CN212447649U - Trailer - Google Patents

Abstract

The utility model discloses a trailer, which comprises a trailer frame, wherein the trailer frame comprises two vertical frames which are arranged in front and back, and wheels are arranged under the vertical frames; the trailer frame also comprises an intermediate frame, the two vertical frames are provided with racks and connecting rod parts, the racks and the connecting rod parts of the two vertical frames are arranged on the intermediate frame, and the two vertical frames, the two racks, the intermediate frame and the two connecting rod parts are combined to form a four-bar mechanism sharing the intermediate frame; the trailer also comprises a synchronous linkage mechanism, wherein the synchronous linkage mechanism comprises two linkage parts, the first ends of the two linkage parts are respectively connected with the racks of the two vertical frames, and the second ends of the two linkage parts are movably connected with the middle frame so as to drive the two four-bar mechanisms to synchronously open and close through the synchronous linkage mechanism. It has the following advantages: the trailer frame can be folded and unfolded quickly, and is more stable and reliable in the unfolded state.

Description

Trailer

Technical Field

The utility model relates to a house technical field especially relates to a trailer.

Background

Existing collapsible trailers, such as cn201210293571.x, CN201210572499.4, US9073564B2, comprise a trailer frame, which comprises a folding frame and wheels. The folding bicycle frame comprises four rectangular scissors mechanisms and four telescopic pipes. The scissor mechanisms comprise at least one scissor unit, the upper end parts of every two adjacent scissor mechanisms are rotationally connected together through an upper connecting seat, and the lower end parts of every two adjacent scissor mechanisms are rotationally connected together through a lower connecting seat; the upper end of the extension tube is fixedly connected with the upper connecting seat, the lower end of the extension tube fixedly penetrates through the lower connecting seat, and the wheel is arranged at the lower end of the extension tube. The existing portable folding trailer has the following defects: firstly, a telescopic pipe in a folding frame is always kept in a vertical state, and the telescopic pipe is subjected to torque in the processes of unfolding, folding and trailer walking, so that the service life of the folding frame is shortened due to the torque; secondly, the telescopic pipe comprises two pipe fittings, so that the material cost is increased; thirdly, the telescopic pipe can clamp the hand in the opening process, and the use safety performance needs to be improved. In view of the above disadvantages, the applicant proposes a solution, in which a portable folding trailer includes a trailer frame, the trailer frame includes a folding frame and wheels, the folding frame includes four rectangular scissors mechanisms, each of the scissors mechanisms includes at least one scissors unit, the upper ends of every two adjacent scissors mechanisms are rotatably connected together through an upper connecting seat, and the lower ends of the two adjacent scissors mechanisms are rotatably connected together through a lower connecting seat; the lower connecting seat is connected with a supporting rod, the lower end of the supporting rod penetrates through the lower connecting seat, the lower end of the supporting rod is connected with the wheel, the upper end of the supporting rod is rotatably connected with a sliding connecting piece, and the sliding connecting piece is connected to a shearing type unit of the shearing type mechanism in a sliding mode. The above solution can solve the above-mentioned disadvantages, but there is a need for further improvement in stability.

SUMMERY OF THE UTILITY MODEL

The utility model provides a trailer, it has overcome portable folding trailer in the background art and has existed not enough.

The utility model provides an adopted technical scheme of its technical problem is:

a trailer comprises a trailer frame, wherein the trailer frame comprises two vertical frames which are arranged in front and back, and wheels are arranged below the vertical frames; the trailer frame also comprises an intermediate frame, the two vertical frames are provided with racks and connecting rod parts, the racks and the connecting rod parts of the two vertical frames are arranged on the intermediate frame, and the two vertical frames, the two racks, the intermediate frame and the two connecting rod parts are combined to form a four-bar mechanism sharing the intermediate frame; the trailer also comprises a synchronous linkage mechanism, wherein the synchronous linkage mechanism comprises two linkage parts, the first ends of the two linkage parts are respectively connected with the racks of the two vertical frames, and the second ends of the two linkage parts are movably connected with the middle frame so as to drive the two four-bar mechanisms to synchronously open and close through the synchronous linkage mechanism.

In one embodiment: the first side of the rack and the first side of the connecting rod part are rotatably connected with the vertical frame, the second side of the rack and the second side of the connecting rod part are rotatably connected with the middle frame, and the rack and the connecting rod part of the four-bar linkage mechanism in the unfolding state are arranged up and down.

