A plankton net fixing device for collecting early resources of fish

Abstract

The present invention discloses a fixing device for a plankton net for collecting early fish resources. Its structure includes a towing rope, a fixing mechanism, and a biological net. The towing rope is installed on the top of the fixing mechanism. Four partition rods are connected to the outside of the central cylinder in cooperation with spring tube sleeves and telescopic rods to form a "rice" - shaped structure, which can separate and block the inlet of the inlet ring, isolate mature large fish outside, avoid mature large fish being discharged into the net body, and prevent the net body from being broken; through the elastic connection of the torsion shaft and the outer support rod, the outer support rod can be elastically adjusted in angle of rotation. Through twelve outer support rods and the external contact plate, the four support rods inside the net body can be contacted. At this time, the net body is effectively撑开 to form a funnel - shaped structure, which can effectively prevent the net body from being compressed into a flat state after being subjected to water pressure when entering the water, and improve the effect of collecting early fish resources. It should be noted that there is a Chinese character "撑开" in the original text which might be a typo or an incomplete expression. I translated it as "撑开" for now, but it might need to be adjusted according to the correct Chinese content. If it's supposed to be something like "fully opened", it should be translated more accurately.

Description

Technical Field

[0001] This invention relates to the field of planktonic net technology, and more specifically, to a planktonic net fixing device for collecting early fish resources. Background Technology

[0002] Early fish resources refer to the resource status of fish in the early developmental stages such as eggs and fry. This is one of the most effective ways to understand the reproductive ecological characteristics of fish. By observing early fish resources, we can explore and discover the spawning characteristics, egg size, color, and developmental stage of fish, clarify the different characteristics of different fish in the early developmental stage, explore the early developmental patterns of fish, and discover the beauty of early fish development. By fixing plankton nets on both sides of a boat with a fixed device, the boat can move the plankton nets to collect plankton in the water, thereby enabling the collection of early fish resources.

[0003] However, the existing fixing devices installed on both sides of the boat to secure the plankton net have the following shortcomings: the fixing devices fix the plankton net to both sides of the boat, and after the plankton net sinks into the water, mature large fish can easily enter the plankton net, causing it to break and become damaged. In addition, the fixing devices are not able to open up the inside of the plankton net, so after the plankton net sinks into the water, it is compressed into a flat state by the water pressure, making it difficult to effectively collect early fish resources. Summary of the Invention

[0004] The technical solution adopted by this invention to achieve its technical objective is: a plankton net fixing device for collecting early fish resources, the structure of which includes a traction rope, a fixing mechanism, and a plankton net. The traction rope is installed on the top of the fixing mechanism, and the fixing mechanism is installed at both ends of the plankton net. The plankton net includes a net body, a top support ring, support rods, and a bottom support ring. The top support ring is fixedly installed on the top of the net body. Support rods are provided inside the net body. The top support ring is connected to the top of the support rod. The lower end of the support rod is connected to the bottom support ring. The top support ring is installed inside the upper end of the fixing mechanism. The bottom support ring is installed inside the lower end of the fixing mechanism. There are four support rods, which are located at the four positions where the top support ring and the bottom support ring are connected. The four support rods support the net body, allowing the net body to expand and form a funnel-shaped structure.

[0005] As a further improvement of the present invention, the fixing mechanism includes a support ring mechanism, a clamping mechanism, an outer support mechanism, and a bottom support base. The clamping mechanism is installed inside the support ring mechanism in a clamped manner, and the lower end inside the support ring mechanism is clamped with the upper end of the top support ring. The middle of the bottom of the clamping mechanism is connected to the top of the outer support mechanism. The outer support mechanism is located inside the net body, and the outer end of the outer support mechanism abuts against the support rod. The lower end of the outer support mechanism passes through the inside of the bottom support ring by clearance fit, and the bottom support ring is installed inside the bottom support base in a clamped manner through the outer support mechanism. Grooves are provided at four positions inside the bottom support base, which are matched with the bottom of the outer support mechanism.

