] like Figures 1 to 7 One embodiment of the present application provides a ladder foot, which can also be called a foot shell, wherein the ladder foot of this embodiment includes: a main shell 6 for connecting the ladder legs, and a moving wheel 2 arranged on one side of the main shell 6. The lower end of the main shell 6 is provided with an anti-skid portion 65. The anti-skid portion 65 can be an anti-skid pad fixed to the lower end of the main shell 6, and its lower end surface has an anti-skid pattern 651, which can be bonded and fixed to the lower end of the main shell 6.

[0047] In this embodiment, the moving wheel 2 can be manipulated to move between a first position and a second position higher than the first position. When the moving wheel 2 is in the first position, the lowest point of the moving wheel 2 is lower than the anti-skid portion 65, so that the moving wheel 2 provides support; when the moving wheel 2 is in the second position, it is higher than the anti-skid portion 65, so that the anti-skid portion 65 provides support. The moving wheel 2 is configured to be manipulated to switch between the first position and the second position along the up and down direction (a straight line direction). The moving wheel 2 switches between the first position and the second position in translation. The up and down movement switching path of the moving wheel 2 is a straight line path, which does not move along a curve or a discount path. The moving path is simple, easy to use, and has a reliable structure. The straight line direction is the up and down direction as a whole, specifically the length direction of the installed ladder leg. Because it moves with the ladder leg, the straight line direction is sometimes vertical and sometimes oblique, depending on the state of the ladder leg.

[0048] The moving wheel 2 of the ladder foot provided in this embodiment has its first position and second position being two upper and lower positions when the state is switched. The moving wheel 2 does not need to rotate or swing, and can switch between the first position and the second position only by moving linearly up and down, thereby not requiring a large operating space.

[0049] When using a ladder with the ladder feet, if the front-to-back distance cannot meet the specified requirements, the moving wheels 2 can be lowered to the first position, and the anti-slip portion 65 can be suspended in the air, so that the ladder can be moved forward and backward by rolling on the moving wheels 2. After the movement is completed, the moving wheels 2 are switched to the second position, the anti-slip portion 65 contacts the ground, and the ladder returns to a normal state, and then the ladder can be used normally.

[0050] The ladder feet of this embodiment can quickly realize the switching between the mobile and fixed modes of the ladder. The ladder does not need to be disassembled to switch between the mobile and fixed states, which is easy to manage and not easy to lose. In addition, the ladder feet of this embodiment have a reliable structure, are easy to operate, and occupy little space.

[0051] A container 62 is provided on one side of the main housing 6. The cross-sectional area of ​​the container 62 is smaller than that of the main housing 6, and the main housing 6 and the container 62 may be an integrally formed structure. The container 62 has a cavity with an opening facing downward, and the upper end of the cavity is blocked by a top wall 625. A linkage body 4 is provided in the cavity, and the moving wheel 2 is rotatably connected to the lower end of the linkage body 4; the linkage body 4 is restricted to slide up and down in the cavity along the up and down direction, thereby driving the moving wheel 2 to switch between the first position and the second position.

[0052] The main shell 6 has a main side wall surrounding the outside of the main cavity 61, and a symmetrically arranged connecting protruding rod 611 is provided in the main cavity 61. The two ends of the main side wall are respectively connected to the two opposite short side walls of the container 62, and the linkage shaft 7 passes through the two opposite long side walls. The lower end of the main side wall is connected to the main bottom wall, and the anti-slip part 65 is fixedly installed on the bottom side of the main bottom wall. A plurality of external reinforcing ribs located outside the main cavity 61 and a plurality of internal reinforcing ribs located inside the main cavity 61 are provided between the main bottom wall and the main side wall. The main bottom plate is a flange structure supported on the lower end of the main side wall, and its outer edge is located outside the main side wall and extends to connect with the outer wall of the container 62.

[0053] In this embodiment, the main housing 6 is provided with an operating member 5 to which force can be applied. The operating member 5 is connected to the linkage body 4 via a linkage shaft 7. The operating member 5 can rotate around the central axis of the linkage shaft 7; wherein the central axis is a horizontal axis, which is perpendicular to the moving direction of the linkage body 4.

[0054] The operating member 5 has a first operating position corresponding to the first position and a second operating position corresponding to the second position. The operating member 5 has a force application portion for receiving force, and the operating member 5 is moved by force application, and switches between the first operating position and the second operating position, thereby driving the moving wheel 2 to switch between the first position and the second position.

