초록 ▼

The invention relates to an otter board (20) which may be used for generating a spreading force in connection with trawl fishing. The otter board according to the invention comprises at least two foils (1-3) which are suspended between a number of longitudinally extending ribs (5, 6, 10, 17, 26, 27)

The invention relates to an otter board (20) which may be used for generating a spreading force in connection with trawl fishing. The otter board according to the invention comprises at least two foils (1-3) which are suspended between a number of longitudinally extending ribs (5, 6, 10, 17, 26, 27) in such a way that at least one tapered channel is formed in which the flow of water is passing through the otter board. The channels are curved and formed so that water is ejected at a high speed in relation to the towing speed in a direction slightly downwards and along a respective end section of an adjacent lower or intermediate foil extending from the outlets of the channels, whereby turbulence is prevented from occurring even at high angles of attack of the otter board.

대표청구항 ▼

[ What is claimed is:] [1.] An otter board for connecting a trawl to a towing vessel comprising:a lower foil, an upper foil and at least two substantially parallel longitudinal ribs which arrange the upper foil above the lower foil, the upper foil having a rear edge, the upper foil and lower foil be

[ What is claimed is:] [1.] An otter board for connecting a trawl to a towing vessel comprising:a lower foil, an upper foil and at least two substantially parallel longitudinal ribs which arrange the upper foil above the lower foil, the upper foil having a rear edge, the upper foil and lower foil being symmetrical about a central axis, extending generally along a length of the otter board, the upper foil and lower foil having opposed surfaces, each foil being curved and forming at least one channel therebetween, the lower foil having an end section which extends in a longitudinal direction from the rear edge of the upper foil, a center portion of the rear edge being closer to the lower foil than portions on opposite ends of the rear edge of the upper foil, the channel having a taper in a direction of water flowing through the channel such that a speed of the water exiting the channel is higher than a speed at an entrance to the channel, the water passing therethrough being directed down to and along a top side of the end section of the lower foil.