[0006] As a further improvement of the present invention, the support ring mechanism includes an inlet mechanism, a pin shaft, a clamping groove, and an installation groove. The bottom of the inlet mechanism is embedded with an installation groove, and the top support ring is installed inside the installation groove at the bottom of the inlet mechanism. The pin shaft passes through the clamping groove inside the inlet mechanism, and the clamping groove is embedded in the inner wall of the inlet mechanism. The outer end of the clamping mechanism is installed inside the clamping groove on the inner wall of the inlet mechanism by clearance fit. The installation groove is in a ring structure and has the same shape, size, and structure as the top support ring, and can just insert and install the top support ring into the installation groove. At the same time, it is connected and fixed by the pin shafts provided at four positions on the outside.

[0007] As a further improvement of the present invention, the clamping mechanism includes a central cylinder, a spring tube sleeve, a telescopic rod, and a clamping block. The outer end face of the central cylinder is welded to the inner end of the spring tube sleeve, and the inner end of the telescopic rod passes through the outer end of the spring tube sleeve by clearance fit. The outer end of the telescopic rod is welded with a clamping block, and the clamping block is installed inside the clamping groove on the inner wall of the inlet mechanism by clearance fit. The middle of the bottom of the central cylinder is connected to the top of the outer support mechanism. There are four spring tube sleeves, telescopic rods, and clamping blocks, and their structures are exactly the same, and they are distributed at four positions on the outside of the central cylinder, forming a "cross" structure.

[0008] As a further improvement of the present invention, the inlet mechanism includes an inlet ring, a lower guide piece, and a partition rod. The bottom of the inlet ring is embedded with an installation groove, and the top support ring is installed inside the installation groove at the bottom of the inlet mechanism. The inner wall of the upper end of the inlet ring is welded to the outer end of the lower guide piece, and the inner end of the lower guide piece is welded with a partition rod. The inner end of the partition rod abuts against the outer wall of the central cylinder. There are four lower guide pieces and partition rods, and they are distributed at four positions inside the inlet ring. The lower guide piece is installed at an inclined angle with the outer end higher and the inner end lower. At the same time, the four partition rods cooperate with the spring tube sleeve and the telescopic rod to be connected to the outside of the central cylinder to form a "rice" - shaped structure, which can separate and block the inlet of the inlet ring.

[0009] As a further improvement of the present invention, the external support mechanism includes a threaded rod, an adjusting mechanism, a lower top block, and an elastic locking block. The threaded rod is welded to the top of the adjusting mechanism, and the top of the adjusting mechanism is screwed into the center of the bottom end of the central cylinder through the threaded rod. The lower end of the adjusting mechanism is welded to the lower top block. The adjusting mechanism is located inside the mesh body, and the outer end of the external support mechanism abuts against the support rod. The outer end of the lower top block is provided with an elastic locking block, and the lower top block is engaged with the bottom support ring inside the bottom support seat through the elastic locking block. There are four elastic locking blocks, which are distributed in four directions on the outer side of the lower top block.

[0010] As a further improvement of the present invention, the adjustment mechanism includes a vertical rod, a torsion shaft, an outer support rod, and an abutment plate. A threaded rod is welded to the upper end of the vertical rod, and the interior of the vertical rod is hinged to the inner end of the outer support rod through the torsion shaft. The outer end of the outer support rod is axially connected to the middle of the inner side of the abutment plate. The outer end face of the abutment plate abuts against the support rod. The vertical rod is located in the middle of the inner side of the net body. There are twelve outer support rods and twelve abutment plates, and they are arranged in groups of four. The four outer support rods in each group are distributed in four directions on the outside of the vertical rod. At the same time, the length of the three groups of outer support rods gradually decreases from top to bottom.

[0011] The beneficial effects of this invention are as follows:

[0012] 1. The fixing mechanism and the biological net are fixed to the side of the boat by four towing ropes. Then the net is submerged in the water. At this time, the early fish resources enter through the inlet ring, and the four lower guide plates installed at the upper end of the inlet ring guide the early fish resources into the net for collection. At the same time, four separator rods, together with spring tube sleeves and telescopic rods, are connected to the outside of the central cylinder to form a "rice" shaped structure, which can separate and block the inlet of the inlet ring, and can isolate mature large fish to prevent them from being discharged into the net and causing the net to break.

[0013] 2. The torsion shaft inside the upright is elastically connected to the outer support rod, allowing the outer support rod to be adjusted by elastic angle rotation. The twelve outer support rods and the external contact plate can abut against the four support rods inside the net body. Furthermore, the four elastic locking blocks on the outside of the lower top block can improve the firmness of locking the bottom support ring into the bottom support base. This pulls the net body down and locks it into the bottom support ring. At this time, the net body is effectively opened to form a funnel-shaped structure, which can effectively prevent the net body from being compressed into a flat state due to water pressure after entering the water, thus improving the effectiveness of early fish resource collection. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a planktonic net fixing device for collecting early fish resources according to the present invention.

