TRAWL DOOR

Abstract

A trawl door forms a height and a length and has several curved and overlapping plates including a leading plate which extend in the height direction. The trawl door forms a towing face having a towing bracket and an opposite trawl face having a bridle bracket. The trawl door has at least one regulation means for adjusting a hydrodynamic surface of the trawl door. The regulation means has at least one through opening or at least one cut out, a hatch displaceable in the length direction and a hatch actuator, where the hatch covers the through opening or the cut out when the hatch is in a closed position, and the regulation means is positioned on the towing face of the leading plate.

Claims

1. A trawl door forming a height and a length, the trawl door comprising several curved and overlapping plates including a leading plate which extend in the height direction, the trawl door forms a towing face comprising a towing bracket and an opposite trawl face comprising a bridle bracket, the trawl door comprises at least one regulation means for adjusting a hydrodynamic surface of the trawl door, said regulation means comprises at least one through opening or at least one cut out, a hatch displaceable in the length direction and a hatch actuator, where the hatch covers the through opening or the cut out when the hatch is in a closed position, wherein the regulation means is positioned on the towing face of the leading plate.

2. The trawl door according to claim 1, wherein the at least one through opening is located at the trailing edge of the leading plate.

3. The trawl door according to claim 1, wherein the at least one cut out is located at the trailing edge of the leading plate.

4. The trawl door according to claim 1, wherein the regulation means is positioned at an upper leading plate.

5. The trawl door according to claim 1, wherein the regulation means is positioned at a lower leading plate.

6. The trawl door according to claim 1, wherein the regulation means is positioned at an intermediate leading plate.

7. The trawl door according to claim 2, wherein the regulation means is positioned at an upper leading plate.

8. The trawl door according to claim 3, wherein the regulation means is positioned at an upper leading plate.

9. The trawl door according to claim 2, wherein the regulation means is positioned at a lower leading plate.

10. The trawl door according to claim 3, wherein the regulation means is positioned at a lower leading plate.

11. The trawl door according to claim 2, wherein the regulation means is positioned at an intermediate leading plate.

12. The trawl door according to claim 3, wherein the regulation means is positioned at an intermediate leading plate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In the following is described examples of preferred embodiments illustrated in the accompanying drawings, wherein:

[0015] FIG. 1 shows a pelagic trawl door according to the invention, the trawl door is seen from a towing face, and the trawl door constitutes a port side door in a pair of trawl doors;

[0016] FIG. 2 shows in the same scale as FIG. 1, the trawl door from the opposite side, the trawl face, and the trawl door constitutes a star-board door in a pair of trawl doors;

[0017] FIG. 3 shows in a different scale in perspective a star-board trawl door with a number of through openings in a leading plate;

[0018] FIG. 4 shows the same as FIG. 3 in a second embodiment with a cut out in the leading plate;

[0019] FIG. 5A-B show in a different scale a side view of the leading plate and a regulation means, A: open position, B: closed position;

[0020] FIG. 6A-B show in a different scale in a perspective view a portion of a leading plate from the trawl face and the regulation means, A: open position, B: closed position;

[0021] FIG. 7A-B show in a different scale in a perspective view a lower end portion of a port side trawl door from the trawl face, and a portion of the regulation means, A: open position, B: closed position; and

[0022] FIG. 8A-B show the same as FIGS. 7A-B in the second embodiment, A: open position, B: closed position.

DETAILED DESCRIPTION OF THE DRAWINGS

[0023] In the drawings, the reference numeral 1 indicates a pelagic trawl door provided with a regulation means 2 for adjusting a hydrodynamic area of the trawl door 1. The trawl door 1 has a height H that is greater than the length L. The trawl door 1 shown in the figures, forms in use an upper section 3, a middle section 4 and a lower section 5. The upper section 3 and the lower section 5 are shown angled relative to the middle section 4, as best seen in FIGS. 3 and 4.

[0024] The upper section 3 comprises an upper frame 30. The lower section 5 comprises a lower frame 59. The middle section 4 extends between an upper intermediate frame 40 and a lower intermediate frame 49.