In one embodiment: the four-bar linkage is a parallelogram four-bar linkage.

In one embodiment: the link portion constitutes a chassis.

In one embodiment: the first ends of the two linking parts are respectively and rotatably connected with the racks of the two vertical racks, and the second ends of the two linking parts can synchronously move up and down along the middle rack.

In one embodiment: the middle frame is provided with a connecting shaft which can move up and down, and the second ends of the two linkage parts are rotatably connected with the connecting shaft.

In one embodiment: the middle frame is provided with a sliding chute which is arranged up and down, and the connecting shaft is suitable for being assembled and connected in the sliding chute.

In one embodiment: the middle frame is provided with a limiting position, and the four-bar mechanism is in an unfolded state when the connecting shaft is propped against the limiting position from bottom to top.

In one embodiment: the four-bar linkage mechanism is connected with the middle frame and the rack to limit the four-bar linkage mechanism to be in an unfolding state.

In one embodiment: the limiting mechanism comprises an upward limiting surface fixedly arranged on the middle frame, and the end part of the rack is in an unfolded state when being supported against the limiting surface.

In one embodiment: the trailer frame is symmetrically arranged front and back relative to the middle frame.

In one embodiment: the trailer also comprises a handle which is connected on a vertical frame of the trailer frame.

In one embodiment: the trailer frame is provided with the surrounding baffle frame, the surrounding baffle frame comprises two side baffle frames and two end baffle frames which can be respectively rotatably connected with the two vertical frames, and the two side baffle frames and the two end baffle frames can be matched to form the surrounding baffle frame.

In one embodiment: the side blocking frame comprises two scissors-shaped connecting rods, the four ends of each scissors-shaped connecting rod are two inner ends and two outer ends respectively, the two scissors-shaped connecting rods are arranged side by side in the front and back direction, the adjacent inner ends of the two scissors-shaped connecting rods are rotatably connected together through a middle connecting seat, the middle connecting seat positioned at the lower side is rotatably connected to the middle frame, and the lower outer ends of the two scissors-shaped connecting rods can be rotatably connected to the two vertical frames respectively.

In one embodiment: a first locking mechanism is arranged between the middle connecting seat and the middle frame.

In one embodiment: a second locking mechanism is arranged between the end blocking frame and the vertical frame.

In one embodiment: a middle telescopic pipe is connected between two middle connecting seats of the two scissors-shaped connecting rods, the outer end parts of the two scissors-shaped connecting rods are connected with side connecting seats, a side telescopic pipe is connected between the two side connecting seats, the side telescopic pipe comprises a lower pipe and an upper pipe which is connected with the lower pipe in a sliding manner, and the upper end of the lower pipe is fixedly provided with a matching seat; a positioning mechanism is arranged between the upper end of the end baffle frame and the matching seat of the scissors-shaped connecting rod.

Compared with the background technology, the technical scheme has the following advantages:

the two vertical frames, the two racks, the middle frame and the two connecting rod parts are distributed and combined to form the four-bar mechanism sharing the middle frame, the two linkage parts are driven to synchronously move up and down to drive the two racks to synchronously open and close, so that the two four-bar mechanisms are driven to synchronously open and close through the synchronous linkage mechanism, on one hand, the smoothness and the convenience of opening and closing are improved, the quick folding and unfolding can be realized, and on the other hand, the trailer frame in the unfolding state is more stable and reliable.

The first ends of the two linkage parts are respectively and rotatably connected with the racks of the two vertical frames, and the second ends of the two linkage parts can synchronously move up and down along the middle frame, so that the structure is simple, and the synchronization is stable and reliable.

The trailer frame is provided with the enclosing and blocking frame, the enclosing and blocking frame comprises two side blocking frames and two end blocking frames which can be respectively rotatably connected to the two vertical frames, the two side blocking frames and the two end blocking frames can be matched to form the enclosing and blocking frame, the end blocking frames can be independently turned over to the horizontal direction to lengthen the bottom surface of the trailer or placed down to contain long objects, and the side blocking frames can be turned over to the horizontal direction to widen the bottom surface of the trailer or placed down to contain wider objects.

