A telescopic arm and a tail end slider gap adjustable structure thereof, engineering machinery

Abstract

The utility model discloses a telescopic arm and tail end sliding block gap adjustable structure thereof, engineering machinery, including support board, sliding block and adjusting block, support board is arranged between the outer arm and inner arm of telescopic motion can be carried out, sliding block is arranged between support board and outer arm, when the telescopic motion of outer arm relative to inner arm is carried out, and the outer arm is supported through sliding block, adjusting block is embedded in coaxial mounting hole of sliding block, support board and inner arm, adjusting block can carry out the up and down movement of axial in coaxial mounting hole, and then drive the up and down movement of sliding block, realize the gap adjustment between sliding block and outer arm, the technical scheme provided by the utility model makes the simple, efficient operation of adjusting gap, can save a lot of maintenance time and cost for customer, and each component structure is simple, and the manufacturing cost is low, and is easy to realize.

Description

Technical Field

[0001] This utility model relates to an adjustable gap structure for the slider at the tail end of a telescopic arm, belonging to the field of telescopic arm technology. Background Technology

[0002] Telescopic booms are widely used in various types of construction machinery. During their telescopic movement, they typically rely on front and rear sliders for support. With repeated use, these sliders wear down, increasing the gap between them and the boom body. This exacerbates swaying during boom movement, affecting the stability and safety of the equipment. Currently, there are mature solutions for the front slider, easily adjusting the gap using adjustable threaded blocks or screws. However, for the rear slider, since it is fixed to the inner end of the boom and difficult to access from the outside, the common method is to completely remove the inner boom and then adjust or replace the slider. This method is labor-intensive, time-consuming, costly, and causes prolonged downtime for the customer.

[0003] The currently published patent application number is 202210771734.4, and the patent title is: "An Adjustable Slider Assembly and Telescopic Boom." This patent discloses a tail-end slider structure with an adjustment window on the outer arm. The slider, wedge block, and screw constitute the adjustment mechanism. When the gap needs to be adjusted, the adjustment window is first opened, and then the screw is rotated. The screw drives the wedge block to move, and the wedge block uses its inclined surface to drive the slider to move up and down, ultimately achieving the adjustment of the gap.

[0004] However, the above technical solutions have the following shortcomings:

[0005] 1) The adjustment window is too large, which affects the strength of the arm body. In particular, the sliders on all four sides use this structure, which has a more serious impact and poses a safety hazard.

[0006] 2) The wedge-shaped slider and adjusting block have a complex structure, are difficult to machine, and have a high cost.

[0007] 3) The adjusting screw has no anti-loosening structure, resulting in poor reliability. Summary of the Invention

[0008] This invention provides an adjustable gap structure for the slider at the tail end of a telescopic arm, which addresses the shortcomings of existing technologies.

[0009] This utility model is achieved according to the following technical solution:

[0010] In a first aspect, this utility model provides a structure with an adjustable gap between the sliders at the tail end of a telescopic arm, comprising:

[0011] A support plate is positioned between the outer and inner arms, which are capable of telescopic movement.

[0012] A slider is arranged between the support plate and the outer arm. When the outer arm extends or retracts relative to the inner arm, the slider supports the outer arm.

[0013] An adjusting block is embedded in a coaxial mounting hole opened on the slider, support plate and inner arm. The adjusting block can move axially up and down in the coaxial mounting hole, thereby driving the slider to move up and down, and realizing the adjustment of the gap between the slider and the outer arm.

[0014] In some embodiments, the coaxial mounting hole is a stepped hole, which is divided into three parts: a first through hole on the inner arm; a second through hole on the support plate, the inner diameter of which is smaller than that of the first through hole; and a third through hole on the slider.

[0015] In some embodiments, the adjusting block is divided into an upper adjusting block and a lower adjusting block; the lower adjusting block is embedded in the first through hole, and the upper adjusting block is embedded in the second through hole and the third through hole, and the upper adjusting block and the lower adjusting block are fixed together; after the adjusting block moves upward axially, the lower adjusting block can push the support plate and the slider upward.

