Polar midwater trawl

Abstract

The application discloses a polar ice zone middle layer trawl, which comprises a trawl frame, an automatic releaser, a net and two lifting ropes with rings; the trawl frame comprises a control crossbar, a sliding upper cable, a gravity lower cable and two sliding steel ropes; the sliding upper cable is a net upper cable, the gravity lower cable is a net lower cable, and the sliding steel ropes are net side cables; the gravity lower cable is equipped with a weight; the two ends of a first lifting rope are connected with the two ends of the gravity lower cable respectively, and the two ends of a second lifting rope are connected with the two ends of the sliding upper cable respectively; the automatic releaser is arranged in the middle of the control crossbar and adopts a quick-release buckle design, so that the first lifting ring of the first lifting rope and the second lifting ring of the second lifting rope fixed in the automatic releaser can be released in sequence quickly in the polar extremely cold weather, and the polar ice zone trawl operation can avoid sea ice.

Description

Technical Field

[0001] This invention relates to sampling nets for marine fish surveys in polar ice areas, particularly for sampling mid-to-upper-level fish. Specifically, it relates to a mid-level trawl net for polar ice areas. Background Technology

[0002] The polar oceans, including the Southern Ocean and the Arctic Ocean, are important response areas to global climate change and play a crucial role in the global marine ecosystem. The unique geographical conditions of these oceans provide stable habitats for marine life such as fish, making them vital areas for global fisheries resource management and sustainable development. Marine biological resources, including fish, have always been an important component of polar expeditions worldwide. Appropriate survey nets are typically selected based on different research objectives, including common Bongo nets, IKMT nets, and frame trawls.

[0003] Countries around the world utilize the brief summer window for polar and oceanographic expeditions, but the persistent sea ice in high-latitude regions with long ice-covered periods remains a primary limiting factor for these expeditions. Research indicates that global climate change has prompted many species, including fish, to migrate towards the poles, leading to corresponding changes in their population structure, life history, and resource replenishment migration processes. Therefore, the geographical and temporal scope of marine biological resource surveys should be continuously expanded, extending spatially towards higher latitudes and temporally towards year-round operation.

[0004] Currently, frame trawls are commonly used to conduct surveys of fish and other biological resources in polar seas. During sampling, the net openings remain open at all times. In the extreme polar environment, sea ice can easily enter the survey nets. The hard and sharp sea ice not only easily damages the survey nets but also poses great difficulties for sampling, significantly limiting the spatial and temporal scope of polar marine biological surveys. Summary of the Invention

[0005] The present invention aims to provide a mid-level trawl net for polar ice areas, enabling avoidance of sea ice during trawl operations in polar ice areas.

[0006] The technical solution of the present invention is: a mid-level trawl net for polar ice areas, comprising a trawl net frame, an automatic release device, a net cover, and two slings with lifting rings in the middle;

[0007] The trawl frame includes a control crossbar, a sliding upper beam, a gravity lower beam, and two sliding steel cables. Both ends of the control crossbar and the gravity lower beam are equipped with cable locking rings, and both ends of the sliding upper beam are equipped with circular rings. The two sliding steel cables pass through the circular rings at both ends of the sliding upper beam, and their tops are connected to the cable locking rings at the ends of the control crossbar, and their bottoms are connected to the cable locking rings at the ends of the gravity lower beam. The connection of the control crossbar, the gravity lower beam, and the two sliding steel cables forms a towing force-bearing body and a slide rail.

[0008] The four connecting ends of the net are respectively connected to the two ends of the sliding upper line and the two ends of the gravity lower line. The sliding upper line, the gravity lower line and the sliding steel cable form an effective trawl net opening. The sliding upper line is the upper line of the net, the gravity lower line is the lower line of the net, and the sliding steel cable is the side line of the net.

[0009] The lower gravity line is equipped with a weight;

[0010] The first sling is connected to both ends of the lower gravity cable, and the second sling is connected to both ends of the upper sliding cable.

