WO2008105665A1

WO2008105665A1 - Trap

Info

Publication number: WO2008105665A1
Application number: PCT/NO2008/000053
Authority: WO
Inventors: Hans Ovesen
Original assignee: Abel-As
Priority date: 2007-02-20
Filing date: 2008-02-12
Publication date: 2008-09-04
Also published as: NO325514B1; NO20070960A

Abstract

Present invention relates to a trap for shellfish, especially for crabs and lobsters. The trap comprises at least two main parts (1, 2), wherein the first main part (1 ) has larger cross section than the second main part (2), in such a way that the second main part (2) can be pushed into the first main part (1 ). The main parts are performed with corresponding lock devices, wherein the second main part can not be pulled out of the first main part unless the lock devices are opened, and they also comprises an entrance (4) and an output (3). The trap also comprises a bait box (10) being fastened to one of the main parts. The main parts (1, 2), and preferably the bait box, are performed of a perforated, stiff material.

Description

Trap

The present invention relates to a trap for crabs, lobsters and the similar, according to the preamble of patent claim 1.

Background

In most cases, when fishermen fish crabs, lobsters or the similar, they use traps being placed on the bed of the sea/lake, and collected later. The traps have an entrance where the crab/lobster/crawfish can enter, but not exit, and an output whereby the fisherman can take out the catch from the trap. Besides, the traps have different systems for fastening bait.

Throughout the times, there have been used many different types of traps for crab- and/or lobster-fishing. The traditional traps are made of wood, where wood planks are placed in a distance from each other in order to constitute a rectangle. On both opposing short ends, the traps are provided with a net, stretching inwards and defining a guiding path whereby the crabs and/or lobsters crawl, and are thus trapped in the inner of the trap. Bait is placed in the centre of the trap, either hung in a hook, in a baitbag or just loose in the trap. Such traps are still being sold, and may, for instance, be bought from Grønneviken AS, Bergen, Norway.

Traditional traps like that must, however, be wet long before use, in order to sink. It is also normal to put stones in the trap. Thus, when the trap is full of catch, it will be very heavy to pull up. Besides, both the wood and the net in the net entrance must be controlled and maintained. Traps like this demand a lot of space both during storage and transport.

Another type of traps often being used, are collapsible traps of net, having ribs holding the trap distended. During transport and storage, the ribs are placed on top of each other, and thus the trap occupies a minimum of space. Such traps are, for example, produced of Elbe, and may be bought in sports stores. However, in areas having strong streams, and/or stoney ground, there is a large risk that the traps either collapse, or that the net are torn apart and the catch may exit from the trap. Another disadvantage with these traps is that crabs and/or lobsters may be stuck in the net when the trap should be emptied. Thus, it might be a time-consuming work to empty the trap.

From US 4,301 ,612 and US 4,258,496 it is known lobster traps having stiff, perforated walls. The trap of US 4,301 ,612 has an inner part being shorter than an outer part, but there is no suggestion in any of these patents that the inner part should be pushed out of the outer part and thereby elongating the trap, it is rather the opposite.

Norplasta AS, Stjørdal, Norway, produces traps of plastic, where all sides are stiff, and which have entrances on both short ends. An opening for output is placed on a side being perpendicular to the entrance-sides. These traps are delivered unmounted, and it takes about two hours for an experienced installer to prepare them for use. With exception of the entrance-sides, the trap is not perforated, and in order to make these traps sink when they are thrown on sea, one has to make a layer of concrete on the bottom of the trap. In all the known traps, the organisms entering the trap will get hold of the bait. After a relatively short period of time, the bait will thus be eaten, and the trap will no longer attract crabs and lobsters. Type and amount of bait is a challenge for the fishermen, and may involve a considerable cost. To minimize the amount of bait for each trap will thus be very advantageous.

Object

The main object of the present invention is to provide a trap having an easily changed size, in such a way that the trap occupies less space during storage, but does not collapse during use and/or when lowering and raising from the sea. A further object is that the trap should be designed in such a way that the crabs and/or lobsters do not get hold of the bait, but that the bait stays in the trap until the fisherman removes it. Another object is that it should be possible to empty the trap fast and easily, and further, the trap should demand little maintenance and be cost efficient to produce.