[0016] In some embodiments, a nut sleeve coaxial with the first through hole is fixed therein, the top surface of the nut sleeve does not extend beyond the top surface of the inner arm, and the bottom surface of the nut sleeve protrudes beyond the bottom surface of the inner arm; the outer peripheral surface of the lower part of the adjusting block is provided with threads, the lower part of the adjusting block is connected to the nut sleeve to form a helical pair, the upper part of the adjusting block is clearance-fitted with the second and third through holes, and the rotating adjusting block can drive the support plate and the slider to move up and down.

[0017] In some embodiments, the upper surface of the adjustment block has a vertically downward extending slot or a vertically upward extending protrusion in the center area of ​​the top surface; the outer arm has an adjustment hole, the adjustment hole and the slot or protrusion are on the same straight line along the extension and retraction direction of the outer arm, after the outer arm moves, the slot or protrusion can be aligned with the adjustment hole, and then a wrench is inserted from the adjustment hole to press against the slot or protrusion and rotate the adjustment block.

[0018] In some embodiments, the inner diameter of the third through hole is larger than that of the first through hole but smaller than that of the first through hole; the upper part of the adjusting block has a T-shaped cross-section in the vertical direction, and at least one threaded hole is provided on the flange structure of the upper part of the adjusting block; the slider or support plate is provided with a groove that mates with the threaded hole; the screw is screwed into the threaded hole, forming a helical pair with the upper part of the adjusting block; after the outer arm moves, the adjusting hole aligns with the screw, and the wrench extends from the adjusting hole to drive the screw to rotate; when the rotated screw is inserted into the groove, it can prevent the adjusting block from rotating circumferentially in the stepped hole, and the screw plays an anti-loosening role; when the rotated screw is disengaged from the groove, the screw releases its anti-loosening role on the adjusting block.

[0019] In some embodiments, the top surface of the upper part of the adjusting block is provided with a positioning groove or positioning protrusion that is connected to the threaded hole and slot or the protrusion. When the upper part of the adjusting block is rotated, the position of the positioning groove or positioning protrusion is observed to ensure that the screw can be inserted into the slot.

[0020] In some embodiments, the top surface of the lower part of the adjusting block is provided with a groove, and the upper part of the adjusting block is inserted into the groove; the upper part of the adjusting block is provided with at least one through hole opened along its axial direction, and the lower part of the adjusting block is provided with a threaded hole coaxial with the through hole. After the screw passes through the through hole, it is tightened in the threaded hole to fix the upper part and the lower part of the adjusting block together.

[0021] In some embodiments, a ring of protrusions is provided around the top surface of the support plate, the slider is attached to the top surface of the support plate, and the ring of protrusions limits the slider's position.

[0022] Secondly, this utility model provides a telescopic arm, including an outer arm, an inner arm, and the aforementioned telescopic arm tail end slider gap adjustable structure.

[0023] Thirdly, this utility model provides an engineering machine, including the above-mentioned adjustable clearance structure for the tail end slider of a telescopic arm; or, including the above-mentioned telescopic arm.

[0024] The beneficial effects of this utility model are:

[0025] 1) The slider gap can be adjusted by opening only a small hole in the outer arm, which has little impact on the strength of the arm body and high reliability.

[0026] 2) Adjusting the gap is simple and efficient, saving customers a lot of maintenance time and costs.

[0027] 3) Each component has a simple structure, low manufacturing cost, and is easy to implement.