[0015] Figure 2This is a three-dimensional structural diagram of the biological network of the present invention.

[0016] Figure 3 This is a three-dimensional split structure diagram of the fixing mechanism of the present invention.

[0017] Figure 4 This is a bottom view and a partially enlarged structural schematic diagram of the support ring mechanism of the present invention.

[0018] Figure 5 This is a three-dimensional and top-view structural diagram of the import mechanism of the present invention.

[0019] Figure 6 This is a three-dimensional and partially enlarged structural schematic diagram of the external support mechanism of the present invention.

[0020] Figure 7 This is a front view and a partially enlarged structural schematic diagram of the adjustment mechanism of the present invention.

[0021] In the diagram: Traction rope - S, Fixing mechanism - G, Biological net - W, Net body - w2, Top support ring - w6, Support rod - w3, Bottom support ring - w9, Support ring mechanism - g3, Engaging mechanism - g7, External support mechanism - g1, Bottom support seat - g5, Inlet mechanism - g31, Pin shaft - g36, Engaging groove - g39, Mounting groove - g34, Center cylinder - g74, Spring tube sleeve - g78, Telescopic rod - g72, Engaging block - g75, Inlet ring - 1h, Lower guide plate - 1d, Separator rod - 1f, Threaded rod - g16, Adjusting mechanism - g17, Lower top block - g18, Elastic locking block - g12, Upright rod - 6g, Torsion shaft - 6n, External support rod - 6v, Contact plate - 6d. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings: Example

[0023] As attached Figure 1 To be continued Figure 5 As shown:

[0024] This invention discloses a plankton net fixing device for collecting early fish resources. Its structure includes a traction rope S, a fixing mechanism G, and a plankton net W. The traction rope S is installed on top of the fixing mechanism G, and the fixing mechanism G is installed at both ends of the plankton net W. The plankton net W includes a net body w2, a top support ring w6, a support rod w3, and a bottom support ring w9. The top support ring w6 is fixedly installed on the top of the net body w2. The support rod w3 is provided inside the net body w2. The top support ring w6 is connected to the top of the support rod w3, and the lower end of the support rod w3 is connected to the bottom support ring w9. The top support ring w6 is installed inside the upper end of the fixing mechanism G, and the bottom support ring w9 is installed inside the lower end of the fixing mechanism G.

[0025] The four support rods w3 are located at the four positions where the top support ring w6 and the bottom support ring w9 connect. The four support rods w3 support the net body w2, allowing the net body w2 to expand into a funnel-shaped structure, thereby improving the effectiveness of the net body w2 in collecting and storing early fish resources.

[0026] The fixing mechanism G includes a support ring mechanism g3, a locking mechanism g7, an outer support mechanism g1, and a bottom support g5. The locking mechanism g7 is locked inside the support ring mechanism g3, and the lower end of the support ring mechanism g3 is locked to the upper end of the top support ring w6. The bottom middle of the locking mechanism g7 is connected to the top of the outer support mechanism g1. The outer support mechanism g1 is located inside the net body w2, and the outer end of the outer support mechanism g1 abuts against the support rod w3. The lower end of the outer support mechanism g1 passes through the bottom support ring w9 with a clearance fit, and the bottom support ring w9 is locked and installed inside the bottom support g5 by the outer support mechanism g1.

[0027] The bottom support g5 has grooves in four directions inside, which match the bottom of the outer support mechanism g1. The bottom of the outer support mechanism g1 passes through the bottom support ring w9 and is embedded in the groove of the bottom support ring w9, so that the bottom of the net body w2 can be firmly installed inside the bottom support g5.

[0028] The supporting ring mechanism g3 includes an inlet mechanism g31, a pin g36, a locking groove g39, and a mounting groove g34. The bottom of the inlet mechanism g31 is embedded in the mounting groove g34, and the top support ring w6 is installed inside the mounting groove g34 at the bottom of the inlet mechanism g31. The pin g36 passes through the locking groove g39 of the inlet mechanism g31. The locking groove g39 is embedded in the inner wall of the inlet mechanism g31. The outer end of the locking mechanism g7 is installed in the locking groove g39 on the inner wall of the inlet mechanism g31 with clearance fit.