[0011] The automatic release device is located in the middle of the control crossbar and adopts a quick-release buckle design, which enables the rapid and sequential release of the first ring of the first sling and the second ring of the second sling, which are fixed in the automatic release device in extreme cold weather.

[0012] Furthermore, the weight is a ring-shaped weight with an arc-shaped groove on the top, which can control the towing posture of the net and lock the sliding upper line through the arc-shaped groove when the net is closed in the sea surface ice area.

[0013] Furthermore, the automatic release device is equipped with a telescopic locking pin;

[0014] The automatic release device has two radial grooves at its front end. The front radial groove can be used to insert the first lifting ring, and the rear radial groove can be used to insert the second lifting ring.

[0015] The front end of the automatic release device has an axial circular through hole perpendicular to the radial groove;

[0016] The front end of the telescopic locking pin is located inside the circular through hole and can move back and forth along the axial direction of the circular through hole. The telescopic movement of the telescopic locking pin can lock and fix the two lifting rings or release the first and second lifting rings in sequence.

[0017] Furthermore, the automatic release device also includes a drive motor, a gear assembly, and a ring buckle;

[0018] The drive motor is located at the tail end of the telescopic locking pin inside the automatic release device body. The tail end of the telescopic locking pin is provided with a straight row of gear teeth. The drive motor is connected to the gear teeth through the gear assembly.

[0019] The drive motor is controlled by a depth sensor. Once the set depth condition is reached, the controller drives the motor to run via an electrical signal. The drive motor adopts a unidirectional control design. It runs clockwise according to the controller's set parameters. When not running under commands, the drive motor is locked in the clockwise direction. The drive motor can rotate freely in the counterclockwise direction without being controlled by the controller.

[0020] When the drive motor runs according to the set parameter instructions, the drive motor rotation motion control gear assembly rotates clockwise, the telescopic locking pin moves to the rear end of the automatic release device, and the first and second lifting rings are released in sequence. The sliding upper line and the gravity lower line slide down to the bottom of the net by their own gravity.

[0021] The buckle is set on the outer wall of the automatic release device and connected to the telescopic locking pin inside the automatic release device. Before the net is laid, the lifting ring connected with the sliding upper line and the gravity lower line is inserted into the two radial grooves at the front end of the automatic release device, and the buckle on the outer wall of the automatic release device is pulled to drive the telescopic locking pin through the radial grooves at the front end of the automatic release device to lock the two lifting rings.

[0022] Furthermore, a spring is provided between the tail end of the telescopic locking pin and the inner tail of the automatic release device. When the drive motor drives the gear to move the telescopic locking pin backward, the spring's rebound force increases the backward movement force of the telescopic locking pin, thereby reducing the power consumption of the automatic release device.

[0023] Furthermore, the gear assembly includes a large gear, a small gear, and a gear support; the large gear is connected to the drive motor and the small gear respectively and drives the small gear to run; the small gear meshes with the teeth below the telescopic locking pin and drives the telescopic locking pin to extend and retract.

[0024] The beneficial technical effects of this invention are as follows: 1. The combined design of control crossbars, sliding upper line, gravity lower line, and sliding steel cable enables control of the net's stress point and maintenance of the net's opening posture; 2. The arched groove design at the top of the encircling weight in the gravity lower line allows for quick locking of the sliding upper line when it slides to the bottom; 3. The combined design of the telescopic locking pin, spring, drive motor, and gear assembly in the automatic release device enables release control of the sliding upper line and gravity lower line, with the drive motor's operation controlled by a depth sensor; 4. The combined mechanical force of the spring and motor greatly reduces motor power loss, enabling the release device to maintain long-term operation in polar low-temperature environments; 5. This invention controls the opening and closing of the net opening through the automatic release device to prevent sea ice from entering the net, enhancing the net's ability to avoid sea ice and adapt to polar ice trawling operations; 6. This invention uses a combination design of multiple crossbars and steel cables, resulting in a simple structure, significantly reducing the net's weight, and improving operability. Attached Figure Description

[0025] Appendix Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0026] Appendix Figure 2 This is a schematic diagram of the structure of the trawl frame of the present invention;

[0027] Appendix Figure 3 This is a schematic diagram of the automatic release device of the present invention.

