Unlocking mechanism and riding vehicle carrier

Abstract

The utility model discloses an unlocking mechanism and riding vehicle bracket, and it relates to the field of vehicle-mounted riding vehicle bracket. Its technical scheme main points include: unlocking mechanism includes the unlocking wrench of acting on the pull rod, the unlocking wrench rotatably sets up the support chassis, the unlocking wrench is located between the front end and rear end of support chassis, and is close to the rear end. The utility model will arrange unlocking wrench between the front end and rear end of support chassis, can realize the hidden arrangement of unlocking wrench, avoid unlocking wrench to be exposed to the rear end of support chassis, thereby avoid the risk of unlocking wrench failure after being collided, improve security. The traction support is installed to the tail of the car, and can control the support chassis to go up and down through the elevating system, and the user experience is optimized, and the riding vehicle of bearing greater weight, such as electric power-assisted bicycle etc.

Description

Technical Field

[0001] This utility model relates to the field of vehicle-mounted bicycle brackets, and more specifically, it relates to an unlocking mechanism and a bicycle bracket. Background Technology

[0002] A Chinese patent with publication number CN116461433A discloses a bicycle mounting bracket, which includes a connecting rod, a flipping device, a support rod device, and a pole device. The connecting rod consists of an upper connecting rod and a lower connecting rod, which are connected by a flipping device. The flipping device includes a flipping seat, a handle, a pull rod, a handle seat, a positioning pin, and a spring.

[0003] However, the above patent still has the following problems: 1. The handle and handle seat are located at the end of the upper connecting rod, which not only increases the length of the fixing frame, but also poses a risk of failure after being hit, and is also more laborious; 2. For heavier bicycles, it is more laborious to move the bicycle onto the support rod device. Utility Model Content

[0004] In view of the shortcomings of the existing technology, one of the objectives of this utility model is to provide an unlocking mechanism in which the unlocking wrench is arranged between the front and rear ends of the support base. This enables the unlocking wrench to be hidden, avoiding the unlocking wrench being exposed at the rear end of the support base, thereby avoiding the risk of the unlocking wrench failing after being hit and improving safety.

[0005] To achieve the above objectives, the present invention provides the following technical solution: An unlocking mechanism for unlocking a locking mechanism on a support base frame, the locking mechanism including a pull rod; The unlocking mechanism includes an unlocking wrench that acts on a pull rod, and the unlocking wrench is rotatably mounted on a support base. The unlocking wrench is located between the front and rear ends of the support frame, and closer to the rear end.

[0006] Furthermore, the support base includes a support rod through which the unlocking wrench extends; or, the support base includes multiple support rods, with the unlocking wrench located between two adjacent support rods.

[0007] Furthermore, the pull rod is provided with a fixing ring, the locking mechanism also includes a locking spring acting on the fixing ring, and the unlocking wrench includes a push plate part acting on the fixing ring, the push plate part and the locking spring being located on both sides of the fixing ring respectively.

[0008] Furthermore, a pivot shaft is provided on the support base, and the unlocking wrench includes a wrench bracket mounted on the pivot shaft.

[0009] Furthermore, the wrench bracket includes a bent portion mounted on a pivot shaft, a push plate portion extending from one end of the bent portion, and a lever arm portion extending from the other end of the bent portion.

[0010] Furthermore, the support base includes a guide tube, and the end of the pull rod extends into the guide tube.

[0011] Furthermore, the support base includes a rotating base, a support base rod rotatably connected to the rotating base, and a cover plate disposed on the end of the support base rod away from the rotating base; The cover plate is located at the rear end of the supporting base frame, and the guide tube is disposed on the inner end face of the cover plate; one end of the locking spring is in contact with the fixing ring, and the other end is in contact with the cover plate.

[0012] Furthermore, the unlocking wrench also includes a handle, which is located at the outer bottom of the support base rod; When locked, the cover plate protrudes from the handle, with the outer bottom wall of the support rod as the reference plane.

[0013] Another objective of this invention is to provide a bicycle bracket that includes the aforementioned unlocking mechanism.

