WO2006008646A2

WO2006008646A2 - Marine traps

Info

Publication number: WO2006008646A2
Application number: PCT/IB2005/002207
Authority: WO
Inventors: Patrick John Quill
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-07-14
Filing date: 2005-07-11
Publication date: 2006-01-26
Anticipated expiration: 2007-01-14
Also published as: WO2006008646A3

Abstract

A frame (1) for a marine trap, the frame (1) comprising a length of bar formed into a frame configuration (2, 3, 4). Preferably, the bar comprises a metal core inserted in a pipe made of a plastics material. A method of producing the marine trap frame (1) is also disclosed.

Description

MARINE TRAPS

The invention relates to marine traps, for example lobster pots, fish cages and white fish traps.

Traditional marine traps such for example as traditional lobster pots suffer from corrosion due to the use of a steel frame. Thus the life of such marine traps has been short. EP-A-1371286 describes an improvement in which the marine traps use a frame which comprises steel bars inserted in plastic pipes for both corrosion resistance and strength. The bars are interconnected by sockets.

The present invention is directed towards providing a marine trap which of simpler construction than disclosed in EP-A-1371286, and which also has a high strength and corrosion resistance. The present invention is also directed towards providing such strength and corrosion resistance with simpler manufacturing than disclosed in EP-A-1371286.

Accordingly, in one non-limiting embodiment of the present invention, there is provided a frame for a marine trap, the frame comprising a length of bar formed into a frame configuration.

The bar may comprise a metal core inserted in a pipe made of a plastics material.

The metal for the core is preferably steel. Other metals may however be used. The plasties material for the pipe is preferably polyethylene. Other plasties materials may however be used.

The pipe may be sealed at its ends to completely enclose the core.

Each seal may comprise a plug which is inserted into the end of the pipe and heat sealed in place. Other types of seal may be used.

Preferably, the plug is made of the same material as the pipe. The plug may however be of a different material to the pipe.

The bar may have 180° bends forming juxtaposed lengths which together form a base of the frame.

The frame may also comprises a transverse length extending across at least one end of the base.

The frame may also comprises a gable end at each end formed by a curved section of bar extending in a generally vertical plane.

The present invention also provides a marine trap comprising a mesh supported by the frame. The mesh may be any suitable and appropriate type of mesh, for example polyvinyl chloride coated galvanised steel mesh. Plastics materials other than polyvinyl chloride may be employed.

The present invention further provides a method of producing a marine trap frame, which method comprises bending a unitary length of bar into the frame configuration.

The bar may be bent with substantially 180° bends to form juxtaposed lengths interconnected by bends at ends of a base of the frame. The bar may be further bent at each end of the base to form a transverse end length. The bar may be further bent at each end of the base to form a gable end.

Preferably, the bar is produced by inserting a metal bar in a plastics pipe.

Preferably, the ends of the pipe are sealed. Also preferably, the ends of the pipe are sealed by inserting a plug into each end of the pipe and heat fusing the plug and the pipe end together.

Preferably, the ends of the pipe and the plugs are pre-heated to a fusion temperature before insertion of the plugs into the pipe ends.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which:

Figure 1 is a perspective view from above of a lobster pot frame of the invention;

Figures 2 and 3 are perspective views of lobster pot bases;

Figure 4 is a perspective view of a top portion for a lobster pot, and which is for mounting on a base;

Figure 5 is a top plan view of the top portion shown in Figure 4 and before the top portion has been bent to the shape shown in Figure 4;

Figure 6 is a part sectional view of an end of a bar and sealing means for sealing the end of the bar; and

Figure 7 shows the end of the bar shown in Figure 6 and sealed.

Referring to Figure 1 , there is shown a lobster pot frame 1 comprising a base 2 and gable ends 3 and 4, all formed from a single length of bar. The bar is bent in a number of bends 5 to form juxtaposed parallel lengths to provide the base 2. At each side, the length of bar continues with a right- angled bend 6 to extend transversely and form a bottom part for the gable ends 3, 4. As shown in Figure 1 , the bar then extends upwardly and around in a generally circular curve so that the end of the bar abuts the first right- angled bend 6.

A lobster pot is completed by inserting a heavy duty mesh of polyvinyl chloride coated galvanised steel (not shown) within the frame 1. The required trap openings for the lobster pot are then formed in the mesh.

As described in more detail below, the bar from which the frame 1 is formed has a thick plastics outer layer. Thus, the full lobster pot does not have any exposed metal. This dramatically reduces the likelihood of corrosion, and it also avoids electrolysis which arises in prior art marine traps having metal-to-metal contact. Further, because the bar of the frame 1 has a steel core, it has a very high strength. Another major advantage is that the frame 1 does not have any joints, giving rise to very low production and material costs.