The telescopic pipe in being connected with between two connecting seats of two scissors form connecting rods, the outer tip dress of two scissors form connecting rods has connect the side connecting seat, is connected with the flexible pipe of side between the connecting seat of both sides, and the flexible pipe of side includes the upper tube of low tube and sliding connection at the low tube, and the low tube upper end has set firmly the cooperation seat, is equipped with positioning mechanism between the cooperation seat of end stop frame upper end and scissors form connecting rod, can not only strengthen joint strength, but also can be used for realizing the location.

Drawings

The present invention will be further described with reference to the accompanying drawings and the following detailed description.

Fig. 1 is a perspective view of a trailer according to a first embodiment in a deployed state.

Fig. 2 is a schematic perspective view of a trailer according to the first embodiment in a semi-collapsed state.

Fig. 3 is a schematic perspective view of a trailer according to the first embodiment in a fully collapsed state.

Fig. 4 is a schematic front view of a trailer according to the first embodiment in a deployed state.

Fig. 5 is a schematic front view of a trailer according to the first embodiment in a semi-collapsed state.

Fig. 6 is a schematic front view of a trailer according to the first embodiment in a fully collapsed state.

Fig. 7 is a perspective view of a trailer according to the second embodiment in a deployed state.

Fig. 8 is a schematic perspective view of a trailer according to the second embodiment in a semi-collapsed state.

Fig. 9 is a schematic front view of a trailer in a deployed state according to the second embodiment of the present invention.

Fig. 10 is a schematic front view of the trailer of the second embodiment in a semi-collapsed state.

Fig. 11 is one of the schematic perspective views of a trailer according to the third embodiment in a deployed state, in which the fencing stand is in an upright state.

Fig. 12 is an enlarged schematic view at B of fig. 11.

Fig. 13 is a perspective view of the trailer according to the third embodiment in a semi-collapsed state, in which the fencing stand is in an upright state.

Fig. 14 is a perspective view of the trailer according to the third embodiment in a fully collapsed state, in which the fencing stand is in an upright state.

Fig. 15 is a second perspective view of the trailer according to the third embodiment in an unfolded state, in which the fender bracket is detached.

Fig. 16 is a third schematic perspective view of the trailer of the third embodiment in a deployed state, in which the rear end stop frame is in a horizontal state.

Fig. 17 is a fourth perspective view of the trailer of the third embodiment in a deployed state, in which the rear end stop is in a hanging-down state.

Fig. 18 is a fifth perspective view of the trailer of the third embodiment in an extended position, wherein the single sideframe is in a horizontal position.

Fig. 19 is a sixth schematic perspective view of a trailer according to the third embodiment in an unfolded state, wherein the single sideframe is in a downwardly hanging state.

Fig. 20 is a seventh perspective view of the trailer according to the third embodiment in an unfolded state in which the side frames and the rear frame are horizontal.

Fig. 21 is an eighth schematic perspective view of a trailer according to the third embodiment in an unfolded state, in which the side frames and the rear frame are in a hanging state.

Fig. 22 is a ninth perspective view of the trailer according to the third embodiment in an unfolded state, in which the side frames and the side frames are in a hanging state.

Detailed Description

Example one

A trailer, please refer to fig. 1 to 6, comprising a trailer frame A and a synchronous linkage mechanism, wherein the trailer frame A comprises two vertical frames 10 arranged in front and back and an intermediate frame 20, and wheels 11 are arranged below the vertical frames 10. The two vertical racks 10 are rotatably provided with racks 30 and link parts 40, the racks 30 and the link parts 40 of the two vertical racks 10 are rotatably provided with intermediate racks 20, and the two vertical racks 10, the two racks 30, the intermediate rack 20 and the two link parts 40 are matched to form four-link mechanisms A1 and A2 of the two common intermediate racks 20; the synchronous linkage mechanism comprises two linkage parts 50, the first ends of the two linkage parts 50 are respectively rotatably connected with the racks 30 of the two vertical frames 10, the second ends of the two linkage parts 50 are movably connected with the middle frame 20 and can synchronously move up and down along the middle frame 20, the two linkage parts 50 are driven to synchronously move up and down through the synchronous up and down movement to drive the two racks 30 to synchronously open and close, so that the two four-bar mechanisms A1 and A2 are driven to synchronously open and close through the synchronous linkage mechanism, on one hand, the convenience of opening and closing is improved, and on the other hand, the trailer frame in the unfolding state is more stable and reliable.