[0014] Furthermore, the bicycle bracket also includes a traction bracket, a support base, and a lifting mechanism disposed between the traction bracket and the support base; The lifting mechanism includes a fixed sleeve connected to the traction bracket and a telescopic sleeve connected to the support base. The telescopic sleeve has an extended state and a retracted state relative to the fixed sleeve; a limiting component is provided between the fixed sleeve and the supporting base frame to engage in the retracted state.

[0015] In summary, this utility model has the following beneficial effects: 1. The unlocking wrench uses a rotating motion to perform the unlocking action, which is convenient and less strenuous to operate; the unlocking wrench is positioned between the front and rear ends of the support frame, which allows for a concealed arrangement of the unlocking wrench, avoiding the risk of the unlocking wrench malfunctioning due to impact, thus improving safety; the unlocking wrench is located near the rear end, which is convenient for placement and operation. 2. Mounting the wrench bracket on the pivot axis simplifies the structure and facilitates production and assembly; 3. The towing bracket is installed at the rear of the car. The support frame can be raised and lowered by the lifting mechanism, which optimizes the user experience and is also convenient for carrying heavy bicycles, such as electric bicycles. 4. The use of limit components can improve the structural strength and stability of the connection between the lifting mechanism and the supporting base, and increase the load-bearing capacity of the bracket. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the unlocking mechanism in Example 1. Figure 1 ; Figure 2 This is a schematic diagram of the unlocking mechanism in Example 1. Figure 2 ; Figure 3 This is a schematic diagram of the unlocking mechanism in Example 1. Figure 3 ; Figure 4 This is a schematic diagram of the unlocking mechanism in Example 1. Figure 4 ; Figure 5 This is a schematic diagram of the unlocking mechanism in Example 1. Figure 5 ; Figure 6 This is a schematic diagram of the bicycle bracket in Example 2. Figure 1 ; Figure 7 This is a schematic diagram of the bicycle bracket in Example 2. Figure 2 ; Figure 8 This is a schematic diagram of the bicycle bracket in Example 2. Figure 3 .

[0017] In the diagram: 11. Rotating base; 111. First locking groove; 112. Second locking groove; 113. Limiting slot; 12. Supporting base rod; 121. Guide groove; 122. Clearance hole; 13. Supporting pivot; 14. Cover plate; 15. Guide tube; 16. Pivot shaft; 17. Reinforcing member; 21. Locking block; 22. Pull rod; 23. Fixing ring; 24. Locking spring; 31. Wrench bracket; 311. Bending part; 312. 313. Push plate; 314. Clearance groove; 32. Lever arm; 4. Handle; 4. Traction bracket; 41. Traction crossbar; 42. Traction vertical bar; 43. Diagonal bar; 44. Bolt and nut assembly; 5. Lifting mechanism; 51. Fixed sleeve; 52. Telescopic sleeve; 53. Gear reducer; 531. Manual input end; 54. Screw assembly; 55. Motor; 56. Housing; 561. Plug; 57. Limiting plate; 58. Auxiliary pipe. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the accompanying drawings.

[0019] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law. Example 1:

[0020] An unlocking mechanism, as shown in the reference Figures 1 to 5 It is used to unlock the locking mechanism on the support base frame; in this embodiment, the support base frame includes a rotating base 11, a support rod 12, a support shaft 13 disposed between the rotating base 11 and the support rod 12, and a cover plate 14 disposed at the end of the support rod 12 away from the rotating base 11; the rotational connection between the support rod 12 and the rotating base 11 is realized through the support shaft 13; the locking mechanism is used to lock the relative position of the support rod 12 and the rotating base 11, so that the support rod 12 cannot rotate.

[0021] Reference Figures 1 to 5 Specifically, the locking mechanism includes a locking block 21, a pull rod 22 connected to the locking block 21, a fixing ring 23 disposed on the pull rod 22, and a locking spring 24 acting on the fixing ring 23; the support base rod 12 is provided with a guide groove 121 that cooperates with the locking block 21, and the rotating base 11 is provided with a first locking groove 111 and a second locking groove 112 that cooperate with the locking block 21; when the locking block 21 moves along the guide groove 121 to be embedded in the first locking groove 111, the support base rod 12 and the rotating base 11 are locked, and the support base frame is in the unfolded state; when the locking block 21 moves along the guide groove 121 to be embedded in the second locking groove 112, the support base rod 12 and the rotating base 11 are locked, and the support base frame is in the folded state.