[0028] 4) The adjusting block has an anti-loosening structure, which ensures high reliability. Attached Figure Description

[0029] The accompanying drawings, as part of this utility model, are used to provide a further understanding of the present utility model. The illustrative embodiments and descriptions of the present utility model are used to explain the present utility model, but do not constitute an undue limitation of the present utility model. Obviously, the drawings described below are merely some embodiments; those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0030] In the attached diagram:

[0031] Figure 1 This is an exploded view of an adjustable gap structure for the tail end slider of a telescopic arm according to this utility model;

[0032] Figure 2 This is a structural diagram of the upper part of the adjusting block of this utility model;

[0033] Figure 3 This is a structural diagram of the support plate of this utility model;

[0034] Figure 4 This is a cross-sectional view of a telescopic arm tail end slider gap adjustable structure according to the present invention;

[0035] Figure 5 for Figure 4 A schematic diagram of the BB side.

[0036] The attached diagram is labeled as follows: 1. Outer arm, 2. Upper part of adjusting block, 3. Slider, 4. Support plate, 5. Lower part of adjusting block, 6. Nut sleeve, 7. Inner arm, 8. Anti-loosening screw, 9. Fixing screw, 10. Adjusting hole, 11. Threaded hole, 12. Slot, 13. Positioning groove, 14. Slot hole, 15. Through hole.

[0037] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0039] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", 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.

[0040] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0041] like Figure 1 , Figure 4 As shown, an adjustable gap structure for the slider at the tail end of a telescopic arm includes a support plate 4, a slider 3, and an adjusting block. The support plate 4 is arranged between the outer arm 1 and the inner arm 7, which are capable of telescopic movement. The slider 3 is arranged between the support plate 4 and the outer arm 1, and supports the outer arm 1 when the outer arm 1 telescopically moves relative to the inner arm 2. The adjusting block is embedded in a coaxial mounting hole opened on the slider 3, the support plate 4, and the inner arm 7. The adjusting block can move axially up and down in the coaxial mounting hole, thereby driving the slider 3 to move up and down, and realizing the gap adjustment between the slider 3 and the outer arm 1.

[0042] The following provides a further explanation of the specific structure of the coaxial mounting hole mentioned above.

[0043] like Figure 4 , Figure 5 As shown, the coaxial mounting hole is a stepped hole, which is divided into three parts: a first through hole on the inner arm 7; a second through hole on the support plate 4, the inner diameter of which is smaller than that of the first through hole; and a third through hole on the slider 3.

[0044] The following provides a further explanation of the specific structure of the aforementioned adjustment block.

[0045] like Figure 1 , Figure 4 , Figure 5 As shown, the adjusting block is divided into an upper adjusting block 2 and a lower adjusting block 5; the lower adjusting block 5 is embedded in the first through hole, and the upper adjusting block 2 is embedded in the second through hole and the third through hole, and the upper adjusting block 2 and the lower adjusting block 5 are fixed together; after the adjusting block moves upward axially, the lower adjusting block 5 can push the support plate 4 and the slider 3 upward.

[0046] Further options, such as Figure 1 , Figure 4 , Figure 5 As shown, a nut sleeve 6 coaxial with it is fixed in the first through hole. The top surface of the nut sleeve 6 does not exceed the top surface of the inner arm 7, and the bottom surface of the nut sleeve 6 protrudes from the bottom surface of the inner arm 7. The outer circumferential surface of the lower part 5 of the adjusting block is provided with threads. The lower part 5 of the adjusting block is connected to the nut sleeve 6 to form a helical pair. The upper part 2 of the adjusting block is in clearance fit with the second and third through holes. The rotating adjusting block can drive the support plate 4 and the slider 3 to move up and down.

[0047] Further options, such as Figure 1 , Figure 4 , Figure 5 As shown, the upper part 2 of the adjustment block has a vertically downward extending slot 14 or a vertically upward extending protrusion in the center area of ​​the top surface; the outer arm 1 has an adjustment hole 10, and the adjustment hole 10 and the slot 14 or the protrusion are on the same straight line along the extension and retraction direction of the outer arm 1. After the outer arm 1 moves, the slot 14 or the protrusion can be aligned with the adjustment hole 10, and then the wrench can be inserted from the adjustment hole 10 and pressed against the slot 14 or the protrusion before the adjustment block is rotated.