The frame of the present invention may comprises a base only, such for example as a base 10 shown in Figure 2. The base 10 is formed from a bar similar to that of the frame 1. However, in this embodiment, the bar forms only transverse end sections 11 and 12 and longitudinal sections 13.

Figure 3 shows an alternative frame 20 which has only one transverse section 21 and longitudinal sections 22. A frame of the invention may comprise a top portion tied to a base such for example as the bases 10 or 20. A top portion 30 is shown in Figure 4. The top portion 30 is manufactured by first forming a length of bar into a generally rectangular shape with a join at 31 , as shown in Figure 5. The end sections of the generally rectangular shape are then bent to form gable ends 35, 36 shown in Figure 4. The longer sides of the generally rectangular shape remain as side bars 37.

The bar from which all of the frames described above are formed comprises a steel core within a pipe of medium density polyethylene material. Figures 6 and 7 show how the bar may be manufactured.

As shown in Figure 6, a pipe 60 of 6m length is provided, and a steel core 62 of 5.96m length is inserted into the pipe 60. This leaves a 2cm length of excess pipe 60 at each end 61. The pipe is made of the medium density polyethylene plastics material.

A plug 63 of the same material as that of the pipe 60 is then provided. Both the pipe end 61 and the plug 63 are simultaneously heated by fittings of a heat fusion machine (not shown). The temperature is preferably 140 - 160⁰C and the duration is preferably 6 seconds. The heated plug 63 is then immediately pushed into the heated pipe end 61. The temperature of the pipe end 61 and the plug 63 causes the plug 63 to become heat fused to the pipe end 61, so that together they form an integral seal 70 at the end of the pipe. This procedure is repeated for the other end of the pipe, so that the steel core 62 then is completely enclosed. Thus the steel core 62 and the pipe 60 form a bar of very high strength, suitable for bending into the desired frame shape, and being corrosion resistant.

It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected. Thus, for example, the heating may be effected at temperatures other than those mentioned above, and the duration of the heating may be other than that mentioned above. The frame of the present invention may comprise a small number of fittings, for example T-joint fittings, at each bar end. The fittings may be heat fused in place. The shape and configuration of the frame may be different to those shown in the drawings. The gable ends may have a generally rectangular shape. The frame may be for a marine trap other than a lobster pot so that, for example, the frame may be for a fish cage or a white fish trap.

Claims

1. A frame for a marine trap, the frame comprising a length of bar formed into a frame configuration.

2. A frame according to claim 1 in which the bar comprises a metal core inserted in a pipe made of a plastics material.

3. A frame according to claim 2 in which the metal for the core is steel.

4. A frame according to claim 1 or claim 2 in which the plastics material is polyethylene.

5. A frame according to any one of the preceding claims in which the pipe is sealed at its ends to completely enclose the core.

6. A frame according to claim 5 in which the seal for each end of the pipe comprises a plug which is inserted into the end of the pipe and heat sealed in place.

7. A frame according to claim 6 in which the plug is made of the same material as the pipe.

8. A frame according to any one of the preceding claims in which the bar has 180° bends forming juxtaposed lengths which together form a base of the frame.

9. A frame according to claim 8 and also comprising a transverse length extending across at least one end of the base.

10. A frame according to claim 8 or claim 9 and also comprising a gable end at each end formed by a curved section of bar extending in a generally vertical plane.

11. A marine trap comprising a mesh supported by a frame according to any one of the preceding claims.

12. A method of producing a marine trap frame, which method comprises bending a unitary length of bar into the frame configuration.

13. A method according to claim 12 in which the bar is bent with substantially 180° bends to form juxtaposed lengths interconnected by bends at ends of a base of the frame.

14. A method according to claim 13 in which the bar is further bent at each end of the base to form a transverse end length.

15. A method according to claim 13 or claim 14 in which the bar is further bent at each end of the base to form a gable end.

16. A method according to any one of claims 12 - 15 in which the bar is produced by inserting a metal bar in a pipe made of a plastics material.

17. A method according to claim 16 in which the ends of the pipe are sealed.

18. A method according to claim 17 in which the ends of the pipe are sealed by inserting a plug into each end of the pipe and heat fusing the plug and the pipe end together.

19. A method according to claim 18 in which the ends of the pipe and the plugs are pre-heated to a fusion temperature before insertion of the plugs into the pipe ends.