[0029] The mounting groove g34 has a ring-shaped structure and is consistent with the shape and size of the top support ring w6. The top support ring w6 can be inserted into the mounting groove g34 and fixed by the pins g36 set on the four outer sides, which improves the firmness of the top support ring w6 inserted into the inlet mechanism g31.

[0030] The engaging mechanism g7 includes a central cylinder g74, a spring sleeve g78, a telescopic rod g72, and an engaging block g75. The outer end face of the central cylinder g74 is welded to the inner end of the spring sleeve g78, and the inner end of the telescopic rod g72 passes through the outer end of the spring sleeve g78 with a clearance fit. The engaging block g75 is welded to the outer end of the telescopic rod g72. The engaging block g75 is installed in the engaging groove g39 on the inner wall of the inlet mechanism g31 with a clearance fit. The bottom middle of the central cylinder g74 is connected to the top of the outer support mechanism g1.

[0031] The spring sleeve g78, telescopic rod g72, and locking block g75 are all provided in four identical positions, distributed on the four sides of the outer side of the central cylinder g74, forming a cross shape. The spring sleeve g78 applies a lateral elastic telescopic force to the telescopic rod g72, allowing the locking block g75 to engage and disengage within the locking groove g39 on the inner wall of the inlet mechanism g31. This facilitates the positioning and installation of the central cylinder g74 in the center of the inlet mechanism g31 or its easy disassembly. During the collection process, the outer support mechanism g1 can be vertically installed inside the net body w2 to open the net body w2 for collection. After the work is completed, the outer support mechanism g1 can be easily removed from inside the net body w2, facilitating the extraction of early-stage fish resources collected inside the net body w2.

[0032] The inlet mechanism g31 includes an inlet ring 1h, a lower guide plate 1d, and a separator rod 1f. The bottom of the inlet ring 1h is embedded in a mounting groove g34, and the top support ring w6 is installed inside the mounting groove g34 at the bottom of the inlet mechanism g31. The upper inner wall of the inlet ring 1h is welded to the outer end of the lower guide plate 1d. The inner end of the lower guide plate 1d is welded with a separator rod 1f, and the inner end of the separator rod 1f abuts against the outer wall of the central cylinder g74.

[0033] There are four lower guide plates 1d and four separator rods 1f, which are distributed in four directions inside the inlet ring 1h. The lower guide plates 1d are installed at an inclined angle with the outer end higher than the inner end. The four lower guide plates 1d can guide the early fish resources into the net body w2 for collection. At the same time, the four separator rods 1f, together with the spring tube sleeve g78 and the telescopic rod g72, are connected to the outside of the central cylinder g74 to form a "rice" shaped structure. This can separate and block the inlet of the inlet ring 1h, and can isolate mature large fish to the outside, so as to prevent mature large fish from being discharged into the net body w2 and to prevent the net body w2 from breaking.

[0034] The specific usage and function of this embodiment are as follows:

[0035] In this invention, when using the plankton net fixing device, four support rods w3 support the net body w2, allowing it to expand into a funnel-shaped structure. Then, the top support ring w6 is inserted into the mounting groove g34 at the bottom of the inlet ring 1h and fixed by four pins g36, improving the stability of the top support ring w6 inside the inlet ring 1h. Next, a spring sleeve g78 applies a lateral elastic telescopic force to the telescopic rod g72, allowing the locking block g75 to engage within the locking groove g39 on the inner wall of the inlet ring 1h. This facilitates the positioning and installation of the central cylinder g74 at the center of the inlet ring 1h. Then, through the connection of the threaded rod g16, the adjusting mechanism g17 is vertically installed inside the middle of the net body w2. The bottom of the adjusting mechanism g17 passes through the bottom support ring w9 and embeds into the groove of the bottom support ring w9, firmly securing the bottom of the net body w2. The net body W2 is installed inside the bottom support g5. At this time, the net body W2 is effectively expanded to form a funnel-shaped structure. The fixing mechanism G and the biological net W are fixed to the side of the boat by four traction ropes S. Then, the net body W2 is submerged in the water. At this time, the early fish resources enter through the inlet ring 1h, and the four lower guide plates 1d installed at the upper end of the inlet ring 1h guide the early fish resources into the net body W2 for collection. At the same time, the four separator rods 1f, together with the spring tube sleeve g78 and the telescopic rod g72, are connected to the outside of the central cylinder g74 to form a "rice" shaped structure, which can separate and block the inlet of the inlet ring 1h, and can isolate mature large fish to the outside, preventing mature large fish from being discharged into the net body W2 and preventing the net body W2 from breaking. After the collection is completed, the biological net W is quickly separated from the inside of the inlet ring 1h by the locking mechanism g7, making it easy to take out the early fish resources collected inside the net body W2. Example

