Crawler assembly and hand truck

Abstract

To provide a crawler assembly and a handcart that are low in cost, stable in structure, and easy to manufacture and assemble in the field of handcart technology. [Solution] A crawler assembly 100 includes a crawler 1 and a load wheel 2. The crawler is formed by joining together multiple crawler blocks, each with a protrusion on the inner surface, the load wheel is located inside the crawler and in load contact with the crawler, and the radial outer surface of the load wheel is formed with a groove that fits into the protrusion. The fit between the protrusion on the crawler block and the groove on the load wheel improves wheel slippage prevention and support capabilities.

Description

[Technical Field]

[0001] The present invention relates to the field of hand truck technology, and more particularly to a crawler assembly and a hand truck. [Background technology]

[0002] A hand truck is an efficient tool for transporting goods, and conventional hand trucks often use standard wheels, which can meet the basic requirement of running on flat and smooth surfaces, and are easy to operate and efficient. However, when operating in harsh environments such as uneven construction sites, soft sand, rough muddy ground, and complex and varied mountain terrain, standard wheels have difficulty adapting, and are easily trapped or the transportation process is very unstable, causing a lot of inconvenience to users.

[0003] Therefore, to accommodate these special usage scenarios, improved trolleys equipped with crawler wheels have been proposed. The crawler wheel design significantly improves the trolley's ability to navigate and stability over these complex terrains, allowing it to easily handle a variety of uneven road surfaces, greatly improving work efficiency and safety.

[0004] In the prior art, for example, application number "201921270180.X" and patent title "Construction Hand Truck Suitable for Complex Terrain" discloses a hand truck with crawler wheels, which includes crawlers and driven wheels located inside the crawlers to support the load. This structure has a small support contact area between the driven wheels and the crawlers, which requires a large design size, resulting in high costs. Furthermore, this structure does not have a positioning structure to restrict the driven wheels' position laterally, which increases the risk of the driven wheels breaking away from the side. In particular, if the size of the driven wheels increases, their center of gravity also increases, making them more susceptible to breaking away from the side. Therefore, this structure in the prior art is expensive and unstable. Summary of the Invention [Problem to be solved by the invention]

[0005] To solve the technical problems of high cost and unstable structure present in the crawler wheel structure of the prior art hand truck, the present invention provides a crawler assembly, in which the protrusions on the crawler blocks fit into the grooves on the load wheels, improving the wheel-off ability and supporting capacity, while reducing the size of the load wheels and reducing costs. [Means for solving the problem]

[0006] The technical solutions of the present invention are as follows:

[0007] 1. A crawler assembly comprising: A crawler formed by joining together a plurality of crawler blocks, each having a protrusion formed on an inner surface thereof; The load wheel is located inside the crawler and is in load contact with the crawler, and has a recessed groove formed on the radial outer surface of the load wheel that holds the projection in engagement with it.

[0008] Furthermore, the plurality of crawler blocks are hingedly connected in sequence from head to tail, and each crawler block is provided with a first hinge connection structure that is hingedly connected to and fitted with the preceding crawler block, and a second hinge connection structure that is hingedly connected to and fitted with the following crawler block.

[0009] Furthermore, the first hinge coupling structure is a first hinge coupling hole, and the second hinge coupling structure is a second hinge coupling hole, and a hinge coupling shaft penetrates the first hinge coupling hole and the second hinge coupling hole of two adjacent crawler blocks to realize hinge coupling of the two crawler blocks, A hinge connection block is provided inside the crawler block, the first hinge connection hole and the second hinge connection hole are formed in the hinge connection block, at least two first hole side molding grooves are formed radially outside the first hinge connection hole in the hinge connection block, and at least two second hole side molding grooves are formed radially outside the second hinge connection hole in the hinge connection block.

[0010] Furthermore, a protrusion is further provided on the front side or the rear side of each of the crawler blocks, and a stopper edge is further formed on the outer edge of the protrusion on each of the crawler blocks.

