Auxiliary step ladder

Abstract

The utility model discloses an auxiliary step ladder, which belongs to the technical field of step ladders and is characterized in that when the auxiliary step ladder is assembled, a user places an auxiliary step frame beside a main step frame and enables a second connecting hole of the auxiliary step frame to directly face a first connecting hole of the main step frame; a first fastener is arranged in the first connecting hole and the second connecting hole in a penetrating mode to enable the main step frame and the auxiliary step frame to be connected together, and a fourth connecting hole of the armrest frame is right opposite to a third connecting hole of a first supporting rod on the auxiliary step frame. The second fastening piece is arranged in the third connecting hole and the fourth connecting hole in a penetrating mode so that the handrail frame and the first supporting rod on the auxiliary step frame can be connected together, assembling of the auxiliary step ladder is completed, tools are not needed for assembling, and assembling of the auxiliary step ladder is more convenient and faster.

Description

Technical Field

[0001] This utility model relates to the field of staircase technology, and in particular to an auxiliary staircase. Background Technology

[0002] Assistive steps help users with mobility impairments ascend and descend higher steps, such as bathtubs and beds. They also assist users in climbing and using higher surfaces. Assistive steps are typically equipped with handrails to help users lean on and move up and down, preventing falls. Currently, for ease of transportation and storage, assistive steps are designed to be modular, allowing users to assemble them at home. However, current assistive steps require specific tools for assembly, such as wrenches and screwdrivers, making the assembly process inconvenient for users. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an auxiliary step ladder that does not require the use of tools for assembly, making the assembly of the auxiliary step ladder more convenient.

[0004] The auxiliary step ladder according to an embodiment of the present utility model includes:

[0005] The main step frame is equipped with a first connecting hole;

[0006] The secondary step frame is provided with a second connecting hole, and the secondary step frame is also provided with a first support rod, the first support rod being provided with a third connecting hole;

[0007] The first fastener is detachably connected to the second connecting hole and the first connecting hole;

[0008] The handrail frame is equipped with a fourth connecting hole;

[0009] The second fastener is detachably connected to the fourth connecting hole and the third connecting hole.

[0010] The auxiliary step ladder according to the embodiment of this utility model has at least the following beneficial effects: When assembling the auxiliary step ladder, the user places the auxiliary step frame next to the main step frame, aligning the second connecting hole of the auxiliary step frame with the first connecting hole of the main step frame. The main step frame and the auxiliary step frame are connected together by using the first fastener through the first and second connecting holes. The fourth connecting hole of the handrail frame is aligned with the third connecting hole of the first support rod on the auxiliary step frame. The handrail frame is connected to the first support rod on the auxiliary step frame by using the second fastener through the third and fourth connecting holes. The assembly of the auxiliary step ladder is completed without the need for tools, making the assembly of the auxiliary step ladder more convenient.

[0011] According to some embodiments of the present invention, the first fastener includes:

[0012] The first nut is fixed to the auxiliary step frame;

[0013] A first screw passes through the first connecting hole and the second connecting hole, and the first screw cooperates with the first nut;

[0014] The first knob is fixed to the first screw.

[0015] According to some embodiments of this utility model, the handrail frame is provided with the fourth connecting hole on both its front and rear sides, the main step frame is also provided with the fifth connecting hole on both its front and rear sides, and the auxiliary step ladder further includes:

[0016] The second support rod has a sixth connecting hole at the bottom and a seventh connecting hole at the top. The second support rod and the auxiliary step frame are respectively located on the front and rear sides of the main step frame.

[0017] The third fastener is detachably connected to the sixth connecting hole and the fifth connecting hole;

[0018] There are at least two second fasteners, and at least one of the second fasteners connects the seventh connecting hole to the fourth connecting hole.

[0019] According to some embodiments of the present invention, the second fastener includes:

[0020] The second screw passes through the fourth connecting hole and the third connecting hole, or passes through the seventh connecting hole and the fourth connecting hole;

[0021] The second nut is fitted into the second screw;

[0022] The second knob is fixed to the second nut.