In this embodiment: the vertical frame 10 comprises two upright posts 12 and two first cross bars 13 fixedly connected to the two upright posts 12, wherein the two first cross bars 13 are arranged at intervals up and down; wheels 11 are mounted below each upright post 12, and the front wheel group of the upright post 12 of the front upright frame is a 360-degree direction wheel, and further, a wheel frame is mounted below the upright post 12, and the wheels 11 are mounted in the wheel frame. The rack 30 includes two first main beams 31 and two second cross bars 32 fixedly connected to the two first main beams 31, a plurality of first support bars are fixedly connected between the two second cross bars 32, a plurality of second support bars are fixedly connected between the two first main beams 31 to form the rack 30, and articles can be loaded on the rack 30. The middle frame 20 includes a third cross bar 21, and middle rods 22 are fixed to both ends of the third cross bar 21. The link portion 40 forms an underframe, which includes two second main beams 41 and two fourth cross bars 42 fixedly connected to the two second main beams 41, and a plurality of third struts are further fixedly connected between the two fourth cross bars 42, so that the link portion 40 forms an underframe to enable objects to be loaded, and thus the trailer frame forms a double-layer trailer frame after being unfolded.

The first ends of the two first main beams 31 of the rack 30 are rotatably connected to the first cross bar 13 of the upright 10 at the upper side, and the second ends of the two first main beams 31 of the rack 30 are rotatably connected to the third cross bar 21 of the intermediate rack 20, so that the first side of the rack 30 is rotatably connected to the upright 10, and the second side of the rack 30 is rotatably connected to the intermediate rack 20. The first ends of the two second main beams 41 of the link portion 40 are respectively rotatably connected to the two vertical columns 12 of the vertical frame 10, and the second ends of the two second main beams 41 of the link portion 40 are respectively rotatably connected to the two intermediate rods 22 of the intermediate frame 20, so that the first side of the link portion 40 is rotatably connected to the vertical frame 10 and the second side is rotatably connected to the intermediate frame 20. The four-bar linkage mechanisms a1 and a2 are parallelogram four-bar linkage mechanisms connected as described above, the trailer frame a is arranged symmetrically front and back with respect to the middle frame 20, and the racks 30 and the link parts 20 of the four-bar linkage mechanisms a1 and a2 in the unfolded state on the trailer frame a are arranged up and down.

The middle rod 22 of the middle frame 20 is provided with a connecting shaft 51 capable of moving up and down, and the second ends of the two linking members 50 are rotatably connected to the connecting shaft 51, so that the second ends of the two linking members 50 are driven to move up and down synchronously by the movement of the connecting shaft 51. In the concrete structure: the middle rod 22 of the middle frame 20 is provided with a sliding slot 23 arranged along the upper and lower direction, the connecting shaft 51 is adapted to be assembled and connected in the sliding slot 23, and the second ends of the two linking members 50 are respectively rotatably connected to the two ends of the connecting shaft 51 extending out of the sliding slot 23. Two interlocking members 50 are provided between each of the intermediate bars 22 and the first main beams 31, as required. The intermediate frame 20 is provided with a limit position 24 as required, and the four-bar linkage a1, a2 is in the unfolded state when the connecting shaft 51 is pushed against the limit position 24 from bottom to top. The limiting position is, for example, the top groove wall of the sliding groove 23, the trailer frame is kept in the unfolding state through the limitation, and the limiting position 24 and the connecting shaft are matched to form a limiting mechanism for limiting the trailer frame in the unfolding state. The sliding groove not only plays a role in guiding, but also plays a role in limiting, is simple and convenient to operate, and can be opened or folded in one step.

The trailer of this embodiment further comprises a handle 14, the lower end of the handle 14 being rotatably attached to the first rail 13 of an upright 10 of the trailer frame a, and the upper end being provided with a handle 141.

Example two

It differs from the previous embodiment in that: referring to fig. 7 to 10, the limiting mechanism connects the third cross bar 21 of the middle shelf 20 and the first main beam 31 of the rack 30 to limit the four-bar linkage mechanism in the unfolded state. The limiting mechanism comprises a lug 24 fixedly arranged at the tail end of the third cross bar 21, and the upper end surface of the lug 24 forms an upward arranged limiting surface; the rotation axes of the first main beam 31 and the third cross bar 21 are higher than the limiting surface, and the end of the first main beam 31 is supported against the limiting surface, and the four-bar linkage mechanisms A1 and A2 are in a spread state.