[0036] As attached Figure 6 To be continued Figure 7 As shown:

[0037] The external support mechanism g1 includes a threaded rod g16, an adjustment mechanism g17, a lower top block g18, and an elastic locking block g12. The threaded rod g16 is welded to the top of the adjustment mechanism g17, and the top of the adjustment mechanism g17 is spirally installed inside the bottom center of the central cylinder g74 through the threaded rod g16. The lower end of the adjustment mechanism g17 is welded with the lower top block g18. The adjustment mechanism g17 is located inside the mesh body w2, and the outer end of the external support mechanism g1 abuts against the support rod w3. The outer end of the lower top block g18 is provided with an elastic locking block g12, and the lower top block g18 uses the elastic locking block g12 to engage the bottom support ring w9 inside the bottom support g5.

[0038] The elastic locking blocks g12 are provided in four positions and are distributed on the four sides of the lower top block g18. The four elastic locking blocks g12 can improve the firmness of the bottom support ring w9 being locked and installed inside the bottom support g5, thereby pulling down and locking the net body w2 inside the bottom support ring w9.

[0039] The adjustment mechanism g17 includes a vertical rod 6g, a torsion shaft 6n, an outer support rod 6v, and a contact plate 6d. A threaded rod g16 is welded to the upper end of the vertical rod 6g, and the vertical rod 6g is hinged to the inner end of the outer support rod 6v through the torsion shaft 6n. The outer end of the outer support rod 6v is axially connected to the middle of the inner side of the contact plate 6d. The outer end face of the contact plate 6d abuts against the support rod w3. The vertical rod 6g is located in the middle of the inner side of the net body w2.

[0040] The external support rods 6v and the contact plates 6d are each provided in twelve units, and four units are arranged in a group. The four external support rods 6v in each group are distributed on the four sides of the outside of the upright 6g. At the same time, the length of the three groups of external support rods 6v gradually decreases from top to bottom. The twelve external support rods 6v and the external contact plates 6d can abut against the four support rods w3 inside the net body w2, effectively expanding the net body w2 to form a funnel-shaped structure. This can effectively prevent the net body w2 from being compressed into a flat state after entering the water and being subjected to water pressure, thereby improving the effect of early fish resource collection.

[0041] The specific usage and function of this embodiment are as follows:

[0042] In this invention, during installation, the upper end of the upright 6g is installed at the bottom center of the central cylinder g74 via the threaded rod g16, making the upright 6g stand vertically inside the net body w2. Simultaneously, the torsion shaft 6n inside the upright 6g is elastically connected to the outer support rod 6v, allowing the outer support rod 6v to be adjusted by elastic angle rotation. The twelve outer support rods 6v and the external contact plate 6d provide contact with the four support rods w3 inside the net body w2. Furthermore, the four elastic locking blocks g12 on the outer side of the lower top block g18 enhance the firmness of the bottom support ring w9 being locked inside the bottom support base g5, thereby pulling the net body w2 down and locking it inside the bottom support ring w9. At this point, the net body w2 effectively expands to form a funnel-shaped structure, effectively preventing the net body w2 from being compressed into a flat state by water pressure after entering the water, thus improving the effectiveness of early fish resource collection.

[0043] Any technical solution that achieves the above-mentioned technical effects by utilizing the technical solutions described in this invention, or by designing similar technical solutions by those skilled in the art under the inspiration of the technical solutions described in this invention, falls within the protection scope of this invention.