[0011] Furthermore, the protrusion has a stripe shape along the running direction, the cross section of the protrusion is arc-shaped, the cross section of the groove is arc-shaped, and the top of the protrusion is tightly fitted into the bottom of the groove.

[0012] Furthermore, the crawler assembly further includes a connecting frame, the load wheels are symmetrically arranged on both the left and right sides of the connecting frame, the protrusions are symmetrically arranged on each of the crawler blocks, and stopper edges are further formed on the left and right edges of each of the crawler blocks.

[0013] Furthermore, a plurality of load wheels are provided on both the left and right sides of the connecting frame, and the plurality of load wheels are divided into M sets, where M≧2, and a certain interval is provided between every two adjacent sets of load wheels.

[0014] Furthermore, the crawler assembly further includes a guide wheel, a trapezoidal groove formed on the radially outer surface of the guide wheel, and the guide wheel is interference-fitted with a protrusion on the crawler block via an inclined surface of the trapezoidal groove.

[0015] Another aspect of the present invention provides a hand truck, which includes at least one crawler assembly as described above.

[0016] Furthermore, the handcart further includes a tray and a bracket, the tray is attached to the connecting frame of the crawler assembly via the bracket, a through groove is formed on both the left and right sides of the connecting frame extending in the front-to-rear direction, the bracket is a U-shaped bracket, the heads of the mounting bolts on both the left and right sides of the U-shaped bracket are positioned in the through groove, and the connecting frame is an aluminum extrusion. [Effects of the Invention]

[0017] After adopting the above technical solutions, the crawler assembly and hand truck provided by the present invention have the following beneficial effects compared with the prior art: 1. The crawler assembly provided by this invention has grooves on the load wheels that fit into the protrusions on the crawler blocks, improving the ability to prevent wheels from slipping off and supporting the load wheels. It also allows the size of the load wheels to be reduced, thereby reducing costs. 2. The crawler assembly provided by this invention has load wheels symmetrically arranged on both the left and right sides of the connecting frame, and protrusions symmetrically arranged on each crawler block. The two-wheel design can improve the load capacity and structural stability. In addition, baffle plates are formed on the left and right edges of each crawler block to regulate the position of the load wheels on both the left and right sides, thereby further improving the ability to prevent wheels from slipping off. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a structural schematic diagram of the crawler assembly of the first embodiment at a left viewing angle. [Figure 2] FIG. 1 is a structural schematic diagram of the crawler assembly of the first embodiment at a right viewing angle. [Figure 3] FIG. 2 is an enlarged view of part A in FIG. [Figure 4] FIG. 1 is a structural schematic diagram of two adjacent crawler blocks hinged together in the first embodiment. [Figure 5] FIG. 2 is a structural schematic diagram of the crawler block of the first embodiment at a first viewing angle. [Figure 6]FIG. 10 is a schematic structural view of the crawler block of the first embodiment at a second viewing angle. [Figure 7] FIG. 2 is a cross-sectional view of a load wheel and a crawler according to the first embodiment. [Figure 8] FIG. 2 is a cross-sectional view of a guide wheel and a crawler according to the first embodiment. [Figure 9] FIG. 10 is a structural schematic diagram of a hand truck according to a second embodiment. [Figure 10] 10 is a structural schematic diagram of a connecting frame and a bracket according to a second embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is for illustrative purposes only and does not constitute any limitation on the present invention and its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without any creative work are also within the scope of protection of the present invention.

[0020] It should be noted that the terminology used herein is for the purpose of describing particular embodiments and is not intended to limit the exemplary embodiments of the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and when used herein, the terms "comprises" and / or "includes" are understood to indicate the presence of features, steps, operations, devices, assemblies, and / or combinations thereof.

[0021] In describing the present invention, it should be understood that the orientations or positional relationships indicated by directional terms, such as "front, back, up, down, left, right," "lateral, longitudinal, vertical, horizontal," and "top, bottom" are generally based on the orientations or positional relationships shown in the drawings, and are intended solely to facilitate the description and simplification of the present invention; unless otherwise stated, these directional terms do not indicate or suggest that the indicated devices or elements have a particular orientation or must be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present invention; and the directional terms "inside, outside" refer to the inside or outside of the outline of each member itself.