[0025] The trawl door 1 comprises in a known way several curved or cambered overlapping plates. The trawl door 1 is shown with four curved plates. More specifically the trawl door 1 is shown with four upper curved plates 31, 32, 33, and 34, respectively, which extend between, and are fastened to, the upper intermediate frame 40 and the upper frame 30. The trawl door 1 is further shown with four intermediate curved plates 41, 42, 43, and 44, respectively, which extend between, and are fastened to, the upper intermediate frame 40 and the lower intermediate frame 49. The trawl door 1 is further shown with four lower curved plates 51, 52, 53, and 54, respectively, which extend between, and are fastened to, the lower intermediate frame 49 and the lower frame 59. The curved plates 31-34, 41-44, 51-54 are arranged spaced apart such that water may flow between the upper plates 31-34, between the intermediate plates 41-44, and between the lower plates 51-54.

[0026] Several reinforcing ribs 11 are welded to the plates 31-34, 41-44, and 51-54 at a towing face of the plates 31-34, 41-44, and 51-54 as seen in FIGS. 1, 7A-B, and 8A-B.

[0027] The trawl door 1 is shown provided with several weight plates 55 at the lower frame 59.

[0028] A towing bracket 64 for a towing cable (not shown) is positioned in the upper portion of the middle section 4 at the leading edge and at the towing face of the leading plate 41 as shown in FIG. 1. The towing bracket 64 is fastened to the upper intermediate frame 40. The towing cable connects the trawl door 1 to a fishing vessel (not shown).

[0029] An upper bridle bracket 63 is positioned at the upper frame 30 at the trailing edge at the trawl door's 1 trawl face. A lower bridle bracket 65 is positioned at the lower frame 59 at the trailing edge at the trawl door's 1 trawl face. Bridles (not shown) connect the trawl door 1 to a fishing trawl (not shown).

[0030] At least one of the leading plates 31, 41, 51 are in one embodiment provided with at least one through opening 21. The trawl door 1 is shown with several through openings 21, 213 in the leading plate 31 and several through openings 21, 215 in the leading plate 51, see FIGS. 2, 3 and 7A, 7B. In an alternative embodiment at least one of the leading plates 31, 41, 51 are provided with at least one cut out 22. The cut out 22, 223 is shown positioned at the trailing edge of the leading plate 31 as shown in FIGS. 4 and 8A, 8B. The cut out 22, 225 is shown positioned at the trailing edge of the leading plate 51.

[0031] The regulation means 2 comprises the through opening 21 or the cut out 22. The regulation means 2 further comprises a displaceable hatch 23, and a hatch actuator 24, see FIGS. 5A, 5B, 6A, 6B. The hatch actuator 24 displaces the hatch 23 between an open position and a closed position. The hatch actuator 24 is in a first end portion fastened to the leading plate 31, 41, 51, and in an opposite second end portion fastened to the hatch 23. In the closed position the hatch 23 covers the through opening 21 or the cut out 22. In the open position the hatch 23 is retracted towards the leading edge of the leading plate 31, 41, 51 such that water is free to flow through the through opening 21 or cut out 22. The hatch actuator 24 may be remotely operated and the hatch actuator 24 may position the hatch 23 in an optional position between fully closed and fully open. The hatch actuator 24 may be a hydraulic linear actuator. The hatch actuator 24 may be an electrically operated linear actuator.

[0032] The hatch 23 is displaced along guides 26. The guides 26 are positioned at the towing face of the leading plate 31, 41, 51 which is provided with through openings 21 or cut out 22. The guides 26 follows the curved profile of the leading plate 31, 41, 51. The guides 26 are shown one on each side of the through openings 21 or cut out 22.

[0033] The hatch 23 may be made of a flexible material. In an alternative embodiment the hatch 23 may comprise several plates that are articulated connected by one or more hinges 27, as seen in FIG. 6A, 6B. In both embodiments the hatch 23 follows the profile of the leading plate 31, 41, 51 as shown in FIG. 6B.

[0034] The through openings 21 or the cut out 22 and the hatch 23 cover a portion of the leading plate 31, 41, 51 in the height direction H. The through openings 21 or the cut out 22, and the hatch 23 may cover a portion of the leading plate 31, 41, 51 between two adjacent ribs 11.

[0035] 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.

[0036] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.