NO345744B1

NO345744B1 - A buoy and a method for controlled feeding of a line connected to a fishing gear.

Info

Publication number: NO345744B1
Application number: NO20191428A
Authority: NO
Inventors: Rolf Knutsen
Original assignee: Active Fishing Buoys As
Priority date: 2019-12-03
Filing date: 2019-12-03
Publication date: 2021-07-12
Also published as: WO2021112687A1; EP4068958A1; EP4068958A4; NO20191428A1

Description

A BUOY AND A METHOD FOR CONTROLLED FEEDING OF A LINE CONNECTED TO A FISHING GEAR

The present disclosure is related to a buoy for an underwater object such as a fishing gear. More specifically, the disclosure is related to a buoy for storing rope connected to a fishing gear such as for example a pot for catching fish and crustaceans, and fishing nets.

A report from the EU Commission named “Lost fishing gear – a trap for our ocean” states that 8 million tonnes of plastics go into the sea each year, among which a large amount of fishing gear. Each year about 20% of EU fishing gear is lost or discarded at sea, which indicates a total of 640.000 tonnes worldwide each year. The impacts on the environment are serious with regards to for example animal welfare, chemical contamination that has disruptive effect on species, negative effect on human health due to toxicity in the food chain. Lost fishing gear has also great negative economical consequence for both fisheries and aquaculture sector, and the society in general.

The invention disclosed herein, has for its object to reduce the amount of fishing gear that is lost unintentionally or accidentally. Two main reasons for loosing fishing gear unintentionally or accidentally are: the fishing gear is transported by sea current to depths being greater than the rope connecting the fishing gear to the buoy; and the fishing gear is set in steep seafloor topography which results in the fishing gear sliding to larger depths resulting in submerging of the buoy. Fishing gear lost in this way results in so-called ghost fishing wherein the fishing gear may fish for several years.

Publication US 4,778,442 discloses a buoy for storing rope attachable to an underwater object such as a lobster pot. The buoy comprises a reel for carrying the rope. The reel is arranged rotatable inside a buoyancy element. When the lobster pot is thrown into the sea, the reel rotates inside the buoyancy element and feeds out the rope until the lobster pot lands on a sea bottom. When transported prior to use, the rope is stored on the reel within the buoy so that nuisance and danger of tangled ropes are eliminated. The buoy may be provided with a manually operated brake means to prevent the reel from rotating. Without engaging the brake manually, the reel is likely to rotate also when the buoy is subject to minor forces caused for example by wind and current. If the brake has been engaged, the rope is prevented from rotating for example if the fishing gear is set in steep seafloor topography which results in the fishing gear sliding to larger depths.

Publication US 5,376,035 discloses a power winding, self-setting marker buoy comprising an elongated middle portion to each end of which is connected a spherical end portion enlarged with respect to the middle portion. The spherical end portions are provided with integrated weight elements arranged eccentric with respect to the middle portion to prevent continued rotation of the buoy and thus prevent continued pay out of anchor line when an anchor arranged at a free end of the anchor line reached the bottom of a sea.

Publication WO 2007/001191 discloses an acoustic buoy which is provided for ascending from a submerged position in the water to a surface. The buoy has a storing structure for a line which is connected to a submerged object, the other end is attached to the buoy. When the buoy ascends in the water, the buoy rotates around its central axis, thereby paying out the line.

The invention has for its object to remedy or to reduce at least one of the drawbacks of the prior art, or at least provide a useful alternative to prior art.

The object is achieved through features, which are specified in the description below and in the claims that follow.

The invention is defined by the independent patent claims. The dependent claims define advantageous embodiments of the invention.

According to a first aspect of the invention there is provided a buoy for storing rope connected to an underwater object such as a fishing gear, wherein the buoy comprises: - a spool for storing at least a portion of a rope wound around a perimeter of the spool; - at least one rotation control element rotationally rigid connected to the spool, wherein a vertical buoyancy vector defining a buoyancy centre and the buoyancy of the rotation control element, and a vertical mass vector defining a centre of gravity and the mass of the buoy, are coaxial when there is no drag in the rope, and the buoyancy vector is closer to a centre axis of the spool than a resulting vertical mass vector when the buoy is subject to a drag in the rope exceeding a predetermined level, whereupon the rotation control element capsizes and the spool rotates accordingly, and the rope is unwound from the spool until the drag in the rope is reduced below said predetermined level, or until all of the rope is unwound from the spool.

By the term buoyancy centre is meant the centre of gravity of the water displaced by the submerged portion of the buoy.