[0028] The reference numerals and components involved in the accompanying drawings are shown below:

[0029] 1 is the trawl net frame; 2 is the automatic release device; 3 is the netting.

[0030] 11 is the control bar; 12 is the sliding upper beam; 13 is the sliding steel cable; 14 is the gravity lower beam; 15 is the lifting ring; 16 is the sling; 17 is the weight.

[0031] 21 is a radial groove; 22 is a circular through hole; 23 is a telescopic locking pin; 24 is a spring; 25 is a drive motor; 26 is a large gear; 27 is a small gear; 28 is a gear bracket; 29 is a gear tooth. Detailed Implementation

[0032] The present invention will now be further described with reference to the embodiments and the accompanying drawings.

[0033] Please refer to the appendix. Figures 1-3 A polar ice mid-level trawl net includes a trawl net frame 1, an automatic release device 2, a net 3, and two slings 16 with a middle hanging ring 15.

[0034] The trawl frame 1 includes a control crossbar 11, a sliding upper beam 12, a gravity lower beam 14, and two sliding steel cables 13. Both ends of the control crossbar 11 and the gravity lower beam 14 are equipped with cable locking rings, and both ends of the sliding upper beam 12 are equipped with rings. The two sliding steel cables 13 pass through the rings at both ends of the sliding upper beam 12, and their tops connect to the cable locking rings at the ends of the control crossbar 11, while their bottoms connect to the cable locking rings at the ends of the gravity lower beam 14. The connection of the control crossbar 11, the gravity lower beam 14, and the two sliding steel cables 13 forms a towing force-bearing body and a slide rail.

[0035] The four connecting ends of the net 3 are respectively connected to the two ends of the sliding upper line 12 and the two ends of the gravity lower line 14. The sliding upper line 12, the gravity lower line 14, and the sliding steel cable 13 form an effective trawl net opening. The sliding upper line 12 is the upper line of the net, the gravity lower line 14 is the lower line of the net, and the sliding steel cable 13 is the side line of the net.

[0036] The lower gravity line 14 is equipped with a weight 17. The weight 17 is a ring-shaped weight, and the top of the weight 17 is designed with an arc-shaped groove, which can control the towing posture of the net and lock the sliding upper line through the arc-shaped groove when the net is closed in the sea surface ice area.

[0037] The first sling is connected to both ends of the lower gravity cable 14, and the second sling is connected to both ends of the upper sliding cable 12. The automatic release device 2 is located in the middle of the control crossbar 11 and adopts a quick-release buckle design, which enables the rapid and sequential release of the first ring of the first sling and the second ring of the second sling, which are fixed in the automatic release device 2, even in extremely cold polar weather.

[0038] The automatic release device 2 is equipped with a telescopic locking pin 23. The front end of the automatic release device 2 has two radial grooves 21; the front radial groove can accommodate a first lifting ring, and the rear radial groove can accommodate a second lifting ring. The front end of the automatic release device 2 has an axial circular through hole 22 perpendicular to the radial grooves 21. The front end of the telescopic locking pin 23 is located within the circular through hole 22 and can retract axially along the circular through hole. The telescopic movement of the telescopic locking pin 23 locks and secures the two lifting rings 15 or releases the first and second lifting rings sequentially.