[0022] It should also be noted that the use of terms such as "first" and "second" to define components is intended to facilitate distinction between corresponding components, and unless otherwise specified, the terms have no special meaning and therefore cannot be understood to limit the scope of protection of the present invention.

[0023] Example 1 1 to 3, this embodiment provides a crawler assembly 100 for use in a vehicle such as a hand truck. The crawler assembly 100 includes a crawler 1 and a plurality of load wheels 2. The crawler 1 is formed by joining a plurality of crawler blocks 11 together, and each of the crawler blocks 11 has a protrusion 111 formed on the inner surface thereof. The load wheels 2 are located inside the crawler 1 and are in load contact with the crawler 1, and the load wheels 2 apply their gravity to the crawler 1. The number of load wheels 2 can be adjusted as needed, and a groove 21 is formed on the radial outer surface of each load wheel 2. When the crawler 1 runs, the load wheels 2 rotate and are always engaged with the protrusion 111 on at least one crawler block 11 via the groove 21.

[0024] As described above, the crawler assembly 100 provided by this embodiment differs from the prior art in that, due to the fit between the grooves 21 on the load wheels 2 and the protrusions 111 on the crawler blocks 11, on the one hand, the support area is increased, allowing the size of the load wheels 2 to be reduced for the same load capacity, reducing costs and increasing the load capacity for the same size load wheels 2; on the other hand, the protrusions 111 act as stoppers for the grooves 21, effectively preventing the load wheels 2 from detaching sideways, improving structural stability and safety. Furthermore, in this embodiment, the crawler 1 is installed by connecting multiple crawler blocks 11, and all the protrusions 111 are not a continuous unit but are separated into multiple crawler blocks 11. Since the complete protrusion requires a certain degree of flexibility, only soft materials such as rubber can be used. In this embodiment, the crawler blocks 11 and the protrusions 111 thereon can be made of rigid materials such as metal or hard plastic, improving strength and reliability.

[0025] 4 to 6, in this embodiment, the plurality of crawler blocks 11 are connected together using a hinge connection method. Specifically, the plurality of crawler blocks 11 are hinged together in sequence, and each crawler block 11 has the same structure. Each crawler block 11 is provided with a first hinge connection structure 1121 that can be hingedly connected to the preceding crawler block 11 and fitted thereto, and a second hinge connection structure 1122 that can be hingedly connected to the succeeding crawler block 11 and fitted thereto. For example, the first hinge connection structure 1121 can be an axis and the second hinge connection structure 1122 can be a hole, or the first hinge connection structure 1121 can be a hole and the second hinge connection structure 1122 can be an axis, or both the first hinge connection structure 1121 and the second hinge connection structure 1122 can be holes, and the hinge connection can be achieved by inserting the hinge connection axis 1123.

[0026] Preferably, in this embodiment, the first hinge connection structure 1121 is the first hinge connection hole 11211, and the second hinge connection structure 1122 is the second hinge connection hole 11221. When connecting the two adjacent crawler blocks 11, the first hinge connection hole 11211 and the second hinge connection hole 11221 are inserted through the hinge connection shaft 1123 into the first hinge connection hole 11211 and the second hinge connection hole 11221, and are connected and positioned via fasteners such as screws and nuts, thereby realizing the hinge connection of the two adjacent crawler blocks 11. Furthermore, in this embodiment, a hinge connection block 112 is formed protruding from the central inner part of the crawler block 11, and the first hinge connection hole 11211 and the second hinge connection hole 11221 are formed in the hinge connection block 112, the front side of the hinge connection block 112 where the first hinge connection hole 11211 is provided protrudes from the main body of the crawler block 11, and a connecting groove 1124 is formed in the middle of this protruding part to fit with the rear side of the hinge connection block 112 where the second hinge connection hole 11221 is provided, and the first hinge connection hole 11211 is formed by penetrating on both the left and right sides of this protruding part, and the second hinge connection hole 11221 is formed by penetrating on the rear side of the hinge connection block 112.

