Multifunctional foldable cart ladder

Abstract

The utility model provides a multifunctional foldable cart ladder, which relates to the field of ladders, and is characterized in that cart structures are mounted at the lower ends of two upright posts of any ladder frame, and each cart structure comprises a wheel set and a bearing plate; the ladder frame where the cart structure is located serves as a rear frame, the other ladder frame serves as a front frame, the opposite sides of two stand columns of the rear frame serve as the inner side of the rear frame, a wheel set is installed at the lower end of each stand column, and each wheel set comprises an upper pipe base, a rotating sleeve, a spring and a trundle. A receding groove is formed in the surface of one side of each wheel carrier, the receding grooves extend in the axial direction of the corresponding stand columns and penetrate through the upper end face and the lower end face of the wheel carrier, and when the two ladder frames are folded and the bearing plate is located at the second overturning station, the stand columns of the front frame are embedded into the receding grooves. Compared with an existing foldable cart ladder, the lower ends of the ladder frame stand columns do not need to be bent, the overall structural stability and strength of the foldable ladder are better, operation is easier and more convenient when the foldable cart ladder is used, and work efficiency can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of ladders, especially to a multifunctional foldable trolley ladder. BACKGROUND

[0002] Folding ladders are commonly used tools for high-altitude operations. In addition to folding ladders, some other tools or goods are usually carried during operation. These tools or goods need to be carried by manpower or using a trolley, which is low in efficiency and high in cost. To alleviate this problem, engineers have developed a foldable trolley ladder, which is a folding ladder with a trolley function, can simultaneously meet the requirements of high-altitude operation and carrying operation, and can not only improve work efficiency but also save costs.

[0003] The trolley structure of the foldable trolley ladder includes wheels and a supporting plate. There are mainly two installation methods for installing the trolley structure on the folding ladder in the prior art:

[0004] The first method is to rotate the wheels at the lower end of the main ladder frame and rotate the supporting plate at the lower end of the auxiliary ladder frame. Additional buckles are provided on the main ladder frame and / or the auxiliary ladder frame to lock the folded and closed main ladder frame and auxiliary ladder frame when the trolley function is applied.

[0005] When using this foldable trolley ladder, the wheels and the supporting plate need to be manually rotated separately, the buckles need to be manually opened or closed separately, and the main ladder frame and the auxiliary ladder frame need to be manually opened or locked separately. This method has the problems of complicated operation and inconvenient use.

[0006] The second method is to connect the wheels and the supporting plate together through a rotating sleeve, install the rotating sleeve at the lower end of the main ladder frame, and rotate the wheels and the supporting plate simultaneously to the two sides of the main ladder frame. To avoid the situation that the lower end of the auxiliary ladder frame blocks the wheels or the supporting plate when the main ladder frame and the auxiliary ladder frame are folded and closed, the lower end of the auxiliary ladder frame is designed as a curved section that curves outward to avoid the wheels and the supporting plate. Additional buckles are provided on the main ladder frame and / or the auxiliary ladder frame to lock the folded and closed main ladder frame and auxiliary ladder frame when the trolley function is applied.

[0007] For this foldable trolley ladder, when the trolley function is applied, stepping on the supporting plate can simultaneously open the wheels, which is more convenient than the first method. However, at least the following problems exist:

[0008] (1) The curvature of the lower end of the main ladder frame changes the stress distribution of the main ladder frame, causing local stress concentration, thereby affecting the carrying capacity of the ladder and reducing the overall structural stability and strength of the folding ladder;

[0009] (2) the main ladder frame and / or the auxiliary ladder frame need to be additionally buckled, and the buckle needs to be manually opened or locked to open or lock the folded main ladder frame and auxiliary ladder frame, so that the opening and folding of the folding ladder are relatively complicated, the folding ladder is inconvenient to use, the opening and closing smoothness of the folding ladder is affected, and the working efficiency is low;

[0010] (3) the wheels and the supporting plate are installed at the lower end of the main ladder frame during ladder climbing through the rotating sleeve, the rotating sleeve occupies the space between the lowermost step and the ground, the step spacing is too large, the climbing is affected, and certain safety hazards exist. Utility model content

[0011] The utility model discloses a multifunctional foldable trolley ladder, which aims to alleviate the above technical problems of the existing foldable trolley ladder.