A rotational control element configured for capsizing only when subject to a drag in a rope exceeding a predetermined level has the effect that the rope is unwound in a stepwise manner. This has the advantage that rope will normally not be unwound from the spool when the buoy is subject to water current and/or wind, and even small waves resulting in a temporarily drag in the rope that does not exceed the predetermined level resulting in capsizing of the rotation control element. This again has the advantage the superfluous rope is stored on the spool instead of being in or at a surface of the water. A superfluous portion of the rope floating in or at a surface of water may cause problems for a propeller of a surface vessel passing over the rope, or the rope may be cut by such a propeller. A cut rope of is likely to result in lost fishing gear.

In one embodiment, a buoyancy means of the buoy may comprise the at least one rotation control element. Thus, the rotation control element may form part of the buoyancy means of the buoy. In one embodiment, at least a portion of the spool also forms part of the buoyancy means of the buoy.

In one embodiment, a buoyancy means of the buoy may be the rotation control element. In such an embodiment the rotational control element provides a total buoyancy of the buoy. In another embodiment, the rotation control element and the spool provide a total buoyancy of the buoy.

In still another embodiment of the buoy according to the invention, the rotation control element further comprising an orientation element configured for bringing the rotation control element in a specific position when the buoy is not subject to a drag in the rope, i.e. unloaded. Such an orientation element may be a weight element arranged in or on a portion of the rotation control element. Alternatively, or additionally, the orientation element may be an additional buoyancy means arranged protruding from a portion of the rotation control element.

Preferably, the rotation control element comprises two parts, each part arranged at an end portion of the spool. This has the effect that the portion of unwound rope is stored between the rotation control elements. The portion of unwound rope may therefore be protected by the rotation control elements.

When seen perpendicular to a longitudinal axis of spool, the rotation control element may have a form selected from the group consisting of an ellipse, a trapezoid, a triangle, a rectangle, and a quadrate. For a rotation control element in the form of an ellipse, the stepwise capsizing and thus the unwinding of the rope depends on the largest dimension of the ellipse. Similarly, for a rotation control element in the form of a trapezoid, a triangle, a rectangle, or a quadrate, the stepwise capsizing and thus the unwinding of the rope depends inter alia on a distance between a centre axis of the spool and the “corners” of the rotational control element. The larger the distance, the larger the drag from the rope is required to effect capsizing of the rotation control element. If the rotation control element is provided with substantially even thickness, the force required for capsizing the rotation control element, and thus the buoy, depends only on the distance between the centre axis of the spool and the “corners” of the rotational control element.

In one embodiment, when the rotation control element is non-loaded, i.e. not subject to a drag from the rope, a top portion of the rotation control element may be closer to each other than a bottom portion of the control means being submerged. Tests have shown that such inclined rotation control elements, may have positive effect with respect to minimizing effect from wind and currents, especially for relatively slender rotation control element, and the visibility of the rotation control element.

As an alternative to provide the rotational control element selected from the group consisting of an ellipse, a trapezoid, a triangle, a rectangle and a quadrate, the rotation control element may be formed as a circular disc or a polygonal when seen perpendicular to a longitudinal axis of spool, or as a sphere. However, such circular disc, polygonal, or sphere requires said orientation means in the form of a weight means, and/or in the form of a buoyancy means, arranged off-centre of the disc, polygonal or sphere in order to prevent free rotation of the rotation control element.

In a second aspect of the invention, there is provided a method for controlling feeding a rope from a buoy to a submerged object, wherein the method comprises:

- providing a buoy according to the first aspect of the invention,

- winding at least a portion of the rope onto the spool of the buoy,

- connecting an end portion of the rope to the object and submerging the object.

Preferably, the method may comprise providing a buoy having a buoyancy capable of carrying the object above a sea bottom when all rope has been unwound from the spool.

This has the effect that the buoy will not sink if the object, such as a fishing gear, does not rest on the sea bottom.

Alternatively, the method may comprise providing a buoy having a buoyancy being less than a gravity force from the submerged object being above a sea bottom when all rope has been unwound from the spool. This has the effect that the buoy will be submerged if the object, such as a fishing gear, does not rest on the sea bottom.

Preferably, the method may comprise providing a rope having a length being at least 20%, preferably 50% and most preferably 100% longer than a water depth at the intended location of use. Thus, the likelihood for all rope to be unwound from the spool of the buoy is limited.

In the following is described examples of preferred embodiments illustrated in the accompanying drawings, wherein:

Fig. 1a shows a perspective view of a buoy according to a first embodiment of the present invention;

Fig. 1b shows a buoy seen perpendicular to a longitudinal axis of the spool of the buoy, the buoy having similarities with the buoy seen in fig.1a;

Fig. 2a shows in a larger scale a rotation control element only, in a neutral position when not subject to a drag from a rope;

Fig. 2b shows the rotation control element in fig.2a when subject to a drag from a rope prior to capsizing the rotation control element;

Fig. 3 shows in a smaller scale a perspective view of a buoy according to a second embodiment of the present invention;

Fig. 4 shows a perspective view of a buoy according to a third embodiment of the present invention; and

Fig. 5 shows a perspective view of a buoy according to a fourth embodiment of the present invention.