[0039] The automatic release device 2 also includes a drive motor 25, a gear assembly, and a ring buckle. The drive motor 25 is located at the tail end of the telescopic locking pin 23 within the main body of the automatic release device 2. The tail end of the telescopic locking pin 23 has a straight row of gear teeth 29, and the drive motor 25 is connected to the gear teeth 29 through the gear assembly. The operation of the drive motor 25 is controlled by a depth sensor. After reaching the set depth condition, the controller drives the motor to run via an electrical signal. The drive motor adopts a unidirectional control design, running clockwise according to the controller's set parameter instructions. In non-instruction operation, the drive motor is locked in a clockwise direction. The drive motor is not controlled by the controller in a counterclockwise direction and can rotate freely. When the drive motor runs according to the set parameter instructions, the rotation of the drive motor controls the gear assembly to rotate clockwise, the telescopic locking pin moves towards the rear end of the automatic release device, and the first and second lifting rings are released in sequence. The sliding upper line and the gravity lower line slide down to the bottom of the net under their own gravity.

[0040] The buckle is set on the outer wall of the automatic release device 2 and connected to the telescopic locking pin 23 inside the automatic release device 2. Before the net is laid, the hanging ring 15 connected with the sliding upper line and the gravity lower line is inserted into the two radial grooves 21 at the front end of the automatic release device, and the buckle on the outer wall of the automatic release device is pulled to drive the telescopic locking pin through the radial grooves at the front end of the automatic release device to lock the two hanging rings 15.

[0041] A spring 24 is provided between the tail end of the telescopic locking pin 23 and the inner tail end of the automatic release device 2. When the drive motor drives the gear to move the telescopic locking pin backward, the spring rebound force can increase the backward movement force of the telescopic locking pin, thereby reducing the power consumption of the automatic release device.

[0042] The gear assembly includes a large gear 26, a small gear 27, and a gear bracket 28. The large gear 26 is connected to the drive motor 25 and the small gear 27 respectively and drives the small gear 27 to run. The small gear 27 meshes with the teeth 29 below the telescopic locking pin 23 and drives the telescopic locking pin to extend and retract.

[0043] In use, before deploying the net, the sliding steel cable 13 is passed through the rings at both ends of the sliding upper cable 12 and connected to the control crossbar 11 and the gravity lower cable 14 to form the main body of the trawl net frame. The lifting ring 15 is tied to the middle of the sling 16, and the two ends of the sling 16 are connected to the two ends of the sliding upper cable 12 and the gravity lower cable 14, respectively. The lifting ring 15 connected to the sliding upper cable 12 and the gravity lower cable 14 is inserted into the radial groove 21 in the automatic release device 2. The ring on the outer wall of the telescopic locking pin 23 is pulled through the radial groove 21 at the front end of the automatic release device 2 to lock the lifting ring. When the net reaches the survey water layer, the automatic release device 2 drives the drive motor through the depth sensor. The large gear 26 drives the small gear 27 to rotate clockwise. The small gear 27, through its meshing with the gear teeth 29, drives the telescopic locking pin 23 to move backward. The combined mechanical force of the spring 24's rebound force and the gear rotation accelerates the backward movement of the telescopic locking pin 23, completing the release of the gravity lower line 14. When the net is retrieved to the sea surface, the automatic release device 2 drives the drive motor through the depth sensor to repeat the step of releasing the gravity lower line 14, completing the release of the sliding upper line 12, and realizing the closure of the survey net opening to avoid floating ice on the sea surface.