[0012] To achieve the above-mentioned purpose, the utility model embodiment adopts the following technical scheme:

[0013] The utility model embodiment provides a multifunctional foldable trolley ladder, which comprises two ladder frames hingedly connected at the upper end and a trolley structure installed at the lower end of two stand columns of any ladder frame.

[0014] The trolley structure comprises a wheel set and a supporting plate.

[0015] Each stand column lower end is respectively installed with a group of wheel sets, and each group of wheel sets comprises an upper pipe seat, a rotating sleeve, a spring and a caster.

[0016] The upper pipe seat, the spring and the rotating sleeve are arranged from top to bottom on the lower end of the stand column, and the upper pipe seat is fixedly connected to the corresponding stand column.

[0017] One side of the rotating sleeve is fixedly connected or integrally connected with a wheel bracket, and the caster is rotatably installed on the wheel bracket.

[0018] The lower end surface of the upper pipe seat forms a first cam curve, and the upper end surface of the rotating sleeve forms a second cam curve capable of engaging with the first cam curve.

[0019] The supporting plate is arranged at the rear side of the rear frame; the supporting plate has opposite first and second side edges, and each end of the first side edge is fixedly connected or integrally connected with a supporting plate seat, the supporting plate seat comprises a first limiting surface and a second limiting surface, and the two supporting plate seats are correspondingly hingedly connected to the lower ends of the two upright columns of the rear frame; the supporting plate has two turnover positions, in a state where the supporting plate is at the first turnover position, the supporting plate is upwardly folded relative to the rear frame to abut the first limiting surface against the lower end surface of the rotating sleeve, and the spring is in a free state; in a state where the supporting plate is at the second turnover position, the supporting plate is downwardly folded relative to the rear frame to abut the second limiting surface against the lower end surface of the rotating sleeve to upwardly press the rotating sleeve, so that the first cam surface and the second cam surface are engaged; one of the lower end surface of the wheel frame and the plate surface of the supporting plate is provided with a positioning groove, and the other is provided with a positioning protrusion, in the second turnover position of the supporting plate, the positioning protrusion is clamped into the positioning groove to circumferentially position the rotating sleeve corresponding to the upright column.

[0020] The wheel frame is provided with an avoiding groove on one side surface, the avoiding groove extends axially along the upright column and penetrates the upper end surface and the lower end surface of the wheel frame, in a state where the two ladder frames are closed and the supporting plate is at the second turnover position, the upright column of the front frame is embedded in the avoiding groove.

[0021] In an optional technical solution of the embodiment, of the two ladder frames, one is a main ladder frame which is hingedly connected with multiple layers of footboards from top to bottom between the two upright columns, and the other is a sub-ladder frame, and the stroller structure is installed on the sub-ladder frame.

[0022] In an optional technical solution of the embodiment, the wheel set further comprises a gasket ring, and the gasket ring is sleeved outside the upright column corresponding to the rotating sleeve and the supporting plate seat.

[0023] In an optional technical solution of the embodiment, in the wheel set, the upper end of the spring is fixedly connected or circumferentially positioned on the upper pipe seat, and the lower end of the spring is fixedly connected or circumferentially positioned on the rotating sleeve, and in a state where the supporting plate is at the first turnover position, the wheel frame is rotated to the inner side of the rear frame.

[0024] In an optional technical solution of the embodiment, the lower end surface of the wheel frame is provided with the positioning protrusion, and the plate surface of the supporting plate is provided with the positioning groove, and the positioning groove extends along the front-rear direction of the supporting plate and penetrates one end of the first side edge of the supporting plate.

[0025] In an optional technical solution of the embodiment, the avoiding groove of the side surface of the wheel frame has a semicircular cross section.