[0023] According to some embodiments of this utility model, the seventh connecting hole and the third connecting hole are respectively provided with a first anti-rotation structure. The first anti-rotation structure cooperates with the head of the second screw to restrict the degree of freedom of the second screw to rotate around the axis.

[0024] According to some embodiments of the present invention, the bottom of the first support rod is provided with an eighth connecting hole, and there are at least two third fasteners, at least one of which is detachably connected to the eighth connecting hole and the fifth connecting hole.

[0025] According to some embodiments of the present invention, the front and rear sides of the main step frame are respectively provided with the first connecting hole, and there are at least two sixth connecting holes. The positions of the two sixth connecting holes correspond to the first connecting hole and the fifth connecting hole, respectively. At least one third fastener can detachably connect the sixth connecting hole and the first connecting hole.

[0026] According to some embodiments of the present invention, the third fastener includes:

[0027] The third screw passes through the sixth connecting hole and the fifth connecting hole, or through the eighth connecting hole and the fifth connecting hole, or through the sixth connecting hole and the first connecting hole;

[0028] The third nut is fitted into the third screw;

[0029] The third knob is fixed to the third nut.

[0030] According to some embodiments of this utility model, the sixth connecting hole and the eighth connecting hole are respectively provided with a second anti-rotation structure. The second anti-rotation structure cooperates with the head of the third screw to restrict the degree of freedom of the third screw to rotate around the axis.

[0031] According to some embodiments of the present invention, the front and rear sides of the handrail frame are respectively provided with a plurality of fourth connecting holes, and the plurality of fourth connecting holes are distributed at intervals along the vertical direction. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of an auxiliary step ladder according to an embodiment of the present invention;

[0033] Figure 2 This is an exploded view of an auxiliary step ladder according to an embodiment of the present invention;

[0034] Figure 3 yes Figure 2 Enlarged diagram of A in the middle;

[0035] Figure 4 yes Figure 2 Enlarged diagram of B in the diagram;

[0036] Figure 5 This is an exploded view of an auxiliary step ladder according to an embodiment of the present invention from another angle;

[0037] Figure 6 yes Figure 5 An enlarged diagram of C in the diagram.

[0038] Reference numerals: Main step frame 100, first connecting hole 110, fifth connecting hole 120, auxiliary step frame 200, second connecting hole 210, first support rod 220, third connecting hole 230, eighth connecting hole 240, first fastener 300, first screw 310, first knob 320, handrail frame 400, fourth connecting hole 410, second fastener 500, second screw 510, second nut 520, second knob 530, second support rod 600, sixth connecting hole 610, seventh connecting hole 620, third fastener 700, third screw 710, third nut 720, first anti-rotation structure 800, second anti-rotation structure 900. Detailed Implementation

[0039] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0040] In the description of this utility model, it should be understood that the terms front, back, up, down, axial, circumferential, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0041] In the description of this utility model, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly specifying the number of indicated technical features or their sequential relationship.

[0042] In the description of this utility model, it should be noted that terms such as "setting," "installing," and "connecting" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0043] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of this utility model, not all embodiments.

[0044] Reference Figures 1 to 6 As shown in the figure, this utility model embodiment provides an auxiliary step ladder.

[0045] The auxiliary step ladder includes a main step frame 100, a secondary step frame 200, a first fastener 300, a handrail frame 400, and a second fastener 500.

[0046] The main step frame 100 is provided with a first connecting hole 110 that runs horizontally through it, and the auxiliary step frame 200 is provided with a second connecting hole 210 that runs horizontally through it. The position of the second connecting hole 210 corresponds to the position of the first connecting hole 110. A first fastener 300 passes through the first connecting hole 110 and the second connecting hole 210 to make the main step frame 100 and the auxiliary step frame 200 detachably connected.

[0047] The first connecting hole 110 can be located on the front or rear side of the main step frame 100. The first connecting hole 110 extends through the front and rear direction. Alternatively, the first connecting hole 110 can be provided on the front and rear sides of the main step frame 100 respectively. The second connecting hole 210 is located on the front side of the auxiliary step frame 200 and extends from front to back.