[0048] Preferred solutions, such as Figure 2 As shown, the slot 14 on the upper part 2 of the adjusting block is an internal hexagonal slot, but it can also be other forms, such as a cross slot or a triangular slot. If it is a protrusion, it can be an external hexagonal slot. A small hole is made in the outer arm, just enough for tools (such as an internal hexagonal wrench) to pass through and for easy observation, to minimize the impact on the strength of the arm body.

[0049] The following provides a further explanation of the anti-loosening structure of the aforementioned adjusting block.

[0050] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the inner diameter of the third through hole is larger than that of the first through hole, but smaller than that of the first through hole; the upper part 2 of the adjusting block has a T-shaped cross-section in the vertical direction, and at least one threaded hole 11 is provided on the flange structure of the upper part 2 of the adjusting block, and the slider 3 is provided with a groove 12 that mates with the threaded hole 11; the anti-loosening screw 8 is screwed into the threaded hole 11, forming a helical pair with the upper part 2 of the adjusting block; after the outer arm moves, the adjusting hole 10 is aligned with the anti-loosening screw 8, and the wrench is inserted from the adjusting hole to drive the anti-loosening screw to rotate; when the rotated anti-loosening screw is inserted into the groove, it can prevent the adjusting block from rotating circumferentially in the stepped hole; when the rotated anti-loosening screw 8 is disengaged from the groove 12, the anti-loosening screw 8 releases its anti-loosening effect on the adjusting block.

[0051] Preferred solutions, such as Figure 2As shown, the upper part 2 of the adjusting block is provided with two threaded holes 11 that are 180 degrees apart. Of course, the slider 3 is also provided with two slots 12 that are 180 degrees apart.

[0052] It should be noted that the slot 12 is not limited to being set on the slider 3; the slot 12 can also be set on the support plate 4.

[0053] Further options, such as Figure 2 As shown, the top surface of the upper part 2 of the adjusting block is provided with a positioning groove 13 or a positioning protrusion that is connected to the threaded hole 12 and the slot hole 14 or the protrusion. When the upper part 2 of the adjusting block is rotated, the position of the positioning groove 13 or the positioning protrusion is observed to ensure that the anti-loosening screw 8 can be inserted into the slot 12.

[0054] The following provides a further explanation of the specific connection structure between the upper and lower parts of the aforementioned adjusting block.

[0055] like Figure 1 , Figure 4 , Figure 5 As shown, the top surface of the lower part 5 of the adjusting block is provided with a groove, and the upper part 2 of the adjusting block is inserted into the groove; the upper part 2 of the adjusting block is provided with at least one through hole 15 opened along its axial direction, and the lower part 5 of the adjusting block is provided with a threaded hole coaxial with the through hole 15. The fixing screw 9 passes through the through hole 15 and is tightened in the threaded hole to fix the upper part 2 and the lower part 5 of the adjusting block together.

[0056] Preferred solutions, such as Figure 2 , Figure 5 As shown, the upper part 2 of the adjusting block is provided with two through holes 15 that are 180 degrees apart. Of course, the lower part 5 of the adjusting block is also provided with two threaded holes that are 180 degrees apart.

[0057] The following provides a further explanation of the specific connection structure between the aforementioned support plate and slider.

[0058] like Figure 1 , Figure 4 , Figure 5 As shown, a ring of protrusions is provided around the top surface of the support plate 4. The slider 3 is attached to the top surface of the support plate 4, and the ring of protrusions limits the slider 3.

[0059] It should be noted that the support plate 4 needs to have a certain strength, and the adjusting block 5 needs to have a certain diameter to prevent deformation under pressure. One, two, or three adjusting blocks can be set in the slider 3 and the support plate 4.

[0060] As can be seen from the above, this utility model provides an adjustable structure for the slider gap at the tail end of a telescopic arm. The nut sleeve 6 is welded together with the inner arm 7. The upper part 2 and the lower part 5 of the adjusting block are fixed together by the fixing screw 9. The slider 3 and the support plate 4 are placed between the adjusting blocks and have a small gap with the adjusting blocks. The anti-loosening screw 8 and the slot of the slider 3 are used to prevent the adjusting blocks from loosening.