[0026] In the alternative technical solution of the embodiment, a ladder leg is fixed or integrally connected on each of the two support plate seats, the ladder leg is located outside the rear frame and extends outside the support plate from the second side of the support plate to the first side of the support plate, the ladder leg has a contact surface for contacting the ground, when the support plate is in the second overturning position, the contact surface faces the front side of the rear frame, and when the support plate is in the first overturning position, the contact surface faces the lower side of the rear frame.

[0027] In the alternative technical solution of the embodiment, a turning edge is arranged on the second side of the support plate, when the support plate is in the first overturning position, the turning edge extends towards the rear side of the rear frame.

[0028] In the alternative technical solution of the embodiment, a blocking edge is arranged on the first side of the support plate, when the support plate is in the first overturning position, the blocking edge extends towards the front side of the rear frame.

[0029] Further alternatively, two wheel-avoiding grooves are arranged on the blocking edge at intervals.

[0030] The multifunctional foldable trolley ladder provided by the embodiment comprises a ladder body and a trolley structure arranged at the lower end of the ladder body, the trolley structure has two states of unfolding and folding:

[0031] (1) When the two ladder frames of the ladder body are opened, the multifunctional foldable trolley ladder is used as a ladder to climb, at this time, the trolley structure is in the folded state, and the support plate is in the first overturning position of being folded upwards relative to the stand column;

[0032] (2) When the two ladder frames of the ladder body are closed:

[0033] (2.1) If the multifunctional foldable trolley ladder is needed to be used as a trolley, then the two ladder frames are closed, and the trolley structure is unfolded, due to the special wheel set structure, the wheels can be rotated to the front side of the stand column at the same time as the support plate, at this time, due to the fact that the stand column of the front frame is embedded into the avoiding groove on the surface of one side of the wheel frame, and the positioning protrusion is clamped into the positioning groove to position the rotating sleeve circumferentially to the corresponding stand column, the multifunctional foldable trolley ladder is used as a trolley;

[0034] (2.2) When the multifunctional foldable trolley ladder needs to be stored, the two ladder frames are closed, and the trolley structure remains in the folded state.

[0035] The multifunctional foldable trolley ladder provided by the embodiment can open the wheels while applying the trolley function by treading on the supporting plate, and the structure design that the avoiding groove is arranged on the side surface of the wheel frame, the avoiding groove extends along the corresponding column and penetrates the upper end surface and the lower end surface of the wheel frame, and the column of the front frame is embedded in the avoiding groove in the state that the two ladder frames are closed and the supporting plate is in the second turnover station can avoid the operation of locking the two ladder frames separately when the trolley is used, and the use is more convenient and efficient, and in addition, the lower end of the column of the two ladder frames does not need to be bent in the structure, so that the structural strength of the folding ladder can be guaranteed, and the stability when the folding ladder is used as a ladder is strengthened.

[0036] For other function effects that can be achieved by the embodiment, refer to the specific embodiment part of the specification. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the specific embodiment of the utility model or the technical scheme in the prior art, the drawings needed to be used in the specific embodiment or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0038] Figure 1 The overall structure isometric view of the multifunctional foldable trolley ladder provided by the embodiment of the utility model in the open state and the state that the supporting plate is in the first turnover station;

[0039] Figure 2 The local structure enlarged view of area A in the embodiment of the utility model; Figure 1

[0040] Figure 3 The overall structure front view of the multifunctional foldable trolley ladder provided by the embodiment of the utility model in the folded state and the state that the supporting plate is in the first turnover station;

[0041] Figure 4 The overall structure rear view of the multifunctional foldable trolley ladder provided by the embodiment of the utility model in the folded state and the state that the supporting plate is in the first turnover station;

[0042] Figure 5 The overall structure side view of the multifunctional foldable trolley ladder provided by the embodiment of the utility model in the folded state and the state that the supporting plate is in the first turnover station;

[0043] Figure 6 The local structure enlarged view of area B in the embodiment of the utility model; Figure 5

[0044] Figure 7 ​​The overall structure isometric view of the multifunctional foldable trolley ladder in the folded state and the supporting plate in the second overturning station is provided by the utility model embodiment;