[0048] The auxiliary step frame 200 is provided with an upwardly extending first support rod 220, the first support rod 220 is provided with a third connecting hole 230 that runs horizontally through it, and the handrail frame 400 is provided with a fourth connecting hole 410 that runs horizontally through it. The position of the fourth connecting hole 410 corresponds to the position of the third connecting hole 230. The second fastener 500 passes through the third connecting hole 230 and the fourth connecting hole 410 to make the first support rod 220 and the handrail frame 400 detachably connected.

[0049] When assembling the auxiliary step ladder, the user places the auxiliary step frame 200 next to the main step frame 100, with the second connecting hole 210 of the auxiliary step frame 200 aligned with the first connecting hole 110 of the main step frame 100. The main step frame 100 and the auxiliary step frame 200 are connected together by using the first fastener 300 through the first connecting hole 110 and the second connecting hole 210. The fourth connecting hole 410 of the handrail frame 400 is aligned with the third connecting hole 230 of the first support rod 220 on the auxiliary step frame 200. The handrail frame 400 is connected to the first support rod 220 on the auxiliary step frame 200 by using the second fastener 500 through the third connecting hole 230 and the fourth connecting hole 410. This completes the assembly of the auxiliary step ladder without the need for tools, making the assembly of the auxiliary step ladder more convenient.

[0050] In some embodiments, refer to Figure 4 As shown, the first fastener 300 includes a first nut, a first screw 310, and a first knob 320.

[0051] The first nut is installed inside the auxiliary step frame 200, and the axis of the first nut coincides with the axis of the second connecting hole 210. The first knob 320 is installed on the head of the first screw 310 so that the first knob 320 and the first screw 310 rotate synchronously.

[0052] Align the second connecting hole 210 of the auxiliary step frame 200 with the first connecting hole 110 of the main step frame 100. Then, insert the first screw 310 into the auxiliary step frame 200 by passing it through the first connecting hole 110 and the second connecting hole 210 in sequence. Then, rotate the first knob 320 in the forward direction to screw the first screw 310 into the first nut inside the auxiliary step frame 200, so that the first screw 310 engages with the first nut, thereby making the main step frame 100 detachably connected to the auxiliary step frame 200. By rotating the first knob 320 in the reverse direction, the first screw 310 is unscrewed from the first nut, thereby allowing the main step frame 100 and the auxiliary step frame 200 to be disassembled.

[0053] Users can rotate the first knob 320 to drive the first screw 310 to rotate, thereby tightening or loosening the first screw 310 and the first nut. Users do not need to use tools to assemble the main step frame 100 and the auxiliary step frame 200, making the assembly of the auxiliary step ladder more convenient.

[0054] In some embodiments, refer to Figures 1 to 3 As shown, the handrail 400 has a U-shaped structure with both ends bent downwards. The front and rear ends of the handrail 400 are respectively provided with a fourth connecting hole 410 that runs through the front and rear directions.

[0055] Reference Figure 5 and Figure 6 As shown, the main step frame 100 has a fifth connecting hole 120 on both the front and rear sides.

[0056] The auxiliary step ladder is also provided with a second support rod 600 and a third fastener 700. The bottom of the second support rod 600 is provided with a sixth connecting hole 610 that runs through the front and back direction, and the top of the second support rod 600 is provided with a seventh connecting hole 620 that runs through the front and back direction. The second support rod 600 is located on the front side of the main step frame 100, and the auxiliary step frame 200 is located on the rear side of the main step frame 100. The third fastener 700 passes through the sixth connecting hole 610 and the fifth connecting hole 120, so that the second support rod 600 can be detachably connected to the front side of the main step frame 100.

[0057] Two second fasteners 500 are provided. One second fastener 500 passes through the fourth connecting hole 410 at the front end of the handrail 400 and the seventh connecting hole 620 of the second support rod 600. The other second fastener 500 passes through the fourth connecting hole 410 at the rear end of the handrail 400 and the third connecting hole 230 of the first support rod 220, thereby making the first support rod 220 and the second support rod 600 detachably connected to the front and rear ends of the handrail 400, respectively.