[0027] At least two first hole-side molding grooves 11212 are formed radially outward of each first hinge coupling hole 11211 in the hinge coupling block 112. As shown in Figures 4 and 5, taking the left-side first hinge coupling hole 11211 as an example, the two first hole-side molding grooves 11212 are located at the upper left and lower right, respectively, and are arranged closely together, so that the first hinge coupling holes 11211 that penetrate from left to right are formed at the groove bottoms of the two first hole-side molding grooves 11212. To ensure effective connection of the crawler blocks 11, high dimensional accuracy of the crawler blocks 11 is required. Therefore, this embodiment is preferably manufactured by pressure casting. In this embodiment, the front side of the hinge connection block 112, where the first hinge connection hole 11211 is provided, is installed to protrude from the main body of the crawler block 11, facilitating the hinge connection between each crawler block 11. The first hole side molding groove 11212 may also be provided at the upper and lower positions of this protruding part, thereby simplifying the mold; in this case, the mold design only needs to be opened and closed in the vertical direction, and no sliding mechanism is required.

[0028] Similarly, at least two second hole-side molding grooves 11222 are formed radially outward of the second hinge coupling hole 11221 in the hinge coupling block 112, and as shown in Figures 5 and 6, there are a total of three second hole-side molding grooves 11222, two of which are located at the upper left and upper right, respectively, and the third second hole-side molding groove 11222 is located at the rear, and the three second hole-side molding grooves 11222 are arranged closely together, thereby forming the second hinge coupling hole 11221 that penetrates left and right at the groove bottoms of the three second hole-side molding grooves 11222. Because the protrusions 111 are present on the left and right sides of the crawler block 11, the third second hole-side molding groove 11222 is arranged at the rear, which facilitates mold design and processing.

[0029] 4 and 5, in this embodiment, a protrusion 113 is provided on the front side of each crawler block 11, and preferably two such protrusions 113 are provided symmetrically, so that when two adjacent crawler blocks 11 come into contact, the rear crawler block 11 comes into contact with the front crawler block 11 via the protrusion 113, with a small contact area, and as a result, there is a gap between the adjacent crawler blocks 11, for example, between the left and right of the two protrusions 113, making it easier to remove foreign objects and preventing foreign objects from becoming trapped between the two crawler blocks 11. Of course, in other embodiments, the protrusion 113 can also be provided on the rear side of each crawler block 11, and the position and size and shape of the protrusions 113 can be set as needed.

[0030] 1 and 2, the crawler assembly 100 of this embodiment further includes a connection frame 3, and the load wheels 2 are symmetrically disposed on both the left and right sides of the connection frame 3. The two symmetrical load wheels 2 can share a single connection shaft, and protrusions 111 are symmetrically disposed on both the left and right sides of the connection frame 3 corresponding to each crawler block 11. This two-wheel design can improve the load capacity and structural stability.

[0031] Preferably, in this embodiment, stopper edges 114 are further formed on the left and right edges of each crawler block 11, i.e., the outer edges of each protrusion 111, to regulate the positions of the load wheels 2 located on both the left and right sides, thereby further improving the ability to prevent wheels from running off.

[0032] Preferably, in this embodiment, multiple load wheels 2 are provided on both the left and right sides of the connecting frame 3, although the specific number can be set as needed. The multiple load wheels 2 on each side are divided into M sets, where M is greater than or equal to 2, for example, 3 sets as shown in Figures 1 and 2, each set containing three load wheels 2, with a certain interval between every two adjacent sets of load wheels 2 that is greater than the distance between any two adjacent load wheels 2 in a set, making it easier to remove foreign objects.

