Patent ID: 6732468
Filing Date: 2004-05-11
Classification: A01K,D04C,D07B

Abstract:
A trawl which during field operations in a water entrained environment becomes disposed about a central axis, the trawl comprising:a plurality of mesh cells, each mesh cell including at least three mesh bars, during field operations of the trawl in a water entrained environment at least a portion of at least one of said mesh bars of at least one of the mesh cells exhibiting a hydrofoil-like effect that aids in increasing a performance characteristic of a trawl system, that portion of mesh bars which exhibit the hydrofoil-like effect being: a. offset from the central axis of the trawl; b. formed with a hydrofoil shape that: i. has a lay with a loose, corkscrew-shaped pitch establishing a groove; and ii. is oriented to establish leading and trailing edges for that portion of mesh bars which exhibit the hydrofoil-like effect, both: (1) the lay of that portion of mesh bars which exhibit the hydrofoil-like effect having an orientation relative to a receding direction; and (2) the leading edge of that portion of mesh bars which exhibit the hydrofoil-like effect, when normalized to the receding direction relative to said central axis, residing at a side of said mesh bar, that are selected from a group consisting of: â€ƒ(a) a left-hand lay, and the leading edge being a right side of said mesh bar as viewed in the receding direction; and â€ƒ(b) a right-hand lay, and the leading edge being a left side of said mesh bar as viewed in the receding direction; so that movement of the mesh bar through the water entrained environment relative to a water flow vector creates a pressure differential across that portion of mesh bars which exhibit the hydrofoil-like effect thereby establishing a lift vector relative to the central axis of the trawl, the water flow vector being neither parallel nor perpendicular to the mesh bar; c. each of the mesh bars intersecting with at least one other mesh bar; and d. that portion of mesh bars which exhibit the hydrofoil-like effect being formed from a material that resists a tendency to compress during field operation; whereby the lift vector created by movement of the mesh bars which have a portion that exhibits the hydrofoil-like effect through the water entrained environment during field operations increases the performance characteristic of the trawl which is selected from a group consisting of increased trawl volume, improved trawl shape, reduced vibration, reduced noise, and reduced drag.