[0058] The second support rod 600 is detachably connected to the main step frame 100 via a third fastener 700, allowing users to assemble the second support rod 600 and the main step frame 100 themselves. The first support rod 220 is detachably connected to the rear end of the handrail frame 400 via a second fastener 500, and the second support rod 600 is detachably connected to the front end of the handrail frame 400 via another second fastener 500, allowing users to assemble the second support rod 600, the first support rod 220, and the handrail frame 400 themselves. Furthermore, the first support rod 220 and the second support rod 600 are connected to the front and rear ends of the handrail frame 400 respectively, which helps to make the handrail frame 400 more stable and prevent the handrail frame 400 from swaying.

[0059] In some embodiments, refer to Figure 3 As shown, there are two second fasteners 500. Each second fastener 500 is provided with a second screw 510, a second nut 520 and a second knob 530. The second knob 530 is installed on the outside of the second nut 520 and rotates synchronously with the second nut 520.

[0060] In the second fastener 500 used to connect the front end of the handrail 400 and the second support rod 600, the second screw 510 passes through the fourth connecting hole 410 at the front end of the handrail 400 and the seventh connecting hole 620 at the top of the second support rod 600. The second nut 520 engages with the tail end of the second screw 510. The user can tighten or loosen the second nut 520 relative to the second screw 510 by rotating the second knob 530, thereby making the second support rod 600 detachably connected to the front end of the handrail 400.

[0061] In the second fastener 500 used to connect the rear end of the handrail frame 400 and the first support rod 220, the second screw 510 passes through the third connecting hole 230 at the top of the first support rod 220 and the fourth connecting hole 410 at the rear end of the handrail frame 400. The second nut 520 cooperates with the tail end of the second screw 510 and is used to tighten or loosen the second nut 520 relative to the second screw 510 by rotating the second knob 530, thereby making the first support rod 220 detachably connected to the rear end of the handrail frame 400.

[0062] Users can rotate the second knob 530 to drive the second nut 520 to rotate, thereby tightening or loosening the second screw 510 and the second nut 520. This eliminates the need for users to use tools to assemble the handrail frame 400, the first support rod 220, and the second support rod 600, making the assembly of the auxiliary step ladder more convenient.

[0063] In some embodiments, refer to Figure 3 As shown, a first anti-rotation structure 800 is provided on the side wall of the seventh connecting hole 620. The first anti-rotation structure 800 makes the front end of the seventh connecting hole 620 polygonal. The third connecting hole 230 is also provided with a first anti-rotation structure 800 on its side wall. The first anti-rotation structure 800 makes the front end of the third connecting hole 230 polygonal. The shape of the first anti-rotation structure 800 matches the shape of the head of the second screw 510. When the head of the second screw 510 abuts against the first anti-rotation structure 800, it prevents the second screw 510 from rotating in the seventh connecting hole 620 or the third connecting hole 230.

[0064] The first anti-rotation structure 800, utilizing the third connecting hole 230 and the seventh connecting hole 620, prevents the second screw 510 from rotating. Without the user needing to use tools to clamp the head of the second screw 510 to prevent its rotation, the user can simply turn the second knob 530 to tighten or loosen the tail end of the second screw 510. This eliminates the need for the user to use tools to assemble the handrail frame 400, the first support rod 220, and the second support rod 600, making the assembly of the auxiliary step ladder more convenient.

[0065] In some embodiments, refer to Figures 1 to 2 As shown, the bottom of the first support rod 220 is also provided with an eighth connecting hole 240 that runs through the front and rear directions. There are two third fasteners 700. One third fastener 700 passes through the sixth connecting hole 610 of the second support rod 600 and the fifth connecting hole 120 on the front side of the main step frame 100, so that the second support rod 600 can be detachably connected to the front side of the main step frame 100. The other third fastener 700 passes through the eighth connecting hole 240 of the first support rod 220 and the fifth connecting hole 120 on the rear side of the main step frame 100, so that the first support rod 220 can be detachably connected to the rear side of the main step frame 100.