[0055] Specifically, the operating member 5 is pressed down to switch it from the first operating position to the second operating position, and the moving wheel 2 is lifted and retracted. When the ladder needs to be moved to lower the moving wheel 2, the operating member 5 is manually lifted up, and the elastic member can assist in applying force to the linkage body 4, switching the operating member 5 from the first operating position to the second operating position, which is convenient for manual operation.

[0056] The linkage shaft 7 is lifted or lowered together with the linkage body 4. When the operating member 5 is switched from the first operating position to the second operating position, it rotates around the central axis and lifts the linkage shaft 7. When the operating member 5 is switched to the first operating position, it is positioned at the first operating position by its own structure, and when it is switched to the second operating position, it is positioned at the second operating position by its own structure.

[0057] like Figure 5-Figure 7 As shown, the operating member 5 has a first positioning plane 521 and a second positioning plane 522 set at an angle, and a stopper 671 is fixedly provided on one side of the main housing 6. An additional body 67 is provided on one side of the main housing 6, and the additional body 67 and the main housing 6 can be an integral structure. The stopper 671 is a planar structure provided on the additional body 67. The operating member 5 rotates around the central axis so that the first positioning plane 521 and the second positioning plane 522 are switched to contact and position with the stopper 671. The angle is 60 to 120 degrees. Figure 7As shown, the angle between the first positioning plane 521 and the second positioning plane 522 is 90 degrees. At this time, the first positioning plane 521 and the second positioning plane 522 are perpendicular to each other, so that the operating member 5 is positioned stably when switching to the first operating position or the second operating position.

[0058] When the operating member 5 is located at the first operating position, the first positioning plane 521 contacts and positions the limiting platform 671. At this time, the position of the operating member 5 is as follows: Figure 6 When the operating member 5 is pressed down and the operating member 5 is located at the second operating position, the second positioning plane 522 contacts and positions the limiting platform 671; the distance between the linkage shaft 7 and the limiting platform 671 is a variable distance, and the variable distance is greater when the second positioning plane 522 contacts and positions the limiting platform 671 than when the first positioning plane 521 contacts and positions the limiting platform 671.

[0059] In order to achieve both convenient operation and stable positioning, and to avoid unexpected position movement after switching to the desired position, the vertical distance between the central axis and the second positioning plane 522 is more than 1.5 times the vertical distance between the central axis and the first positioning plane 521. More preferably, the vertical distance between the central axis and the second positioning plane 522 is between 2 times the vertical distance between the central axis and the first positioning plane 521 and 4 times the vertical distance between the central axis and the first positioning plane 521. More preferably, the vertical distance between the central axis and the second positioning plane 522 is between 2.5 times the vertical distance between the central axis and the first positioning plane 521 and 3.5 times the vertical distance between the central axis and the first positioning plane 521. The vertical distance between the central axis and the second positioning plane 522 is L2, and the vertical distance between the central axis and the first positioning plane 521 is L1, wherein L2≥1.5*L1, further, 4*L1≥L2≥2*L1, and further, 3.5*L1≥L2≥2.5*L1.

[0060] In order to facilitate the switching of the operating member 5 between the first operating position and the second operating position, a transition arc surface 523 is provided between the first positioning plane 521 and the second positioning plane 522. Figure 7 As shown, the transition arc surface 523 is a ¼ arc. When the moving wheel 2 carries the ladder, the linkage shaft 7 exerts force on the cam plate 52 to form a torque for the cam plate 52 to rotate upward, which will be further increased when other heavy objects are carried. In order to prevent the operating member 5 from automatically switching positions under the influence of the torque, the length L3 of the first positioning plane 521 is greater than the radius of the transition arc surface 523, and the length L3 of the first positioning plane 521 is greater than the vertical distance L1 between the central axis and the first positioning plane 521.

[0061] It should be noted that any numerical value recorded herein includes all values ​​of the lower value and the upper value that increase by one unit from the lower limit to the upper limit, and there is an interval of at least two units between any lower value and any higher value. For example, if the value of the number of a component or the process variable (such as the above-mentioned angle, etc.) is described to be from 60 to 120 degrees, preferably from 70 to 110 degrees, and more preferably from 80 to 100 degrees, the purpose is to illustrate that the specification also explicitly lists values ​​such as 65 to 85, 88 to 111, 72 to 101, 79 to 95. These are just examples that want to be clearly expressed, and it can be considered that all possible combinations of the numerical values ​​listed between the minimum value and the maximum value are clearly described in the specification in a similar manner. And, unless otherwise specified, all ranges include endpoints and all numbers between the endpoints.