The invention

The object is fulfilled with a trap according to the characterizing part of patent claim 1. Further advantageous features are stated in the independent claims.

The trap comprises at least two main parts; a first main part and a second main part; and an entrance and an output to remove the catch. The first and second main parts have the same shape, and have one open side. The area of the cross section of the second main part is less than the area of the first main part, in such a way that the second main part may be pushed into the first main part. However, the difference in area is so small that there will be no space between the outer sides of the second main part, and the inner sides of the first main part. The second main part is pushed into the first main part with the open side first, so that when the second main part is completely or partly pushed into the first main part, the trap is closed. In those cases where the trap comprises more than two main parts, the middle parts will be open in both ends, and the trap will have a telescopic function when pushing together. The first and second main parts of the trap, are performed with corresponding locking devices, in such a way that when the second main part is pushed into the first, it can not simply be drawn out again. In a preferred embodiment of the present invention, these locking devices comprise corresponding flanges on the first and second main part, inwards flange on the first main part, and outwards flange on the second main part. When the second main part is drawn out, the outward flange will interfere with the inward flange of the first main part, and the second main part may thus not be drawn out of the first main part. The trap comprises further a bait box being releasably mounted in one of the main parts, and may be completely removed from the trap. The fisherman may thus have two sets of bait boxes, so that replacement of bait in the bait box may be done on shore. Besides, the bait box is designed in such a way that the crabs and/or lobsters do not get hold of the bait, but still such that smell might get out and attract crabs and/or lobsters. An advantageous design of the bait box is a rectangular box of perforated stiff material, but to ensure that the smell enters the trap, it is a further advantage if the lid is not perforated. The lid is preferably larger than the rest of the box, in such a way that the lid of the bait box bears against the surface of one of the main parts, while the rest of the box stays in the inner of the trap. The bait box may be locked to the trap in many ways which will be known to a person skilled of the art.

In those cases where the trap comprises two main parts, and the bait box is mounted in the first main part, it is designed in such a way that the lid bears against the upper side of the first main part, while the rest of the box reaches into the trap. If the second main part is pushed into the first main part, it will impinge the bait box, and the movement will stop. If, however, the bait box is mounted in the second main part, it is designed in such a way that it reaches a distance up from the second main part, and if the second main part is pushed into the first main part, the first main part will impinge the bait box, and the movement will stop. Accordingly, when the bait box is mounted in the trap, it stops the second main part from being pushed into the first main part. In those cases where the trap comprises more main parts, the bait box will only stop locking of two adjacent main parts. The other main parts must be locked in another way, in order to prevent unintentionally pushing together.

With a trap according to the present invention, the trap will occupy considerably less space during transport and storage, at the same time as it is ensured that the trap does not collapse during use. When the bait box is inserted, it will not be possible for the second main part to slide into the first main part, and thus the trap will have maximum size during the fishing. When the fisherman has emptied the trap for catch, he may easily replace the bait box, and thus the trap is immediately ready to be put out again. However, if the fisherman shall not use the trap at once, he will remove the bait box, and push the second main part into the first main part. The trap is made of a stiff material. In this context, by "stiff' it is meant a material being stiff enough to maintain the shape of the trap even under the stress being at the seabed and during lowering and raising of the trap from the water. Further, the material should not provide flowability to the trap, as the trap should sink and lay at the bed of the water. In order to achieve a stable placing at the bed, and to avoid that the trap tips over due to streams, it is an advantage that the material is perforated, or is treated in another way to achieve a corresponding function. A preferred embodiment of the present invention is produced by using perforated plastic.

The trap according to the present invention has at least one flat side being designed to bear against the bed. When the fisherman put out the trap, he can not be certain how it will be placed on the seabed. It will thus be an advantage if the side being designed to bear against the bed has extra weight, either due to choice of material, or by molding extra weight in this side. In most cases, when the fisherman lets go of the trap, it will automatically turn in such a way that the most heavy side faces downward. In a preferred embodiment, the trap has the shape of a prism having a quadrangle cross section, preferably a square cross section. The trap is provided with at least one entrance, being designed as a one-way valve; the crab/lobster may enter, but not exit. There are several known solutions to this problem, which will be known to a person skilled of the art. The most known solution is a net- entrance where the diameter is declining gradually, and where the opening towards the inner of the trap is centered in a distance from the floor in the trap. All known entrances may be used in the trap according to the present invention, but those without moveable parts such as springs or the similar, are preferred. It is a further object that the trap should demand little maintenance, and the entrance demanding less maintenance will thus be especially preferred.