Claims

1. A plankton net fixing device for collecting early fish resources, comprising a traction rope (S), a fixing mechanism (G), and a plankton net (W), wherein the traction rope (S) is mounted on top of the fixing mechanism (G), and the fixing mechanism (G) is mounted at both ends of the plankton net (W), characterized in that: The biological net (W) includes a net body (w2), a top support ring (w6), a support rod (w3), and a bottom support ring (w9). The top support ring (w6) is fixedly installed on the top of the net body (w2). The support rod (w3) is provided inside the net body (w2). The top support ring (w6) is connected to the top of the support rod (w3). The lower end of the support rod (w3) is connected to the bottom support ring (w9). The top support ring (w6) is installed inside the upper end of the fixing mechanism (G), and the bottom support ring (w9) is installed inside the lower end of the fixing mechanism (G). The fixing mechanism (G) includes a support ring mechanism (g3), a locking mechanism (g7), an outer support mechanism (g1), and a bottom support (g5). The locking mechanism (g7) is locked inside the support ring mechanism (g3), and the lower end of the support ring mechanism (g3) is locked to the upper end of the top support ring (w6). The bottom middle of the locking mechanism (g7) is connected to the top of the outer support mechanism (g1). The outer support mechanism (g1) is located inside the net body (w2), and the outer end of the outer support mechanism (g1) abuts against the support rod (w3). The lower end of the outer support mechanism (g1) passes through the bottom support ring (w9) with a clearance fit, and the bottom support ring (w9) is locked and installed inside the bottom support (g5) through the outer support mechanism (g1). The support ring mechanism (g3) includes an inlet mechanism (g31), a pin (g36), a locking groove (g39), and a mounting groove (g34). The bottom of the inlet mechanism (g31) is embedded in the mounting groove (g34), and the top support ring (w6) is installed inside the mounting groove (g34) at the bottom of the inlet mechanism (g31). The pin (g36) passes through the locking groove (g39) of the inlet mechanism (g31), and the locking groove (g39) is embedded in the inner wall of the inlet mechanism (g31). The outer end of the locking mechanism (g7) is installed in the locking groove (g39) on the inner wall of the inlet mechanism (g31) with a clearance fit. The engaging mechanism (g7) includes a central cylinder (g74), a spring sleeve (g78), a telescopic rod (g72), and an engaging block (g75). The outer end face of the central cylinder (g74) is welded to the inner end of the spring sleeve (g78), and the inner end of the telescopic rod (g72) passes through the outer end of the spring sleeve (g78) with a clearance fit. The outer end of the telescopic rod (g72) is welded with an engaging block (g75), and the engaging block (g75) is installed in the engaging groove (g39) on the inner wall of the inlet mechanism (g31) with a clearance fit. The bottom middle of the central cylinder (g74) is connected to the top of the outer support mechanism (g1). The import mechanism (g31) includes an import ring (1h), a lower guide plate (1d), and a separator rod (1f). The bottom of the import ring (1h) is embedded with a mounting groove (g34), and the top support ring (w6) is installed inside the mounting groove (g34) at the bottom of the import mechanism (g31). The upper inner wall of the import ring (1h) is welded to the outer end of the lower guide plate (1d), and the inner end of the lower guide plate (1d) is welded with a separator rod (1f). The inner end of the separator rod (1f) abuts against the outer wall of the central cylinder (g74). The external support mechanism (g1) includes a threaded rod (g16), an adjusting mechanism (g17), a lower top block (g18), and an elastic locking block (g12). The threaded rod (g16) is welded to the top of the adjusting mechanism (g17), and the top of the adjusting mechanism (g17) is spirally installed inside the center of the bottom end of the central cylinder (g74) through the threaded rod (g16). The lower end of the adjusting mechanism (g17) is welded with a lower top block (g18). The adjusting mechanism (g17) is located inside the mesh body (w2), and the outer end of the external support mechanism (g1) abuts against the support rod (w3). The outer end of the lower top block (g18) is provided with an elastic locking block (g12), and the lower top block (g18) uses the elastic locking block (g12) to engage the bottom support ring (w9) inside the bottom support base (g5). The adjustment mechanism (g17) includes a vertical rod (6g), a torsion shaft (6n), an outer support rod (6v), and an abutment plate (6d). A threaded rod (g16) is welded to the upper end of the vertical rod (6g), and the interior of the vertical rod (6g) is hinged to the inner end of the outer support rod (6v) through the torsion shaft (6n). The outer end of the outer support rod (6v) is axially connected to the middle of the inner side of the abutment plate (6d). The outer end face of the abutment plate (6d) abuts against the support rod (w3). The vertical rod (6g) is located in the middle of the inner side of the net body (w2).

Images