[0062] Among them, the operating member 5 cannot switch between the first operating position and the second operating position spontaneously. The operating member 5 requires the operator to apply force to switch it between the first operating position and the second operating position. Specifically, for the convenience of operation, the operating member 5 includes an operating handle 51 and a cam plate 52 arranged at one end of the operating handle 51; the first positioning plane 521 and the second positioning plane 522 are adjacent vertical side surfaces on both sides of the cam plate 52; the linkage shaft 7 is passed through the cam plate 52. The distance between the linkage shaft 7 and the first positioning plane 521 is smaller than the distance between the linkage shaft 7 and the second positioning plane 522. The limit platform 671 is fixedly arranged on one side of the accommodating body 62.

[0063] From the perspective of the vertical projection on the plane where the first positioning plane 521 is located, the operating handle 51 and the linkage shaft 7 are respectively located on both sides of the transition arc surface 523, and then when the force is applied to the operating member 5, the operating member 5 rotates with the transition arc surface 523 as a support point, so that the operating member 5 can smoothly switch between the first operating position and the second operating position.

[0064] The lower opening of the accommodating body 62 is higher than the lower end surface of the anti-slip portion 65. The accommodating body 62 is also provided with an elastic member, which applies a downward elastic force to the linkage body 4. The linkage body 4 has a wheel-mounting cavity for accommodating the moving wheel 2 and a spring-accommodating cavity with an opening facing upward; the elastic member is a cylindrical spring 8 accommodated in the spring-accommodating cavity; the cylindrical spring 8 is compressed between the bottom wall of the spring-accommodating cavity and the top wall 625 of the accommodating body 62.

[0065] The elastic member applies a force to the linkage body 4 to move toward the first position, thereby preventing the moving wheels 2 of the ladder foot from moving unexpectedly during use of the ladder, and maintaining the ladder in a stable moving position. Combined with the above-mentioned limitation on the length L3 of the first positioning plane 521, the foot shell (ladder foot) of this embodiment is further provided with an elastic member to further prevent the operating member 5 from lifting up by itself when supported by the moving wheels 2, thereby ensuring the smooth movement of the ladder.

[0066] The upper end of the linkage body 4 is provided with two spring-containing cavities arranged side by side. A plurality of reinforcing plates 42 are provided between the cavity walls of the two spring-containing cavities. Two cylindrical springs 8 are respectively accommodated in the two spring-containing cavities, and jointly apply a force to the linkage body 4. Long grooves 45 are provided on the two opposite side walls of the linkage body 4; and a plurality of reinforcing plates 42 are located between the two long grooves 45. The plurality of reinforcing plates 42 are located above the linkage shaft 7 to enhance the structural strength of the linkage body 4 above the linkage shaft 7.

[0067] The moving wheel 2 is rotatably connected to the linkage body 4 through the wheel shaft 3; the linkage body 4 is provided with an axial hole for the wheel shaft 3 to pass through; the axial hole is located at the lower end of the long slot 45. The long slot 45 extends downward from the upper end of the linkage body 4 to the axial hole.

[0068] The two opposite side walls of the housing body 62 are respectively provided with guide long holes 623; the guide long holes 623 are located outside the long groove 45, and the two positions are roughly corresponding, and the extension direction is the same, and both extend up and down. The linkage shaft 7 passes through the guide long hole 623 and moves up and down along the guide long hole 623. The two ends of the linkage shaft 7 are respectively threadedly connected with fixing bolts 1. The linkage shaft 7 passes through the cam plate 52, the linkage body 4, and the housing body 62, and intercepts the fixing bolts 1 at both ends. The upper end of the guide long hole 623 is covered and blocked by the top wall 625 of the housing body 62.

[0069] In one embodiment of the present application, a ladder is provided. The ladder is an aluminum ladder, which has ladder bars, pedals, and ladder feet connected to the lower ends of the ladder bars. The multi-step pedals are connected between two ladder bars. The ladder feet adopt the ladder feet in the above embodiment.

[0070] How to use: When the work requirements are met, the ladder does not need to be moved. When it is needed, step on the operating member 5 to put the moving wheels 2 in the retracted state, the ladder feet are in stable contact with the ground, and the ladder is positioned for normal use. When the work requirements cannot be met and the ladder needs to be moved, lift the operating member 5 to put the moving wheels 2 in the lowered state, and the ladder in the empty state can be directly pushed to move forward and backward.

[0071] It should be understood that the above description is for illustration and not for limitation. By reading the above description, many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art. Therefore, the scope of the present teachings should not be determined with reference to the above description, but should be determined with reference to the appended claims and the full scope of equivalents possessed by these claims. For the purpose of comprehensiveness, all articles and references, including the disclosures of patent applications and announcements, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to abandon the main housing content, nor should it be considered that the inventor has not considered the subject matter as part of the disclosed utility model subject matter.