[0033] 3 to 6, in this embodiment, the protrusions 111 on the crawler blocks 11 are strip-shaped along the traveling direction, the protrusions 111 on the same side of each crawler block 11 are in the same longitudinal plane, and the grooves 21 on the load wheels 2 are formed over the entire radial outer surface of the load wheels 2. Preferably, as shown in Fig. 7, the cross section of the protrusions 111 on the crawler blocks 11 is arc-shaped, and the cross section of the grooves 21 on the load wheels 2 is arc-shaped, with the arc-shaped tops of the protrusions 111 being tightly fitted with the arc-shaped bottoms of the grooves 21, thereby improving the support capacity, and there is a certain gap between the arc-shaped left and right sides of the protrusions 111 and the arc-shaped left and right sides of the grooves 21, making steering easier.

[0034] 1 and 2, the crawler assembly 100 of this embodiment further includes guide wheels 4, which are provided on both the front and rear sides of the entire crawler 1 and symmetrically on the left and right sides of the connecting frame 3, and which have a certain height relative to the load wheels 2. They are mainly used for steering and not for carrying loads. Furthermore, as shown in FIG. 8, a trapezoidal groove 41 is formed on the radial outer surface of the guide wheel 4, and the guide wheel 4 is in tight contact with the arc-shaped side edge of the protrusion 111 on the crawler block 11 via the inclined surface of this trapezoidal groove 41, so that the bottom surface of the trapezoidal groove 41 does not contact the arc-shaped top of the protrusion 111, facilitating steering.

[0035] As can be seen from the above, the crawler assembly provided in this embodiment has improved anti-skid and support capabilities due to the engagement between the protrusions on the crawler blocks and the grooves on the load wheels, and the crawler assembly also has the characteristics of being low cost, stable in structure, and easy to manufacture and assemble.

[0036] Example 2 9 and 10 , this embodiment provides a hand truck 500, which includes at least one crawler assembly 100 described in embodiment 1. Specifically, the hand truck 500 of this embodiment includes two crawler assemblies 100, a handle 200, and a tray 300, the handle 200 being provided on the tray 300, the left bottom of the tray 300 being attached to the connection frame 3 of one of the crawler assemblies 100 via two brackets 400, and the right bottom of the tray 300 being attached to the connection frame 3 of the other crawler assembly 100 via two brackets 400. Of course, in other embodiments, the number of crawler assemblies 100 can be configured as needed, for example, one or more.

[0037] In this embodiment, the bracket 400 is a U-shaped bracket and is installed in an inverted manner, and the connecting frame 3 is preferably made of an aluminum section, such as GY-4080C aluminum section, with through-slots 31 formed on both its left and right sides in the front-to-rear direction. When installing the bracket 400, the left and right sides of the bracket 400 are connected via mounting bolts 51, mounting nuts 52, and support tubes 53, respectively. The heads of the mounting bolts 51 can be placed in the through-slots 31, making it easy to adjust the front-to-rear positions of the bracket 400 and tray 300 relative to the connecting frame 3, and then lock them in place after adjustment. This installation allows the crawler assembly 100 to be compatible with trays 300 and brackets 400 of various sizes. For example, even if the size of the tray 300 changes and the spacing between the two brackets 400 on the same side changes, installation can be easily performed without requiring the connecting frame 3 to drill multiple mounting holes.

[0038] As can be seen from the above, the hand truck provided by this embodiment employs the crawler assembly described in the first embodiment, and has the features of a stable structure, easy steering, and easy installation.

[0039] The above description is merely a preferred specific embodiment of the present invention, and the protection scope of the present invention is not limited thereto. Those skilled in the art may make equivalent substitutions or modifications based on the technical solutions of the present invention and the ideas of the invention within the technical scope disclosed in the present invention, and these shall also be included in the protection scope of the present invention. [Explanation of symbols]

[0040] Crawler assembly 100, handle 200, tray 300, bracket 400, hand cart 500, Crawler 1, crawler block 11, protrusion 111, hinge connection block 112, first hinge connection structure 1121, first hinge connection hole 11211, first hole side molding groove 11212, second hinge connection structure 1122, second hinge connection hole 11221, second hole side molding groove 11222, hinge connection shaft 1123, connecting groove 1124, protrusion 113, stopper edge 114, load wheel 2, recessed groove 21, connecting frame 3, through groove 31, guide wheel 4, trapezoidal groove 41, mounting bolt 51, mounting nut 52, support tube 53.