[0044] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A mid-level trawl net for polar ice areas, characterized in that: Includes a trawl frame (1), an automatic release device (2), a net (3), and two slings (16) with a middle lifting ring (15). The trawl frame (1) includes a control crossbar (11), a sliding upper beam (12), a gravity lower beam (14), and two sliding steel cables (13). Both ends of the control crossbar (11) and the gravity lower beam (14) are provided with steel cable locking rings, and both ends of the sliding upper beam (12) are provided with circular rings. The two sliding steel cables (13) pass through the circular rings at both ends of the sliding upper beam (12), and their tops are connected to the steel cable locking rings at the ends of the control crossbar (11), and their bottoms are connected to the steel cable locking rings at the ends of the gravity lower beam (14). The connection of the control crossbar (11), the gravity lower beam (14), and the two sliding steel cables (13) forms a dragging force-bearing body and a slide rail. The four connecting ends of the net (3) are respectively connected to the two ends of the sliding upper line (12) and the two ends of the gravity lower line (14). The sliding upper line (12), gravity lower line (14) and sliding steel cable (13) form an effective trawl net opening. The sliding upper line (12) is the upper line of the net, the gravity lower line (14) is the lower line of the net, and the sliding steel cable (13) is the side line of the net. The lower gravity line (14) is equipped with a weight (17). The first sling is connected to both ends of the lower gravity beam (14), and the second sling is connected to both ends of the upper sliding beam (12). The automatic release device (2) is located in the middle of the control crossbar (11) and adopts a quick-release buckle design, which can quickly release the first ring of the first sling and the second ring of the second sling fixed in the automatic release device (2) in the order of the polar cold weather. The automatic release device (2) is equipped with a telescopic locking pin (23); The automatic release device (2) has two radial grooves (21) at its front end. The first lifting ring can be inserted into the radial groove on the front side, and the second lifting ring can be inserted into the radial groove on the rear side. The front end of the automatic release device (2) is provided with an axial circular through hole (22) perpendicular to the radial groove (21). The front end of the telescopic locking pin (23) is located in the circular through hole (22) and can move back and forth along the axial direction of the circular through hole. The telescopic locking pin (23) can lock and fix the two lifting rings (15) or release the first lifting ring and the second lifting ring in sequence. The automatic release device (2) also includes a drive motor (25), a gear assembly, and a ring buckle; The drive motor (25) is located at the tail end of the telescopic locking pin (23) inside the main body of the automatic release device (2). The tail end of the telescopic locking pin (23) is provided with a straight row of gear teeth (29). The drive motor (25) is connected to the gear teeth (29) through the gear assembly. The drive motor (25) is controlled by a depth sensor. After the set depth condition is reached, the controller drives the motor to run through an electrical signal. The drive motor adopts a unidirectional control design. It runs clockwise according to the controller's set parameter instructions. When not running under instructions, the drive motor is locked in the clockwise direction. The drive motor can rotate freely in a counter-clockwise direction, independent of the controller. When the drive motor runs according to the set parameter instructions, the drive motor rotation motion control gear assembly rotates clockwise, the telescopic locking pin moves to the rear end of the automatic release device, and the first and second lifting rings are released in sequence. The sliding upper line and the gravity lower line slide down to the bottom of the net by their own gravity. The buckle is set on the outer wall of the automatic release device (2) and connected to the telescopic locking pin (23) inside the automatic release device (2). Before the net is laid, the hanging ring (15) connected with the sliding upper line and the gravity lower line is inserted into the two radial grooves (21) at the front end of the automatic release device, and the buckle on the outer wall of the automatic release device is pulled to drive the telescopic locking pin through the radial groove at the front end of the automatic release device to lock the two hanging rings (15).

2. The polar ice mid-layer trawl net according to claim 1, characterized in that: The weight (17) is a ring-shaped weight, and the top of the weight (17) is designed with an arc-shaped groove, which can lock the sliding upper line through the arc-shaped groove when the net is closed in the sea surface ice area.

3. The polar ice mid-layer trawl net according to claim 1, characterized in that: A spring (24) is provided between the tail end of the telescopic locking pin (23) and the inner tail of the automatic release device (2).

4. The polar ice mid-layer trawl net according to claim 1, characterized in that: The gear assembly includes a large gear (26), a small gear (27) and a gear bracket (28); the large gear (26) is connected to the drive motor (25) and the small gear (27) respectively and drives the small gear (27) to run; the small gear (27) meshes with the gear teeth (29) below the telescopic locking pin (23) and drives the telescopic locking pin to extend and retract.

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