Claims

1. A ladder foot, characterized in that: include: A main housing, wherein a non-slip portion is provided at the lower end of the main housing; A moving wheel is arranged on one side of the main shell, and the moving wheel can be manipulated to move in a straight line between a first position and a second position higher than the first position; when the moving wheel is at the first position, the lowest point of the moving wheel is lower than the anti-slip part, so that the moving wheel provides support; when the moving wheel is at the second position, it is higher than the anti-slip part, so that the anti-slip part provides support.

2. The ladder foot according to claim 1, characterized in that: A accommodating body is provided on one side of the main shell; the accommodating body has a cavity with an opening facing downward; a linkage body is provided in the cavity, and the movable wheel is rotatably connected to the lower end of the linkage body; the linkage body is restricted to slide up and down in the cavity along the up and down directions, thereby driving the movable wheel to switch between the first position and the second position.

3. The ladder foot according to claim 2, characterized in that: The main housing is provided with an operating member; the operating member is connected to the linkage body through a linkage shaft; the operating member can rotate around the central axis of the linkage shaft; The operating member has a first operating position corresponding to the first position and a second operating position corresponding to the second position; The operating member has a force-applying portion for receiving force, and the operating member generates an action by applying force, and switches between a first operating position and a second operating position, thereby driving the moving wheel to switch between the first position and the second position; when the operating member switches from the first operating position to the second operating position, it rotates around the central axis and lifts the linkage shaft.

4. The ladder foot according to claim 3, characterized in that: The operating member has a first positioning plane and a second positioning plane arranged at an angle, and the angle is 60 to 120 degrees; A limit platform is fixedly arranged on one side of the main housing; the operating member rotates around the central axis so that the first positioning plane and the second positioning plane are switched to contact and position with the limit platform; when the operating member is located at the first operating position, the first positioning plane is contacted and positioned with the limit platform; When the operating member is located at the second operating position, the second positioning plane contacts and is positioned with the limiting platform; The distance between the linkage shaft and the limit platform is a variable distance, and the variable distance when the second positioning plane is in contact with the limit platform is greater than when the first positioning plane is in contact with the limit platform.

5. The ladder foot according to claim 4, characterized in that: The operating member includes an operating handle and a cam plate arranged at one end of the operating handle; the first positioning plane and the second positioning plane are adjacent vertical side surfaces on both sides of the cam plate; the linkage shaft passes through the cam plate; the distance between the linkage shaft and the first positioning plane is smaller than the distance between the linkage shaft and the second positioning plane; the two opposite side walls of the container body are respectively provided with guide long holes; the linkage shaft passes through the guide long hole and moves up and down along the guide long hole.

6. The ladder foot according to claim 5, characterized in that: The vertical distance between the central axis and the second positioning plane is L2, and the vertical distance between the central axis and the first positioning plane is L1, wherein L2≥1.5*L1, further, 4*L1≥L2≥2*L1, and further, 3.5*L1≥L2≥2.5*L1.

7. The ladder foot according to claim 6, characterized in that The length of the first positioning plane is L3, wherein L3>L1.

8. The ladder foot according to claim 6, characterized in that: A transition arc surface is provided between the first positioning plane and the second positioning plane, and the transition arc surface is a quarter arc; the length of the first positioning plane is greater than the radius of the transition arc surface.

9. The ladder foot according to claim 4, characterized in that: The accommodating body is further provided with an elastic member, and the elastic member applies a downward elastic force to the linkage body.

10. The ladder foot according to claim 9, characterized in that The linkage body has a wheel-mounting cavity for accommodating a moving wheel and a spring-containing cavity with an opening facing upward; the elastic member is a cylindrical spring accommodated in the spring-containing cavity; the cylindrical spring is compressed between the bottom wall of the spring-containing cavity and the top wall of the accommodating body.

11. The ladder foot according to claim 10, characterized in that The upper end of the linkage body is provided with two spring-containing cavities arranged side by side; a plurality of reinforcing plates are provided between the cavity walls of the two spring-containing cavities; two side walls of the linkage body facing each other are provided with long grooves; a plurality of reinforcing plates are located between the two long grooves; The movable wheel is rotatably connected to the linkage body via a wheel axle; the linkage body is provided with an axial hole for the wheel axle to pass through; the axial hole is located at the lower end of the long slot; the long slot extends downward from the upper end of the linkage body to the axial hole and ends.

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