The entrance and the output may advantageously be designed on one main part each, but one may also consider embodiments where both are preformed on one main part, and where the other main part only constitutes a box for storage of catch. For practical reasons, however, it is very advantageous that the entrance and the output are placed on opposite sides, and preferably on the sides not being affected by the pushing together when the main parts are pushed into each other.

In a preferred embodiment of the present invention, the entrance is designed with an inwardly inclined wall, fastened to the upper edge of the opening, in such a way that the crab or lobster must displace this in order to get into the trap. The wall is longer than the opening of the trap, in such a way that the wall bears against the floor, in a distance from the opening. If the opening does not constitute the whole width of the trap, the inclined wall should be as wide as the trap. This is to avoid openings which may be used as escape routes, between the wall and the walls of the trap.

To further secure that it is not possible for the crab and/or lobster to get out of the trap, it is an advantage to design a corresponding wall fastened to the lower edge of the opening, stretching upwards and inwards until it impinge the downward wall. This wall will, in the following, be referred to by the "lower wall". In cases with one lower and one upper wall, the upper wall does not need to be so long as it bears against floor of the trap, but it is an advantage if it is so long that it passes the point of contact with the lower wall. The inclined walls may be hinged in the upper, respectively lower, edge of the opening of the trap. In this case it will be necessary with springs to ensure that the walls return to their original position, and do not stand open. In an alternative, preferred embodiment, the walls are made of a flexible material, and the use of hinges and springs are thereby avoided. In this context, by "flexible material", it is meant a material being sufficiently flexible for a crab and/or lobster to displace it sufficient to get into the trap, but also stiff enough to make the wall return to its original form and position afterwards. This may be achieved in many ways, for instance by using a stiff material cut into strips. The trap is also performed with an output where the fisherman may remove the catch. The output is preferably placed opposite to the entrance. In a specially preferred embodiment, the whole side opposite of the entrance is covered by a lid which may be opened, and when the trap is lifted and the output faces downward, the trap will automatically be emptied once the lid is opened. The need to lift out the catch manually will thus be removed. In a specially preferred embodiment, the ropes wherewith the trap is lowered and raised in the water, are fastened to the entrance side, and thus may the trap simply be raised, the output-lid opened, and the catch will be on the deck of the bout. The lid may be fastened in many ways, which will be obvious to a person skilled of the art. However, solutions demanding no maintenance are preferred.

Example

The invention will in the following be described with reference the enclosed figures, where

Figure 1 shows the trap in a condition where the main parts are pushed together, seen sidelong above from the entrance-side, Figure 2 shows the trap of Figure 1 , in a position wherein the main parts are not pushed together,

Figure 3 shows the trap when pushed together, seen sidelong above from the output- side.

According to the preferred embodiment shown in the enclosed figures, a trap comprises two main parts, a first main part 1 and a second main part 2. The second main part 2 may be pushed into the first main part 1 , as shown in Figures 1 and 3. All sides of both main part 1 and main part 2 are performed with a number of perforations 5. The side of main part 1 being opposite to the open side wherein main part 2 is pushed, is performed with an output-lid 3. In the preferred embodiment shown in Figure 3, the lid is designed in such a way that it passes on the outside of main part 1. The second main part 2 is performed with an entrance 4, on the side being opposite to the open side entering main part 1. In the embodiment shown in Figure 1 and 2, the entrance is provided with two inwardly, inclining walls, an upper 6, and a lower 12, fastened to the upper and lower edge of the opening, respectively. The walls 6, 12 are larger than the opening 4 of the trap, in such a way that they fill the cross section of the trap. The upper wall 6 is so long that it stretches beyond the point of contact with the lower wall 12, as shown in Figure 1 and 2.

