SU551019A1 - Fixture to open the mouth of the trawl - Google Patents

Description

one

The invention relates to industrial fisheries and can be used with a fishing tackle rig.

A device for vertical opening of a trawl is known, being a body of a convex-concave profile having a circular shape in plan and equipped with fasteners.

The known fixture can be mounted on the trawl only at one point of the top pick (in the center), which is not enough to open the trawl, so that the amps are small. With an increase in the area of adaptation, it becomes cumbersome and cannot therefore be used in industrial fisheries, since it cannot displace the currently used as spacer devices of the fishery, and

the latter, with an increase in trawling in the future, in the TopMoaoNf mc in the development of industrial fishing.

In order to improve hydrodynamic expansion & the forces and the possibility of installing it anywhere on the selection of the trawl, in the device for the vertical opening of the trawl mouth the spherical surfaces bounding the casing are located one relative to the other in such a way that in the longitudinal section of the line connecting the ends of the arcs form an acute angle smoothly match your wife.

In this case, the fastening elements of the housing can be made in the form of brackets.

FIG. 1 shows schematically an arrangement for vertical opening of a trawl; in fig. 2 - the same device located on the trawl, top view; in fig. 3 and 4 - sections A-A and BB in FIG. 2, in a perspective view.

The fixture is a body of a convex-concave profile and has a circular shape in plan.

Claims (2)

The body is formed by spherical surfaces 1 and 2, which are located one relative to the other in such a way that in a longitudinal section the lines connecting the ends of the arcs form an acute angle and the ends of the arcs themselves are smoothly conjugated along the circumferential radii of radii By the flow of water, droplet-shaped hull profiles can be formed not only in its diametral plane, but also in planes at an angle to it, due to the displacement of spherical surfaces 1 and 2. Between spherical surfaces A sealed cavity is formed, filled with a floating filler 3, which can be used, for example, foam material based on microspheres SPB-1, which is a high-strength closed cellular material. Filler 3 can withstand high pressure from 2OO to 250 kgf / cm, it has a specific density of 0.65-0.70 kgf / cm and water absorption, approximately 2%. The body is made of metal, plastic or any other material, and the thickness of its walls is selected depending on the type of the latter. The housing is equipped with fasteners made in the form of brackets 4 and 5. Brackets 4 are located on a spherical surface 1 and serve to fix the device on the upper selection 6 of the trawl, and brackets 5 on a spherical surface 2 serve to be fixed on an additional false-selection cable 7 that repeats the configuration of the upper selection of the trawl, moreover, 4 and 5 are located from the front and rear edges of the body at distances that provide the specified angle of attack of the device. The device for vertical opening of the trawl mouth works as follows. The fixture is attached to the trawl with links from the trawl strip 8, forming an angle of attack oL equal to 2O-40 with respect to the counter-flow of water to create a hydrodynamic force. As a result of this fastening of the device in the central part of the upper selection 6, its body has a direct flow around the counter flow. Adaptations mounted on the remaining part of the upper part are obliquely flowed along and are somewhat rotated in the transverse plane. In forward flow, the device acts as a wing of low elongation, creating a hydrodynamic force T which is decomposed into a horizontal component TR (drag) and a vertical component R, (lifting force). The hydrodynamic lift force R 2 is collapsed with the hydrostatic lift force P created by the buoyancy of the tool. Under the action of the total force (H 2 R), the trawl opens vertically, moreover Rj is larger than R, since the first increases with increasing speed in direct proportion to the square of the speed, and the latter remains constant. When installing the device on the wing of the trawl, the flow is carried out along a drop-shaped profile, which is less pronounced, but preserves in the whole range of working angles of the oncoming flow. Due to the rotation of the device on the trawl wing in the transverse plane, besides the resistance force RX and the lift force z ", an additional force R ,, arises that increases the horizontal opening of the trawl, complements the work of the trawl boards, rounds the mouth of the trawl and gives it more favorable form. Partial decrease in lift with oblique flow compared with direct flow can be compensated by mounting devices on the wings in large quantities. In the process of trawling, a device for vertical opening of the mouth of the trawl is installed with the help of fasteners at any point of the upper selection of the trawl at the angle of attack to the oncoming water flow, while ensuring an increase in the hydrodynamic lifting force of the selection. The described device for vertical opening of the trawl, as compared with the known, can be installed anywhere on the selection of the trawl and creates a high hydrodynamic force, thereby increasing the vertical opening of the trawl and catch of fish. Claim 1. A device for opening the trawl mouth, is equipped with a body of convex-concave profile, having a circular shape in plan and equipped with fasteners, characterized in that, in order to increase the hydrodynamic thrust force and the possibility of installing it on any part of the trawl, spherical the surfaces bounding the body are located relative to each other in such a way that in the longitudinal section the lines connecting the ends blow, form an acute angle, and the ends of the arcs are smoothly matched. 2. Device according to claim 1, characterized in that the fastening elements are in the form of brackets. FIG. 2 flow Fig.Z R. FIG.