[0061] When the gap needs to be adjusted, first slowly move the telescopic arm so that the locking screw 8 is aligned with the adjustment hole of the outer arm 1. Use an Allen wrench to loosen the locking screw 8 through the adjustment hole. Then, continue to slowly move the telescopic arm so that the center Allen socket of the upper part 2 of the adjusting block is aligned with the adjustment hole 10 of the outer arm 1. Use an Allen wrench to rotate the upper part 2 of the adjusting block through the adjustment hole 10. At this time, the lower part 5 of the adjusting block will rotate together. Under the reaction force of the thread of the nut sleeve 6, the adjusting block will move up and down, thereby driving the slider 3 to move up and down, realizing the adjustment of the gap. Finally, slowly move the telescopic arm so that the locking screw 8 is aligned with the adjustment hole 10 of the outer arm 1, and tighten the locking screw 8.

[0062] It should be noted that when rotating the upper part 2 of the adjusting block, attention should be paid to the stopping position of the positioning groove to ensure that the anti-loosening screw can be smoothly inserted into the slot 12 of the slider 3.

[0063] In summary, this utility model provides an adjustable gap structure for the slider at the tail end of a telescopic arm, achieving the following effects:

[0064] 1) The slider gap can be adjusted by opening only a small hole in the outer arm, which has little impact on the strength of the arm body and high reliability.

[0065] 2) Adjusting the gap is simple and efficient, saving customers a lot of maintenance time and costs.

[0066] 3) Each component has a simple structure, low manufacturing cost, and is easy to implement.

[0067] 4) The adjusting block has an anti-loosening structure, which ensures high reliability.

[0068] The telescopic arm provided by this utility model is described below. The telescopic arm described below and the telescopic arm tail end slider gap adjustable structure described above can be referred to and correspond to each other.

[0069] The present invention provides a telescopic arm, including an outer arm, an inner arm, and an adjustable gap structure for the slider at the tail end of the telescopic arm as described in any of the above embodiments.

[0070] The beneficial effects achieved by the telescopic arm provided by this utility model are consistent with the beneficial effects achieved by the adjustable gap structure of the telescopic arm tail end slider provided by this utility model, so they will not be repeated here.

[0071] The following describes the engineering machinery provided by this utility model. The engineering machinery described below can be referred to in correspondence with the telescopic boom described above.

[0072] The engineering machinery provided by this utility model may include a telescopic boom as described in any of the above embodiments.

[0073] The beneficial effects achieved by the engineering machinery provided by this utility model are consistent with the beneficial effects achieved by the telescopic boom provided by this utility model, so they will not be repeated here.

[0074] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0075] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features found in other embodiments but not others, combinations of features from different embodiments are also within the scope of protection of this invention and form different embodiments. For example, in the embodiments described above, those skilled in the art can use them in combination based on known technical solutions and the technical problems to be solved by this application.

[0076] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A structure with adjustable clearance for the slider at the tail end of a telescopic arm, characterized in that, include: A support plate is positioned between the outer and inner arms, which are capable of telescopic movement. A slider is arranged between the support plate and the outer arm. When the outer arm extends and retracts relative to the inner arm, the slider supports the outer arm. An adjusting block is embedded in a coaxial mounting hole opened on the slider, support plate and inner arm. The adjusting block can move axially up and down in the coaxial mounting hole, thereby driving the slider to move up and down, and realizing the adjustment of the gap between the slider and the outer arm.

2. The adjustable clearance structure of the telescopic arm tail end slider according to claim 1, characterized in that: The coaxial mounting hole is a stepped hole, which is divided into three parts: A first through hole is formed on the inner arm; The inner diameter of the second through hole formed on the support plate is smaller than that of the first through hole; A third through hole is formed on the slider.