[0045] Figure 8 For Figure 7 The local structure of the C area is enlarged;

[0046] Figure 9 The assembly position relation schematic diagram of the upper pipe seat, the rotating sleeve and the spring of the wheel set in the free state of the spring is provided in the multifunctional foldable trolley ladder of the utility model embodiment, and the wheel frame is not shown;

[0047] Figure 10 The other structure schematic diagram of the ladder foot is provided in the multifunctional foldable trolley ladder of the utility model embodiment Figure 1 ;

[0048] Figure 11 The other structure schematic diagram of the ladder foot is provided in the multifunctional foldable trolley ladder of the utility model embodiment Figure 2 .

[0049] Icon: 110-main ladder frame;111-step board;120-subordinate ladder frame;1-stand column;2-wheel set;21-upper pipe seat;210-first cam surface;22-rotating sleeve;220-second cam surface;221-wheel frame;2210-avoidance groove;23-spring;24-castor;25-gasket ring;3-supporting plate;301-first side;302-second side;31-supporting plate seat;3101-first limiting surface;3102-second limiting surface;32-ladder foot;320-contact surface;321-recess;33-flange;34-baffle;340-castor avoidance groove;41-positioning groove;42-positioning convex. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical scheme and advantages of the utility model embodiments clearer, the technical scheme in the utility model embodiments will be described clearly and completely below in combination with the drawings in the utility model embodiments. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. The components of the utility model embodiments described and shown in the drawings here can be arranged and designed in various different configurations.

[0051] Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the claimed utility model, but only represents selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative labor belong to the scope of protection of the utility model.

[0052] It should be noted that like reference numerals and letters refer to like items in the drawings, and thus once an item is defined in one drawing, it is not necessary to further define and explain it in subsequent drawings.

[0053] In the description of the utility model, it should be explained that the terms "upper", "lower", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, and are merely for the convenience of describing the utility model and simplifying the description, and thus cannot be understood as indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as limiting the utility model. In addition, the terms "first", "second", "third" and the like are merely used for differentiation in description, and cannot be understood as indicating or implying relative importance.

[0054] In addition, the terms "horizontal" and "vertical" do not mean that the components must be absolutely horizontal or vertical, but can be slightly inclined. For example, "horizontal" merely means that it is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0055] In the description of the utility model, it should also be explained that, unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium, or can be connected internally between two elements. For ordinary skilled persons in the art, the specific meanings of the above terms in the utility model can be understood according to the specific circumstances.

[0056] Some embodiments of the utility model will be described in detail below with reference to the drawings. In the case of no conflict, the following examples and features in the examples can be combined with each other.

[0057] The embodiment provides a multifunctional foldable trolley ladder, referring to Figures 1 to 9 The multifunctional foldable trolley ladder comprises two ladder frames which are hingedly connected at upper ends and a trolley structure which is installed at the lower ends of the two upright columns 1 of any ladder frame. The trolley structure comprises a wheel set 2 and a supporting plate 3; the ladder frame where the trolley structure is located is taken as a rear frame, the other ladder frame is taken as a front frame, and the opposite side of the two upright columns 1 of the rear frame is taken as the inner side of the rear frame; a set of wheel sets 2 is respectively installed at the lower ends of each upright column 1, and each set of wheel sets 2 comprises an upper pipe seat 21, a rotating sleeve 22, a spring 23 and a caster 24.

[0058] Specifically, the upper tube seat 21, spring 23, and rotating sleeve 22 are sleeved from top to bottom on the lower end of the column 1, and the upper tube seat 21 is fixedly connected to the corresponding column 1. A wheel frame 221 is fixedly or integrally connected to one side of the rotating sleeve 22, and a caster 24 is rotatably mounted on the wheel frame 221. The lower end face of the upper tube seat 21 forms a first cam surface 210, and the upper end face of the rotating sleeve 22 forms a second cam surface 220 that can mesh with the first cam surface 210. The spring 23 is configured in a free state to allow the upper end face of the rotating sleeve 22 and the lower end face of the upper tube seat 21 to be spaced apart from each other along the axial direction (length direction) of the corresponding column 1 and to be misaligned with each other along the circumferential direction of the corresponding column 1. The rotating sleeve 22 can move axially and rotate circumferentially relative to the corresponding column 1, and when the rotating sleeve 22 moves relative to the column 1 to the state where the first cam surface 210 and the second cam surface 220 are meshed, the wheel frame 221 is located on the front side of the corresponding column 1.

