AU2005100038A4 - Prawn and flounder D-net - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT PRAWN FLOUNDER D-NET The following statement is a full description of this invention, including the recommended method of using it: o PRAWN and FLOUNDER D-NET The following statement is a full description of this invention, including the t recommended method of using it.

OO This invention pertains to catching prawns and flounder in a different manner to the usual C method used with standard dip nets consisting of an open face with a bag attached thereto. (It is to be noted that the use of the term 'prawn' in Australia, is 'shrimp' in America, and would be other names in different countries, and that numerous species of both prawn and flounder 00 10 exist. In this case, the names 'prawn' and 'flounder' are those commonly used in Australia.) Prawns have a very fast reaction ability that requires skill, good equipment, and 0 ounderstanding to overcome, and this invention caters for at least some of the need.

A common dip net is comprised of only three parts, being A metal frame shape in one q- 15 plane that forms the opening, to which is attached the net bag, and the handle that is o attached to the said frame. My invention differs to this description by having six parts, and o otherwise as described in the following: This invention comprises a partial enclosure (here referred to as the that is placed over the animals concerned, that has a wire or other piece sprung across its base at the back end by the means of spring tension as in drawings Figures 2 and 3, so as to complete a shape.

Other shapes may be used without altering the principle of the cage. Synthetic netting is attached to this shape.

A netting bag is attached to the frame. The base meshes of this bag are then threaded onto the wire, and the bottom sides of the frame are then forced closer together against the tension of the metal so as to allow the wire to be hooked to each side in the corners. This wire is preferably of smooth stainless steel of higher tensile, so that it has some springiness against shape distortion, is strong against the hooks bending, while being non abrasive to the netting meshes.

A stiff monofilament line is threaded through the meshes some distance down the bag, and the ends swaged together so as to complete a circle, the purpose of which is to hold the bag open between the D and the monofitament ring. The monofilament is substantially nonabrasive on the meshes. While stiff enough to hold the bag open, it is flexible enough so as not to readily kink out of shape, yet if it is it can be bent by hand back into a circular shape.

A stainless stub tube is welded to the top of the frame so as to accept a handle that may be either over or within the stub. This stub is flattened at the welded end for the dual purpose of making the weld to the frame, and for the secure fixing of a plastic handle over it by means of heating the plastic and fitting it over the stub to over the flattened part, where the plastic is then squeezed to the shape of the stub and held until cool, when it then forms a secure and firm fit, so that no pins or binding are required. This method also allows for altering the angle of the handle by heat bending to suit the desire of particular users.

The frame of the D may be made from any metal or suitable synthetic material, but in a preferred example it is stainless steel rod of about 6 mm diameter so as to be rust free in a marine environment. The rod should be of such tensile properties as to be somewhat springy, for four reasons it is less able to be bent out of shape when in use or by accident for ease of achieving a taut netting on the D, the front is held closer to the top with a wire bent for the purpose to decrease the distance in that direction while the netting is attached, after which the hook is released and the netting is then tautened further by the spring action of the metal frame trying to return to its original shape for attaching the wire as in section and to automatically adjust the tension of the netting as it expands and contracts in wet and dry conditions.

Prawni Flounder 0-NetPae2o3 Page 2 of 3 o Looking at the drawings, Fig. 1 shows the shape of the head of the D-net from a diagonal o front angle that is not yet fitted with the wire, and at this time the distance between the two (N lower corners is greater than after the wire is sprung to them-t Fig. 2 shows from a roar view that the wire 1 (without netting attached for the purpose of this explanation) has been affixed Ct 5 to the rear corners of the frame 2 after forcing the said corners together against the spring n ~tension orf the frame. This then completes the D shape of the base of the head. Fig. 3 is from 00 a front raised angle view that more clearly illustrates the wire fixing method after it has been threaded through the lower meshes of the bag. Since one third of the bag meshes are threaded onto this wire, it facilitates replacement of bags when necessary, this being faster than the slinging method of attachment used for the rest of the net. Fig. 4 is an overall View of 00 the device showing that an insert handle 1 may be fitted, and the circle of monofi lament 2 is o holding the bag open for the free passage of the catch towards the far end of the bag.

o A preferred size of the D is approximately 250 mm from the wire to the front of the D, and 250 mm across the D, and 250 mm from the base to the stub weld, however larger dimensions Vfl may be used for catching other species. The length of the bag is preferred to be o approximately 1800 mm. or longer, since when some quantity of catch is in the far end of the o bag and may attempt to escape when trying for another catch, one twist or fold can be caused behind the monofilament ring by arm action of the user, thus blocking the exit way for the time being. The long bag is also an advantage because when some volume of catch begins to drag heavily upon the users arm, the end of the bag with its catch may be placed into the small punt (that is used by prawners to carry the battery for the light plus the catch) and left there while the net is operated and each subsequent catch then added, and thus all drag is eliminated. In any case a bag that is too short will allow the catch to more easily escape.

In use for catching prawns% the D is lowered through the water over a prawn at a steady rate and at a speed so as to not cause a pressure wave that prawns react to, until the D is flat upon the bottom and thus encages the prawn until it can be directed by a variety of means, to anywhere into the bag behind the wire. At this stage, the net is pulled back towards the user, and the resistance of the bag in the water causes the net bag to drag across the rearwards opening of the 0 (and this action also causes a pressure wave that the prawn flips away from and further back into the bag) thus cutting off all escape for the animals, when by raising the head of the device higher, the catch is moved further towards the end of the bag by gravitational effect and/or shaking.

In use for catching flounder that largely lay flat on the bottom, the fish is approached head on, the head of the device is slanted with the front of the 0 higher so as to clear the fish, and the wire placed onto the bottom just in front of the flounders nose. When the front of the 0 is then lowered so as to touch the flounders back, it immediately -swims straight ahead into the bag, which is then operated as for prawns.

When using a normal dip net for catching bottom prawns (as different to swimming prawns) it is necessary to use movement of an underwater light to create the force wave that causes the prawn to flip into the dip net. However my invention allows a number of nets to be used by a number of people with only one person having the light that shows the prawns for the others, who can walk at some distance away from the light, encage their prawn, and stamp their foot in front of the 0 to cause the force wave that causes the prawn to flip back into the net bag.

When prawns are partially buried or within seaweed, they can be still encaged and caught in situ with this invention, but with standard nets they require chasing into the open water first, often losing them as they quickly flip away. By extending the handle length, prawn can be caught off the bottom from waters to 3 metres deep from a boat, but this is not possible with a standard dip net.

Claims (3)

1. A prawn and flounder catching device comprised of 6 parts, which I call "D-net" because of the shape of the head part

2. The D-net device of claim 1 wherein the head of the device is a partial cage to which netting is attached to make a partial enclosure, the said enclosure made 0O 10 more complete by engagement with the bottom sand or other, leaving then only one Sopening at the back end of the cage, to which is attached a bag or cod end for holding the target species.

3. A semi-flexible line threaded through the meshes of the bag or cod end as in 2, the purpose of which is to hold the said bag in an open state for the passage of the target species further into the bag. S4. A wire, twine, rod, or other as shown in Fig. 3, that is used for connecting the two rear corners of the head for the purposes of completing the D shape of the frame, and for the partial attachment of the bag to the frame. The use of a non-rusting material for the making of the frame so as to suit marine waters use, and which has a sufficient memory property to suit the spring type action required as described in the description of the frame.