3. The adjustable clearance structure of the telescopic arm tail end slider according to claim 2, characterized in that: The adjusting block is divided into an upper adjusting block and a lower adjusting block; the lower adjusting block is embedded in the first through hole, and the upper adjusting block is embedded in the second through hole and the third through hole, and the upper adjusting block and the lower adjusting block are fixed together; after the adjusting block moves upward in the axial direction, the lower adjusting block can push the support plate and the slider upward.

4. The adjustable clearance structure of the telescopic arm tail end slider according to claim 3, characterized in that: A nut sleeve coaxial with the first through hole is fixed therein. The top surface of the nut sleeve does not extend beyond the top surface of the inner arm, and the bottom surface of the nut sleeve protrudes beyond the bottom surface of the inner arm. The lower outer circumferential surface of the adjusting block is threaded, and the lower part of the adjusting block is connected to the nut to form a helical pair. The upper part of the adjusting block is clearance-fitted with the second and third through holes. The rotating adjusting block can drive the support plate and the slider to move up and down.

5. The adjustable clearance structure of the telescopic arm tail end slider according to claim 4, characterized in that: The upper part of the adjustment block has a vertically downward extending slot or a vertically upward extending protrusion in the center area of ​​the top surface. The outer arm is provided with an adjustment hole. The adjustment hole and the slot or protrusion are on the same straight line along the extension and retraction direction of the outer arm. After the outer arm moves, the slot or protrusion can be aligned with the adjustment hole. Then, a wrench is inserted from the adjustment hole and pressed against the slot or protrusion before rotating the adjustment block.

6. The adjustable clearance structure of the slider at the tail end of the telescopic arm according to claim 5, characterized in that: The inner diameter of the third through hole is larger than the inner diameter of the first through hole, but smaller than the inner diameter of the first through hole. The upper part of the adjusting block has a T-shaped cross-section in the vertical direction. At least one threaded hole is provided on the flange structure of the upper part of the adjusting block. The slider or support plate is provided with a groove that mates with the threaded hole. The screw is screwed into the threaded hole and forms a helical pair with the upper part of the adjusting block. After the outer arm moves, once the adjustment hole aligns with the screw, the wrench is inserted through the adjustment hole and drives the screw to rotate. When the rotated screw is inserted into the slot, it prevents the adjusting block from rotating circumferentially in the stepped hole, and the screw plays an anti-loosening role; when the rotated screw is removed from the slot, the screw releases its anti-loosening role on the adjusting block.

7. The adjustable clearance structure of the telescopic arm tail end slider according to claim 6, characterized in that: The top surface of the upper part of the adjustment block is provided with a positioning groove or positioning protrusion that is connected to the threaded hole, slot or protrusion. When the upper part of the adjustment block is rotated, the position of the positioning groove or positioning protrusion is observed to ensure that the screw can be inserted into the slot.

8. The adjustable clearance structure of the telescopic arm tail end slider according to claim 3, characterized in that: The top surface of the lower part of the adjusting block is provided with a groove, and the upper part of the adjusting block is inserted into the groove; The upper part of the adjusting block is provided with at least one through hole along its axial direction, and the lower part of the adjusting block is provided with a threaded hole coaxial with the through hole. After the screw passes through the through hole, it is tightened in the threaded hole to fix the upper part and the lower part of the adjusting block together.

9. The adjustable clearance structure of the slider at the tail end of the telescopic arm according to claim 1, characterized in that: The top surface of the support plate has a raised ring around its perimeter. The slider fits against the top surface of the support plate and is limited by the raised ring.

10. A telescopic arm, comprising an outer arm and an inner arm, characterized in that: It also includes a telescopic arm tail end slider gap adjustable structure as described in any one of claims 1 to 9.

11. An engineering machinery, characterized in that: It includes the telescopic arm tail end slider gap adjustable structure as described in any one of claims 1 to 9; or, it includes the telescopic arm as described in claim 10.

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