[0022] Reference Figures 1 to 5 The elastic force of the locking spring 24 is transmitted to the locking block 21 through the fixing ring 23 and the pull rod 22, so that the locking block 21 tends to move into the locking groove, thereby maintaining the locked state.

[0023] Reference Figures 1 to 5 In this embodiment, the cover plate 14 is located at the rear end of the support base, and the inner end face of the cover plate 14 is provided with a guide tube 15; the end of the pull rod 22 extends into the guide tube 15, and a buffer gap is formed between the end of the pull rod 22 and the inner end face of the guide tube 15; the guide tube 15 plays a guiding and supporting role for the pull rod 22, and the buffer gap is used to realize the movement of the pull rod 22; that is, when switching from the locked state to the unlocked state, the end of the pull rod 22 moves along the guide tube 15 toward the inner end face of the guide tube 15.

[0024] Reference Figures 1 to 5 Locking springs 24 are respectively sleeved on guide tube 15 and pull rod 22, and one end of locking spring 24 contacts fixed ring 23, and the other end contacts inner end face of cover plate 14; locking spring 24 is kept in compressed state and has pre-tight elastic force.

[0025] Reference Figures 1 to 5In this embodiment, the support base includes a support rod 12, and the locking mechanism is disposed on the inner side of the support rod 12. In other optional embodiments, the support base may also include multiple parallel support rods, and the locking mechanism is disposed between two adjacent support rods. This is not a limitation.

[0026] Reference Figures 1 to 5 In this embodiment, the unlocking mechanism acts on the locking mechanism to perform the unlocking action; specifically, in this embodiment, the unlocking mechanism includes an unlocking wrench, which is rotatably mounted on the support base; and the unlocking wrench is located between the front end and the rear end of the support base, and closer to the rear end.

[0027] Reference Figures 1 to 5 The unlocking wrench uses a rotating motion to perform the unlocking action, which is convenient and less strenuous. The unlocking wrench is positioned between the front and rear ends of the support frame, which allows for a concealed arrangement of the unlocking wrench and avoids the risk of it malfunctioning due to impact, thus improving safety. The unlocking wrench is also located near the rear end, which facilitates its placement and operation.

[0028] Reference Figures 1 to 5 In this embodiment, the unlocking wrench includes a wrench bracket 31 and a cylindrical handle 32 connected to the wrench bracket 31. The wrench bracket 31 and the handle 32 are fixedly connected by screws. The cylindrical handle 32 makes it easier to hold and apply force, thus optimizing the user experience. In other optional embodiments, the wrench bracket 31 and the handle 32 can also be integrally formed, which is not limited here.

[0029] Reference Figures 1 to 5 Specifically, in this embodiment, a pivot shaft 16 is provided on the inner side of the support base rod 12, and the pivot shaft 16 is located above the locking spring 24. Preferably, in this embodiment, the wrench bracket 31 is mounted on the pivot shaft 16, so the wrench bracket 31 can rotate around the pivot shaft 16. Mounting the wrench bracket 31 on the pivot shaft 16 simplifies the structure and facilitates production and assembly. Of course, in other optional embodiments, the wrench bracket can also be sleeved on the pivot shaft, or the pivot shaft can be fixedly mounted on the wrench bracket, and then the pivot shaft passes through the support base rod. There are no restrictions here.

[0030] Reference Figures 1 to 5Specifically, in this embodiment, the wrench bracket 31 includes a bent portion 311 mounted on the pivot shaft 16, a push plate portion 312 extending from one end of the bent portion 311, and a lever arm portion 314 extending from the other end of the bent portion 311; wherein, the push plate portion 312 contacts the fixing ring 23, and the push plate portion 312 and the locking spring 24 are respectively located on both sides of the fixing ring 23; by directly contacting the push plate portion 312 of the wrench bracket 31 with the fixing ring 23 to transmit the unlocking driving force, the structure can be simplified and the stable transmission of force can be facilitated.

[0031] Reference Figures 1 to 5 Preferably, the push plate 312 is provided with a relief groove 313 that cooperates with the pull rod 22. The relief groove 313 avoids interference between the push plate 312 and the pull rod 22, and increases the contact area between the push plate 312 and the fixed ring 23, thereby improving the stability of the transmission.

