SU466876A1 - Hydrodynamic device for vertical opening of the trawl mouth - Google Patents

Description

one

FIELD OF THE INVENTION The invention relates to the field of commercial fishing and can be used for the vertical opening of a trawl mouth.

A hydrodynamic device is known for vertical opening of the mouth of the trawl, consisting of a spacer of a streamlined shape and a device for fastening it to the upper selection.

However, such a device does not make it possible to regulate the value of the spreading force over a wide range depending on the conditions of fishing.

In order to improve the operational properties of the device, the spacer is made in the form of a hemisphere, having two symmetrically located cutouts of the figured shape, the lower edge of each of which lies in a plane parallel to the base of the hemisphere, and the top in a plane perpendicular to the base of the hemisphere, and is located the center of the hemisphere at a distance equal to 0.25-0.3 of its radius.

In addition, in the proposed device, a device for attaching a spacer element to the upper selection consists of rings, loosely worn in a c, formed by the lower edges of the notches and hemispheres.

FIG. 1 shows the proposed device, the general view, axonometric data: in FIG. 2 - then

top view; in fig. 3 - the same, side view; in fig. 4 is one of the options for mounting the device on the trawl.

The proposed device is a spacer, made in the form of a hemisphere 1 with two symmetrically arranged notches 2 and 3.

The lower edge 4 of each notch lies in a plane parallel to the base of the hemisphere 1, and the upper 5 lies in a plane perpendicular to the base of the hemisphere and is located from the center of the hemisphere at a distance equal to 0.25-0.3 of its radius.

Cuts 2 and 3 are separated from each other by a jumper 6, which serves to strengthen the whole structure, and are located in such a way. that their lower edges 4 form with the lower edge 7 hemispheres 1 through 8. 8. On the latter, rings 9 are freely attached, which serve to mount the device on the trawl.

For the same purpose, the tide 10 with a hole 11, which is present on the surface of the hemisphere 1, also serves.

The preferred location of the devices is the areas of the netting, starting from the middle of the wing to the point of intersection of the oblique areas in the area of the tug, and the trawl (see Fig. 4).

On the inner side 12, one ring 8 is fixed, and in the next row there is 13

tide 10 and the second ring 9, so that the front edges 14 of the notches 2 and 3 are oriented along the transverse row trawl.

A trawl is equipped with a number of spacers determined by calculation in accordance with the specific conditions of operation of the trawl.

If a certain number of devices are not placed in the same series on both wings, then they can be installed in two rows on each side, but under the condition that their mutual influence on each other is excluded.

When the trawl is lowered, the net canvas sets the orientation of the devices and they immediately begin to work when released into WATER. In this case, even the opening of the trawl is ensured by the diverting force of the spherical spacer elements.

In the process of trawling, the net canvas stretches the rings 9 to the sides, due to which the devices are mounted on the trawl in the working position and create a hydrodynamic force due to the flow around it.

At the same time, due to the chosen shape of the spacer element, its longitudinal axis up to 30 ° to one side or the other from the direction of towing does not significantly affect the distance force and the opening of the trawl does not change.

When hauling a trawl, when the net fabric forms a tight rope, the rings 9 move to the central web 6 and the tension of the net cloth is not transmitted to the device.

The orientation of the devices at the expense of the netting of the trawl ensures their operation in the system of the trawl in any necessary directions in accordance with the plane of the netting.

To equip the upper parting, the spacer elements are made of polymeric materials with positive buoyancy, such as polyethylene, and to equip the bottom part, they are made of materials with negative buoyancy, such as fiberglass.

For hardening in ca 8, the spacer element can be made so that the center of the inner hemisphere is offset from the center of the outer hemisphere towards the tide 10.

For especially harsh conditions as in C 8 and lintel 6 may be reinforced with metal rods.

Subject invention

Claims (2)

1. Hydrodynamic device for vertical opening of the mouth of the trawl, consisting of a spacer of a streamlined shape and a device for fastening it to the upper selection, characterized in that, in order to improve the performance properties, the spacer element is made in the form of a hemisphere having two symmetrically cut notches figured forms, the edge of each of which lies in a plane parallel to the base of the hemisphere, and the top is in a plane perpendicular to the base of the hemisphere, and is located from the center of the hemisphere at a distance and equal to 0.25-0.3 of its radius. 2. The device according to claim 1, characterized in that, in order to ensure uniform load, the device for attaching the spacer element to the upper selection consists of rings loosely attached to each other, formed by the lower edges of the notches and hemispheres. P Phie if.