EXAMPLE III

It differs from the previous embodiment in that: referring to fig. 11 to 22, the trailer frame a is mounted with a barrier frame, the barrier frame includes two side barrier frames 60 and two end barrier frames 70 respectively rotatably mounted on the two vertical frames 10, and the two side barrier frames 60 and the two end barrier frames 70 can cooperate to form the barrier frame.

The end stop frame 70 can be rotatably attached to the first cross bar 13 on the upper side of the vertical frame 10 so that the end stop frame 70 can rotate relative to the vertical frame 10, the end stop frame 70 can be positioned in an upright state, a horizontal state and a drooping state by rotating, a second locking mechanism is arranged between the end stop frame 70 and the vertical frame 10, and at least the end stop frame 70 and the vertical frame 10 can be locked by the second locking mechanism so as to be kept in the upright state and the horizontal state. The second locking mechanism is, for example, a latch, etc., and the specific structure is described by taking the latch as an example, the rear frame 70 is provided with a first locking shaft 71 capable of sliding along the rear frame 70, a first elastic body 72 is provided between the first locking shaft 71 and the rear frame 70, the vertical frame 10 is fixedly provided with a plug plate 73, the plug plate 73 is concavely provided with two locking slots corresponding to the vertical state and the horizontal state, respectively, the first locking shaft 71 is inserted into the locking slots under the elastic force of the first elastic body 72, and then the two are kept at the positions, the first locking shaft 71 is slid to be separated from the locking slots, then the two can freely rotate, and is adjusted to a proper position, and the first locking shaft 71 is inserted into the locking slots under the elastic force of the first elastic body when the first locking shaft 71 is released.

The side blocking frame 60 comprises two scissors-shaped connecting rods 61, four ends of each scissors-shaped connecting rod 61 are two inner ends and two outer ends, the two scissors-shaped connecting rods 61 are arranged side by side in the front-back direction, the adjacent inner ends of the two scissors-shaped connecting rods 61 are rotatably connected together through a middle connecting seat 62, the middle connecting seat 62 positioned on the lower side is rotatably connected to a third cross rod 21 of the middle frame 20, side connecting seats 63 are fixedly arranged at the outer ends of the two scissors-shaped connecting rods 61, the side connecting seats 63 positioned on the lower side can be rotatably connected to a first cross rod 13 positioned on the upper side of the vertical frame 10, so that the side blocking frame 60 can rotate relative to the trailer frame A, and the side blocking frame 60 can be positioned in an upright state, a horizontal state. Through the structure, the side blocking frame 60 can stretch and retract along with the trailer frame, so that the integrated synchronous stretching and retracting can be realized, and the supporting strength and the connection strength can be enhanced. A first locking mechanism is arranged between the middle connecting seat 62 and the third cross bar 21 of the middle frame 20, and at least the side baffle frame 60 and the trailer frame A can be locked through a second locking mechanism so as to be kept in an upright state and a horizontal state. The second locking mechanism is like a bolt, a clamping connection and the like.

Further, in this embodiment, a middle extension tube 64 is connected between two middle connection seats 62 of the two scissors-shaped connection rods 61, a side extension tube 65 is connected between two side connection seats 63, the side extension tube 65 includes a lower tube and an upper tube slidably connected to the lower tube, a lower end of the lower tube is fixedly connected to the lower side connection seat, an upper end of the upper tube is fixedly connected to the upper side connection seat, and an upper end of the lower tube is fixedly connected to a matching seat 66; a positioning mechanism such as a latch 67 is provided between the upper end of the end stop 70 and the mating seat 66 of the scissors-shaped link 61, and the latch 67 is inserted into the end stop 70 and the mating seat 66.

The above description is only a preferred embodiment of the present invention, and therefore the scope of the present invention should not be limited by this description, and all equivalent changes and modifications made within the scope and the specification of the present invention should be covered by the present invention.