Positional indications such as for example right, upper, lower, refer to the position shown in the figures.

In the figures, same or corresponding elements are indicated by same reference numerals. For clarity reasons some elements may in some of the figures be without reference numerals.

A person skilled in the art will understand that the figures are just principle drawings. The relative proportions of individual elements may also be strongly distorted.

In the figures reference numeral 1 denotes a buoy according to the present invention.

The buoy 1 comprises a spool 3 for storing at least a portion of a rope (not shown) wound around a perimeter of the spool 3. When in use, the rope provides a connection between the buoy 1 and an object, such as a fishing gear typically in the form of a fish or crustacean pot, or a fishing net. The buoy 1 further comprises a rotation control element 5, 5’ that is fixedly connected to the spool 3 in a rotationally rigid manner so that the spool 3 rotates when the rotation control element 5, 5’ rotates. The figures show two rotation control elements 5, 5’ spaced apart by means of the spool 3. It should be clear that in another embodiment, the buoy 1 may be provided with only one rotation control element 5. In an embodiment wherein the buoy 1 is provided with a single rotation control element 5, the spool 3 may be arranged between the rotation control element 5 and a buoyancy means known per se, such as for example a spherical buoy.

The buoy 1 is configured so that a vertical buoyancy vector defining a buoyancy centre and the buoyancy of the rotation control element 5, 5’, and a vertical mass vector defining a centre of gravity and the mass of the buoy 1, are coaxial when there is no drag in the rope, and the buoyancy vector is closer to a centre axis of the spool than a resulting mass vector when the buoy 1 is subject to a drag in the rope exceeding a predetermined level, whereupon the rotation control element 5, 5’ capsizes and the spool 3 rotates accordingly, and the rope is unwound from the spool 3 until the drag in the rope is reduced below said predetermined level, or until all of the rope is unwound from the spool 3.

In figures 1a and 1b, the buoy 1 comprises a first rotation control element 5 and a second rotation control element 5’ arranged at each end portion of the spool 3. The rotation control element 5, 5’ and the spool 3 is made in one piece from the same material. The material is selected from a suitable material such as for example polyethylene. The buoy 1 may be hollow or made from a foam.

In the embodiment shown in figures 1a and 1b, a buoyancy of the buoy 1 is the sum of buoyancy of the rotation control element 5, 5’ and the buoyancy of the spool 3.

As best seen in fig.1a, each of the rotational control element 5, 5’ has a form of a trapezoid wherein a bottom portion is smaller than a top portion. This has the effect that rotational control elements 5, 5’ tends to orient themselves, and thus the buoy 1, with at least a portion of the bottom portion submerged.

In figures 1a and 1b the top portion of the rotation control elements 5, 5’ are closer to each other than a bottom portion of the rotation control elements 5, 5’ being submerged. In a prototype of such a buoy 1, tests surprisingly show that such inclined rotation control elements 5, 5’ has advantages with respect to reduced influence from wind and water current, while at the same time being easy to see for personnel being on a vessel. The reduced influence from wind may be explained by the reduced effective, vertical area of the rotation control elements 5, 5’. Obviously, a “flat” rotation control element, i.e. a rotation control element having a portion above water level being small with respect to a surface area being submerged, will further reduce an influence from wind. However, such a configuration will have negative effect on visibility for personnel being on a vessel, and also a negative effect with respect to current.

In fig.1a the spool 3 has an oblong cross-sectional area. A portion of the spool is provided with a reduced cross-sectional area. Although being relatively slender, a force from a drag in a rope has a relatively long arm thereby creating a relatively large turning moment. A difference between figures 1a and 1b is the form of the spool 3 which in fig.1b is provided with a circular cross-sectional area.

Figures 2a and 2b show a rotation control element 5 only. However, it is to be understood that the rotation control element 5 in a position of use, is connected to a spool mating with the aperture 35. The rotation control element 5 shown may form part of a buoy that may be provided with for example a spherical buoyancy means and a spool for mating with the aperture 35 of the rotation control element 5.

In fig.2a the rotation control element 5 is in a neutral position in a water WL, a position being typical when there is no drag from a rope providing a turning moment on a spool. In such a neutral position, a vertical mass vector MV defining a centre of gravity and the mass of the buoy, are coaxial with a vertical buoyancy vector BV defining a buoyancy centre and the buoyancy of the rotation control element 5.