[0066] The third fastener 700 is detachably connected to the bottom of the first support rod 220 and the rear side of the main step frame 100, which helps to improve the connection strength between the first support rod 220 and the main step frame 100, making the first support rod 220 more stable.

[0067] In some embodiments, refer to Figures 1 to 6As shown, the second support rod 600 is provided with two sixth connecting holes 610, which are distributed vertically at intervals. The front and rear sides of the main step frame 100 are respectively provided with a first connecting hole 110 that runs through in the front-rear direction. The first connecting hole 110 on the rear side of the main step frame 100 is used to connect the auxiliary step frame 200. There are three third fasteners 700. The first third fastener 700 passes through the sixth connecting hole 610 on the lower side of the second support rod 600 and the first connecting hole 110 on the front side of the main step frame 100. The second third fastener 700 passes through the sixth connecting hole 610 on the upper side of the second support rod 600 and the fifth connecting hole 120 on the front side of the main step frame 100. The third third fastener 700 passes through the eighth connecting hole 240 of the first support rod 220 and the fifth connecting hole 120 on the rear side of the main step frame 100.

[0068] Using two third fasteners 700 to connect the bottom of the second support rod 600 and the front side of the main step frame 100 helps to improve the connection strength between the second support rod 600 and the main step frame 100, making the second support rod 600 more stable.

[0069] In some embodiments, refer to Figure 5 and Figure 6 As shown, there are three third fasteners 700. Each third fastener 700 is provided with a third screw 710, a third nut 720 and a third knob 730. The third knob 730 is installed on the outside of the third nut 720 and rotates synchronously with the third nut 720.

[0070] In the third fastener 700 used to connect the rear side of the main step frame 100 and the first support rod 220, the third screw 710 passes through the fifth connecting hole 120 on the rear side of the main step frame 100 and the eighth connecting hole 240 at the bottom of the first support rod 220. The third nut 720 cooperates with the tail end of the third screw 710. The user can tighten or loosen the third nut 720 relative to the third screw 710 by rotating the third knob 730, thereby making the first support rod 220 detachably connected to the rear side of the main step frame 100.

[0071] Two third fasteners 700 are used to connect the front side of the main step frame 100 and the second support rod 600. One third screw 710 passes through the fifth connecting hole 120 on the front side of the main step frame 100 and the sixth connecting hole 610 on the upper side of the bottom of the second support rod 600. The other third screw 710 passes through the first connecting hole 110 on the front side of the main step frame 100 and the sixth connecting hole 610 on the lower side of the bottom of the second support rod 600. Two third nuts 720 respectively engage with the tail ends of the two third screws 710. The user can tighten or loosen the third nuts 720 relative to the third screws 710 by rotating the third knob 730, thereby making the second support rod 600 detachably connected to the front side of the main step frame 100.

[0072] Users can turn the third knob 730 to drive the third nut 720 to rotate, thereby tightening or loosening the third screw 710 and the third nut 720. This eliminates the need for users to use tools to assemble the main step frame 100, the first support rod 220, and the second support rod 600, making the assembly of the auxiliary step ladder more convenient.

[0073] In some embodiments, refer to Figure 6 As shown, each sixth connecting hole 610 has a second anti-rotation structure 900 on its sidewall, which makes the front end of the sixth connecting hole 610 polygonal; the eighth connecting hole 240 also has a second anti-rotation structure 900 on its sidewall, which makes the rear end of the eighth connecting hole 240 polygonal.

[0074] The second anti-rotation structure 900 matches the shape of the third screw 710, and the second anti-rotation structure 900 abuts against the head of the third screw 710 to restrict the degree of freedom of rotation of the third screw 710.

[0075] The second anti-rotation structure 900, utilizing the sixth connecting hole 610 and the eighth connecting hole 240, prevents the third screw 710 from rotating. Without the user needing to use tools to clamp the head of the third screw 710 to prevent its rotation, the user can simply turn the third knob 730 to tighten or loosen the tail end of the third screw 710. This eliminates the need for the user to use tools to assemble the main step frame 100, the first support rod 220, and the second support rod 600, making the assembly of the auxiliary step ladder more convenient.