In order to achieve sufficient flexibility, and besides for the waterflow, the walls 6, 12 of the opening 4, are provided with a number of splits 7. In the preferred embodiment shown in the figures, all of the trap is made of plastic, the walls 6, 12 included. The thickness of the walls 6, 12 is, however, less than the thickness of the walls of the rest of the trap, and when they additionally are performed with splits 7, they will be experienced as flexible. In the shown embodiment, the splits 7 of wall 6, are broken off by cross connectors 8, to stiffening and strengthening the wall. However, it is an advantage that the splits are open in the free end of the wall. The main part 1 is, on the upper side, provided with a hole 9, for receiving a bait box 10. The bait box is designed in such a way that it reaches downward in main part 1 , from the hole 9, and prevents thus that the second main part 2 can be pushed into the first main part 1. If there is an attempt to push the second main part 2 into the first main part when the bait box is inserted, the second main part will impinge the bait box, and prevent further movement. Figures 1 and 3 show the trap without the bait box 10, while Figure 2 shows the bait box fastened in the hole 9. The bait box is also performed of perforated plastic, but the lid is not perforated in order to prevent that the smell leaks out of the trap.

To ensure that the trap has the correct orientation in the water, it is, in the shown embodiment, molded steel bars 11 in the bottom. When the trap should be used, the fisherman puts bait in the bait box 10, pulls main part 2 out of main part 1 , and fastens the bait box in the hole 9. The main part 2 is thus locked in outer position, and the trap has maximum size during use. The trap is then lowered onto the seabed. Crabs and/or lobsters scenting the bait will try to get into the trap, by entering through the entrance 4, and force the inclining walls 6, 12 to the side. When the crab and/or lobster are inside the trap, the inclining wall 6, 12 will return to their original position. The crab and/or lobster will be trapped in the trap. The fisherman raises the trap to the surface, and lifts it into the boat. He, then opens the output lid 3, and may remove the catch manually. In a preferred embodiment, the rope, used to raise/lower the trap, is fastened to the same side as the entrance, in such a way that the fisherman may raise the trap onto the deck and thereafter open the lid so that the catch will fall out by itself.

Claims

1. Trap for shellfish, especially crabs and lobsters, characterized by

- the trap comprises at the least two main parts (1 , 2), wherein the first main part (1) has larger cross section than the second main part (2), in such a way that the second main part

(2) may be pushed into the first main part (1),

- the main parts are performed with corresponding locking devices, whereby the second main part may not be pushed out of the first main part (1) unless the locking devices are opened, - the main parts comprise an entrance (4) and an output (3), and

- at least the main parts (1 , 2) are performed of a perforated, stiff material.

2. Trap according to claim 1 , characterized in that the main parts (1 , 2) have a quadrangle cross section.

3. Trap according to claims 1 or 2, characterized in that the trap further comprises a bait box (10) releasable fastened to one of the main parts.

4. Trap according to claim 3, characterized in that one of the main parts (1 , 2), preferrably the first main part (1), is performed with a hole in its upper side (9), and that the bait box is fastened into the hole (9) when the trap is pushed out, the bait box thus prevents the second main part (2) from being pushed into the first main part (1).

5. Trap according to claims 3 or 4, characterized in that the bait box (10) is designed in such a way that the organisms entering the trap do not get hold of the bait.

6. Trap according to any of claims 3-5, characterized in that the bait box (10) is made of a perforated, stiff material.

7. Trap according to any of the preceding claims, characterized in that the entrance (4) and the output (3) is placed on one main part (1 , 2) each, and preferably in such a way that the entrance and the output are on opposing sides when the trap is mounted.

8. Trap according to any of the preceding claims, characterized in that the entrance (4) is provided with an inwardly, inclining wall (6), fastened at the upper edge of the opening of the trap, as the organism entering the trap must displace the wall (6).

9. Trap according to claim 8, characterizing in that the entrance, is further provided with an inwardly, inclining wall (12) fastened at the lower edge of the opening (4) of the trap.

10. Trap according to any of claims 8 or 9, characterized in that the walls (6, 12) are performed with splits.

11. Trap according to any of the preceding claims, characterized in that it is molded weight-elements, preferably steel bars (11), in the bottom of the trap.