Claims

1. 1. A crawler assembly comprising: A crawler (1) formed by joining together a plurality of crawler blocks (11), each having a protrusion (111) formed on an inner surface thereof; A crawler assembly comprising: a load wheel (2) located inside the crawler (1) and in load contact with the crawler (1), the load wheel (2) having a groove (21) formed on its radially outer surface that holds the projection (111) in engagement with the load wheel (2).

2. The crawler assembly of claim 1, characterized in that the plurality of crawler blocks (11) are hingedly connected in sequence from head to tail, and each crawler block (11) is provided with a first hinge connection structure (1121) that is hingedly connected to and fits with the previous crawler block (11) and a second hinge connection structure (1122) that is hingedly connected to and fits with the subsequent crawler block (11).

3. The first hinge coupling structure (1121) is a first hinge coupling hole (11211), and the second hinge coupling structure (1122) is a second hinge coupling hole (11221), which penetrates the first hinge coupling hole (11211) and the second hinge coupling hole (11221) of two adjacent crawler blocks (11) via a hinge coupling axis (1123) to realize hinge coupling of the two crawler blocks (11); A crawler assembly as described in claim 2, characterized in that a hinge connection block (112) is provided inside the crawler block (11), the first hinge connection hole (11211) and the second hinge connection hole (11221) are formed in the hinge connection block (112), at least two first hole side molding grooves (11212) are formed radially outward of the first hinge connection hole (11211) in the hinge connection block (112), and at least two second hole side molding grooves (11222) are formed radially outward of the second hinge connection hole (11221) in the hinge connection block (112).

4. 2. The crawler assembly according to claim 1, wherein a protrusion (113) is further provided on the front side of each crawler block (11) or the rear side of each crawler block (11), and a stop edge (114) is further formed on the outer edge of the protrusion (111) in each crawler block (11).

5. 2. The crawler assembly according to claim 1, wherein the protrusion (111) has a stripe shape along the traveling direction, the cross section of the protrusion (111) is arc-shaped, the cross section of the groove (21) is arc-shaped, and the top of the protrusion (111) is tightly fitted into the bottom of the groove (21).

6. The crawler assembly according to any one of claims 1 to 5, characterized in that the crawler assembly further includes a connecting frame (3), the load wheels (2) are symmetrically arranged on both the left and right sides of the connecting frame (3), the protrusions (111) are also symmetrically arranged on each of the crawler blocks (11), and stopper edges (114) are further formed on the left and right edges of each of the crawler blocks (11).

7. The crawler assembly according to claim 6, characterized in that a plurality of load wheels (2) are provided on both the left and right sides of the connecting frame (3), the plurality of load wheels (2) are divided into M sets, M≧2, and a fixed interval is provided between every two adjacent sets of load wheels (2).

8. The crawler assembly according to claim 1 or 5, characterized in that the crawler assembly further includes a guide wheel (4), a trapezoidal groove (41) formed on the radial outer surface of the guide wheel (4), and the guide wheel (4) is fitted tightly with a protrusion (111) on the crawler block (11) via an inclined surface of the trapezoidal groove (41).

9. A hand truck comprising at least one crawler assembly according to any one of claims 1 to 8.

10. 10. The handcart (500) according to claim 9, further comprising a tray (300) and a bracket (400), the tray (300) being attached to a connecting frame (3) of the crawler assembly via the bracket (400), a through groove (31) penetrating in the front-to-rear direction being formed on both the left and right sides of the connecting frame (3), the bracket (400) being a U-shaped bracket, the heads of the mounting bolts (51) on both the left and right sides of the U-shaped bracket being positioned in the through groove (31), and the connecting frame (3) being an aluminum profile.

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