[0059] The support plate 3 is located on the rear side of the rear frame; the support plate 3 has opposing first side 301 and second side 302 (see reference). Figure 7 The first side 301 has a support plate seat 31 fixed or integrally connected to both ends. The support plate seat 31 includes a first limiting surface 3101 and a second limiting surface 3102. The two support plate seats 31 are hinged to the lower ends of the two columns 1 of the rear frame in a one-to-one correspondence. The support plate 3 has two flipping positions, see reference. Figures 1 to 6 as well as Figure 9 With the support plate 3 in the first flipping position, the support plate 3 folds upward relative to the rear frame until the first limiting surface 3101 abuts against the lower end face of the rotating sleeve 22, and the spring 23 is in a free state; Reference Figure 7 and Figure 8 When the support plate 3 is in the second flipping position, it folds downward relative to the rear frame until the second limiting surface 3102 abuts against the lower end face of the rotating sleeve 22, thereby pressing the rotating sleeve 22 upward and causing the first cam surface 210 to mesh with the second cam surface 220. At this time, the wheel frame 221 is located in front of the corresponding column 1. One of the lower end face of the wheel frame 221 and the plate surface of the support plate 3 is provided with a positioning groove 41 and the other is provided with a positioning protrusion 42. The support plate 3 is in the second flipping position. Figure 7 and Figure 8 In the second flipping position shown, the positioning protrusion 42 is inserted into the positioning groove 41 to circumferentially position the rotating sleeve 22 on the corresponding column 1.

[0060] A avoiding recess 2210 is arranged on the side surface of the wheel frame 221, which extends along the corresponding column 1 and penetrates the upper end surface and the lower end surface of the wheel frame 221, and in the state that the two ladder frames are closed and the support plate 3 is in the second overturning position, the column 1 of the front frame is embedded in the avoiding recess 2210. The avoiding recess 2210 has various optional cross-sectional shapes, for example, but not limited to, in some optional embodiments of the embodiment, the cross section of the avoiding recess 2210 on the side surface of the wheel frame 221 is semicircular.

[0061] The multifunctional foldable trolley ladder provided by the embodiment includes a ladder body and a trolley structure arranged at the lower end of the ladder body, and the trolley structure has two states of unfolding and folding:

[0062] (1) When the two ladder frames of the ladder body are opened, the multifunctional foldable trolley ladder is used as a ladder to climb, at this time, the trolley structure is in the folded state as shown in Figure 1 , the support plate 3 is in the first overturning position of being folded upward relative to the column 1, and the wheel set structure state is referred to Figure 9 .

[0063] (2) When the two ladder frames of the ladder body are closed:

[0064] (2.1) If the multifunctional foldable trolley ladder is needed to be used as a trolley, then the two ladder frames are closed, and the trolley structure is unfolded, and the unfolded trolley structure is as shown in Figure 7 and Figure 8 , the support plate 3 is in the second overturning position of being unfolded downward relative to the column 1. Due to the special wheel set structure, the caster 24 can be rotated to the front side of the column 1 at the same time as the support plate 3, at this time, the column 1 of the front frame is embedded in the avoiding recess 2210 on the side surface of the wheel frame 221, and the positioning protrusion 42 is clamped into the positioning recess 41 to position the rotating sleeve 22 in the corresponding column 1, so that the multifunctional foldable trolley ladder is used as a trolley;

[0065] (2.2) When the multifunctional foldable trolley ladder needs to be stored, the two ladder frames are closed, and the trolley structure remains in the folded state, as shown in Figures 2 to 6 , and the wheel set structure state is referred to Figure 9 .