Claims (17)

1. A trailer comprises a trailer frame, wherein the trailer frame comprises two vertical frames which are arranged in front and back, and wheels are arranged below the vertical frames; the method is characterized in that: the trailer frame also comprises an intermediate frame, the two vertical frames are provided with racks and connecting rod parts, the racks and the connecting rod parts of the two vertical frames are arranged on the intermediate frame, and the two vertical frames, the two racks, the intermediate frame and the two connecting rod parts are combined to form a four-bar mechanism sharing the intermediate frame; the trailer also comprises a synchronous linkage mechanism, wherein the synchronous linkage mechanism comprises two linkage parts, the first ends of the two linkage parts are respectively connected with the racks of the two vertical frames, and the second ends of the two linkage parts are movably connected with the middle frame so as to drive the two four-bar mechanisms to synchronously open and close through the synchronous linkage mechanism.

2. A trailer in accordance with claim 1, wherein: the first side of the rack and the first side of the connecting rod part are rotatably connected with the vertical frame, the second side of the rack and the second side of the connecting rod part are rotatably connected with the middle frame, and the rack and the connecting rod part of the four-bar linkage mechanism in the unfolding state are arranged up and down.

3. A trailer in accordance with claim 1, wherein: the four-bar linkage is a parallelogram four-bar linkage.

4. A trailer in accordance with claim 1, wherein: the link portion constitutes a chassis.

5. A trailer in accordance with claim 1 or 2 or 3 or 4, wherein: the first ends of the two linking parts are respectively and rotatably connected with the racks of the two vertical racks, and the second ends of the two linking parts can synchronously move up and down along the middle rack.

6. A trailer in accordance with claim 5, wherein: the middle frame is provided with a connecting shaft which can move up and down, and the second ends of the two linkage parts are rotatably connected with the connecting shaft.

7. A trailer in accordance with claim 6, wherein: the middle frame is provided with a sliding chute which is arranged up and down, and the connecting shaft is suitable for being assembled and connected in the sliding chute.

8. A trailer in accordance with claim 6, wherein: the middle frame is provided with a limiting position, and the four-bar mechanism is in an unfolded state when the connecting shaft is propped against the limiting position from bottom to top.

9. A trailer in accordance with claim 1 or 2 or 3 or 4, wherein: the four-bar linkage mechanism is connected with the middle frame and the rack to limit the four-bar linkage mechanism to be in an unfolding state.

10. A trailer in accordance with claim 9, wherein: the limiting mechanism comprises an upward limiting surface fixedly arranged on the middle frame, and the end part of the rack is in an unfolded state when being supported against the limiting surface.

11. A trailer in accordance with claim 1 or 2 or 3 or 4, wherein: the trailer frame is symmetrically arranged front and back relative to the middle frame.

12. A trailer in accordance with claim 1 or 2 or 3 or 4, wherein: the trailer also comprises a handle which is connected on a vertical frame of the trailer frame.

13. A trailer in accordance with claim 1 or 2 or 3 or 4, wherein: the trailer frame is provided with the surrounding baffle frame, the surrounding baffle frame comprises two side baffle frames and two end baffle frames which can be respectively rotatably connected with the two vertical frames, and the two side baffle frames and the two end baffle frames can be matched to form the surrounding baffle frame.

14. A trailer in accordance with claim 13, wherein: the side blocking frame comprises two scissors-shaped connecting rods, the four ends of each scissors-shaped connecting rod are two inner ends and two outer ends respectively, the two scissors-shaped connecting rods are arranged side by side in the front and back direction, the adjacent inner ends of the two scissors-shaped connecting rods are rotatably connected together through a middle connecting seat, the middle connecting seat positioned at the lower side is rotatably connected to the middle frame, and the lower outer ends of the two scissors-shaped connecting rods can be rotatably connected to the two vertical frames respectively.

15. A trailer in accordance with claim 14, wherein: a first locking mechanism is arranged between the middle connecting seat and the middle frame.

16. A trailer in accordance with claim 14, wherein: a second locking mechanism is arranged between the end blocking frame and the vertical frame.

17. A trailer in accordance with claim 14, wherein: a middle telescopic pipe is connected between two middle connecting seats of the two scissors-shaped connecting rods, the outer end parts of the two scissors-shaped connecting rods are connected with side connecting seats, a side telescopic pipe is connected between the two side connecting seats, the side telescopic pipe comprises a lower pipe and an upper pipe which is connected with the lower pipe in a sliding manner, and the upper end of the lower pipe is fixedly provided with a matching seat; a positioning mechanism is arranged between the upper end of the end baffle frame and the matching seat of the scissors-shaped connecting rod.

Images