[0032] Reference Figures 1 to 5 To avoid the locking spring 24, a clearance groove is also provided in the middle of the lever arm 314. In this embodiment, the lever arm 314 extends through the support base rod 12, and the bottom wall of the support base rod 12 is provided with a clearance hole 122 that cooperates with the lever arm 314. That is, the lever arm 314 extends through the clearance hole 122, and interference is avoided when the lever arm 314 rotates. The handle 32 is connected to the extended end of the lever arm 314 and is located at the outer bottom of the support base rod 12. In this embodiment, the handle 32 of the unlocking wrench is arranged at the outer bottom of the support base rod 12, which facilitates operation and optimizes the user experience. In other optional embodiments, the lever arm can also extend from the side wall of the support base rod, and then the handle can be arranged on the outer side of the support base rod. There is no limitation here.

[0033] Reference Figures 1 to 5 In the locked state, the elastic force of the locking spring 24 is transmitted to the wrench bracket 31 through the fixing ring 23, causing the lever arm 314 to contact the inner end of the clearance hole 122, preventing the unlocking wrench from rotating clockwise, thus limiting its movement and maintaining its stability. When performing the unlocking action, the operator pulls the handle 32, causing the unlocking wrench to rotate counterclockwise. The push plate 312 drives the fixing ring 23 to move towards the rear end, and then the pull rod 22 drives the locking block 21 to move until it disengages from the first locking groove 111, entering the unlocked state. In the unlocked state, the support base rod 12 rotates upward around the support shaft 13. When the locking block 21 rotates to be opposite the second locking groove 112, it is embedded in the second locking groove 112, re-entering the locked state.

[0034] Reference Figures 1 to 5In this embodiment, the bending portion 311 includes an arc-shaped segment that fits against the pivot shaft 16, thereby ensuring rotational stability. The lever arm portion 314 can be lengthened to save more effort. Preferably, in the locked state, with the outer bottom wall of the support base 12 as the reference plane, the cover plate 14 protrudes from the handle 32. That is, with the outer bottom wall of the support base 12 as the reference plane, the bottommost end of the cover plate 14 is lower than the bottommost end of the handle 32, so the cover plate 14 provides protection and shielding for the handle 32. If the cover plate 14 contacts the ground, the handle 32 will not contact the ground, thus providing protection. Looking from the rear end of the support base to the front end, the cover plate 14 shields the handle 32, which not only improves aesthetics but also prevents accidental operation. Example 2:

[0035] A bicycle bracket, as shown in the reference Figures 1 to 8 It includes the unlocking mechanism in Embodiment 1; in this embodiment, the bicycle bracket also includes a traction bracket 4 and a lifting mechanism 5; wherein, the lifting mechanism 5 is disposed between the traction bracket 4 and the support base; the traction bracket 4 is installed at the rear of the car, and the support base can be raised and lowered by the lifting mechanism 5, which optimizes the user experience and is also convenient for carrying bicycles with a large weight, such as electric bicycles.

[0036] Reference Figures 1 to 8 In this embodiment, the lifting mechanism 5 includes a fixed sleeve 51 connected to the traction bracket 4 and a telescopic sleeve 52 connected to the rotating base 11 of the supporting frame. The telescopic sleeve 52 is embedded in the fixed sleeve 51 and can move relative to the fixed sleeve 51 to realize the lifting function. In this embodiment, the lifting mechanism 5 is a one-piece structure, and the travel of the telescopic sleeve 52 can meet the requirements, thereby simplifying the structure and reducing costs. Of course, in other optional embodiments, the lifting mechanism 5 can also adopt a two-piece structure or a three-piece structure, etc., which is not limited here.

[0037] Reference Figures 1 to 8 In this embodiment, both the fixed sleeve 51 and the telescopic sleeve 52 are hollow square tubes, which facilitates connection with the traction bracket 4 and the support base and effectively ensures the structural strength and stability of the connection. Of course, in other optional embodiments, the fixed sleeve 51 and the telescopic sleeve 52 can also be round tubes or other shapes, which are not limited here.