[0066] The multifunctional foldable trolley ladder provided by the embodiment can open the wheels while stepping on the supporting plate when the trolley function is applied, and the structure design that the avoiding groove 2210 is arranged on the side surface of the wheel frame 221, the avoiding groove 2210 extends along the axis of the corresponding stand 1 and penetrates the upper end surface and the lower end surface of the wheel frame 221, and the stand 1 of the front frame is embedded in the avoiding groove 2210 in the state that the two ladder frames are closed and the supporting plate 3 is in the second turnover position can avoid the operation of separately locking the two ladder frames when the trolley is used, and the use is more convenient and efficient, and in addition, the lower ends of the stands of the two ladder frames do not need to be bent in this structure, so that the structural strength of the folding ladder can be ensured and the stability when the folding ladder is used as a ladder can be improved.

[0067] In the optional embodiment of the embodiment, one of the two ladder frames is the main ladder frame 110 in which a plurality of footboards 111 are hingedly arranged from top to bottom between the two stands 1, and the other is the auxiliary ladder frame 120, and the trolley structure is arranged on the auxiliary ladder frame 120, so that the influence of the climbing caused by the too large distance between the footboards can be avoided.

[0068] Continuing to refer to Figures 1 to 9 In the optional embodiment of the embodiment, the wheel set 2 further comprises a gasket ring 25, which is arranged on the outside of the corresponding stand 1 and between the rotating sleeve 22 and the supporting plate seat 31. The gasket ring 25 is preferably made of metal material to reduce the wear of the rotating sleeve 22 and improve the service life of the multifunctional foldable trolley ladder.

[0069] Referring to Figures 1 to 6 In the optional embodiment of the embodiment, in the wheel set 2, the upper end of the spring 23 is fixed or circumferentially positioned on the upper pipe seat 21, and the lower end of the spring 23 is fixed or circumferentially positioned on the rotating sleeve 22, and the wheel frame 221 is rotated to the inner side of the rear frame in the state that the supporting plate 3 is in the first turnover position.

[0070] Referring to Figures 1 to 8 , especially referring to Figure 3 and Figure 8 In the optional embodiment of the embodiment, the lower end surface of the wheel frame 221 is provided with a positioning protrusion 42, and the plate surface of the supporting plate 3 is provided with a positioning groove 41, the positioning groove 41 extends along the front-rear direction of the supporting plate 3 and one end penetrates the first side edge 301 of the supporting plate 3, and the positioning groove 41 can penetrate or not penetrate the supporting plate 3 along the thickness direction of the supporting plate 3.

[0071] In an optional embodiment of the present embodiment, two ladder legs 32 are respectively fixed or integrally connected on the two support plate seats 31 of the support plate 3, the ladder legs 32 are located outside the rear frame and extend outside the support plate 3 from the second side edge 302 of the support plate 3 towards the first side edge 301 of the support plate 3, the ladder legs 32 have a contact surface 320 for contacting the ground, when the support plate 3 is in the state of the second overturning station, the contact surface 320 faces the front side of the rear frame, and when the support plate 3 is in the state of the first overturning station, the contact surface 320 faces the lower side of the rear frame, so as to avoid that the lower end of the stand 1 blocks the overturning of the support plate 3, and to ensure the bearing force of the rear frame of the two ladder frames when the ladder is used as a ladder to climb. In addition, anti-skid sleeves or anti-skid plates can also be respectively arranged at the lower ends of the ladder legs 32 and the front frame, so as to further improve the stability of the ladder when climbing. In the present embodiment, the ladder legs 32 have various specific optional structural forms, which can be "L" shaped as shown in Figures 1 to 8 , can be block-shaped as shown in Figure 10 and Figure 11 , and when the ladder legs 32 are in the block shape as shown in Figure 10 and Figure 11 , the optional but not limited recesses 321 are arranged on the surfaces of the ladder legs 32 which face the inner sides of the corresponding rear frames, as shown in Figure 11 , when the support plate 3 is in the state of the second overturning station and the contact surface 320 faces the front side of the rear frame, the ladder legs 32 are located outside the rear frame and the corresponding stand 1 is limited in the recesses 321.