[0076] In some embodiments, refer to Figure 1 and Figure 2 As shown, the front and rear ends of the handrail frame 400 are respectively provided with multiple fourth connection holes 410. The multiple fourth connection holes 410 are distributed at intervals from top to bottom, and the positions of the fourth connection holes 410 at the front and rear ends are respectively arranged opposite to each other.

[0077] The handrail 400 is connected to the third connecting hole 230 of the first support rod 220 and the seventh connecting hole 620 of the second support rod 600 through the fourth connecting hole 410 at different heights. The user can adjust the height of the handrail 400 to suit the user's height.

[0078] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. An auxiliary step ladder, characterized in that, include: The main step frame is equipped with a first connecting hole; The secondary step frame is provided with a second connecting hole, and the secondary step frame is also provided with a first support rod, the first support rod being provided with a third connecting hole; The first fastener is detachably connected to the second connecting hole and the first connecting hole; The handrail frame is equipped with a fourth connecting hole; The second fastener is detachably connected to the fourth connecting hole and the third connecting hole.

2. The auxiliary step ladder according to claim 1, characterized in that, The first fastener includes: The first nut is fixed to the auxiliary step frame; A first screw passes through the first connecting hole and the second connecting hole, and the first screw cooperates with the first nut; The first knob is fixed to the first screw.

3. The auxiliary step ladder according to claim 1, characterized in that, The handrail frame is provided with the fourth connecting hole on both its front and rear sides, and the main step frame is also provided with the fifth connecting hole on both its front and rear sides. The auxiliary step ladder also includes: The second support rod has a sixth connecting hole at the bottom and a seventh connecting hole at the top. The second support rod and the auxiliary step frame are respectively located on the front and rear sides of the main step frame. The third fastener is detachably connected to the sixth connecting hole and the fifth connecting hole; There are at least two second fasteners, and at least one of the second fasteners connects the seventh connecting hole to the fourth connecting hole.

4. The auxiliary step ladder according to claim 3, characterized in that, The second fastener includes: The second screw passes through the fourth connecting hole and the third connecting hole, or passes through the seventh connecting hole and the fourth connecting hole; The second nut is fitted into the second screw; The second knob is fixed to the second nut.

5. The auxiliary step ladder according to claim 4, characterized in that, The seventh connecting hole and the third connecting hole are respectively provided with a first anti-rotation structure. The first anti-rotation structure cooperates with the head of the second screw to restrict the degree of freedom of the second screw to rotate around the axis.

6. The auxiliary step ladder according to claim 3, characterized in that, The bottom of the first support rod is provided with an eighth connecting hole, and there are at least two third fasteners, at least one of which is detachably connected to the eighth connecting hole and the fifth connecting hole.

7. The auxiliary step ladder according to claim 6, characterized in that, The main step frame is provided with the first connecting hole on the front and rear sides respectively, and there are at least two sixth connecting holes. The positions of the two sixth connecting holes correspond to the first connecting hole and the fifth connecting hole respectively. At least one of the third fasteners can be detachably connected to the sixth connecting hole and the first connecting hole.

8. The auxiliary step ladder according to claim 7, characterized in that, The third fastener includes: The third screw passes through the sixth connecting hole and the fifth connecting hole, or through the eighth connecting hole and the fifth connecting hole, or through the sixth connecting hole and the first connecting hole; The third nut is fitted into the third screw; The third knob is fixed to the third nut.

9. The auxiliary step ladder according to claim 8, characterized in that, The sixth connecting hole and the eighth connecting hole are respectively provided with a second anti-rotation structure. The second anti-rotation structure cooperates with the head of the third screw to restrict the degree of freedom of the third screw to rotate around the axis.

10. The auxiliary step ladder according to claim 3, characterized in that, The handrail frame is provided with a plurality of fourth connecting holes on its front and rear sides, and the plurality of fourth connecting holes are distributed at intervals along the vertical direction.

Images