[0038] Reference Figures 1 to 8In this embodiment, the lifting mechanism 5 also includes a drive assembly disposed between the fixed sleeve 51 and the telescopic sleeve 52. In this embodiment, the drive assembly includes two power input ends, namely an electric input end and a manual input end. The combination of electric and manual input not only enables automatic lifting using a motor, which is more labor-saving, but also allows for manual lifting in the event of a power outage, thus optimizing the user experience. Of course, in other optional embodiments, the drive assembly may use only one power input end, or the power input end may be a pneumatic input end, etc., which is not limited here.

[0039] Reference Figures 1 to 8 Specifically, the drive assembly includes a gear reducer 53 fixedly mounted on the top of the fixed sleeve 51, and a lead screw assembly 54 disposed between the gear reducer 53 and the telescopic sleeve 52. The gear reducer 53 is provided with an electric input end and a manual input end 531, and the electric input end is connected to a motor 55. The manual input end 531 is a non-cylindrical shaft, which facilitates connection with a hand tool to achieve manual lifting. In this embodiment, the lifting mechanism 5 also includes a housing 56, which is disposed on the top of the fixed sleeve 51. The housing 56 covers the motor 55 and the gear reducer 53 for protection. The housing 56 is provided with a cover 561 opposite to the manual input end 531. After opening the cover 561, the hand tool is inserted into the housing 56 and connected to the manual input end 531 to perform manual lifting.

[0040] Reference Figures 1 to 8 In this embodiment, the fixed sleeve 51 and the traction bracket 4 are detachably connected, which facilitates the installation, disassembly and maintenance of the lifting mechanism 5. An auxiliary tube 58 is fixedly provided on the outer wall of the fixed sleeve 51. The traction bracket 4 and the auxiliary tube 58 are nested together, and two bolt and nut assemblies 44 are provided between the traction bracket 4 and the auxiliary tube 58. The nested fit and the bolt and nut assemblies 44 not only enable the detachable connection, but also improve the stability of the connection. Of course, the fixed sleeve 51 and the traction bracket 4 can also be detachably connected in other ways, which is not limited here.

[0041] Reference Figures 1 to 8Specifically, in this embodiment, the traction bracket 4 includes a traction crossbar 41, a traction vertical bar 42 fixedly connected to the traction crossbar 41, and an inclined bar 43 disposed between the traction crossbar 41 and the traction vertical bar 42. Such a traction bracket 4 can effectively ensure structural strength and stability, thereby improving vehicle safety. The traction vertical bar 42 includes a side opening, through which it is sleeved on the auxiliary tube 58. The bolts of the bolt and nut assembly 44 pass through one side wall of the traction vertical bar 42, the auxiliary tube 58, and the other side wall in sequence. In this embodiment, two bolt and nut assemblies 44 are provided between the traction vertical bar 42 and the auxiliary tube 58, which can both fix it and effectively limit its movement. In other optional embodiments, the number of bolt and nut assemblies 44 can be adjusted as needed, and the auxiliary tube 58 can also be sleeved on the traction vertical bar 42, which is not limited here.

[0042] Reference Figures 1 to 8 The telescopic sleeve 52 has an extended state and a retracted state relative to the fixed sleeve 51. A limiting component is provided between the fixed sleeve 51 and the rotating base 11, which engages in the retracted state. That is, when the telescopic sleeve 52 is in the extended state, the limiting component is in the separated state, and when the telescopic sleeve 52 is in the retracted state, the limiting component is in the engaged state. Therefore, by using the limiting component, the structural strength and stability of the connection between the lifting mechanism 5 and the supporting base frame can be improved, and the load-bearing capacity of the bracket can be improved.

[0043] Reference Figures 1 to 8 In this embodiment, the limiting component and the traction bracket 4 are located on opposite sides of the fixed sleeve 51, which facilitates the arrangement and improves the limiting effect. Of course, in other optional embodiments, multiple limiting components can be provided between the fixed sleeve 51 and the support base, and the limiting components can be set on different side walls of the fixed sleeve 51. This is not a limitation.

[0044] Reference Figures 1 to 8 In this embodiment, the limiting component includes a limiting plug and a limiting slot that cooperates with the limiting plug; the plug-in method facilitates automatic engagement or disengagement; specifically, in this embodiment, the limiting plug includes a limiting insert plate 57 fixedly disposed at the bottom of the outer wall of the fixed sleeve 51, and a limiting slot 113 that cooperates with the limiting insert plate 57 is provided on the rotating base 11; when the telescopic sleeve 52 and the supporting base move downward, the limiting slot 113 separates from the limiting insert plate 57; when the telescopic sleeve 52 and the supporting base move upward, the limiting slot 113 moves to engage with the limiting insert plate 57, thereby achieving limiting; of course, in other optional embodiments, the limiting plug can also adopt a pin or other structure, which is not limited here.