[0072] Referring to Figures 1 to 8 , in an optional embodiment of the present embodiment, a turning edge 33 is further arranged at the second side edge 302 of the support plate 3, the turning edge 33 extends towards the rear side of the rear frame when the support plate 3 is in the state of the first overturning station as shown in Figures 1 to 6 , so that when it is necessary to open the stroller structure, it is only necessary to step on the turning edge 33 downwards to easily open the stroller structure, without the need for manual operation by bending over, and the use is more convenient, which is beneficial to further improve the work efficiency.

[0073] Continuing to refer to Figures 1 to 8 , in an optional embodiment of the present embodiment, a blocking edge 34 is further arranged at the first side edge 301 of the support plate 3, the blocking edge 34 extends towards the front side of the rear frame when the support plate 3 is in the state of the first overturning station as shown in Figures 1 to 6 , the blocking edge 34 extends upwards when the support plate 3 is in the state of the second overturning station as shown in Figure 7 and Figure 8 , for blocking the falling of the transported goods.

[0074] Further optionally, two wheel-avoiding grooves 340 are arranged at the blocking edge 34 in an interval, so as to avoid the wheels when the support plate 3 is in the state of the first overturning station as shown in Figures 1 to 6The first turnover station in the shown state can avoid the caster 24, avoid the caster 24 from protruding from the rear frame obviously, and reduce the folding volume of the multifunctional foldable stroller ladder.

[0075] Finally, it should be noted that: each embodiment in the specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between each embodiment can be referred to each other. The above embodiments in the specification are only used to illustrate the implementation of the present application, and not to limit it. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the implementation of the foregoing embodiments can be modified, or some or all of the technical features can be replaced by equivalents. The modification or replacement does not change the essence of the corresponding embodiment out of the scope of the embodiments of the present application.

Claims

1. A multi-functional foldable trolley ladder characterized by: The stroller structure is installed at the lower end of two upright columns (1) of any of the two ladder frames; The stroller structure comprises a wheel set (2) and a supporting plate (3); the ladder frame where the stroller structure is located is the rear frame, the other ladder frame is the front frame, and the opposite side of the two upright columns (1) of the rear frame is the inner side of the rear frame; A set of wheel sets (2) is installed at the lower end of each upright column (1), and each set of wheel sets (2) comprises an upper tube seat (21), a rotating sleeve (22), a spring (23) and a caster (24); The upper tube seat (21), the spring (23) and the rotating sleeve (22) are arranged from top to bottom on the outside of the lower end of the upright column (1), and the upper tube seat (21) is fixedly connected to the corresponding upright column (1); One side of the rotating sleeve (22) is fixedly or integrally connected with a wheel bracket (221), and the caster (24) is rotatably installed on the wheel bracket (221); The lower end surface of the upper tube seat (21) forms a first cam surface (210), and the upper end surface of the rotating sleeve (22) forms a second cam surface (220) capable of engaging with the first cam surface (210); the spring (23) is configured to keep the upper end surface of the rotating sleeve (22) and the lower end surface of the upper tube seat (21) spaced apart along the axial direction of the corresponding upright column (1) and dislocated along the circumferential direction of the corresponding upright column (1) in a free state; the rotating sleeve (22) can move axially and rotate circumferentially relative to the corresponding upright column (1), and when the rotating sleeve (22) moves relative to the upright column (1) to the state where the first cam surface (210) and the second cam surface (220) are engaged, the wheel bracket (221) is located on the front side of the corresponding upright column (1). The supporting plate (3) is arranged at the rear side of the rear frame; the supporting plate (3) has opposite first and second side edges (301) and (302), the first side edge (301) has two ends each fixedly connected or integrally connected with a supporting plate seat (31), the supporting plate seat (31) comprises a first limiting surface (3101) and a second limiting surface (3102), and the two supporting plate seats (31) are hingedly connected to the lower ends of the two upright columns (1) of the rear frame one by one; the supporting plate (3) has two overturning positions, in a state where the supporting plate (3) is at the first overturning position, the supporting plate (3) is folded upward relative to the rear frame to abut against the lower end surface of the rotating sleeve (22) at the first limiting surface (3101), and the spring (23) is in a free state; in a state where the supporting plate (3) is at the second overturning position, the supporting plate (3) is folded downward relative to the rear frame to abut against the lower end surface of the rotating sleeve (22) at the second limiting surface (3102) to press upward the rotating sleeve (22) so that the first cam curved surface (210) is engaged with the second cam curved surface (220); one of the lower end surface of the wheel frame (221) and the plate surface of the supporting plate (3) is provided with a positioning groove (41), and the other is provided with a positioning protrusion (42), in the second overturning position of the supporting plate (3), the positioning protrusion (42) is clamped into the positioning groove (41) to position the rotating sleeve (22) circumferentially corresponding to the upright column (1); A avoiding groove (2210) is arranged on one side surface of the wheel frame (221), the avoiding groove (2210) extends axially along the upright column (1) and penetrates through the upper end surface and the lower end surface of the wheel frame (221), in a state where the two ladder frames are close to each other and the supporting plate (3) is at the second overturning position, the upright column (1) of the front frame is embedded in the avoiding groove (2210).