In fig.2b a spool (not shown) connected to the rotation control element 5 is subject to a turning moment from a drag in the rope, the drag indicated by arrow RD. The drag in the rope results in a tilting of the rotation control element 5, and the vertical buoyancy vector BV is moved to the right in the figure. If the drag in the rope continues while at the same time the vertical buoyancy vector BV is less than the resulting mass vector, i.e. the vertical mass vector being the sum of the mass vector MV and the drag RD form the line, the resulting vertical mass vector will pass to the right of the vertical buoyancy vector BV, and the rotation control element 5 will capsize and the spool will rotate accordingly. Such a tilting and capsizing will continue until the drag in the rope is reduced below said predetermined level, or until all the rope is unwound from the spool.

Figures 3, 4 and 5 show alternative embodiments of the buoy 1 according to the invention wherein the buoys have a fixed design, i.e. the buoys have predetermined properties.

In fig.3, the rotation control elements are in the form of rectangular prisms 5, 5’ being spaced apart by means of a spool 3 for storing at least a portion of a rope wound around a perimeter of the spool 3.

In fig.4, the rotation control elements are in the form of triangular prisms 5, 5’ being spaced apart by means of a spool 3 for storing at least a portion of a rope wound around a perimeter of the spool 3.

In fig.5, the rotation control elements 5, 5’ have an elliptic form. The elliptic rotation control elements 5, 5’ are spaced apart by means of a spool 3 for storing at least a portion of a rope wound around a perimeter of the spool 3.

From the disclosure herein, it should be clear that the buoy 1 according to the invention provides a certain resistance against rotation when subject to a drag in a rope connected to the spool 3. Providing the spool with redundant rope with respect to an intended depth of use of a fishing gear, the buoy 1 will unwind rope from the spool 3 for example if the fishing gear is subject to an unintended sliding along a seabed slope, while at the same time the rope is kept substantially upright between the fishing gear and the buoy 1.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

Claims

C l a i m s

1. A buoy (1) for storing rope connected to an underwater object such as a fishing gear, the buoy (1) comprises:

- a spool (3) for storing at least a portion of a rope wound around a perimeter of the spool(3) ;

- at least one rotation control element (5, 5’) rotationally rigid connected to the spool (3), c h a r a c t e r i s e d i n that a vertical buoyancy vector (BV) defining a buoyancy centre and the buoyancy of the rotation control element, and a vertical mass vector (MV) defining a centre of gravity and the mass of the buoy, are coaxial when there is no drag in the rope, and the buoyancy vector (BV) is closer to a centre axis of the spool than a resulting mass vector when the buoy (1) is subject to a drag in the rope exceeding a predetermined level, whereupon the rotation control element (5, 5’) capsizes and the spool (3) rotates accordingly, and the rope is unwound from the spool (3) until the drag in the rope is reduced below said predetermined level, or until all of the rope is unwound from the spool (3).

2. The buoy (1) according to claim 1, wherein a buoyancy means of the buoy comprises the at least one rotation control element (5, 5’).

3. The buoy (1) according to claim 2, wherein a buoyancy means of the buoy (1) is the rotation control element (5, 5’).

4. The buoy (1) according to any one of claims 1 to 3, wherein the rotation control element (5, 5’) further comprises an orientation element configured for bringing the rotation control element (5, 5’) in a specific position when the buoy (1) is not subject to a drag from a rope.

5. The buoy (1) according to any one of the preceding claims, wherein the rotation control element (5, 5’) comprises two parts, each part arranged at an end portion of the spool (3).

6. The buoy (1) according to any one of the preceding claims, wherein, when seen perpendicular to a longitudinal axis of spool (3), the rotation control element (5, 5’) has a form selected from the group consisting of an ellipse, a trapezoid, a triangle, a rectangle, and a quadrate.

7. The buoy (1) according to claim 5 and 6, wherein, when the rotation control element (5, 5) is non-loaded, a top portion of the two parts of the rotation control element is closer to each other than a bottom portion of the rotation control elements being submerged.

8. The buoy (1) according to claim 1, wherein the spool (3) has a cross-section selected from the group consisting of a circle, a polygonal, an ellipse, and rectangular with rounded corners.

9. A method for controlling feeding a rope from a buoy (1) to an object to be submerged, c h a r a c t e r i s e d i n that the method comprises:

- providing a buoy (1) according to any one of claims 1-8,

- winding at least a portion of the rope onto the spool (3) of the buoy (1),

- connecting an end portion of the rope to the object, and submerging the object.

10. The method according to claim 9, wherein the method comprises providing a buoy (1) having a buoyancy capable of carrying the object above a sea bottom when all rope has been unwound from the spool (3).

11. The method according to claim 9, wherein the method comprises providing a buoy (1) having a buoyancy being less than a gravity force from the submerged object being above a sea bottom when all rope has been unwound from the spool (3).

12. The method according to claim 9, wherein the method comprises providing a rope having a length being at least 30% longer than a water depth at the intended location of use.