[0045] Reference Figures 1 to 8In this embodiment, the rotating base 11 includes two supporting vertical plates respectively disposed on the two opposite outer walls of the telescopic sleeve 52. The top walls of the two supporting vertical plates are respectively provided with limiting slots 113 that cooperate with the limiting inserts 57; that is, the limiting inserts 57 are simultaneously embedded in the limiting slots 113 on the two supporting vertical plates, thereby improving the limiting effect.

[0046] Reference Figures 1 to 8 Preferably, in this embodiment, a reinforcing member 17 through which the supporting shaft 13 passes is provided on the inner side of the supporting base rod 12; the supporting base rod 12 is a square tube, and the reinforcing member 17 is a square tube or a U-shaped tube, matching the supporting base rod 12; by providing the reinforcing member 17 on the inner side of the supporting base rod 12 and having the supporting shaft 13 pass through the reinforcing member 17, the structural strength and stability of the supporting base frame can be effectively improved, thereby improving the load-bearing capacity of the bracket, making it suitable for heavier bicycles; of course, the reinforcing member 17 can also be provided on the outer side of the supporting base rod 12, or reinforcing members can be provided on both the inner and outer sides of the supporting base rod 12, and the reinforcing member can also be a solid structure, etc., without limitation.

Claims

1. An unlocking mechanism for unlocking a locking mechanism on a support base, the locking mechanism comprising a pull rod; Its features are: The unlocking mechanism includes an unlocking wrench that acts on a pull rod, and the unlocking wrench is rotatably mounted on a support base. The unlocking wrench is located between the front and rear ends of the support frame, and closer to the rear end.

2. The unlocking mechanism according to claim 1, characterized in that: The support base includes a support rod through which the unlocking wrench extends; or, the support base includes multiple support rods, with the unlocking wrench located between two adjacent support rods.

3. The unlocking mechanism according to claim 1, characterized in that: The pull rod is provided with a fixing ring, the locking mechanism also includes a locking spring acting on the fixing ring, and the unlocking wrench includes a push plate part acting on the fixing ring. The push plate part and the locking spring are respectively located on both sides of the fixing ring.

4. The unlocking mechanism according to claim 1, characterized in that: The support base is provided with a pivot shaft, and the unlocking wrench includes a wrench bracket mounted on the pivot shaft.

5. The unlocking mechanism according to claim 4, characterized in that: The wrench bracket includes a bent portion mounted on a pivot shaft, a push plate portion extending from one end of the bent portion, and a lever arm portion extending from the other end of the bent portion.

6. The unlocking mechanism according to claim 3, characterized in that: The support frame includes a guide tube, and the end of the pull rod extends into the guide tube.

7. The unlocking mechanism according to claim 6, characterized in that: The support base includes a rotating base, a support rod rotatably connected to the rotating base, and a cover plate disposed on the end of the support rod away from the rotating base; The cover plate is located at the rear end of the supporting base frame, and the guide tube is disposed on the inner end face of the cover plate; one end of the locking spring is in contact with the fixing ring, and the other end is in contact with the cover plate.

8. The unlocking mechanism according to claim 7, characterized in that: The unlocking wrench also includes a handle, which is located at the outer bottom of the support base rod; When locked, the cover plate protrudes from the handle, with the outer bottom wall of the support rod as the reference plane.

9. A bicycle bracket, characterized in that: Includes the unlocking mechanism as described in any one of claims 1-8.

10. The bicycle bracket according to claim 9, characterized in that: The bicycle bracket also includes a traction bracket, a support base, and a lifting mechanism disposed between the traction bracket and the support base; The lifting mechanism includes a fixed sleeve connected to the traction bracket and a telescopic sleeve connected to the support base. The telescopic sleeve has an extended state and a retracted state relative to the fixed sleeve; a limiting component is provided between the fixed sleeve and the supporting base frame to engage in the retracted state.

Images