2. The multi-functional foldable cart ladder of claim 1, wherein: Among the two ladder frames, one of the ladder frames is a main ladder frame (110) having a plurality of step plates (111) hingedly connected from top to bottom between the two upright columns (1), and the other is a sub-ladder frame (120), and the stroller structure is installed on the sub-ladder frame (120).

3. The multi-functional foldable cart ladder of claim 1, wherein: The wheel set (2) further comprises a gasket ring (25), and the gasket ring (25) is sleeved outside the upright column (1) and located between the rotating sleeve (22) and the supporting plate seat (31).

4. The multi-functional foldable cart ladder of claim 1, wherein: In the wheel set (2), the upper end of the spring (23) is fixed or circumferentially positioned on the upper pipe seat (21), and the lower end of the spring (23) is fixed or circumferentially positioned on the rotating sleeve (22), and in a state where the supporting plate (3) is at the first overturning position, the wheel frame (221) is rotated to the inner side of the rear frame.

5. The multi-functional foldable cart ladder of claim 1, wherein: The lower end surface of the wheel frame (221) is provided with the positioning protrusion (42), the plate surface of the supporting plate (3) is provided with the positioning recess (41), the positioning recess (41) extends along the front-rear direction of the supporting plate (3) and one end of the positioning recess (41) penetrates the first side edge (301) of the supporting plate (3).

6. The multi-functional foldable cart ladder of claim 1, wherein: The lateral surface of the wheel frame (221) is provided with the avoiding recess (2210) in a semicircular cross section.

7. The multi-functional foldable cart ladder of claim 1, wherein: Two ladder legs (32) are respectively fixed or integrally connected on the two supporting plate seats (31), the ladder legs (32) are located outside the rear frame and extend outside the supporting plate (3) from the second side edge (302) of the supporting plate (3) to the first side edge (301) of the supporting plate (3), the ladder legs (32) have a contact surface (320) for contacting the ground, in the state of the second overturning station, the contact surface (320) faces the front side of the rear frame, in the state of the first overturning station, the contact surface (320) faces the lower side of the rear frame.

8. The multi-functional foldable cart ladder of claim 1, wherein: A turn-up edge (33) is further arranged on the second side edge (302) of the supporting plate (3), in the state of the first overturning station, the turn-up edge (33) extends towards the rear side of the rear frame.

9. The multi-functional foldable cart ladder of claim 1, wherein: A stop edge (34) is further arranged on the first side edge (301) of the supporting plate (3), in the state of the first overturning station, the stop edge (34) extends towards the front side of the rear frame.

10. The multi-functional foldable cart ladder of claim 9, wherein: Two wheel avoiding grooves (340) are arranged on the stop edge (34) in an interval manner.

Images